World of Ham Radio 1997/WOHR97_AmSoft_(1997-02-01).iso/usenets/1995_06/_antenna.txt

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The World of Ham Radio CD-ROM


From [e-mail] Wed 07 Jun 95 15:45:43
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From: Frank Donovan <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: *software models
Date: Tue, 6 Jun 1995 21:50:47 -0400
Organization: Southgate Internet Host
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Robert,

I've been using ELNEC for years for modelling stacked Yagis (3 over 3 on 40M,
5 over 5 on 20M, 6 over 6 on 15M etc).  It also quite suitable for
other antennas such as verticals, quads and dipoles.  Its an excellent
model, very easy to use; however, more easily used for antenna analysis than
design.

Use of ELNEC for design requires many trial-and-error passes.  It
works, but automated antenna models such as YO by Brian Beezley can try
tens of thousands of trial values in the time it takes u to enter just
one new variable in ELNEC!  However, the last version of YO that I tried
did not support stacked Yagis...

By the way, last week I received a copy of W7EL's new antenna modelling
software, EZNEC, and it is a wonderful new product, incorporating NEC2
as the modelling engine.   Its the first model I've tried that produces
believable results for Beverage antennas.

I've never tried QuickYagi, so I can't comment on it.

73!
Frank
W3LPL


On 3 Jun 1995, Robert wrote:

> Any one used the W7EL elnec OR Quickyagi by WA7RAI ??
> comments please!  either one do stacked yagi over ground??
> --
> 73 Robert  WB5CRG  [e-mail]
>
>


From [e-mail] Wed 07 Jun 95 15:45:44
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From: [e-mail]
Subject: Re: *software models
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Date: Wed, 7 Jun 1995 15:15:34 GMT

In <[e-mail]>, Frank Donovan <[e-mail]> writes:
>Use of ELNEC for design requires many trial-and-error passes.  It
>works, but automated antenna models such as YO by Brian Beezley can try
>tens of thousands of trial values in the time it takes u to enter just
>one new variable in ELNEC!  However, the last version of YO that I tried
>did not support stacked Yagis...
>Frank
>W3LPL
>
>On 3 Jun 1995, Robert wrote:
>
>> Any one used the W7EL elnec OR Quickyagi by WA7RAI ??
>> comments please!  either one do stacked yagi over ground??
>> --
>> 73 Robert  WB5CRG  [e-mail]
>>

YO will do stacked yagis but only in free space.  Great for the VHF guys
but a bit of a pain for HF.  Beezley's AO (Antenna Optimizer) will do
stacked yagis over ground though.  It's kind of like Mininec with the
optimizer kernel from YO added so it will optimize the stack.

Rick Craig, N6ND
[e-mail]

From [e-mail] Wed 07 Jun 95 15:45:48
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (andrew peter.cropley)
Subject: Re: 2m QUAD headaches....
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Date: Mon, 5 Jun 1995 12:40:59 GMT
Lines: 26

In article <3qmb6j$[e-mail]>,
Todd Little <[e-mail]> wrote:
>In article <[e-mail]>
>[e-mail] (Nathan Fisher) wrote:
>
>>
>> Hi Ho!
>>
>> I've just spent two days trying to make a good 2m quad, and am quite
>> frustrated!  I was told that no matching device was required when feeding

   I built the one that was in QST a few months back.

   I used #8 copper grounding wire ( the article called for #10 , but #8
 yields a little more bandwidth). The antenna was pretty easy to build.

   The original article said something like 11db gain for less than $11
But the materials in my area were more than double the authors quoted prices.
I turn around and built mine (boom and spreaders) out of Schedule 40 PVC tubes
work great and it will never rot from the rain. Works great I talk with my
friend Bob (N2ZAN) across town on 1/2 a watt and were both full quieting.

    Andy Cropley

        KG2AQ


From [e-mail] Wed 07 Jun 95 15:45:50
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From: [e-mail] (Jay Kesterson K0GU)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2m QUAD headaches....
Date: 6 Jun 1995 13:50:15 GMT
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Nathan Fisher ([e-mail]) wrote:

: I've just spent two days trying to make a good 2m quad, and am quite
: frustrated!  I was told that no matching device was required when feeding
: the driven element, and thatn a near 50 ohm impedance would develop if
: I just opened the square on a side, spaced them, 1/2" apart, and hooked
: on the braid and center to the two ends.  Nope.

: One other question while you're replying:  I also tried to make a
: "curcular" quad, which is greatly favored in construction -- I'm
: using railroad signal wire, which is *extremely* stiff, (steel core,
: copper clad, wild pvc jacket) and is already in a coil.  Same swr results
: as above square design when unmatched.  Will a similar gamma match
: fix the standing waves?

: Nathan Fisher
:  N0ZYC

Nathan what are you using for the elements on the 2m quad in the first
paragraph? I just built a four element quad on 6m and made a very foolish
mistake. I used wire with a PVC jacket. The PVC jacket slows down the
velocity factor of the wire so much that my directors looked like
reflectors. My quad had a back-to-front ratio instead of front-to-back.
It was about three db better off the back of the antenna. This would also
likely make the SWR very bad. I took the quad down, stripped off the PVC,
and now the quad works as expected.

73, Jay  K0GU                  [e-mail]

From [e-mail] Wed 07 Jun 95 15:45:53
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From: [e-mail] (Martin Deeley)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 6 Meter Quad
Date: 5 Jun 1995 17:34:26 +1000
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Gary W. Duffield ([e-mail]) wrote:
: I am looking for some measurements on a 3 to 4 element, 6meter quad.

: Anyone have any ideas?

: Gary N7NQM
why not make it a vee quad or delta loop? That way you don't need to
insulate anything (almost).
I used to use a 5 ele version from here as VK3TGF(Thank God its Friday!)
and worked Texas on 10W.
Ele spacings were about the same as most quagis, fed was by gamma
match,and ele circumferences were based on active element at 0.97Lambda.
(to allow for the capacitance of insulated wire used at the tops of the
elements.


From [e-mail] Wed 07 Jun 95 15:45:54
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: 6 meter Yagi beam
Date: Wed, 7 Jun 1995 00:20:31 -0400
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Anyone interested in a portable 6 m yagi 3 element portable antenna?

From [e-mail] Wed 07 Jun 95 15:45:58
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From: [e-mail] (Steve Byan)
Newsgroups: rec.radio.amateur.antenna,rec.radio.shortwave
Subject: Re: ?? Radio West Ferrite Ant
Date: Mon, 05 Jun 1995 12:11:11 -0400
Organization: Hitachi Computer Products, Inc.
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In article <3pu8fu$cmn$[e-mail]>,
[e-mail] (Carl Lovitt) wrote:

> [The Radio West ferrite loop] antenna uses 6 [ferrite rods].

What configuration? Are they bundled, or glued end-to-end?

Thanks,
-Steve

--
Steve Byan                                  internet: [e-mail]
Hitachi Computer Products (America), Inc.
1601 Trapelo Road                           phone: [phone]
Waltham, MA 02154                           FAX: [phone]

From [e-mail] Wed 07 Jun 95 15:45:59
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Zack Lau (KH6CP))
Subject: Re: Aerials for VHF and UHF airband?
References: <(none)> <3puqgc$[e-mail]> <[e-mail]> <[e-mail]>
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Gary Coffman ([e-mail]) wrote:
: Standing currents in excess of 100 ma are often used with good
: results. This requires an RF *power* transistor be used for
: the preamp. Suitable bipolar devices are those used in CATV
: trunk amplifiers. Better are the new GASFET power transistors
: becoming available. There's a good example of the latter in
: one of the Microwave Update volumes from ARRL.

Actually, you generally want the *older* GaAs devices for VHF
and low UHF (below 400 MHz). The new ones are often optimized
for higher frequencies, which tends to degrade VHF performance.

Is anyone making GaAs devices optimized for VHF receivers?
--
Zack Lau  KH6CP/1           2 way QRP WAS
                           8 States on 10 GHz
Internet: [e-mail]   10 grids on 2304 MHz

From [e-mail] Wed 07 Jun 95 15:46:00
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Gary Coffman)
Subject: Re: Aerials for VHF and UHF airband?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <(none)> <3puqgc$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 7 Jun 1995 16:15:21 GMT
Lines: 35

In article <[e-mail]> [e-mail] (Zack Lau (KH6CP)) writes:
>Gary Coffman ([e-mail]) wrote:
>: Standing currents in excess of 100 ma are often used with good
>: results. This requires an RF *power* transistor be used for
>: the preamp. Suitable bipolar devices are those used in CATV
>: trunk amplifiers. Better are the new GASFET power transistors
>: becoming available. There's a good example of the latter in
>: one of the Microwave Update volumes from ARRL.
>
>Actually, you generally want the *older* GaAs devices for VHF
>and low UHF (below 400 MHz). The new ones are often optimized
>for higher frequencies, which tends to degrade VHF performance.

The only point on which we disagree is the meaning of "new". :-)
I used it only in the sense of newer than bipolar.

The dimensions of the channel and the area of the metalization
determine (to a large extent) the frequency range of optimum
operation. Power devices have to have larger areas to handle
the higher currents (current density per unit area is pretty
much a constant), so power GASFETs generally work better at
lower frequencies than small signal GASFETS (assuming both were
optimized as well as possible by their designers for the same
(higher) frequency range). If you can get a GASFET originally
designed for your intended frequency range, so much the better,
but if you *have* to use a GASFET optimized for a higher frequency
range, the power variety will perform better at the lower frequency
than the small signal variety.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Wed 07 Jun 95 15:46:01
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From: [e-mail] (Brice Wightman)
Subject: Re: antenna theory        1/3
Message-ID: <[e-mail]>
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Gary V. Deutschmann Sr. ([e-mail]) writes:
> BEWARE, if you pick up any ARRL literature, it's inundated with gross
> errors in both mathematics and formula.

I would appreciate an example or two from, say, the Antenna Handbook.  I
would like to check this out because I have not spotted any errors and
maybe I have deceived myself.

--
===========================================================================
Brice Wightman                                    [e-mail]
Ottawa, Canada                                                       VE3EDR
===========================================================================

From [e-mail] Wed 07 Jun 95 15:46:02
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From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: antenna theory        1/3
Date: 6 Jun 1995 01:55:55 GMT
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[e-mail] (Brice Wightman) wrote:
>
>
> Gary V. Deutschmann Sr. ([e-mail]) writes:
> > BEWARE, if you pick up any ARRL literature, it's inundated with gross
> > errors in both mathematics and formula.
>
> I would appreciate an example or two from, say, the Antenna Handbook.  I
> would like to check this out because I have not spotted any errors and
> maybe I have deceived myself.
>
I can't give an example from the Antenna Handbook, but my 1994
copy of the ARRL Handbook pg 17-17 under Fig 38 states "because
the feed method on the cubical quad is balanced, use a 4:1 balun."

The quad shown in the figure shows the DE loop being fed directly
with 75 ohm coax having a length of 251/f(MHz).  I believe the
correct caption should read "use a 1:1 balun."  OTOH, if the feedline
is run away from the DE at right angles to the radiated pattern,
then radiated rf falling on the coax shield will be from both
sides of the element equally, and will be equal and opposite vectors
which will cancel and no RF will appear on the shield. thus, no
balun is required in this case.  IMHO, baluns are potentially
lossy devices and should only be used when required.

All in all, I have found the ARRL Handbooks to be mostly correct,
but considering the old tradition of the Handbook being the "bible"
of ham radio, I believe a lot more editing could be done to find and
correct similar errors.  Lately however, the handbooks seem to
indicate the Bigger is Better,  even the ads tout the large number
of pages.  I just don't agree on that one - quality is a desirable
goal, whether that means big or small.

73,
Don W3FPR

From [e-mail] Wed 07 Jun 95 15:46:03
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From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: antenna theory        1/3
Date: 6 Jun 1995 06:47:10 GMT
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;   [e-mail] (Gary V. Deutschmann Sr.) writes:
;  BEWARE, if you pick up any ARRL literature, it's inundated with gross
;  errors in both mathematics and formula.
;
;  Their educational books, designed as teaching tools have so many errors
;  that they become useless for the purpose intended.
;
;  I have the ARRL Handbooks and other publicattions dating as far back as 1959
;  when they knew how to read and write.  But current publications are totally
;  useless.
;
;  There is a book on the market similar to the ARRL Antenna Book, I don't
;  know the name as I do not have a copy, but have read portions of the
;  book from our club library and found no errors and the formuli were correct.
;
;  Something I can't say about the formuli in the ARRL antenna book.
;
;  Gary Deutschmann  N0ZOI

Gary,

I'm sure that the ARRL would be very appreciative if you'd point out the
errors you found. Believe it or not, they really want the books to be
accurate -- but it's a huge task for the people who do the editing in
addition to their other jobs. Personally, I think they've done a terrific
job, and their publications are a real bargain. But by all means, let them
know when you find errors.

73,
Roy Lewallen, W7EL



From [e-mail] Wed 07 Jun 95 15:46:04
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From: [e-mail] (Jeffrey W. Lawson)
Newsgroups: rec.radio.amateur,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc
Subject: BA1404
Date: 7 Jun 1995 17:46:04 GMT
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                I have 1000 BA1404 stereo transmitter chips. If your
        interested, I'm at [e-mail]

        p.s. All sells include full data sheets


From [e-mail] Wed 07 Jun 95 15:46:04
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From: Al Bolton <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Butternut vertical-info needed
Date: 6 Jun 1995 11:40:18 +0100
Organization: Demon Internet News Service
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Hello,

I have just acquired a used Butternut vertical antenna, model HF6V, which
covers from 80m to 10m (including 30m and 12/17m). Although I understand how
this antenna works in theory I do not have any instructions or a manual to help
me set it up correctly. I know there are numerous accesories available for it
also.

I'm also very interested in using this Butternut on 160m and would be
interested in your experience of it on this band.

Any information you may have available on the HF6V would be really appreciated
and I would be most interested in buying any accessories you may have surplus
to requirements (especially a 160m coil)! Bits for it in the UK are VERY
expensive and not easily available second hand.

Please reply by Email or to the newsgroups.

Thank you,
---------------
Al Bolton
OK8VSQ/OM/G4VSQ
Caversham, UK
---------------

From [e-mail] Wed 07 Jun 95 15:46:05
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From: [e-mail]
Subject: Re: Butternut vertical-info needed
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In article <[e-mail]>, <[e-mail]> writes:
> Path:
rocksanne!rochester!casaba.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!
howland.reston.ans.net!pipex!demon!boltons.demon.co.uk!Al
> From: Al Bolton <[e-mail]>
> Newsgroups: rec.radio.amateur.antenna
> Subject: Butternut vertical-info needed
> Date: 6 Jun 1995 11:40:18 +0100
> Organization: Demon Internet News Service
> Lines: 24
> Sender: [e-mail]
> Message-ID: <[e-mail]>
> Reply-To: [e-mail]
> NNTP-Posting-Host: dispatch.demon.co.uk
> X-Newsreader: Demon Internet Simple News v1.29
> X-Posting-Host: boltons.demon.co.uk
>
> Hello,
>
> I have just acquired a used Butternut vertical antenna, model HF6V, which
> covers from 80m to 10m (including 30m and 12/17m). Although I understand how
> this antenna works in theory I do not have any instructions or a manual to
help
> me set it up correctly. I know there are numerous accesories available for it
> also.
>
> I'm also very interested in using this Butternut on 160m and would be
> interested in your experience of it on this band.
>
> Any information you may have available on the HF6V would be really
appreciated
> and I would be most interested in buying any accessories you may have surplus
> to requirements (especially a 160m coil)! Bits for it in the UK are VERY
> expensive and not easily available second hand.
>
> Please reply by Email or to the newsgroups.
>
> Thank you,
> ---------------
> Al Bolton
> OK8VSQ/OM/G4VSQ
> Caversham, UK
> ---------------
>
Al,
I have a HF6V and should have a manual somewhere. If you can not find
one locally, I will be glad to send you a copy. If I can be of assistance,
please send me your postal address.

73,
John  AA2OZ


From [e-mail] Wed 07 Jun 95 15:46:06
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Comments on GAP Antennas, Anyone?
Message-ID: <[e-mail]>
Date: 5 Jun 95 20:47:20 -0700
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Wonder if anyone has any experience with GAP antennas; specifically the
Challenger DX-VIII?  Would appreciate any comments.  My current antenna only
goes to 40M and I would like to go to 80.

Thanks,
[e-mail]

From [e-mail] Wed 07 Jun 95 15:46:14
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Comments on GAP Antennas, Anyone?
Date: 7 Jun 1995 09:08:36 -0400
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I have an older GAP and some other antennas (including a Butternut) here
and have had a chance to compare them. The GAP is a very poor performer on
the low bands, and a low dipole beats it badly-nearly two S units at DX.
So does the Butternut but it has a large radial system.

I don't think they've changed the design technoligy in the antenna, so I
expect they still are poor antennas (especially for low bands), as most
short stub loaded minimal ground verticals are. On the other hand they do
radiate better than no antenna at all!

73 Tom

From [e-mail] Wed 07 Jun 95 15:46:14
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Rafael Solis)
Subject: Diamond CP-4A
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Need info about the Diamond CP-4A antenna. It is advertised as a
10,15,20 and 40 m antenna. Does anyone out in cyberspace heard
good/bad things about it?  Please post or e-mail your comments.

Many thanks and 73

Rafael  (KE6JSR)

PS:  It's on sale at AES for $149.95









From [e-mail] Wed 07 Jun 95 15:46:15
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From: Gene Mason <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Elevated radials: measured results
Date: 3 Jun 1995 19:18:13 GMT
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Tom... Good work! Wouldnt you expect the results to be the same on 20m and
up. WIth the exception that the degradation in wave angle to be more
pronounced.? - Gene KZ5V


From [e-mail] Wed 07 Jun 95 15:46:16
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From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Elevated radials: measured results
Date: 6 Jun 1995 06:34:00 GMT
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;   William Osborne <[e-mail]> writes:
;  [e-mail] (W8JI  Tom) wrote:
;  >Clarification of my post:
;  >
;  >I didn't intend to post the earlier posting to the net, so let me clarify
;  >the
;  >reason I wrote it. The data *may* certainly turn out to be accurate, but
;  >I have two problems with the data at this point.
;  >
;  >The first is what I consider a poor choice of words in the five IEEE
;  >papers that were published. Words like built, constructed, and
;  >measured were used over and over by the author of the IEEE papers
;  >when he was actually describing computer modeling results. If the
;  >reader casually viewed these papers, he could easily believe the
;  >antenna systems discussed were built and measured. They were not.
;
;  Roy, I understood your post to say the data was measured and then
;  compared to NEC-2/3 results..did I miss understand your posting?
;  >

You understood it correctly. It was NEC-3.

Roy Lewallen, W7EL




From [e-mail] Wed 07 Jun 95 15:46:17
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Elevated radials: measured results
Date: 6 Jun 1995 10:12:31 -0400
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> Wouldnt you expect the results to be the same on 20m and
>up. WIth the exception that the degradation in wave angle to be more
>pronounced.? - Gene KZ5V

I don't know Gene. The only thing I know is that more measurements need to
be done, and the feedline should be isolated in those tests. If the
feedline isn't isolated too many variables creep in, such as feedline
radiation, the ground connected to the feedline, etc.

The second thing is that the tests should be a series of tests at the same
height.That would prevent data clutter from masking the real results. Some
of the data clutter would be that comparing a ground mounted 120 radial
system to an elevated system at a  substantially different height can
distort the readings. Instead of measuring the efficiency improvement the
wave angle and path losses are changed.  So if we tested a elevated system
at a substantially different height, the full field pattern at all wave
angles must be measured. That is sort of like comparing apples to oranges,
because a 120 radial system at the higher height may still be vastly
superior! How much is from the elevated radials improving the efficiency,
and how much is from the height reducing propagation losses and modifying
the pattern?

From [e-mail] Wed 07 Jun 95 15:46:18
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From: [e-mail] (Michaelc Johnson)
Newsgroups: rec.radio.amateur.antenna
Subject: G5RV mast material
Date: 4 Jun 1995 23:14:56 -0600
Organization: Wasatch Communications
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Greetings,


I just bought a G5RV 80-10 antenna from MFJ along with one of their tuners.
I'd like to install the antenna as an inverted V with the apex at the peak of
my roof.  I'd like to tether the ends at either end of my yard.

My question is what to use for mast material.  I'd rather not use lumber
because the wind in West Jordan, Utah is bad.  I'd rather not use a metal
mast because the ladder line radiates on certain frequencies and doesn't
like to be near metal.

Has anybody ever tried Schedule 40 PVC pipe with wooden reinforcement
inside?  I was at the lumber yard the other day and noticed that 1.25-inch
doweling sold as stair railing is an almost perfect fit inside 1.25-inch PVC
pipe.  Not too expensive.   Not very pretty either.  But it might work.

Thanks in advance for any comments or suggestions.

73,

Mike Johnson
K7RVX
3861 Westland Drive
West Jordan, Utah 84088
801-280-2476
[e-mail]

--
Michaelc Johnson, user of the UniBoard System @ wasatch.com
E-Mail: [e-mail]
--------------------------------------------------------------------------
       The Wasatch Communications Group public access Bulletin Board
              Salt Lake City, Utah, USA    801-272-3792 (data)
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From [e-mail] Wed 07 Jun 95 15:46:19
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (George L. Hiscox)
Subject: Re: G5RV mast material
Message-ID: <[e-mail]>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
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Michaelc Johnson ([e-mail]) wrote: : Greetings,


: I just bought a G5RV 80-10 antenna from MFJ along with one of their tuners.
: I'd like to install the antenna as an inverted V with the apex at the peak of
: my roof.  I'd like to tether the ends at either end of my yard.

: My question is what to use for mast material.  I'd rather not use lumber

One thing that might work well for you is a telescoping fiberglass pole
sold for use in window washing applications.  Some of the hams down here
in SoCal use those for emergency antenna supports.  You can get them in
various lengths.

One consideration in using fiberglass is protection from UV radiation.
That might be handled by the application of a UV resistant spray paint.

George
---
| George L. Hiscox                |  Very funny Scotty...Now  |
| [e-mail]              |  beam down my clothes!!!  |
| WA6RIK @ WB6YMH.#soca.ca.usa.na |  ^^^^^^^^^^^^^^^^^^^^^^^  |


From [e-mail] Wed 07 Jun 95 15:46:19
From: [e-mail] (Claton Cadmus)
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!uunet!in1.uu.net!rosevax!hamlink!fredmail
Newsgroups: rec.radio.amateur.antenna
Subject: G5rv Mast material
Message-ID: <[e-mail]>
Date: Tue, 06 Jun 1995 11:13:10
X-FTN-To: All
Lines: 42

Hello Mike you wrote:


MI>My question is what to use for mast material.  I'd rather not use lumber
  >because the wind in West Jordan, Utah is bad.  I'd rather not use a metal
  >mast because the ladder line radiates on certain frequencies and doesn't
  >like to be near metal.

MI>Has anybody ever tried Schedule 40 PVC pipe with wooden reinforcement
  >inside?  I was at the lumber yard the other day and noticed that 1.25-inch
  >doweling sold as stair railing is an almost perfect fit inside 1.25-inch PVC
  >pipe.  Not too expensive.   Not very pretty either.  But it might work.

Windy conditions and feedline radition are both valid concerns.  I have
use PVC pipe and don't recommend it.  You don't say how high above the
peak of the house roof you want to get the top of the "V".  For maderate
heights I'd recommend you use 1x6 and 1x4 knotless wood glued and
screwed in a "T" configuration.  See end view below.

    _______________________
   l       1x6             l
   l_______________________l
            l     l
            l 1x4 l
            l     l
            l     l
            l_____l

Make sure you seal and paint this well.  It should last for many years.

Hope this helps,

73 de  Claton Cadmus,  KA0GKC
   ______________________________________________________________
  |     FIDOnet= Claton Cadmus 1:282./100                        |
  |    INTERnet= [e-mail]                    |
  |   PACKETnet= KA0GKC@WB0GDB.#STP.MN.USA.NA                    |
   --------------------------------------------------------------

 * SLMR 2.1a * Is scientific progress suppose to smoke that way?



From [e-mail] Wed 07 Jun 95 15:46:20
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: G5RV--any good?
Date: 5 Jun 1995 20:20:17 GMT
Organization: Oberlin College, Oberlin, Ohio
Lines: 6
Message-ID: <3qvou1$[e-mail]>
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Am considering a G5RV for 80-10m, hoping that my autotuner will be
happier with it than it has been with a ground-mounted Butternut.
I'd put it up as a rather twisted inverted V (in a very difficult
situation for hf antennas other than pricey verticals).  How well
does your G5RV work for you?  Thanks for the warnings/testimonials.
73 de Bill KB8USZ/AE [e-mail]

From [e-mail] Wed 07 Jun 95 15:46:21
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: G5RV--any good?
Message-ID: <[e-mail]>
Date: 5 Jun 95 20:32:36 -0700
References: <3qvou1$[e-mail]>
Distribution: world
Organization: Brigham Young University
Lines: 21

In article <3qvou1$[e-mail]>, [e-mail] writes:
> Am considering a G5RV for 80-10m, hoping that my autotuner will be
> happier with it than it has been with a ground-mounted Butternut.
> I'd put it up as a rather twisted inverted V (in a very difficult
> situation for hf antennas other than pricey verticals).  How well
> does your G5RV work for you?  Thanks for the warnings/testimonials.
> 73 de Bill KB8USZ/AE [e-mail]


I borrowed a G5RV for my vacation last summer in the mountains.  I put it up
about 30 feet and stretched it nearly straight across in "T" dipole fashion.  I
powered it with my Kenwood TS850 SAT and had no trouble at all getting good
tuned SWR below 1.5:1, usually better than that.  I liked it so well, that I
purchased my own two months ago, and am waiting for the snow to melt (12 feet
still in some places and the road won't open until 4 Jul this year -- we
usually get up there for Memorial Day <grin>).  I left the ties up in the
trees, so all I have to do is hoist it up.  I am a believer -- catch ya on 80
sometime this summer -- late summer <grin>.

Milt


From [e-mail] Wed 07 Jun 95 15:46:23
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From: [e-mail] (Victor Falkteg)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ham-Ant Digest V95 #238
Date: 6 Jun 95 16:35:31 GMT
Organization: ucsd usenet gateway
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NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]


>Date: 5 Jun 1995 13:54:54 -0400
>From: [e-mail] (W8JI  Tom)
>Subject: Vertically polarized noise question
>
>>  I have no sources to back this up, but I think the reason that "man
>>made noise sources" are held to be vertically polarized is that they are
>>local in nature and the noise propagates by ground wave.
>
>That is part of the way I understand the problem also. It is because
>horizonally polarized waves are attenuated more rapidly along the earth.
>This is one reason, path attenuation.
>
Yes, but another reason is that many mane made sources of noice are
vertical, for examble bigger electricity cables in buildning, street light
structures and so on.

>The second effect is that noise can be accumulated from many directions.
>Simple horizontal polarized antennas generally have at least two nulls
>while most simple vertically polarized antennas are omni-directional, and
>so respond to noise from 360 degrees. This is another reason, antenna
>"compass heading" directivity.
>
Yes, but in fact horizontal and vertical antennas are identical, if you
don't take the influence of the ground in the picture. An 1/4 GP is
identical in the pattern meassured in the respect of the antenna even if you
have it horizontal ! So it is not the antenna that matters instead it is the
orienteision ofd the antenna that is interesting... Or what do you say about
a halv wave dipole, horizontal or veritical ?

The best way to minimaze influence from main made noice sources is in my
opinion to use an antenna with a very narrow directivity pattern and weak
side lobes together with some kind of positioning system !

An interesting way may be to use two antenna systems some distance apart and
use some kind of matrix to separate noise from the signal. The usable signal
is (hopefully) identically strong from both systems. Man made sources are
ususally located not to far from the antennas, so the level on the noise
from one specific noice source will not be identically strong from both
systems.... I have not tested this, but i should work ?!?!

73:s de SM0MRJ Victor


************************************
Victor E. Falkteg
[e-mail]
Phone  -46  (0)8  531 873 22
Mobile  -46  (0)10  218 20 57
************************************


From [e-mail] Wed 07 Jun 95 15:46:24
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Edward Stafford)
Subject: Re: Health ramifications of using headset
Sender: [e-mail] (News Admin)
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In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>From: [e-mail] (Gary Coffman)
>Subject: Re: Health ramifications of using headset
>Date: Thu, 25 May 1995 16:07:17 GMT

>In article <[e-mail]> [e-mail]
>(Michael Sattler, San Francisco) writes:
>>
>>Well, not actually from the headset, but from the resultant practice of
>>keeping the HT with a quarter-wave antenna clipped to a belt in front or
>>back of one's chest/abdomen.  Since signals radiate outward, am I
>>absorbing a lot more than if I held the HT to my ear and had the antenna
>>way away from my head/body?

>Sure, but your trunk has a lot more wetted volume to absorb the power,
>and, unlike the skull, isn't resonant at VHF. The problem at the power
>level produced by HTs is the resonance effect on the skull, and the
>very sensitive to RF structures in the head, such as the eyes. Your
>body can easily absorb the 5 watts or so of RF heating, but your eyes
>can easily be damaged by heating at that level. So the idea is to
>keep the head and eyes as far from the source of RF as practical.
>Belt mounting can do that, as can holding the HT at arm's length
>above the head while transmitting. Both tactics require an external
>microphone. The most damaging thing to do is to hold the HT in
>front of the lips to use the built in microphone. That places
>the antenna directly in line with, and very close to, the eyes.

>Gary
>--
>Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
>Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
>534 Shannon Way             |    Guaranteed!      | [e-mail]
>Lawrenceville, GA 30244     |                     |

What multiple (including fractional) of two meters is your skull?
The human body is pretty close to a whole wavelength.
I do agree though that it is not a good idea to place an antenna so close to
the head. I have always been amazed that people will use a clip to hold their
rubber ducky on their hat. I think Darwin had something to say about that.

73s, Edward

.
Edward Stafford AA0QG     <[e-mail]>
UNISYS Corp.
MS 4963
P.O. Box 64942            Phone: [612] 635-7725
St. Paul, MN 55164-0942   FAX:   [612] 635-7523

From [e-mail] Wed 07 Jun 95 15:46:26
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Health ramifications of using headset
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 7 Jun 1995 15:48:42 GMT
Lines: 13

In article <[e-mail]> [e-mail] (Edward Stafford) writes:
>
>What multiple (including fractional) of two meters is your skull?

Who mentioned 2 meters? The average skull is roughly 0.5 wavelength in
circumference at 440 MHz.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Wed 07 Jun 95 15:46:26
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!news.larc.nasa.gov!night.primate.wisc.edu!sdd.hp.com!gatech!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Helically Wound Antennas
Date: 6 Jun 1995 01:22:57 GMT
Organization: News & Observer Public Access
Lines: 17
Message-ID: <3r0alh$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: grail616.nando.net

[e-mail] (Ron Bean) wrote:
> 2.  Use three separate but closely spaced pvc supports, each with
> its own separate winding for each of three bands.
>
> any ideas, suggestions or experiences would be appreciated.

Ron, I've not had experience with parallel verticals before, but
I have played with parallel dipoles plenty.  I have found that
unless you separate the dipoles by a good bit, there is significant
interaction for even harmonics of the longest dipole.  i.e. a
20 15 10 parallel antenna is a real bear to tune on 10.
Given my prior frustrations, I would recommend the traps.

73,
Don W3FPR
  Free advice it many times worth just what it costs!


From [e-mail] Wed 07 Jun 95 15:46:27
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From: [e-mail] (George J. Molnar)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Indoor antennas- how bad?
Date: Mon, 05 Jun 1995 12:33:16 GMT
Organization: ICG/MagNET [phone]
Lines: 39
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References: <3qtl0j$[e-mail]>
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David Lee <[e-mail]> wrote:

>Can anyone please advise me on the adverse effects of indoor
>antennas versus outside.  Does surrounding plumbing, or indoor construction
>really offer detrimental radiation effects?  I have an indoor dipole and
>a 4BTV vert, and have always wondered.  By the way, I live in a complex
>with strict community regulations.

The biggest problems with indoor antennas are:
1) Typically low height above ground,
2) Proximity to other devices (TV, computers), so RFI/EMI becomes more
of an issue,
3) Coupling to house wiring, pipes, etc, that changes resonances and
efficiencies.

The first two issues aren't all that critical for most people, but #3
can be a headache. Careful planning can help -- I've noticed that 18
inches is a good minimum seperation from existing wiring/pipes/etc for
your indoor antenna. Otherwise, you may just wind up coupling
everything into the house & not getting out.

Also, beware of homes with aluminum/steel siding and foil insulation.

I've been running 40-10m on an indoor loop in my attic for a while
now, with no problems at all. It's about 20 feet above ground, in a
frame attic with no nearby wires. Performance is comparable to my
former outside dipole at the same height. The Kovenant Kops got that
one!

Good luck/73,




George J. Molnar
Highlands Ranch, Colorado, USA
Internet: [e-mail]
Packet Radio: KF2T@N0QCU.#NECO.CO.USA.NA


From [e-mail] Wed 07 Jun 95 15:46:28
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From: [e-mail] (chinook)
Newsgroups: rec.radio.amateur.antenna
Subject: Info - 80M Bilal Isotron
Date: 7 Jun 1995 05:20:15 GMT
Organization: Forewin Technologies Inc.
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I live in a very small lot and antenna sensitive (subsidized housing)
house. Thus max room for wires  is approx 60". (not much for a 80M antenna).
I've looked at & gotten literature on the Bila Isotron antenna. Problem is
do not know anyone who has used one and seen no critiques on them. Wonder
if anyone out there has had experience with them? If so, it would be
greatly appreciated any info be sent my way. Thank you, Jacques VE3TSC

From [e-mail] Wed 07 Jun 95 15:46:29
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From: [e-mail] (Ken Edwards)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Interested in Ham Radio
Date: 5 Jun 1995 13:02:54 GMT
Organization: Bell-Northern Research, Ottawa, Canada
Lines: 49
Sender: cnc23a@b4pph13e (Ken Edwards)
Distribution: world
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References: <3qnqtc$[e-mail]>
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In article <3qnqtc$[e-mail]>, [e-mail] (Ray Cotten) writes:
|>
|> Like the subject says... I'm interested in getting into ham radio.
|> Would like to find a club, magazine, etc... To help me get into it.
|> I live in Inpls, Indiana, USA  would apprecciate anyones help.
|>
|> please reply to.
|>
|> [e-mail]
|>

Hello Ray,

Let me first say congratulations on making such a fine decision %^).

Sencondly, I ould suggest (if you have a scanner), to listen in on
the 2m band, which is 144-148 Mhz and find the various repeaters in
Indy.  Whatever your main intrest is in the hobby, generally the clubs'
meetings are discussed on 2m.

Third, talk with some of your friends or coworkers, especially if they
seem electronically inclined.  Almost every walk of like from janitor (which
I have been) to king (Jordan) are hams.

Fourth, look around your neighborhood.  If you see wires and antennas all
around a house, or several antennas (or one that doesn't look like a CB),
on their auto, ask if they are a ham.  You may even be invited in for a
tour of their 'shack'.

Next, check your local paper.  It may list amateur radio club meetings in
the community section.

Finally, call the ARRL.  This organization is the hams advocate.  They should
be able to give you info on your local clubs.  Their number is [phone].


Hope this was of some help.

And welcome to the hobby !!

--
======================================================================

Ken M. Edwards, PE  Bell Northern Research, Research Triangle Park, NC
[phone] email: [e-mail]    Ham: N4ZBB   Packet: [e-mail]
DX PacketCluster (tm) Node : W4DW

All opinions are my own and do not necessarily reflect the views of
my employer or co-workers, family, friends, congress, or president.

From [e-mail] Wed 07 Jun 95 15:46:30
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail]  (Bill Newkirk)
Subject: Re: Interested in Ham Radio
Message-ID: <[e-mail]>
Sender: [e-mail] (USENET NEWS SYSTEM)
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In <3quv9u$[e-mail]>, [e-mail] (Ken Edwards) writes:
>
>Third, talk with some of your friends or coworkers, especially if they
>seem electronically inclined.  Almost every walk of like from janitor (which
>I have been) to king (Jordan) are hams.

probably a dead end to CB radio...

>
>Next, check your local paper.  It may list amateur radio club meetings in
>the community section.

I'd bet that no club sends meeting info to the star/news. They'd probably run it.
Last time i was up there, Indy was home to a serious wide area repeater
system on 145.25 (i think)...

>Finally, call the ARRL.  This organization is the hams advocate.  They should
>be able to give you info on your local clubs.  Their number is [phone].

This should have been #1. Also CQ, 73, and QST magazines are available
at the local bookstores and other magazine suppliers -- i don't believe
Indianapolis currently has an amateur radio speciality store these days.

>
>Ken M. Edwards, PE  Bell Northern Research, Research Triangle Park, NC
>[phone] email: [e-mail]    Ham: N4ZBB   Packet: [e-mail]
>DX PacketCluster (tm) Node : W4DW

Bill Newkirk WB9IVR                  The Space Coast Amateur Technical Group
Melbourne, FL                       duty now for the future of amateur radio


From [e-mail] Wed 07 Jun 95 15:46:31
Newsgroups: rec.radio.amateur.antenna
Subject: Interested in Ham Radio
From: [e-mail] (Clint Bradford)
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!holonet!colossus.holonet.net!wwswinc!clint.bradford
Distribution: world
Message-ID: <[e-mail]>
Date: Tue,  6 Jun 95 05:56:00 -0500
Organization: WoodyWare Software, Inc. - 516-736-6662
Lines: 29

Subject: Interested in Ham Radio

>>Like the subject says... I'm interested in getting into ham radio.

To prepare for the exams you will need some study material
and more information about classes, examination points
(the exams are given by volunteer Hams in your community),
and clubs in your area.  A number of organizations will be
more than willing to help.  One such organization is the
American Radio Relay League.  Write them at:

  ARRL
  225 Main Street
  Newington, CT  06111

or call them at 1-800-32NEWHAM.

Ask for their "newcomers" package.  It will include more
detailed information, a list of classes and clubs in your
area, and a list of scheduled examinations in your area
also.

If you are near a Radio Shack store, go there and ask for
a book entitled "Now You're Talking".  This book is also
available from the ARRL.  It contains all the information
you need, including study material and sample questions
for the examinations for Novice and Technician licenses.
---
 ■ wcECHO 4.0 ≈ AR-Net: ATTENTION to Details ■ Mira Loma, CA ■ 909-681-6221

From [e-mail] Wed 07 Jun 95 15:46:31
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!agate!overload.lbl.gov!xpat.postech.ac.kr!usenet.hana.nm.kr!usenet.kornet.nm.kr!nms.etri.re.kr!chichi.etri.re.kr!parkyo
From: [e-mail] (Park Youn Ok)
Newsgroups: rec.radio.amateur.antenna
Subject: J-pole antenna for mobile
Date: 7 Jun 1995 08:57:43 GMT
Organization: ETRI
Lines: 43
Message-ID: <3r3pm7$[e-mail]>
NNTP-Posting-Host: chichi.etri.re.kr
X-Newsreader: TIN [version 1.2 PL2]


Hi all!

I made a J-pole antenna for car by simple method.
Following is detail for J-pole antenna for car.
The material is CB mobile antenna.
The performance was very good with 3MHz flat SWR 1.2 or less.
Especially, the performance of urban area(with amny
building) was excellent.
I made it conclusion, J-pole is more powerfull than
5/8 Lamda antenna in urban area.


                                                CB Antenna Mount     Mobile body

                                                  ___________||       50Ohm cable
                                                 /           ||      __________
 =============================================== --------------- ->()
             gab is 1.5~ 2.5cm      ||           \___________||-+    +----------
                                =============================|| |    |
                                     ^                          |    |
                                     |                         ---  ---
                                     |                         ///  ///
                                     +-- Insulator for matching bar
                                         fixing

                               |<-------- 1/4 Lambda ------->|
 |<-----------------------   3/4 Lambda -------------------->|



Best 73! DS3ATF

--
        [e-mail]
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+  Youn Ok Park, DS3ATF
+  Computer Architecture Section, ETRI,
+  P.O Box 106, Yusong,
+  Taejon, 305-600, Korea
+  http://puddle.etri.re.kr/~parkyo
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


From [e-mail] Wed 07 Jun 95 15:46:32
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From: [e-mail] (Steve Byan)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Longwave beam?
Date: Mon, 05 Jun 1995 12:22:18 -0400
Organization: Hitachi Computer Products, Inc.
Lines: 28
Message-ID: <[e-mail]>
References: <3pq05b$[e-mail]> <[e-mail]>
NNTP-Posting-Host: brainiac.hi.com

In article <[e-mail]>, [e-mail] (Zack Lau
(KH6CP)) wrote:

> How about a phased array composed of small receiving
> antennas, possibly loaded with ferrite?

I'm interested in phasing receive antennas in the tropical SWL bands, MW
broadcast band, and LW band. Anyone have any suggestions for a wideband
90-degree phase shift network? Lossy is ok; I figure I can use  a high
dynamic range preamp to overcome 20 or 30 db of loss.

The designs I've seen in QST use narrowband phase shift networks (such as
an L-network, or a coax delay line), which is fine for the ham bands. The
situation is a little different for MW and SW broadcast DXing - I'd like
to cover 500 to 7000 kHz without too much band-switching.

I'm wondering if an R-C lattice network like those used for audio
frequency phase-shifting would be suitable. Anyone have a reference on how
to design these things?

Thanks,
-Steve

--
Steve Byan                                  internet: [e-mail]
Hitachi Computer Products (America), Inc.
1601 Trapelo Road                           phone: [phone]
Waltham, MA 02154                           FAX: [phone]

From [e-mail] Wed 07 Jun 95 15:46:33
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Zack Lau (KH6CP))
Subject: Re: Longwave beam?
References: <3pq05b$[e-mail]> <[e-mail]> <[e-mail]>
Organization: American Radio Relay League
Date: Tue, 6 Jun 1995 01:42:08 GMT
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Steve Byan ([e-mail]) wrote:

: The designs I've seen in QST use narrowband phase shift networks (such as
: an L-network, or a coax delay line), which is fine for the ham bands. The
: situation is a little different for MW and SW broadcast DXing - I'd like
: to cover 500 to 7000 kHz without too much band-switching.

: I'm wondering if an R-C lattice network like those used for audio
: frequency phase-shifting would be suitable. Anyone have a reference on how
: to design these things?

There appears to be an interesting design on page 548 of
Anatol I. Zverev's handbook of filter synthesis.  The details
are awfully sketchy, but my guess is that someone designed
a roughly 25 kHz to 2 MHz baseband differential phase shifter....
Unfortunately, he didn't describe how you got it...
--
Zack Lau  KH6CP/1           2 way QRP WAS
                           8 States on 10 GHz
Internet: [e-mail]   10 grids on 2304 MHz

From [e-mail] Wed 07 Jun 95 15:46:34
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From: [e-mail] (Steve Byan)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Low-Band DXing errata
Date: Tue, 06 Jun 1995 12:54:14 -0400
Organization: Hitachi Computer Products, Inc.
Lines: 27
Message-ID: <[e-mail]>
NNTP-Posting-Host: brainiac.hi.com
Xref: grape.epix.net rec.radio.amateur.antenna:10869 rec.radio.amateur.homebrew:7669

Has anyone else noticed the following error in Devoldere's "Low-band
DXing"? It's in both editions.

In the section on single-wire Beverage antenna matching transformers, the
book gives the following formula for the number of turns on a toroid for a
given inductance:

N = 100 sqrt (L / AL)

(Note that in the second edition, the square-root radical sign is
misprinted as a multiplication.)

The formula is correct for AL values in units of uH/100 turns.

The book contains a table containing AL values for several types of
toroids and the turns-count for transformers to match to 50 ohm and 75 ohm
feedlines. The AL values for the iron-core toroids are given in units that
match the formula, but the AL values for the ferrite toroids are given in
units of mH/1000 turns. Consequently the turns-count for the transformers
that use ferrite cores are too high by a factor of the square-root of 10
(about 3).

--
Steve Byan                                  internet: [e-mail]
Hitachi Computer Products (America), Inc.
1601 Trapelo Road                           phone: [phone]
Waltham, MA 02154                           FAX: [phone]

From [e-mail] Wed 07 Jun 95 15:46:35
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!pipex!demon!ifwtech.demon.co.uk!G3SEK
From: Ian G3SEK <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Low-Band DXing errata
Date: 7 Jun 1995 12:56:31 +0100
Organization: IFWtech
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Sender: [e-mail]
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References: <[e-mail]> <3r24kr$[e-mail]>
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In article: <3r24kr$[e-mail]>  [e-mail] (TIEMANN BRUCE) writes:
:
: Could anyone tell me why toriods are rated in "AL values" such as uH/100
: turns, or mH/1000 turns?  These "AL values" are often mislabled "units"
: but do not have the correct dimensions, which are actually
: inductance/(turns)^2.
:
: Some vendors sell toroids spec'd as nH/(turns)^2, such as Johnson Shop
: Products, and simple dimensional analysis yields the correct procedure to
: get the inductance of a coil wound on one of these.  Numerically, but not
: dimensionally, mH/1000 T = nH/T^2, and (1/10) uH/100 T = nH/T^2.
:
: Could anyone tell me why toriods are rated in "AL values" such as uH/100
: Given that AL values seem to lead to confusion, such as the typo in Low
: Band DXing, and are not even dimensionally correct, why is their use so
: widespread?  I seem to recall quite a bit of space devoted to explanation
: of AL values in one of the license manuals, and also in the ARRL handbook.
: Perhaps this space might be put to better use.

The inductance of coils wound on toroidal cores, pot-cores or any
core with a closely confined magnetic circuit is proportional to
(turns)-squared. AL is the constant of proportionality. The fundamental
units of AL are therefore Henries/T^2, as Bruce correctly worked out.

To obtain more convenient values, these are usually adjusted to
mH, uH or nH - depending largely on the intended inductance range of
the toroids or pot-cores in question.

The problems arise when manufacturers or distributors balk at units
involving "turns^2" (or believe that their customers will). Some of
them decide that it's best to leave the units out completely!

So, Bruce, you were already 99% there.


--
73 from Ian G3SEK            Editor, 'The VHF/UHF DX Book'
                            'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services       Clear technical English - anywhere.


From [e-mail] Wed 07 Jun 95 15:46:36
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From: [e-mail] (Michael K. Davis)
Newsgroups: rec.radio.amateur.antenna
Subject: Magnesium's Conductivity?
Date: Tue, 6 Jun 1995 20:02:36 MST
Organization: Primenet
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NNTP-Posting-Host: ip206.pom.primenet.com
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Does anyone know how well Magnesium tubing would perform in the construction
of a VHF or UHF yagi?   I'm looking to save weight, for backpacking, but have
no information about it's conductivity....

Please reply by mail to [e-mail]

Thanks,  AB6SL

From [e-mail] Wed 07 Jun 95 15:46:36
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From: [e-mail] (WAGNERJW)
Newsgroups: rec.radio.amateur.antenna
Subject: Matching 75 ohm hardline???
Date: 6 Jun 1995 13:13:01 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Sender: [e-mail]
Message-ID: <3r22at$[e-mail]>
Reply-To: [e-mail] (WAGNERJW)
NNTP-Posting-Host: newsbf02.mail.aol.com

Anyone have any experience with matching 75 ohm hardline for use with 50
ohm radios/antennas?

I have seen articles in the past that use 1/4 wavelength sections of
feedline at each end to match 75 to 50 ohms, but I can't find the info
now.

Also, anyone use this setup in UHF repeater service?  Any luck?

Thanks for the experience!

From [e-mail] Wed 07 Jun 95 15:46:37
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From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Matching 75 ohm hardline???
Date: Tue, 6 Jun 1995 14:40:31
Organization: Ericsson Inc.
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References: <3r22at$[e-mail]>
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In article <3r22at$[e-mail]> [e-mail] (WAGNERJW) writes:
>From: [e-mail] (WAGNERJW)
>Subject: Matching 75 ohm hardline???
>Date: 6 Jun 1995 13:13:01 -0400

>Anyone have any experience with matching 75 ohm hardline for use with 50
>ohm radios/antennas?

>I have seen articles in the past that use 1/4 wavelength sections of
>feedline at each end to match 75 to 50 ohms, but I can't find the info
>now.

To match one real impedance to a different one over a limited frequency range
you simply run a 1/4 wave line between, with the impedance being the geometric
mean of the two impedances your trying to match.  The further apart the 2
starting impedances are, the higher the Q and the narrower the bandwith.

The geometric mean of 50 and 75 is SQRT(50*75) or 61.2 ohms.  So run a 1/4
wave section of 61.2 ohm coax wherever you need to match from 50 to 75 ohms
(or 75 to 50 ohms).  Yeah, right.  Where do I get some 61.2 ohm coax?  Good
luck.  If 1/4 wave is only a few inches or so (UHF)  you can make the matching
line from a trace on a PCB with connectors on either end.  Another way would
be to run a 1/4 wave of two 125 ohm lines tied in parallel.  62.5 ohms is
going to be close enough.  There are other options that involve lumped
elements as well.

Hope this is what you were looking for.  Anyone else wish to add to this?

73 Mike KD6PKJ

PS When figuring 1/4 wave, don't forget it's not free air, but approx 0.7 times
as long for many coax cables.

From [e-mail] Wed 07 Jun 95 15:46:39
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!uunet!ftpbox!mothost!lmpsbbs!NewsWatcher!user
From: [e-mail] (Karl Beckman)
Subject: Re: Matching 75 ohm hardline???
Organization: Mot LMPS Analog Data
Date: Wed, 07 Jun 1995 07:44:58 -0500
Message-ID: <CSLE87-070695074458@145.1.114.19>
Followup-To: rec.radio.amateur.antenna
References: <3r22at$[e-mail]> <[e-mail]>
Sender: [e-mail] (LMPSBBS News Account)
Nntp-Posting-Host: 145.1.114.19
Lines: 49

In article <[e-mail]>,
[e-mail] (Mike Groves) wrote:

> In article <3r22at$[e-mail]> [e-mail] (WAGNERJW) writes:
> >From: [e-mail] (WAGNERJW)
> >Subject: Matching 75 ohm hardline???
> >Date: 6 Jun 1995 13:13:01 -0400
>
> >Anyone have any experience with matching 75 ohm hardline for use with 50
> >ohm radios/antennas?
>
> >I have seen articles in the past that use 1/4 wavelength sections of
> >feedline at each end to match 75 to 50 ohms, but I can't find the info
> >now.
>
> To match one real impedance to a different one over a limited frequency range
> you simply run a 1/4 wave line between, with the impedance being the geometric
> mean of the two impedances your trying to match.  The further apart the 2
> starting impedances are, the higher the Q and the narrower the bandwith.
>
> The geometric mean of 50 and 75 is SQRT(50*75) or 61.2 ohms.  So run a 1/4
> wave section of 61.2 ohm coax wherever you need to match from 50 to 75 ohms
> (or 75 to 50 ohms).  Yeah, right.  Where do I get some 61.2 ohm coax?  Good
> luck.  If 1/4 wave is only a few inches or so (UHF)  you can make the matching
> line from a trace on a PCB with connectors on either end.  Another way would
> be to run a 1/4 wave of two 125 ohm lines tied in parallel.  62.5 ohms is
> going to be close enough.  There are other options that involve lumped
> elements as well.
>
> Hope this is what you were looking for.  Anyone else wish to add to this?
>
> 73 Mike KD6PKJ
>
> PS When figuring 1/4 wave, don't forget it's not free air, but approx 0.7 times
> as long for many coax cables.

It's usually quite simple to re-adjust the input point (often a gamma
match) of the antenna to match the 75 ohm cable impedance.  Almost every
transmitter can easily accomodate the 1.5 mismatch at its output connector.
 Unfortunately it is also much harder to find a commercial VSWR meter (or
bridge) that is calibrated for 75 ohm coax, which makes the tuning task a
bit more difficult.

--
Karl Beckman, P.E.                  <     If our English language is so  >
Motorola LMPS.RNSG.Pvt Data         <  precise, why do you drive on the  >
Schaumburg, IL  /  Parma, OH        <  parkway and park on the driveway? >
   Opinions expressed here do not belong to or represent Motorola Inc.
Amateur radio WA8NVW                        NavyMARS NNN0VBH @ NOGBN.NOASI

From [e-mail] Wed 07 Jun 95 15:46:39
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!Germany.EU.net!EU.net!news.sprintlink.net!uunet!in1.uu.net!mr.net!news.mr.net!dawn.mmm.com!news
From: [e-mail] (Gary Hosler - KN0Z)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Matching 75 ohm hardline???
Date: 7 Jun 1995 13:02:49 GMT
Organization: 3M Company
Lines: 22
Message-ID: <3r481p$[e-mail]>
References: <3r22at$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: ghosler.mmm.com
X-Newsreader: IBM NewsReader/2 v1.2

In <3r22at$[e-mail]>, [e-mail] (WAGNERJW) writes:
>Anyone have any experience with matching 75 ohm hardline for use with 50
>ohm radios/antennas?
>
>I have seen articles in the past that use 1/4 wavelength sections of
>feedline at each end to match 75 to 50 ohms, but I can't find the info
>now.
>
>Also, anyone use this setup in UHF repeater service?  Any luck?
>
>Thanks for the experience!

Contact W8ZD, Paul Darwactor at ZD Engineering.  He makes "ends"
for CATV hardline that not only transform the 75 ohm impedance to
50 ohms, but also provide ends (your choice of PL-259 or "N") that
are normally very, very expensive.  Cost,...about $40.00 for a pair.
Just specify frequency (144 mHz, 220, or 440), and the exact outside
diameter of the metalic portion of the shield.  The only downside is
that Paul is backlogged most of the time and thsu you can expect a
wait for the goodies, but they are worth it!  Good Luck!
                                de KN0Z  Gary


From [e-mail] Wed 07 Jun 95 15:46:41
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!uunet!in1.uu.net!psinntp!psinntp!psinntp!psinntp!arrl.org!zlau
From: [e-mail] (Zack Lau (KH6CP))
Subject: Re: Matching 75 ohm hardline???
References: <3r22at$[e-mail]> <[e-mail]>
Organization: American Radio Relay League
Date: Wed, 7 Jun 1995 14:25:06 GMT
X-Newsreader: TIN [version 1.2 PL2]
Message-ID: <[e-mail]>
Lines: 19

Mike Groves ([e-mail]) wrote:
: The geometric mean of 50 and 75 is SQRT(50*75) or 61.2 ohms.  So run a 1/4
: wave section of 61.2 ohm coax wherever you need to match from 50 to 75 ohms
: (or 75 to 50 ohms).  Yeah, right.  Where do I get some 61.2 ohm coax?  Good
: luck.  If 1/4 wave is only a few inches or so (UHF)  you can make the matching
: line from a trace on a PCB with connectors on either end.  Another way would
: be to run a 1/4 wave of two 125 ohm lines tied in parallel.  62.5 ohms is
: going to be close enough.  There are other options that involve lumped
: elements as well.
:

For UHF, many people make matching sections out copper/brass/aluminum
tubing.  The square stuff is nice if you want to bolt a connector to
the side of it.  There are charts and equations in many microwave books
for figuring out the impedance of common geometries.
--
Zack Lau  KH6CP/1           2 way QRP WAS
                           8 States on 10 GHz
Internet: [e-mail]   10 grids on 2304 MHz

From [e-mail] Wed 07 Jun 95 15:46:44
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!agate!dog.ee.lbl.gov!newshub.nosc.mil!news
From: [e-mail]
Subject: Re: Matching 75 ohm hardline???
Message-ID: <[e-mail]>
Lines: 21
Sender: [e-mail] (Network News)
Reply-To: [e-mail]
Organization: NRaD Code 848
X-Newsreader: IBM NewsReader/2 v1.02
References: <3r22at$[e-mail]>
Date: Wed, 7 Jun 1995 15:03:44 GMT

In <3r22at$[e-mail]>, [e-mail] (WAGNERJW) writes:
>Anyone have any experience with matching 75 ohm hardline for use with 50
>ohm radios/antennas?
>
>I have seen articles in the past that use 1/4 wavelength sections of
>feedline at each end to match 75 to 50 ohms, but I can't find the info
>now.
>
>Also, anyone use this setup in UHF repeater service?  Any luck?
>
>Thanks for the experience!

One way to match it at HF for a single band is two short pieces of 50 and
75 ohm cable.  To the end of the 75 ohm hardline, connect a 0.0815 wavelength
50 ohm coax.  Attach a 0.0815 wavelength 75 ohm coax to the other end of the
50 ohm coax (so that they are in series).  The output of the short 75 ohm
section is now 50 ohms.  This works very well at HF but the lengths get a
bit short at UHF.

Rick Craig, N6ND
[e-mail]

From [e-mail] Wed 07 Jun 95 15:46:45
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!pipex!swrinde!emory!cssun.mathcs.emory.edu!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Matching 75 ohm hardline???
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3r22at$[e-mail]>
Date: Wed, 7 Jun 1995 16:28:38 GMT
Lines: 22

In article <3r22at$[e-mail]> [e-mail] (WAGNERJW) writes:
>Anyone have any experience with matching 75 ohm hardline for use with 50
>ohm radios/antennas?
>
>I have seen articles in the past that use 1/4 wavelength sections of
>feedline at each end to match 75 to 50 ohms, but I can't find the info
>now.

Right, the section needs to be of an impedance that's the geometric
mean of the two values you are transforming between. That's 62.5 ohms.
ZD Engineering makes air line transformers for 2 meters, 70 cm, and
23 cm. He offers them to fit on standard sizes of CATV hardline, and
they have an N connector on the other end, so they double as connectors
for the hardline too. A pair for 2 meters that fit 0.5 inch CATV line
costs about $25.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Wed 07 Jun 95 15:46:46
Newsgroups: rec.radio.amateur.antenna
Subject: Mod files
From: [e-mail] (Clint Bradford)
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!holonet!colossus.holonet.net!wwswinc!clint.bradford
Distribution: world
Message-ID: <[e-mail]>
Date: Tue,  6 Jun 95 05:59:00 -0500
Organization: WoodyWare Software, Inc. - 516-736-6662
Lines: 13

Subject: Mod files

>>Im looking at a Standard C-568 tri bander and hope there is a mod for
>>full coverage.

I have hundreds of current Mod files on ATTENTION to Details BBS - but
none for the C568.

Let us know if you find anything!
Clint Bradford, KE6LCS
---
 * TLX v4.00 * ATTENTION to Details BBS - HAM Radio / ASP. 909-681-6210
 ■ wcECHO 4.0 ≈ AR-Net: ATTENTION to Details ■ Mira Loma, CA ■ 909-681-6221

From [e-mail] Wed 07 Jun 95 15:46:46
Path: grape.epix.net!news.sprintlink.net!uunet!in1.uu.net!li.net!bbruhns
From: [e-mail] (Bob Bruhns)
Newsgroups: rec.radio.amateur.antenna
Subject: Need advice on AM
Date: 4 Jun 1995 22:53:41 GMT
Organization: LI Net (Long Island Network)
Lines: 8
Message-ID: <3qtdhl$[e-mail]>
NNTP-Posting-Host: linet01.li.net
X-Newsreader: TIN [version 1.2 PL2]

  Try a window antenna.  I think Radio Shack sells them for cars.  It's a
little wire that sticks to the window glass and connects to an auto radio.
It's meant to be glued to the windshield.  It should work on FM, too.

  Other than that, you could try placing a table or portable radio right
up against a window.  You might encounter a null and not be able to
receive your desired station, although others are audible.  If so, try a
window along another wall.

From [e-mail] Wed 07 Jun 95 15:46:47
Path: grape.epix.net!news.sprintlink.net!hookup!noc.tor.hookup.net!news
From: Jeff Krul <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Subject: NEED HELP!  Respond : Grounding 'Experts' !
Date: 7 Jun 1995 18:19:12 GMT
Organization: EQUIST Inc.
Lines: 23
Message-ID: <3r4qj0$[e-mail]>
NNTP-Posting-Host: jkrul.equist.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
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Xref: grape.epix.net rec.radio.amateur.antenna:10909 rec.radio.amateur.homebrew:7678 rec.radio.amateur.misc:80334 rec.radio.amateur.digital.misc:8794

I am in the process of putting together a new HAM 'shack', and I have
come across an interesting 'snag'.

I have heard, many times before, to be sure the HAM radio ground is NOT
grounded to the house wiring ground system.  Various explanations follow,
usually to avoid having the house wiring turn into a massive antenna.

Anyways, I was SURE to separate the two and overlooked one point . . .
packet !  My TNC uses a serial cable, connected to my computer, which in
turn has a grounded chassis!  Argh!  To top it all off, the serial cable
is NOT the right way to ground to a 'secondary' ground.  Talk about a
'high' resistance path to ground, forming an 'ideal' ground loop!!!!

My question is, "How can I avoid this, and if I cannot, what effect will
grounding to the house ground REALLY have?"  "What are my OTHER options?"

Thanks for your replies in advance,
Jeff
VE3QED

Please e-mail your responses to [e-mail]



From [e-mail] Wed 07 Jun 95 15:46:48
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!news.sprintlink.net!uunet!in1.uu.net!alterdial.uu.net!not-for-mail
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need info on Cushcraft R7!
Date: Sat, 03 Jun 95 21:33:11 EDT
Lines: 8
Message-ID: <3qr2no$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: aosta.home.uu.net
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-Newsreader: NEWTNews & Chameleon -- TCP/IP for MS Windows from NetManage


I have had a Cushcraft R7 for 4 years now. Excellent antenna. 255 DXCC
countries confirmed using the R7. I recommend mounting it 10 feet off the
ground as recommended by Cushcraft. I placed it 125 feet away from the house
because, at ground level, it can radiate a lot of energy into your house if it
is too close. I feed it with buried RG-213. A superior product! Good luck!

Joe KO4EI

From [e-mail] Wed 07 Jun 95 15:46:49
Path: grape.epix.net!news.sprintlink.net!gatech!swrinde!elroy.jpl.nasa.gov!decwrl!pa.dec.com!ninja.zso.dec.com!slugbt.zso.dec.com!rehm
From: [e-mail] (Eric Rehm)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need info on Cushcraft R7!
Date: 5 Jun 1995 21:00:46 GMT
Organization: Digital Equipment Corporation
Lines: 55
Message-ID: <3qvr9u$[e-mail]>
References: <[e-mail]> <3qs90g$[e-mail]>
NNTP-Posting-Host: slugbt.zso.dec.com
X-Newsreader: TIN [version 1.2 PL2]

Gilbert Baron ([e-mail]) wrote:

: If you buy it be sure to use a tilt over
: roof mount if you mount it there. You may be wanting to make
: adjustments and it is HARD to hold it up and set it down into the
: mount all at once. A tilt over mounting is MUCH better.

I've just purchased an R7, and I'm considering various ways
to mount it on my roof.  How did you do it?   Can you describe
the tilt over roof mount and tell me where you got it?

Do others have suggestions on how to mount it?

First - the mast that the R7 is mounted on must be 1.5" to 1.75"
in diameter, so normal TV mast (1.25") WON'T WORK.  So, I've
purchased 6' of 17 gauge 1.675" galvanized steel fence post.

I've considered (and rejected most of) the following options:

1.  Roof peak mount - this is like a tilt over mount -
    it has two trapezoidal flanges that are bolted to 4"
    piece of 1-1/2 tube.

        + Simple.  Tilts too.
        - Must find 1-1/2" mast.  My 1.675 fence post is too large.
          (TV 1.25" mast is too small.) Also, mast must be guyed with
          non-metallic wire. (Suggestions for non-metallic guy wire are
          welcome!)

2.  Tripod mount - the 3' $15 (but fairly sturdy) variety.

        + Sturdy, can accomodate the 6' piece of 1-5/8" 17 Gauge
          steel fence post that might be my mast.
        - Lots of holes (and silicon caulk) in the roof.
          Lots of climbing around in the attic.

3.  Chimney mount

        + Can get the parts at Radio Shack.  Easy to install.
        - Must take it down when needed chimney repairs
          (at the very top / cap) are done.
          Will it put too much stress on my 49 year old chimney?

4.  Vent Pipe Mount

        + Easy, cheap.
        - Not sure that the vent pipe mount is strong enough.  Not
          sure my vent pipe (either cast iron or galvanized steel)
          is strong enough.

5.  Eves Mount

        + Easy, cheap
        - I don't have any eves, so this is not for me.


From [e-mail] Wed 07 Jun 95 15:46:50
Path: grape.epix.net!news.sprintlink.net!gatech!bloom-beacon.mit.edu!news.kei.com!nntp.et.byu.edu!news.byu.edu!hamblin.math.byu.edu!yvax.byu.edu!sandersm
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need info on Cushcraft R7!
Message-ID: <[e-mail]>
Date: 5 Jun 95 20:42:35 -0700
References: <[e-mail]> <3qs90g$[e-mail]> <3qvr9u$[e-mail]>
Distribution: world
Organization: Brigham Young University
Lines: 32

In article <3qvr9u$[e-mail]>, [e-mail] (Eric Rehm) writes:
> Gilbert Baron ([e-mail]) wrote:
>
> : If you buy it be sure to use a tilt over
> : roof mount if you mount it there. You may be wanting to make
> : adjustments and it is HARD to hold it up and set it down into the
> : mount all at once. A tilt over mounting is MUCH better.
>
> I've just purchased an R7, and I'm considering various ways
> to mount it on my roof.  How did you do it?   Can you describe
> the tilt over roof mount and tell me where you got it?
>
> Do others have suggestions on how to mount it?
>

I bought some aluminum fence top post, about 18 feet.  I cut it in half,
pushing the bottom half about 3 feet into the ground at the side of the house.
I bought a coupling piece to hold the two halves in line.  That way I could
lift the top half off, and then lower the antenna into the back yard --
probably not quite as good as a bolted type hinge, but it works.  the mast is
held to the roof at the eaves with an aluminum "U" bracket.  The mast extends
about 4 ft above the roof peak, and which point the antenna  fits on.  I
noticed that SWR went down, as the antenna was raised further above the roof,
and is decent right now.  The tip extends about 36 feet above ground level.
With the "U" bracket at roof level and the other end in the ground, I have had
no trouble with winds.  In fact, we are having a big storm right now:  blew 5
18 wheelers off the road and over on their sides, as well as a 15 ft portion of
my vererable wood fence -- hope the insurance is good <grin>; and my antenna is
still sitting there waving in the wind and ready for use.

Milt


From [e-mail] Wed 07 Jun 95 15:46:51
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!spool.mu.edu!uwm.edu!fnnews.fnal.gov!gw1.att.com!gw2.att.com!pacbell.com!amdahl.com!juts.ccc.amdahl.com!arl00
From: [e-mail] (Arlan R Levitan)
Subject: Re: Need info on Cushcraft R7!
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Arlan R Levitan)
Organization: Amdahl Corporation, Sunnyvale CA
References: <[e-mail]> <3qs90g$[e-mail]> <3qvr9u$[e-mail]>
Date: Tue, 6 Jun 1995 13:11:12 GMT
Lines: 15

I wouldn't use anything but a solid tripod mount on a roof peak. The
R7 really whips around in the wind, and would probably put some nasty
torque on a chimney. A vent pipe mount wouldn't last through your first
QSO.

You should dump the six-foot piece of galavanized pipe and replace it
with a ten footer. If you don't get at least 10 feet above your roof
strange things will happen to your SWR during or after a good rain.
I had mine on a five footer and had to replace it for that reason.

I guyed my R7 with PhillyStran, a vinyl covered kevlar. Expensive, but
very nice stuff. I chose to guy the top of the mast rather than the R7
proper. The original versions of the R7 had a bottom section with rivets
that used to pop under stress...those R7s should be guyed on the antenna
itself, a few feet below the bottom pair of cross bars.

From [e-mail] Wed 07 Jun 95 15:46:51
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (DABLOODGOD)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need info on Cushcraft R7!
Date: 7 Jun 1995 10:28:45 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 6
Sender: [e-mail]
Message-ID: <3r4d2t$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (DABLOODGOD)
NNTP-Posting-Host: newsbf02.mail.aol.com

I mounted mine on a 10' piece of thick wall electrical conduit, with
chimmey straps from radio shack. Seems to have held up well - for about 4
months so far. Not to much success on the bands - this is the low point on
the sun spot cycle though. I like it.

73's de Dave, [e-mail].

From [e-mail] Wed 07 Jun 95 15:46:52
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!news.larc.nasa.gov!news.msfc.nasa.gov!sol.ctr.columbia.edu!howland.reston.ans.net!news.sprintlink.net!usit.net!usenet
From: [e-mail] (Randy Padawer)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.misc
Subject: NEED INFO re MFJ verticals!
Date: 5 Jun 1995 03:38:25 GMT
Organization: Apolog
Lines: 12
Sender: [e-mail]
Message-ID: <3qtu7h$[e-mail]>
NNTP-Posting-Host: padawer.ppp.usit.net
X-Posted-From: InterNews [e-mail]
X-Authenticated: padawer on POP host use.usit.net
Xref: grape.epix.net rec.radio.amateur.antenna:10825 rec.radio.amateur.misc:80166

I'm thinking about buying one of the 80-10 MFJ verticals.  Can anyone
discuss its merits and deficits?  How does it work on 80?... Can it be
heard at all on 80?  Any information would be appreciated.

(((Please, no messages about the Cushcraft or GAP offerings.  I'm
already familiar with those.)))


-----------------------------------------------------------------
Randy Padawer, P.O. Box 1167, Knoxville, TN  37901-1167  U.S.of A
Internet: [e-mail]    Tel: [phone]     Ham: WA4FJF
-----------------------------------------------------------------

From [e-mail] Wed 07 Jun 95 15:46:53
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!bloom-beacon.mit.edu!news.kei.com!simtel!noc.netcom.net!netcom.com!ghiscox
From: [e-mail] (George L. Hiscox)
Subject: Opinions re antenna analyzers?
Message-ID: <[e-mail]>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
X-Newsreader: TIN [version 1.2 PL1]
Date: Tue, 6 Jun 1995 03:38:58 GMT
Lines: 11
Sender: [e-mail]

Looking for opinions, observations, preferences on the Autek, MFJ and
AEA antenna analyzers.

Thanks,

George
---
| George L. Hiscox                |  Very funny Scotty...Now  |
| [e-mail]              |  beam down my clothes!!!  |
| WA6RIK @ WB6YMH.#soca.ca.usa.na |  ^^^^^^^^^^^^^^^^^^^^^^^  |


From [e-mail] Wed 07 Jun 95 15:46:54
Path: grape.epix.net!news.sprintlink.net!pipex!sunic!sunic.sunet.se!erinews.ericsson.se!pc125011.exu.ericsson.se!eus.eusmge
From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Opinions re antenna analyzers?
Date: Tue, 6 Jun 1995 14:46:40
Organization: Ericsson Inc.
Lines: 19
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: pc125011.exu.ericsson.se
X-Newsreader: Trumpet for Windows [Version 1.0 Rev A]

In article <[e-mail]> [e-mail] (George L. Hiscox) writes:

>Looking for opinions, observations, preferences on the Autek, MFJ and
>AEA antenna analyzers.

Don't know about the rest, but I had an oppertunity to borrow an Autek from a
friend before re-installing a home made 10M J-pole antenna on a tower at a
remote base in the mountains.  Putting this 1/2 over 1/4 in place is no small
task and using this analyzer I could easily adjust the match at the feed-point
for best SWR in the FM portion of the band right where it was mounted!  With a
touch of a button I could find the resonant freq, impedance, SWR, or whatever.
What a joy to have.  Hooked up the feed coax and did another quick check in
the shack on the other end and I was done.

I'd never used one on these before, and I will definately add it to my wish
list.

Hope this helps a little,
Mike KD6PKJ

From [e-mail] Wed 07 Jun 95 15:46:54
Path: grape.epix.net!news.sprintlink.net!EU.net!Belgium.EU.net!ping.be!dialup10.hasselt.eunet.be!jan.anker
From: [e-mail] (Jan Anker)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Opinions re antenna analyzers?
Date: Wed, 7 Jun 1995 00:11:40
Organization: Anchor Datacomm
Lines: 15
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: dialup10.hasselt.eunet.be
X-Newsreader: Trumpet for Windows [Version 1.0 Rev A]

In article <[e-mail]> [e-mail] (George L. Hiscox) writes:
>From: [e-mail] (George L. Hiscox)
>Subject: Opinions re antenna analyzers?
>Date: Tue, 6 Jun 1995 03:38:58 GMT

>Looking for opinions, observations, preferences on the Autek, MFJ and
>AEA antenna analyzers.

Bought MFJ-204B: piece of shit!
                               freq not correct, Z by far not correct.
Compared it to WAYNKERR B801B and HP 8405A

What I have heard of AUTEK Z meter,   it seems a good device with some
tolerance on impedance below 30 Ohms. Did not try myself, but seems to be
worth the money.  Have good experience with other AUTEK products.

From [e-mail] Wed 07 Jun 95 15:46:56
Path: grape.epix.net!news.sprintlink.net!uunet!in1.uu.net!nwfocus.wa.com!krel.iea.com!comtch!n0dh
From: [e-mail] (D.C. Henderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Opinions re antenna analyzers?
Date: 7 Jun 1995 17:42:13 GMT
Organization: CompuTech, Spokane WA
Lines: 47
Message-ID: <3r4odl$[e-mail]>
References: <[e-mail]> <[e-mail]>
NNTP-Posting-Host: comtch.iea.com
X-Newsreader: TIN [version 1.2 PL1]

Mike Groves ([e-mail]) wrote:
: In article <[e-mail]> [e-mail] (George L. Hiscox) writes:

: >Looking for opinions, observations, preferences on the Autek, MFJ and
: >AEA antenna analyzers.

Purchased an Autek RF-1 about 6 months ago. And have been reasonably
pleased with it on whole, Appears to make accurate measurements of R,L,C,Z
and SWR... note that R,L,C can only be measured to the nearest ohm so
trying to measure capacitor values on 160 meters down to the last few pf
can be tricky since you move 20 to 30 pf per ohm at this frequency.
if the cap has a z of say 20 ohms this can represent a possible error of
5% or more.

You are obviously paying for the "technology", not the construction in
the case of the RF-1. For what it costs it comes in a dinky, cheap
plastic case and is not very rugged. I would have gladly paid a bit more
to get a more rugged unit, a better display and one more significant
digit in the  read out.

The unit is susceptiple to giving false readings if large signals are
present nearby. This is particularly a problem when trying to work on
large antennas in the 160 and 80 meter bands where strong induced fields
from AM Broadcast staions as far away as 15 miles can effect the unit,
producing erratic and erroneous readings. There seldom any initilal
indication that this is occuring either, except that things "dont make
sense".

The Autek has a very bad reputation when it comes to getting technical
help and authorization for field returns. There have been many accounts
here on the newsgroup about the owners take it or leave it "attitude"
when dealing with unhappy customers. Autek is also paranoid about letting
you have a schematic so you can fix it yourself. From what I've heard the
most frequent compalint has been the display.

Mine however has played flawlessly and so far I have not had a problem or
had to deal with their surley customer service reputation. Would I buy
one again?? Probably, Sure beats trying to haul my old black Booton RX
meter to the top of the tower :-).

As for MFJ never owned one (of their antenna analyzers). I have owned
other MFJ items in the past they all lived up to their name which where I
come from is "Mississippi's Finest Junk". I dont buy from MFJ anymore for
any reason.....been burnt 3 times...

Dave
N0DH/7

From [e-mail] Wed 07 Jun 95 15:46:56
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Opinions re antenna analyzers?
Date: 7 Jun 1995 15:27:00 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 7
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Message-ID: <3r4ui4$[e-mail]>
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I have the Autek and the MFJ 249 and 259. I use the MFJ 259 mostly because
it is easier for me to read meters than digital displays when pruning and
tuning. It also covers wider freq range. That is strictly a matter of
preference though. All three seem like good instruments and resonably
accurate. 73 Tom



From [e-mail] Wed 07 Jun 95 15:46:57
Path: grape.epix.net!news.sprintlink.net!gatech!gt-news!prism!prism!not-for-mail
From: [e-mail] (GT Amateur Radio Club)
Newsgroups: rec.radio.amateur.antenna
Subject: PATCH ANTENNAS????
Date: 5 Jun 1995 00:43:04 -0400
Organization: Georgia Institute of Technology
Lines: 33
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Message-ID: <3qu20o$[e-mail]>
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Hi all...

I have been volunteering a little on the Phase 3D satellite in Orlando, and
I found that it had "patch" antennas on 70 cm. These look basically like
70-cm wide disks of metal, a little ways above the sheet of metal which forms
the bottom of the satellite. There are three of them, supposedly to enable
it to be polarized.

I am very curious about these, because A) they are quite small, B) they looked
fairly simple, and C) I was told the gain is something like 13dB. I was wonder-
ing if this type of an antenna might be a good alternative to a yagi array for
satellite work... if the performance were equal to a standard satellite beam,
it would still be better beacuse it would be a lot less bulky and far less
likely to poke you in the eye. Can anyone shed some light on these... how
do they work, how do you make one, how critical are teh dimensions, what the
pattern looks like, etc. ? I would ask the antenna guru at P3D but my car
is on the fritz so I may not get back over there for a while. Thanks ifor
any help you folks can give me!!!

73 de KD4UGI


******************************************************************************
* MIKE "GATOR" WHALEY         KD4UGI      [e-mail] *
* P.O. Box 510717, Melbourne Beach, FL 32951-0717             [phone] *
*            "Ipecac- isn't that a Genesis album?" --- Joel, MST3K           *
******************************************************************************

--
                        Georgia Tech Amateur Radio Club
                           [e-mail]
                                [phone]


From [e-mail] Wed 07 Jun 95 15:46:58
Path: grape.epix.net!news.sprintlink.net!gatech!bloom-beacon.mit.edu!boulder!spot.Colorado.EDU!tiemann
From: [e-mail] (TIEMANN BRUCE)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Pesky AL values, was Re: Low-Band DXing errata
Date: 6 Jun 1995 17:52:27 GMT
Organization: University of Colorado, Boulder
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References: <[e-mail]>
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Xref: grape.epix.net rec.radio.amateur.antenna:10873 rec.radio.amateur.homebrew:7670

Could anyone tell me why toriods are rated in "AL values" such as uH/100
turns, or mH/1000 turns?  These "AL values" are often mislabled "units"
but do not have the correct dimensions, which are actually
inductance/(turns)^2.

Some vendors sell toroids spec'd as nH/(turns)^2, such as Johnson Shop
Products, and simple dimensional analysis yields the correct procedure to
get the inductance of a coil wound on one of these.  Numerically, but not
dimensionally, mH/1000 T = nH/T^2, and (1/10) uH/100 T = nH/T^2.

Could anyone tell me why toriods are rated in "AL values" such as uH/100
Given that AL values seem to lead to confusion, such as the typo in Low
Band DXing, and are not even dimensionally correct, why is their use so
widespread?  I seem to recall quite a bit of space devoted to explanation
of AL values in one of the license manuals, and also in the ARRL handbook.
Perhaps this space might be put to better use.

Bruce Tiemann
N6URH

From [e-mail] Wed 07 Jun 95 15:46:59
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!gatech!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Pesky AL values, was Re: Low-Band DXing errata
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <3r24kr$[e-mail]>
Date: Wed, 7 Jun 1995 15:38:02 GMT
Lines: 35
Xref: grape.epix.net rec.radio.amateur.antenna:10897 rec.radio.amateur.homebrew:7674

In article <3r24kr$[e-mail]> [e-mail] (TIEMANN BRUCE) writes:
>Could anyone tell me why toriods are rated in "AL values" such as uH/100
>turns, or mH/1000 turns?  These "AL values" are often mislabled "units"
>but do not have the correct dimensions, which are actually
>inductance/(turns)^2.
>
>Some vendors sell toroids spec'd as nH/(turns)^2, such as Johnson Shop
>Products, and simple dimensional analysis yields the correct procedure to
>get the inductance of a coil wound on one of these.  Numerically, but not
>dimensionally, mH/1000 T = nH/T^2, and (1/10) uH/100 T = nH/T^2.
>
>Could anyone tell me why toriods are rated in "AL values" such as uH/100
>Given that AL values seem to lead to confusion, such as the typo in Low
>Band DXing, and are not even dimensionally correct, why is their use so
>widespread?  I seem to recall quite a bit of space devoted to explanation
>of AL values in one of the license manuals, and also in the ARRL handbook.
>Perhaps this space might be put to better use.

AL values are favored for the same reason meters per second are favored
over furlongs per fortnight. And that reason is that most calculations
can be done easily in your head, rather than having to reach for a
calculator. As you note, T^2 is already built into the values, so you
don't have to do that in your head when using AL values to calculate
the number of turns you need for a given inductance.

This is mostly a historical artifact now that all of us routinely have
a scientific calculator close at hand. In the manual arithmetic days,
it saved a bit of work, and another possible source of manual math error.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Wed 07 Jun 95 15:47:00
Path: grape.epix.net!news.sprintlink.net!simtel!col.hp.com!fc.hp.com!jayk
From: [e-mail] (Jay Kesterson K0GU)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quad Antenna and boom material...
Date: 6 Jun 1995 14:28:44 GMT
Organization: Morris is a cat, Morse is a code
Lines: 19
Message-ID: <3r1oms$[e-mail]>
References: <3pcanb$[e-mail]> <3q15n3$[e-mail]>
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: >I'm about to construct a 2 meter 4 element Quad antenna,
: >I chose to use PVC tubing for the supporting arms, but
: >I'm stuck to the boom material. The boom length will be
: >about 1.5 meters long, and the weight will most propably
: >bend the bood... I don't want to use wood, so I was wondering
: >will a mettal boom affect the antenna tunning the same way
: >it affects yagi antennas ?? or since the boom is isolated
: >from the antenna itself an open space effect is produced ??
: 73 de WA0VED

I just designed a 4 element 6m quad on MiniNEC and NEC. When I added
a metal 2" boom to the the model the results didn't change at all. Then
I added a 2" mast to support the boom and again the results didn't
change at all. It appears the the orientation of the boom/mast to the
elements cause little/no effect. However my quad is horizontally
polarized. If your 2m quad is vertically polarized the mast might cause
some problem (as well as the feed line).

73, Jay  K0GU                  [e-mail]

From [e-mail] Wed 07 Jun 95 15:47:00
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: steel wire vs. copper ???
Date: 5 Jun 1995 13:42:30 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 6
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Message-ID: <3qvfm6$[e-mail]>
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Reply-To: [e-mail] (W8JI  Tom)
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So at the risk of another barrage, let me say again. If the iron you use
is powdered up in small enough chunks, and each grain is insulated, and
you put it over the outside of the conductor carrying HF ac or RF current,
and it will increase the inductance. If it is solid iron it will decrease
the inductance. There is more to the issue than permeability. (Sneaking
away now)  ;-) Tom

From [e-mail] Wed 07 Jun 95 15:47:02
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!cs.utexas.edu!news.sprintlink.net!psgrain!nntp.teleport.com!usenet
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: steel wire vs. copper ???
Date: 6 Jun 1995 06:37:18 GMT
Organization: Teleport - Portland's Public Access [phone]
Lines: 19
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;   [e-mail] (Dick Bingham) writes:
;  Gary Coffman ([e-mail]) wrote:
;
;  : I went off the deep end with that post and must apologize. I was far
;  : too dogmatic, and wrong to boot.
;
;  These two lines immediately above my comments are those of a person I
;  respect highly... I have had dealings with other technically brilliant
;  and thorough engineers who are emotional cripples and could NEVER type
;  or say what Gary wrote above.
;
;  de w7wkr


I second that!

Roy Lewallen, W7EL



From [e-mail] Wed 07 Jun 95 15:47:03
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From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: steel wire vs. copper ???
Date: Tue, 06 Jun 95 07:18:11 GMT
Organization: Microserve Information Systems (800)-380-INET
Lines: 22
Distribution: world
Message-ID: <3r0vnu$[e-mail]>
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[e-mail] (W8JI  Tom) wrote:
>The coil was 2" diameter, the slugs were 1/2 inch od.

Just for grins, I tested this myself.  The coil is an air core
single-layer prototype for a plate choke, about 2-1/2" long by 1"
diameter, wound on a hollow styrene form.  When paralleled with a
22 pf capacitor, it resonates at about 3.2 MHz.  Measurements
were made with a GDO loosely coupled to the coil, and I repeated
the tests several times.

For the record, inserting either a brass 8-32 screw or an iron
screwdriver blade into the coil caused the frequency to increase
approximately 10 - 15 KHz.  However, the brass screw merely caused
the frequency to change, whereas the iron also caused the dip to
become shallower and broader.

Apparently, iron *does* reduce the inductance of the coil at HF,
as well as reducing its Q.

73,

Jack  WB3U

From [e-mail] Wed 07 Jun 95 15:47:04
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From: [e-mail] (WalShults)
Newsgroups: rec.radio.amateur.antenna
Subject: Tennis Anyone??
Date: 5 Jun 1995 02:54:11 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 14
Sender: [e-mail]
Message-ID: <3qu9mj$[e-mail]>
Reply-To: [e-mail] (WalShults)
NNTP-Posting-Host: newsbf02.mail.aol.com


I just installed a 4 foot Skip Shooter antenna on a mount behind my car.
I realize
that the antenna is going to smack my trunk from time to time during
highway
travel or hard turns.  I want to use something to protect my trunk from
marring and
scratching.  Any ideas would be appreciated.  I DO NOT want use an old
TENNIS
BALL split in half like most other long antennas I've seen :-)  What will
work well
and not inhibit my signal?  Thank you!

-Wal

From [e-mail] Wed 07 Jun 95 15:47:05
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!cs.utexas.edu!news.sprintlink.net!gatech!gt-news!prism!prism!not-for-mail
From: [e-mail] (GT Amateur Radio Club)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Tennis Anyone??
Date: 5 Jun 1995 03:12:38 -0400
Organization: Georgia Institute of Technology
Lines: 33
Sender: [e-mail]
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[e-mail] (WalShults) writes:


>scratching.  Any ideas would be appreciated.  I DO NOT want use an old
>TENNIS
>BALL split in half like most other long antennas I've seen :-)  What will
>work well
>and not inhibit my signal?  Thank you!
>-Wal

A racquetball???
:-)

Really, I have seen CBers with tennis balls on those antennas for years, and
never realized they were to protect the car's finish. I thought it was to either
damp out vibration or some sort of redneck mating call.

(ducking from the flames)...
-Mike


******************************************************************************
* MIKE "GATOR" WHALEY         KD4UGI      [e-mail] *
* P.O. Box 510717, Melbourne Beach, FL 32951-0717             [phone] *
*            "Ipecac- isn't that a Genesis album?" --- Joel, MST3K           *
******************************************************************************


--
                        Georgia Tech Amateur Radio Club
                           [e-mail]
                                [phone]


From [e-mail] Wed 07 Jun 95 15:47:06
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From: [e-mail] (chinook)
Newsgroups: rec.radio.amateur.antenna
Subject: test
Date: 7 Jun 1995 05:50:05 GMT
Organization: Forewin Technologies Inc.
Lines: 1
Message-ID: <3r3emd$[e-mail]>
NNTP-Posting-Host: slip165-131.on.ca.ibm.net
X-Newsreader: WinVN 0.92.5

test

From [e-mail] Wed 07 Jun 95 15:47:21
Path: grape.epix.net!news.sprintlink.net!news.primenet.com!ip004.phx.primenet.com!nx7u
From: [e-mail] (Scott Townley)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: Tue, 6 Jun 1995 06:00:35 MST
Organization: Primenet
Lines: 43
Message-ID: <[e-mail]>
References: <[e-mail]> <3qngib$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
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In article <[e-mail]> [e-mail] (Mike Groves) writes:
>From: [e-mail] (Mike Groves)
>Subject: Re: The meaning of 'matched'
>Date: Sun, 4 Jun 1995 20:39:09



>>Gary

>I have to admit I haven't followed all of it.  I will profess to the world I
>do not have the background in tube theory that some of my associates do
>however, give me a solid state RF device and I'll whip you out an amp with
>my eyes closed.
>
>Can I take this oppertunity to ask you to clarify a couple of things Gary now
>that I have your attention?  Let's get away from amplifiers for a moment and
>find another type of source to match to.  How about an antenna set up to
>recieve an incoming signal.  We know it's not REALLY a source,  but for the
>sake of the discussion...
>
>If the gain of the antenna was such that an RF signal presented to it (out of
>the air) generated 1uW into a 50 ohm load at a given frequency with little or
>no reflections (a 1:1 or conjagate match with the 50 load), are you implying
>that since 1 uW is being dissapated by the 50 ohm load, and we have a perfect
>match between source and load, that 1uW ALSO  would have to be dissapated by
>the source (the antenna) somehow?

That's always an interesting thought.
The "classical" textbook answer is:  yes.
Let's use the case of a dipole antenna.
The incoming EM wave induces a current on the antenna, which delivers power to
the load.  HOWEVER, this same current obviously must flow through the antenna
radiation resistance (it's in series with the load).  Since physics doesn't
care where that current comes from (from a transmitter or from an external
energy source), the antenna must *radiate* as if the same current were being
supplied by a transmitter.
So what happens is, half the total power in the system is delivered to the
load (that's the power you can see and measure), and the *other* half is
scattered (re-radiated) into space.

And I don't even have my flame-proof suit on...
Scott Townley
[e-mail]

From [e-mail] Wed 07 Jun 95 15:47:23
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From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: Sun, 4 Jun 1995 20:39:09
Organization: Ericsson Inc.
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In article <[e-mail]> [e-mail] (Gary Coffman) writes:

[snip] >                  Now, Mike if you've
>followed all the verbage (and you've got great stamina
if you have), >what is *your* explanation for Tom's reported results?

>Gary

I have to admit I haven't followed all of it.  I will profess to the world I
do not have the background in tube theory that some of my associates do
however, give me a solid state RF device and I'll whip you out an amp with
my eyes closed.

Can I take this oppertunity to ask you to clarify a couple of things Gary now
that I have your attention?  Let's get away from amplifiers for a moment and
find another type of source to match to.  How about an antenna set up to
recieve an incoming signal.  We know it's not REALLY a source,  but for the
sake of the discussion...

If the gain of the antenna was such that an RF signal presented to it (out of
the air) generated 1uW into a 50 ohm load at a given frequency with little or
no reflections (a 1:1 or conjagate match with the 50 load), are you implying
that since 1 uW is being dissapated by the 50 ohm load, and we have a perfect
match between source and load, that 1uW ALSO  would have to be dissapated by
the source (the antenna) somehow?

(I'm a little late in this discussion and am trying to come up to speed.)

Thanks, Mike KD6PKJ

From [e-mail] Wed 07 Jun 95 15:47:24
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: 5 Jun 1995 13:36:34 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 24
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NNTP-Posting-Host: newsbf02.mail.aol.com

Hi Gary and Jeff,

Let me try to come back to speed. I was at a car show all weekend so I
missed everything until I got home today.

I can tell you exactly what I am measuring. But we have to agree on a
couple of things first. The Thevenin or Norton models can not be used
to determine the source efficiency with a non-linear (power limited)
device. The rules for using those models exclude these types of
analysis. If we can't agree about this then there is nothing else we can
agree about because we would be making up our own *rules for the use
of the models*.

The other thing we have to agree on is that the resistance we match to
has does not have to be a real resistance we can measure if power is
removed. The resistance only has to have the characteristics of a
resistance so far as the external circuitry is concerned while the circuit

is operating. Resistance is defined by a change in voltage causing a
certain change in current.

If we can't agree on these points the issue will never be resolved.

73 Tom

From [e-mail] Wed 07 Jun 95 15:47:32
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (David Stockton)
Subject: Re: The meaning of 'matched'
Sender: [e-mail] (SQF News Admin)
Message-ID: <[e-mail]>
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W8JI  Tom ([e-mail]) wrote:

: If we keep insisting that the ratio of voltage to current that defines the
: real (resistive) part of an impedance can't be defined in ohms, like we
: do in those 300 ohm transmission lines, we will continue to have this
: problem.  The circuit "likes to operate" at a certain ratio of E/I at the
: operating power level.


     Ah, now, say I give you an impedence measuring machine (your choice
of vector network analyser or TDR) and one end of a length of 300 Ohm
line. I head off into the sunset paying out line as I go. I bought the
cable in one of those shops that disappear by magic, It is perfect, and
infinitely long.

  By measurement at your end, you cannot see any difference, even with
perfect measuring gear, between the infinite cable with anything or
nothing at the end, and any shorter length (right down to zero) with a
300 Ohm termination.

   We can pour energy into a resistor, and stop. No matter how long we
wait, it doesn't reflect back out. Ditto for an accurately terminated
length of line - there is no reflection, we cannot tell how far away the
resistive load is. If the line length is immense, then no reflection can
return in our lifetime, or whatever period we are concerned with no
matter what is or isn't connected to the end. We end
our experiment thinking we saw a true, real, resistive impedence, never
knowing that if we'd waited longer, it would appear to change.

   Resistors make electrical energy go away (to heat) and so can have a
real impedence component.

   Transmission lines make energy go away (to a distant place) and so
have just as valid a claim to a real impedence component, until the
leading edge of any echo from the far end gets back......

  Transmission lines are great fun

   Just give me an infinite number of infinitesimal inductors and
capacitors and I can assemble something that quacks just like a
resistor!



   Cheers
          David

From [e-mail] Wed 07 Jun 95 15:47:36
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From: William Osborne <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: 7 Jun 1995 14:23:08 GMT
Organization: New Mexico State University
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[e-mail] (Gary Coffman) wrote:

snip snip
>
>Now lets look at what Tom claims he's doing. He is equating the
>presented load at the source with the load seen looking back from
>the other end where the source is now the load. Argh. That's hard
>to say in words.  Let me draw a picture.
>
>                      \ \ transformation
>            ___________\ \__________________
>            |           \ \                |
>            ?                              /
>  XMTR      ?                              \ dummy
>            ?                              /
>           _|_                            _|_
>          ///                             ///
>
>
>Looking from the XMTR to the load through the transformation,
>??? appears as if it were some impedance directly connected
>to the XMTR with a value of dummy*transform. No matching has
>occured. ??? isn't a real resistor. It's just dummy seen through
>the transforming network. XMTR is the source end of the line,
>dummy is the load end of the line. All the source ever sees is
>the dummy, but it has to look through transform to do that.
>
>Ok, now what happens when we look the other way? Dummy is now the
>source looking toward the load which is XMTR. It does *not* see
>??? because that's just its own reflection. (Ok, it could see
>it's own reflection if XMTR presented a a short or open termination,
>and thus forced 100% reflection back through the network, but the
>image would be phase shifted by the network and any transmission
>line.) Otherwise, however, all you can see looking back from dummy
>is some *source resistance* in XMTR terminating the network with a
>real resistance on the XMTR side. At dummy, this will look like
>a value of Rs/transform. From the information given, we have *no*
>idea what the value of that resistance, if any, is. Tom *says* it's
>a value that results in a 1:1 VSWR seen back at dummy for a reverse
>generator. If that's true, then its a real resistance equal to ???,
>but not a reflection, and assuming it can't magically be transparent
>to forward power flow, what we've got now is a conjugate match between
>XMTR and dummy in the forward direction, and the maximum possible power
>transfer, as required by theorem, and 50% efficiency as required by
>analysis of two equal resistors in parallel. But he says efficiency
>is 78%. Both can't be true at the same time.
>
>Gary

Gary I think maybe both things can be true at the sane time if we
remember that this is a very nonlinear situation and that the forward 78%
eff. situation is for a hugh signal while the reverse match is for a very
small signal millwatts as I understand it.  Now if the mw signal is
applied to the 'output' port then the reflected signal will be the result
of the effective load at the tube side of the network xformed through the
network and compared to 50 ohms.  This effective load is the partial of
voltage with respect to current across and through the tube and because
of the filtering action of the network I think we need this partial
derivative applied to only the fundmental frequency terms. We can think
of this as a series expansion of the voltage as a function of current and
then take the derivative of that series.  Now for mw signals the linear
term is the only one that will count and at least for the fundmental
frequency this will be Efund/Ifund which is what the network is
generating a match to in the other direction.  Said another way for very
small signals introducted into the output the tube looks like a resistor
of value E/fund/Ifund where the E and I we are talking about are the
vakues of voltage and current in the high powered signal.  This says
nothing about what happens to a signal fed into the output port which is
of resonable size and it says nothing about what the effective source Z
of the PA is for signals in the forward direction, ie., large signals.

I want to say that this is at this point an untested theory, that I put
out for discussion.

--

William Osborne, AA5ZQ
[e-mail]
505-646-3919



From [e-mail] Wed 07 Jun 95 15:47:37
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!pipex!swrinde!emory!cssun.mathcs.emory.edu!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: The meaning of 'matched'
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <3r1mjf$[e-mail]>
Date: Wed, 7 Jun 1995 16:01:49 GMT
Lines: 32

In article <3r1mjf$[e-mail]> [e-mail] (W8JI  Tom) writes:
>[e-mail] (Jeff Anderson) wrote:
>>If you look at Class C transistor amplifiers, you'll find similar
>>topologies; that is, the network is designed to present a certain load
>>resistance to the collector in order to acheive the desired power
>> output.  It is *not* providing a conjugate match.
>>
>>- Jeff
>
>That's not true. If the goal is maximum efficiency, then the PA is
>designed for a conjugate match, or very close to one if the tank is
>lossy. That is proven by the Maximum Power Transfer Theorem I
>quoted earlier.

Now if you'd just *read* that Maximum Power Transfer Theorem, you'd
quit claiming it says maximum *efficiency* at the matched condition.
It says nothing of the kind. It says maximum *possible* power is
delivered to the load. As your *own* load pull tests demonstrated,
lower load impedances than what you claim represent a conjugate
match deliver *more* power to the load. So to satisfy the maximum
*possible* power transfer, you need a much lower impedance than
the one you claim is a conjugate match in order to be actually
conjugate matched.

When you get this clearly in your head, we can continue.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Wed 07 Jun 95 15:47:39
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From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: Wed, 7 Jun 1995 10:24:21
Organization: Ericsson Inc.
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In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>From: [e-mail] (Gary Coffman)
>Subject: Re: The meaning of 'matched'
>Date: Mon, 5 Jun 1995 20:17:10 GMT

>In article <[e-mail]> [e-mail] (Mike Groves) writes:
>>Can I take this oppertunity to ask you to clarify a couple of things Gary now
>>that I have your attention?  Let's get away from amplifiers for a moment and
>>find another type of source to match to.  How about an antenna set up to
>>recieve an incoming signal.  We know it's not REALLY a source,  but for the
>>sake of the discussion...

>Actually it fits my model of a source. It takes energy in the form
>of EM radiation fields and converts it to energy in the form of an
>alternating current on a wire. I've maintained that we call a source
>any point where a new form of energy arises.

>>If the gain of the antenna was such that an RF signal presented to it (out of
>>the air) generated 1uW into a 50 ohm load at a given frequency with little or
>>no reflections (a 1:1 or conjagate match with the 50 load), are you implying
>>that since 1 uW is being dissapated by the 50 ohm load, and we have a perfect
>>match between source and load, that 1uW ALSO  would have to be dissapated by
>>the source (the antenna) somehow?

>No, that's absurd, and a violation of the law of conservation of
>energy.

Thank you.

>To determine the source impedance of the antenna, we'd need to know
>its open circuit voltage and short circuit current at the feedpoint.

Woah!  I already told you the source impedance was EXACTLY 50 ohms.
I said there were NO reflections due to mis-match from the source to the
load, meaning we have a perfect conjagate match from the source (50+j0) to the
load (50+j0).

>Those two numbers would give us its source impedance. 50 ohms is
>the impedance we can place across its terminals and get 1 uW of
>power to flow through the impedance (with some unknown efficiency).

Because it's MATCHED, the "Transfer Efficiency" IS EXACTLY 100%  into 50 ohms.
That is simply stating that ALL the power the generator (antenna) is
producing is being transferred to the load.

>If we were to place some other value of impedance across the antenna
>terminals, we'd get some other amount of power (and some other unknown
>efficiency).  If we knew the open circuit voltage and short circuit
>current, we'd be able to assign numbers to those powers and efficiencies,
>but without them we can't know. No "matching" is involved here. We're
>just putting various loads on the source.

Matching is EXACTLY what we are doing.  If we were to place "some other value
of impedance" across the antenna terminals, we could calculate EXACTLY what
the mis-match losses would be for ANY impedance.  It's called the standing
wave ratio or SWR for short.  Please look it up in your references.

If you terminated the antenna into EITHER a 25 ohm or 100 ohm impedance,
you have a 2:1 SWR.  11.6% of your signal would not be dissapated in the load,
rather it would be reflected back toward the generator.  The load would only
see .884 uW of power resulting in a Power Transfer Efficiency of 88.4%.

If you terminated the antenna into EITHER a 5 ohm or 500 ohm impedance,
you have a 10:1 SWR.  65.5% of your signal would not be dissapated in the
load, rather it would be reflected back toward the generator.  The load would
only see .345 uW of power resulting in a Power Transfer Efficiency of 34.5%.

And so forth.  Plase note, the terminating impedances could just as well be
inductive or capacitive as long as the magnitude of the reflection coeficient
was the same.  It doesn't matter what the phase angle of the reflection is.

This is 'The meaning of MATCHED'.

Thanks for listening,
Mike Groves  KD6PKJ

From [e-mail] Wed 07 Jun 95 15:47:41
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!emory!cssun.mathcs.emory.edu!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: The meaning of 'matched'
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <[e-mail]> <[e-mail]> <3r4coc$[e-mail]>
Date: Wed, 7 Jun 1995 17:00:00 GMT
Lines: 40

In article <3r4coc$[e-mail]> William Osborne <[e-mail]> writes:
>>Gary
>
>Gary I think maybe both things can be true at the sane time if we
>remember that this is a very nonlinear situation and that the forward 78%
>eff. situation is for a hugh signal while the reverse match is for a very
>small signal millwatts as I understand it.  Now if the mw signal is
>applied to the 'output' port then the reflected signal will be the result
>of the effective load at the tube side of the network xformed through the
>network and compared to 50 ohms.  This effective load is the partial of
>voltage with respect to current across and through the tube and because
>of the filtering action of the network I think we need this partial
>derivative applied to only the fundmental frequency terms. We can think
>of this as a series expansion of the voltage as a function of current and
>then take the derivative of that series.  Now for mw signals the linear
>term is the only one that will count and at least for the fundmental
>frequency this will be Efund/Ifund which is what the network is
>generating a match to in the other direction.  Said another way for very
>small signals introducted into the output the tube looks like a resistor
>of value E/fund/Ifund where the E and I we are talking about are the
>vakues of voltage and current in the high powered signal.  This says
>nothing about what happens to a signal fed into the output port which is
>of resonable size and it says nothing about what the effective source Z
>of the PA is for signals in the forward direction, ie., large signals.
>
>I want to say that this is at this point an untested theory, that I put
>out for discussion.

I'd accept that idea if the reverse signal were constant in phase
with respect to E/I, but it is not, and the tank can't fix that
because the phase of I is directly controlled by the Eg1 of the
tube, and that's not dependent on *anything* in the tube output
circuitry.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Wed 07 Jun 95 15:47:42
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: 7 Jun 1995 15:28:12 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Message-ID: <3r4ukc$[e-mail]>
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quit claiming it says maximum *efficiency* at the matched condition.
>It says nothing of the kind. It says maximum *possible* power is
>delivered to the load. As your *own* load pull tests demonstrated,
>lower load impedances than what you claim represent a conjugate
>match deliver *more* power to the load. So to satisfy the maximum
>*possible* power transfer, you need a much lower impedance than
>the one you claim is a conjugate match in order to be actually
>conjugate matched.

>When you get this clearly in your head, we can continue.

>Gary


The rule:

"Maximum Power Transfer Theorem

 An impedance connected to a source will receive the *maximum possible
power transfer* (the key word is transfer) when it is adjusted to equal
the complex conjugate of the impedance of the source. The load impedance
and the source impedance are then matched on a conjugate -impedance basis.
This is distint from impedance matching on an image impedance basis in
which the source and load impedances are equal."

Please note it says transfer, not amount. But rather than argue about that
I will allow that liberty.

Now, so what? Maximum power occurs at almost the same point in ALL the
amplifiers I analyzed as maximum efficiency. The differences were caused
by tank losses. And using the maximum power point the efficiency was still
way over 50%!!!!

I know this may be a risky statement, but perhaps that 50% model doesn't
apply
to non-linear sources. After all, every book I have says it doesn't!  73
Tom

From [e-mail] Wed 07 Jun 95 15:47:43
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From: [e-mail] (John Morgan)
Newsgroups: rec.radio.amateur.antenna
Subject: Transmitter Sys for sale.
Date: 4 Jun 1995 19:50:53 -0700
Organization: CRL Dialup Internet Access        [phone]  [Login: guest]
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                           MICROWAVE SYSTEM COMPLETE FOR SALE

San/Bar 12 gig Digital microwave with redundant transmitter and recever.
 IncludesI LeeMah status monitor systerm, dryer one side.  Two antennas with
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condition when it was took out of service 9 months ago.  Will require new
wave guide to an from antenna flexible.,  There is a back up battery system
but it would be cost prohibitive to ship.  I believe all the manuals are
intact with schematics.  This unit was use for a 50 pair telephone cable
system  but has many other uses (ie closed data trans . video)
Intro:  the DMR is a quadriphase modulated transmission system which can
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I will fax more specs.  SERIOUS INQUIRES ONLY.  WILL CONSIDER ANY AND ALL
OFFERS.   FAX  [phone]   USA.       Can ship world wide via sea &
surface

contact [e-mail]


From [e-mail] Wed 07 Jun 95 15:47:44
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From: [e-mail] (Bob Bruhns)
Newsgroups: rec.radio.amateur.antenna
Subject: Vertically polarized noise question
Date: 3 Jun 1995 23:23:01 GMT
Organization: LI Net (Long Island Network)
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  I have no sources to back this up, but I think the reason that "man
made noise sources" are held to be vertically polarized is that they are
local in nature and the noise propagates by ground wave.

  Ground wave signals will be vertical with a slight tilt, being dragged
against the ground, in a manner of speaking.  In general, horizontal
signals travelling along the ground suffer cancellation from the ground
reflection, but vertical signals suffer only the ground loss.

  Note that really, really "bad" ground can behave somewhat differently
from typical ground at very low propagation angles, but I think you'll
find the general situation to be as claimed.

From [e-mail] Wed 07 Jun 95 15:47:49
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From: [e-mail] (WA8MSF)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Vertically polarized noise question
Date: 5 Jun 1995 16:06:41 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Hi Tom!

I noticed in your post that you had designed power-line noise location
equipment.  I have a problem with 50/144/222 power line noise in my
location that I am trying to solve in cooperation with the local utility
company.  If I find it (they have limited time to devote) they promise to
come out and tighten/replace offending pole hardware.  I have some time,
but more intense devotion to my problem than they do.  The noise fixing
department works as a subset of the P.R. department (just few enough
resources to amuse whomever deals with the state regulators).

My approach is to drive around with a mobile scanner set to receive 144
MHz AM with a mag-mount antenna on the roof to get close.  To home in on
the problem, I have a 222 beam and an R1 icom scanner that I plan to use
on foot in the locale indicated by the 2M vertical.  That way I can cover
alot of territory and still direction-find with the beam.  Currently I
have to make a front end filter for the R1 since my good radio location
has lots of TV/FM/pager overload that makes listening for line-noise
problematic.

Does this approach sound workable to you?

Please elaborate at length on any peice of this realm that you think
relevant.
I would really like to hear your point of view.

Best regards,
Mike - WA8MSF
Cincinnati, Ohio

From [e-mail] Wed 07 Jun 95 15:48:08
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Vertically polarized noise question
Date: 5 Jun 1995 13:54:54 -0400
Organization: America Online, Inc. (1-800-827-6364)
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>  I have no sources to back this up, but I think the reason that "man
>made noise sources" are held to be vertically polarized is that they are
>local in nature and the noise propagates by ground wave.

That is part of the way I understand the problem also. It is because
horizonally polarized waves are attenuated more rapidly along the earth.
This is one reason, path attenuation.

The second effect is that noise can be accumulated from many directions.
Simple horizontal polarized antennas generally have at least two nulls
while most simple vertically polarized antennas are omni-directional, and
so respond to noise from 360 degrees. This is another reason, antenna
"compass heading" directivity.

The final effect is in wave angle, horizontally polarized antennas (for
low bands) have nulls along the horizion. Vertical antennas respond quite
well to low wave angles. This helps enhance the noise from a vertical
antenna also. This is the final reason, antenna elevation angle
directivity.

BTW, I designed so noise locating systems for a commercial equipment
manufacturer that supplied the power line industry years ago.

73 Tom

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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Vertically polarized noise question
Date: Tue, 06 Jun 95 04:47:42 edt
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> BTW, I designed so noise locating systems for a commercial equipment
> manufacturer that supplied the power line industry years ago.
>
> 73 Tom
>
Are they still around??
This is getting amazing!
Please expound some more on this fact of life.
73 dray AD4RR


From [e-mail] Wed 07 Jun 95 15:48:10
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Vertically polarized noise question
Date: 6 Jun 1995 10:44:52 -0400
Organization: America Online, Inc. (1-800-827-6364)
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>I noticed in your post that you had designed power-line noise >location
equipment.  I have a problem with 50/144/222 power line >noise in my
location that I am trying to solve in cooperation with the >local utility
company.  If I find it (they have limited time to devote) >they promise to
come out and tighten/replace offending pole >hardware.

A well shielded broad-band AM  VHF/UHF receiver will work best for you.
And of course a directional antenna. Perhaps you could borrow a FSM from a
CATV/MATV installer and use a small TV antenna? They work well!

One of the devices I came up with was just exactly that type of equipment,
except I included a broad band amplifier at the various antennas for VHF
low, VHF high, and UHF. That allowed the company to buy existing equipment
and package it differently as a noise locating assembly. The idea was to
get close with the low band stuff and switch up to UHF to pin it down.

This was much better than the original Sprauge noise locator receiver and
whips commonly used.

>My approach is to drive around with a mobile scanner set to receive >144
MHz AM with a mag-mount antenna on the roof to get close.  >To home in on
the problem, I have a 222 beam and an R1 icom >scanner that I plan to use
on foot in the locale indicated by the 2M >vertical.  That way I can cover
alot of territory and still direction-find >with the beam.  Currently I
have to make a front end filter for the R1 >since my good radio location
has lots of TV/FM/pager overload that >makes listening for line-noise
problematic.

>Does this approach sound workable to you?

That sounds like a combination of the two methods above, the Sprauge and
the whip and the TV equipment.

The real problem is if the noise was low band noise. It can follow the
wire for miles and peak and dissappear at 1/2 wave intervals. One piece of
equipment I built that worked very well for low frequency noise was a
broad band ferrite antenna coulped to a very broad band amplifier. It was
like a TRF amplifier that covered over two octaves of BW.  Since the line
noise was from a single sources, it would add over the entire passband and
have a lot of total energy. Random narrow band signals would not make full
use of the pass band.

This device gave a more linear increase in low frequency noise as you
moved along the source since the 1/2 wl spaced peaks and vthe 1/2
wavelength spaced valleys were eliminated. The loopsticks null could also
be used to determine the approximate source of radiation.

I doubt you need such a device, because your noise is on VHF. That device
was mainly useful for locating LF noise on high tension transmission
lines.

I fell into that "job" because the guys trying to locate noise for me
didn't have the correct equipment, nor was it available. I needed to have
a 345 kV line repaired so I could work DX on 160. The real noise source
was several miles away at a sub-station, and was propagated down the
lines! The VHF equipment couldn't detect the noise that was wiping out 160
until it was traced to the sub-station!

It took two years to fix, and 3 months later I moved. ;-)

73 Tom

From [e-mail] Wed 07 Jun 95 15:48:11
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (ChuckB7024)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: VLF Antennas
Date: 5 Jun 1995 01:48:01 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 11
Sender: [e-mail]
Message-ID: <3qu5qh$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (ChuckB7024)
NNTP-Posting-Host: newsbf02.mail.aol.com

What do you want to know... Have worked in the VLF field for over 15
years..
Most of which involved airborne and mobile systems.. I gather you are
intrested in the upper end.. Most of my experince has been in 17khz to
50khz band..
Recomend that you research Omega Nav. systems.  This is in the low freq
band..
Upper you might want to look at Loran C applications...  I don't know what
you need but if you would like some information on anything specific feel
free to contact me ChuckB7024@aol (might take a while)
or voice phone [phone]).

From [e-mail] Wed 07 Jun 95 15:48:12
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!convex!news.dfw.net!fw18.dfw.net!user
From: [e-mail] (Wayne Day)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.misc
Subject: Voyager/Caravan antenna mounting?
Date: Wed, 07 Jun 1995 09:17:50 -0500
Organization: The Day Organization
Lines: 18
Message-ID: <[e-mail]>
NNTP-Posting-Host: fw18.dfw.net
Xref: grape.epix.net rec.radio.amateur.antenna:10894 rec.radio.amateur.misc:80320

We've got a new Plymouth Voyager (same-same as Dodge Caravan) in the family.

Before I take the drill to the van, does anyone have any vehicle-specific
information to pass along?  Have you encountered any problems mounting
your antennas or radios?  Found that 'sweet spot' where the on-board
computer starts playing Donkey Kong when you key up on 440?

Your input will be greatly appreciated!

73 Wayne KF5ZC

 -----------------------------------------------------------------------------
 Wayne Day KF5ZC  Fort Worth,Texas,USA                          |
   CompuServe: 76703,376   Internet: [e-mail]   |  ,__o
    or                     Internet: [e-mail]               |--\_<,
   Member: Bicycle Mobile Hams of America                       (*)/'(*)
 For info on BMHA or the BIKEHAM mailing list: Finger [e-mail]
 -----------------------------------------------------------------------------

From [e-mail] Wed 07 Jun 95 15:48:13
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news.starnet.net!wupost!news.utdallas.edu!corpgate!crchh327.bnr.ca!b4pph13e!cnc23a
From: [e-mail] (Ken Edwards)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.misc
Subject: Re: Voyager/Caravan antenna mounting?
Date: 7 Jun 1995 16:29:58 GMT
Organization: Bell-Northern Research, Ottawa, Canada
Lines: 29
Sender: cnc23a@b4pph13e (Ken Edwards)
Distribution: world
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Xref: grape.epix.net rec.radio.amateur.antenna:10900 rec.radio.amateur.misc:80326

In article <[e-mail]>, [e-mail] (Wayne Day) writes:
|> We've got a new Plymouth Voyager (same-same as Dodge Caravan) in the family.
|>
|> Before I take the drill to the van, does anyone have any vehicle-specific
|> information to pass along?  Have you encountered any problems mounting
|> your antennas or radios?  Found that 'sweet spot' where the on-board
|> computer starts playing Donkey Kong when you key up on 440?
|>
|> Your input will be greatly appreciated!
|>


My wife made a request, no holes in our new Caravan.  So, I bought a Larsen
2/440 Glass mount.  I have been EXTREMELY HAPPY with it.  I have mounted
the antenna on the driver's side upper portion of the rear glass.  You must
be careful to get it below the 'curve' in the glass.  With this setup, the
only problem I have noticed is the radio will have a slight 'thump' sometimes
when I key up.


--
======================================================================

Ken M. Edwards, PE  Bell Northern Research, Research Triangle Park, NC
[phone] email: [e-mail]    Ham: N4ZBB   Packet: [e-mail]
DX PacketCluster (tm) Node : W4DW

All opinions are my own and do not necessarily reflect the views of
my employer or co-workers, family, friends, congress, or president.

From [e-mail] Wed 07 Jun 95 15:48:14
Path: grape.epix.net!news.sprintlink.net!bga.com!news
From: <Unknown> (Robert Redoutey)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.misc
Subject: Re: Voyager/Caravan antenna mounting?
Date: 7 Jun 1995 17:40:49 GMT
Organization: Real/Time Communications - Bob Gustwick and Associates
Lines: 20
Message-ID: <3r4ob2$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: lia-b4.aip.realtime.net
X-Newsreader: WinVN 0.92.6
Xref: grape.epix.net rec.radio.amateur.antenna:10906 rec.radio.amateur.misc:80331

In article <[e-mail]>, [e-mail] (Wayne Day) says:
>
>We've got a new Plymouth Voyager (same-same as Dodge Caravan) in the family.
>
>Before I take the drill to the van, does anyone have any vehicle-specific
>information to pass along?  Have you encountered any problems mounting
>your antennas or radios?  Found that 'sweet spot' where the on-board
>computer starts playing Donkey Kong when you key up on 440?
>
>Your input will be greatly appreciated!
>
>73 Wayne KF5ZC

I have a 87 Voyager, and I mounted it above the inside dome light.
That made easy access. Drilled a hole and stuck it in. Ran coax down along
the inside of the bar between the drivers door and windshield. Have not had
any problems.

Bob Redoutey
KF5KF

From [e-mail] Wed 07 Jun 95 15:48:14
Path: grape.epix.net!news.sprintlink.net!gatech!swrinde!elroy.jpl.nasa.gov!sdd.hp.com!vixen.cso.uiuc.edu!sal!venkat
From: [e-mail] (Venkata Krishnan)
Newsgroups: rec.radio.amateur.antenna
Subject: WANTED: Whip Antenna 2m 144-146MHz
Date: 6 Jun 1995 19:46:15 GMT
Organization: University of Illinois at Urbana
Lines: 9
Message-ID: <3r2ba7$[e-mail]>
NNTP-Posting-Host: sal.cs.uiuc.edu

As the subject says, I need a telescopic antenna for 144-146MHz
If you have one to spare, please let me know (as well as your price)
Thanks.

--
Venkat
Univ of Ill-Noise at Banana-Shampoo     Ph: [phone] (W)
Email: [e-mail]                   [phone] (H)
----------------------------------------------------------------

From [e-mail] Wed 07 Jun 95 15:48:15
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!pipex!oleane!jussieu.fr!univ-lyon1.fr!serra.unipi.it!embiolab.iroe.fi.cnr.it!icesb
From: [e-mail] (Lapo Pieri)
Newsgroups: rec.radio.amateur.antenna
Subject: Yagi simulator: where?
Date: Tue, 6 Jun 1995 09:17:23 GMT
Organization: IROE - CNR
Lines: 11
Message-ID: <[e-mail]>
NNTP-Posting-Host: embiolab.iroe.fi.cnr.it
X-Newsreader: Trumpet for Windows [Version 1.0 Rev A]

I use Yagimax 3.11 and various version of NEC, but I've read an article where
the autor use programs called "Yagi Analisis (ver 3.3)" and "Yagi Optimizer
(ver 4.23)".
Could someone tell me where could I find such programs?
Thank in advance        Lapo  IK5NAX
 ------------------------------------------------------------------------------
 Lapo  Pieri   IK5NAX                         internet: [e-mail]
 @IROE-CNR  (Italy)                                     [e-mail]
 Phone: [phone] (IROE)                 packet: [e-mail]
        [phone] (home)                          [TCP/IP] 44.134.208.174
 ------------------------------------------------------------------------------

From [e-mail] Mon 12 Jun 95 20:37:37
Path: grape.epix.net!news.sprintlink.net!EU.net!news.eunet.fi!newsmaster
From: [e-mail] (Juha Kupiainen)
Newsgroups: rec.radio.amateur.antenna
Subject: 5-band 4-el quad
Date: 11 Jun 1995 15:23:39 GMT
Lines: 17
Message-ID: <3rf1pr$[e-mail]>
NNTP-Posting-Host: jussik.pp.fi
X-Newsreader: WinVN 0.91.6


HI!

Anybody using commercial 4-el 5-band quad?
I'm considering to buy Mike's autoelectric 4-el
5-band quad. Is anybody using this antenna?
What are Your experiences?

I am particularly interested in mechanical structure,
because conditions here in Finland can be very icy.

Antenna is using single feed line with matching
transformer, does it have any affect to the funtion?
(the feeding element is not exactly rectancular shape
on 10,12, 17 and especially not on 20 meter band.)

- de Juha / OH4JK

From [e-mail] Mon 12 Jun 95 20:37:38
Path: grape.epix.net!news.sprintlink.net!hookup!news.kei.com!babbage.ece.uc.edu!cccbbs!randy.true
From: [e-mail] (RANDY TRUE)
Newsgroups: rec.radio.amateur.antenna
Subject: antenna for mustang
Message-ID: <[e-mail]>
Date: Mon, 12 Jun 95 01:52:00 -0500
Distribution: world
Organization: Cincinnati Computer Connection BBS [phone]
Reply-To: [e-mail] (RANDY TRUE)
X-Newsreader: PCBoard Version 15.21
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Lines: 13

I have an 87 Mustang with a hatchback. I am currently using a Larsen
glass mount antenna. Not realy satisfied with the results as compared to
a mag mount, but I don't like what the mag mount does to the paint, and I
want something more permanent without drilling big holes. I've looked at
all the different mounts ( Comet, Diamond, Larsen, Hustler ) and nothing
will work because of the way the top lip of the hatch swings when it's
opened. Any thoughts?

73 de Randy, KD4YKV

... All I need is a Wave and a board to surf it on.
___ Blue Wave/QWK v2.12


From [e-mail] Mon 12 Jun 95 20:37:39
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: antenna theory        1/3
Date: 10 Jun 1995 04:11:49 GMT
Organization: News & Observer Public Access
Lines: 58
Message-ID: <3rb625$[e-mail]>
References: <3r0cjb$[e-mail]> <[e-mail]>
NNTP-Posting-Host: grail705.nando.net

[e-mail] (Jack GF Hill) wrote:
>
> DB Wilhelm <[e-mail]> writes:
>
> > I can't give an example from the Antenna Handbook, but my 1994
> > copy of the ARRL Handbook pg 17-17 under Fig 38 states "because
> > the feed method on the cubical quad is balanced, use a 4:1 balun."
> >
> > The quad shown in the figure shows the DE loop being fed directly
> > with 75 ohm coax having a length of 251/f(MHz).  I believe the
> > correct caption should read "use a 1:1 balun."
> Whoa! Let's just take a quick look here...
> Approximate feedpoint impedance for a "1/2-wave", center-fed is 72
> ohms in free space... (and is a balanced antenna) a full-wave loop has
> a feedpoint impedance of approximately 288 ohms, close enough to 300
> ohm feed or 4:1 for 75 ohm...
>
> Thus, the balun makes sense, and the 4:1 ratio holds...

Where did the 288 ohms come from?  This sounds like the impedance of
a folded dipole.  A full wave loop will be lower, like 110 ohms.
The addition of a reflector or director will lower the driven element
impedance even more depending on spacing, so 75 ohms IS a good value
to feed a quad.

The most significant point is that the figure and the caption are
different in that they suggest the feed impedance should be 75 ohms
in the figure, and 300 ohms in the caption.  One or the other IS
incorrect.

My opinions on baluns are based on experience as well as opinions,
I have added a commercial balun and my VSWR improves, fact is that
anything added at the antenna terminals that improves the VSWR must
have at least some resistance.  The only thing that can
change the SWR is a change in the load impedance or a change in the
transmission line.  I've also seen claims in both advertizing and articles
that a balun will make an antenna more broadband - not so, for if the
antenna is more broadband with *just* the addition of a balun, the
balun is certainly turning part of my precious RF signal into heat.

Baluns do have their uses in reducing common mode currents if common
mode currents actually exist.  The output of a transmission line
feeding a balanced antenna
should be purely differential mode, and if no radiated signal is
coupled back onto the line, that condition will exist. This is true
whether the transmission line is balanced line or coaxial cable.

I am not bashing ARRL at all, I really appreciate what they do and I
can proudly state that I am a life member.  As with any publication
errors can creep in.  The bigger the book, the more errors are likely
unless a much larger amount of checking and editing time is devoted
to the larger book.  I remember some exponential terms in the
equations for the analysis, but I'm not mmoved to find them - that was
info from a project I worked on 15 years ago.

73,
Don W3FPR


From [e-mail] Mon 12 Jun 95 20:37:40
Path: grape.epix.net!news.sprintlink.net!hookup!news.umbc.edu!haven.umd.edu!purdue!news.bu.edu!transfer.stratus.com!usenet
From: "J.Swenson" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: B & W AC 3.5-30 help !
Date: 11 Jun 1995 16:37:38 GMT
Organization: Stratus Computer Inc, Marlboro MA
Lines: 6
Message-ID: <3rf64i$[e-mail]>
NNTP-Posting-Host: jswenson.hqsl.stratus.com
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I just got hold of a Barker & Williamson AC 3.5-30 for free.  It looks to
be in great shape.  Is there any way to check out the mystery tybe in the
middle to make sure it is still ok ?  Is this a good antenna for Ham or
SWL work ? Any special installation instructions that need to be followed
?  Is this worth putting up ?   Thanks in advance for any help !


From [e-mail] Mon 12 Jun 95 20:37:41
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: [e-mail] (Doug Hall)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: B & W AC 3.5-30 help !
Date: Sun, 11 Jun 1995 19:54:43 GMT
Organization: JPS Communications, Inc.
Lines: 32
Message-ID: <3rfhmp$[e-mail]>
References: <3rf64i$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: grail809.nando.net
X-Newsreader: Forte Free Agent v0.46

"J.Swenson" <[e-mail]> wrote:

>I just got hold of a Barker & Williamson AC 3.5-30 for free.  It looks to
>be in great shape.  Is there any way to check out the mystery tybe in the
>middle to make sure it is still ok ?  Is this a good antenna for Ham or
>SWL work ? Any special installation instructions that need to be followed
>?  Is this worth putting up ?   Thanks in advance for any help !

The B&W antenna is a T2FD design (terminated tilted folded dipole,
patented and first described in the 40s, I believe) and the "mystery"
tube in the middle contains a resistor. In the case of the B&W it's a
wirewound resistor, so the impedance of the termination varies over
the band. I forget what the value of the resistor is.

As to whether it's worth putting up, it depends. (Doesn't it always?)
If I remember correctly, the antenna is about 90 feet long. A simple
90 foot dipole fed with ladder line and a good tuner will generally
beat the B&W, especially on the lower freqs. (I know this from
experience, I've tested them against each other.) But the B&W *will*
allow you to work 80-10 meters without a tuner, or at least the one I
tried would, so that's worth noting.  If you can't buy or build a
tuner, maybe the B&W is a good compromise. You can certainly work
people with it and it's better than nothing. But you'll probably
radiate more power with a simple dipole and a good tuner. (And what
constitutes a "good" tuner is the subject of another post :-)

73,
Doug Hall, KF4KL
JPS Communications, Inc.
http://emporium.turnpike.net/J/JPS/jps.html



From [e-mail] Mon 12 Jun 95 20:37:41
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!nntp.crl.com!pacbell.com!tandem!nntp-hub2.barrnet.net!news3.near.net!transfer.stratus.com!usenet
From: "J.Swenson" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Bare or insulated copper for wire antenna ?
Date: 11 Jun 1995 16:27:40 GMT
Organization: Stratus Computer Inc, Marlboro MA
Lines: 7
Message-ID: <3rf5ht$[e-mail]>
NNTP-Posting-Host: jswenson.hqsl.stratus.com
Mime-Version: 1.0
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X-Mailer: Mozilla 1.1b3 (Windows; U; 16bit)

Someone recently said it was crazy to use insulated wire for an antenna.
I have used insulated copper wire on inverted vee's and longwires for
years and have had great results on both xmit/rcv.  Have I really been
missing some great contacts ?  And I thought it was the old sunspot cycle
all this time !  What do you think ?  Anyone ever do a side by side
comparison ?


From [e-mail] Mon 12 Jun 95 20:37:42
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!agate!news.mindlink.net!vanbc.wimsey.com!news.rmii.com!nexus.interealm.com!root
From: [e-mail] (George J. Molnar)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Bare or insulated copper for wire antenna ?
Date: Mon, 12 Jun 1995 00:55:47 GMT
Organization: ICG/MagNET [phone]
Lines: 19
Message-ID: <3rg35f$[e-mail]>
References: <3rf5ht$[e-mail]>
NNTP-Posting-Host: ppp202.interealm.com
X-Newsreader: Forte Free Agent v0.55

"J.Swenson" <[e-mail]> wrote:

>Someone recently said it was crazy to use insulated wire for an antenna.
>I have used insulated copper wire on inverted vee's and longwires for
>years and have had great results on both xmit/rcv.  Have I really been
>missing some great contacts ?  And I thought it was the old sunspot cycle
>all this time !  What do you think ?  Anyone ever do a side by side
>comparison ?

Whoever said it was "crazy" to use insulated wire is the crazy one...
It works just fine and won't degrade your performance in any
appreciable way....just use high quality insulators (as you should
anyway) to avoid dielectric paths at the center and ends. Enjoy!

George J. Molnar
Highlands Ranch, Colorado, USA
Internet: [e-mail]
Packet Radio: KF2T@N0QCU.#NECO.CO.USA.NA


From [e-mail] Mon 12 Jun 95 20:37:43
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!nuclear.microserve.net!pinetree
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Bare or insulated copper for wire antenna ?
Date: Mon, 12 Jun 95 05:18:00 GMT
Organization: Microserve Information Systems (800)-380-INET
Lines: 20
Distribution: world
Message-ID: <3rgj0a$[e-mail]>
References: <3rf5ht$[e-mail]>
NNTP-Posting-Host: pinetree.microserve.com
X-Newsreader: News Xpress Version 1.0 Beta #3

In article <3rf5ht$[e-mail]>,
   "J.Swenson" <[e-mail]> wrote:
>Someone recently said it was crazy to use insulated wire for an antenna.
>I have used insulated copper wire on inverted vee's and longwires for
>years and have had great results on both xmit/rcv.

I'm glad you said that, although I didn't really have any serious doubts.
My last dipole was bare copperclad, and when I took it down after less than
eighteen months, it looked like a WWII penny.  I don't know if it
creates a measurable difference or not, but this oxide *must* increase antenna
wire losses.

This time, I'm using 200' of insulated #13 copperclad, and I even plan to
silicone the ends where it wraps around the insulators, so water can't sneak
in under the insulation.  The new antenna should be up in another week or two,
and I expect it to last considerably longer than the last one.  :)

73,

Jack  WB3U

From [e-mail] Mon 12 Jun 95 20:37:44
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!news.tamu.edu!news.utdallas.edu!corpgate!bcarh189.bnr.ca!nott!cunews!freenet.carleton.ca!FreeNet.Carleton.CA!ae517
From: [e-mail] (Russ Renaud)
Subject: Re: Bare or insulated copper for wire antenna ?
Message-ID: <[e-mail]>
Sender: [e-mail] (Russ Renaud)
Reply-To: [e-mail] (Russ Renaud)
Organization: The National Capital FreeNet
References: <3rf5ht$[e-mail]>
Date: Mon, 12 Jun 1995 11:41:40 GMT
Lines: 23


"J.Swenson" ([e-mail]) writes:
> Someone recently said it was crazy to use insulated wire for an antenna.
> I have used insulated copper wire on inverted vee's and longwires for
> years and have had great results on both xmit/rcv.  Have I really been
> missing some great contacts ?  And I thought it was the old sunspot cycle
> all this time !  What do you think ?  Anyone ever do a side by side
> comparison ?
>
Well, using insulated wire has two advantages over bare wire:

Often precipitation can pick up an electrostatic charge during it's
descent, which it transfers to your antenna upon contact, ie rain QRN.
Using insulated wire will alleviate much of this rain static.

Two, when bare multi-strand wire sits outside over a few years, the outer
layer oxidizes as well as having a very thin layer of crud deposited by
rainfall.  When these strands rub together in the wind, it creates more noise.

*I* don't think you're crazy!  8^)

73 de Russ, va3rr/aa8lu


From [e-mail] Mon 12 Jun 95 20:37:45
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!ix.netcom.com!netnews
From: [e-mail] (Roderick Hart)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Comments on GAP Antennas, Anyone?
Date: 11 Jun 1995 19:17:14 GMT
Organization: Netcom
Lines: 26
Distribution: world
Message-ID: <3rfffq$[e-mail]>
References: <[e-mail]> <3r48ck$[e-mail]>
NNTP-Posting-Host: ix-bal1-18.ix.netcom.com

I have a G5RV, a TNT Windom and a GAP Titan. The Titan out performs
both dipoles under normal circumstances. The Windom is probably the
quietest and most pleasant to listen to, however the top loading of the
GAP must work because there is no comparison on transmit. I really wish
I knew how the GAP works.

<3r48ck$[e-mail]> [e-mail] (W8JI  Tom) writes:
>
>I have an older GAP and some other antennas (including a Butternut)
here
>and have had a chance to compare them. The GAP is a very poor
performer on
>the low bands, and a low dipole beats it badly-nearly two S units at
DX.
>So does the Butternut but it has a large radial system.
>
>I don't think they've changed the design technoligy in the antenna, so
I
>expect they still are poor antennas (especially for low bands), as
most
>short stub loaded minimal ground verticals are. On the other hand they
do
>radiate better than no antenna at all!
>
>73 Tom


From [e-mail] Mon 12 Jun 95 20:37:45
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!Germany.EU.net!EU.net!uunet!mr.net!news.mr.net!inet-serv.com!n0jcf.com!not-for-mail
From: [e-mail] (Chris Elmquist)
Newsgroups: rec.radio.amateur.antenna
Subject: Create CLP5130-1 log periodic
Date: 11 Jun 1995 22:20:17 -0500
Organization: The Basement of N0JCF
Lines: 15
Message-ID: <3rgbph$[e-mail]>
NNTP-Posting-Host: n0jcf.com

Looking for someone who's running this antenna...   I can't seem to
find any ads or pictures of it anywhere anymore...  I'm curious if
it must be mounted at the top of the mast or if it is possible to
have the mast pass through it ??

I want to run it on 6m, 222 and possibly 900 MHz...

any comments ?

Chris

--
Chris Elmquist, N0JCF
[e-mail]
[e-mail]

From [e-mail] Mon 12 Jun 95 20:37:46
Path: grape.epix.net!news.sprintlink.net!pipex!demon!pacsat.demon.co.uk!slewis
From: Simon Lewis <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Cross Field Antennas - Info Pse
Date: 11 Jun 1995 02:46:01 +0100
Organization: None
Lines: 9
Sender: [e-mail]
Message-ID: <[e-mail]>
Reply-To: [e-mail]
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X-Posting-Host: pacsat.demon.co.uk

Be interested to hear from anyone who has built / operated a cross
field antenna. Do they work? and if so how good?
--
+-------------------------------------------------------------------------+
|  73 From:  Simon Lewis GM4PLM - Helensburgh - Strathclyde - Scotland    |
| Packet: GM4PLM @ GB7SAN.#78.GBR.EU   Email: [e-mail]   |
| AMSAT - UK Member 4282     **** SUPPORT YOUR LOCAL AMSAT GROUP ****     |
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From [e-mail] Mon 12 Jun 95 20:37:47
Path: grape.epix.net!news.sprintlink.net!demon!pacsat.demon.co.uk!slewis
From: Simon Lewis <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Design For Mag Loop Antenna
Date: 11 Jun 1995 02:46:00 +0100
Organization: None
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X-Posting-Host: pacsat.demon.co.uk

Anyone got any good mag loop antenna designs to build?
I live in a house with a postage stamp size garden and would like to
play with loops and cross field antennas on 80 - 10m

Help anyone!
--
+-------------------------------------------------------------------------+
|  73 From:  Simon Lewis GM4PLM - Helensburgh - Strathclyde - Scotland    |
| Packet: GM4PLM @ GB7SAN.#78.GBR.EU   Email: [e-mail]   |
| AMSAT - UK Member 4282     **** SUPPORT YOUR LOCAL AMSAT GROUP ****     |
+-------------------------------------------------------------------------+


From [e-mail] Mon 12 Jun 95 20:37:47
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!ix.netcom.com!netnews
From: [e-mail] (Roderick Hart)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: GAP Titan experiences
Date: 11 Jun 1995 19:29:50 GMT
Organization: Netcom
Lines: 25
Distribution: world
Message-ID: <3rfg7e$[e-mail]>
References: <3r9jf1$[e-mail]>
NNTP-Posting-Host: ix-bal1-18.ix.netcom.com

Over the years I have used the Hustler 4btv, Cushcraft R3, and the
Butternut vertical. Just last week I complete the installation of my
GAP Titan. It is the most remarkable antenna I have owned. The
bandwidth is generally as advertised (really below 2:1 on most band)
although mine is resonant below 15m. The few contacts I have made
indicate it out perform my other antennas (TNT and G5RV dipoles). The
GAP is ground mounted and is completely surrounded by trees (nothing
closer 40 to 50 feet). The counterpoise is larger than I thought, but I
am not complaining. I originally bougth the GAP to replace an old R3.
The R3 was mounted on a wooden patio deck and performed well for years.
The GAP does'nt require tuner and is actually hidden from my wife's
view. Best of all the thing WORKS!!!!!!

<3r9jf1$[e-mail]> [e-mail] writes:
>
>Pardon what may be asking a FAQ, but I'm curious about the
>GAP Titan.  I'm seriously considering getting one, but have
>the impression it doesn't work well for some people.  As
>it has exactly what I'm looking for in an hf antenna (on
>paper, anyway) I'd like to hear some real-life experiences
>people have had with this antenna.  As I will be away from
>the newsreader for a while and may miss posted response,
>please e-mail your messages to [e-mail]
>Thanks a lot!  Bill KB8USZ/AE


From [e-mail] Mon 12 Jun 95 20:37:48
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!swrinde!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (Billcunn)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HD-73 rotators
Date: 10 Jun 1995 14:07:18 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 2
Sender: [e-mail]
Message-ID: <3rcn0m$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (Billcunn)
NNTP-Posting-Host: newsbf02.mail.aol.com

I use to one one   I think the company went out of business  You might
check AEmateur Electronic Supply co.  they can tell you more

From [e-mail] Mon 12 Jun 95 20:37:49
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!hookup!news.kei.com!bloom-beacon.mit.edu!news.bu.edu!gw1.att.com!nntpa!not-for-mail
From: [e-mail] (Robert Melchiorre)
Subject: HF dipole question
Message-ID: <[e-mail]>
Sender: [e-mail] (Netnews Administration)
Nntp-Posting-Host: alsun138.cnet.att.com
Organization: AT&T, Allentown, PA
Distribution: usa
Date: Sat, 10 Jun 1995 22:48:12 GMT
Lines: 29

Hello all.

I'm a shortwave listener and want to improve my current dipole antenna.

I just picked up a considerable amount of 5 or 6 twisted conductor wire from
the local trash bin thinking that I could make an excellent compound dipole
antenna by cutting each conductor to a different size.

The limited amount of reading I've done so far suggests that I need to
use spacers between each dipole element.

I'm wondering if I really need to do that and if the twisted wire I have will
have any kind of inductive coupling that makes the separate elements
useless.

Am I worrying about it too excessively?  Will a simple dipole be the
easier/better solution?

Before I actually put this antenna up I thought I would check with the experts.

Thank you in advance.

Bob Melchiorre
[e-mail]

--
                  Robert Melchiorre     [e-mail]

           (the author is solely responsible for the contents herein)

From [e-mail] Mon 12 Jun 95 20:37:50
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!news.telalink.net!uro!jackatak!root
From: [e-mail] (Jack GF Hill)
Subject: Re: HF dipole question
Organization: Jack's Amazing CockRoach Capitalist Ventures
Date: Sun, 11 Jun 1995 14:16:32 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>
Sender: [e-mail] (Superuser)
Lines: 62

[e-mail] (Robert Melchiorre) writes:

> I just picked up a considerable amount of 5 or 6 twisted conductor wire from
> the local trash bin thinking that I could make an excellent compound dipole
> antenna by cutting each conductor to a different size.
Good idea. Way back when, it was common for hams to use ribbon-type
rotor control cable for multi-band dipoles, trimming each wire to be
resonant and "happy" on the band it was cut for.

These antennas worked quite well, with no major element interaction
that *degraded* performance.

> The limited amount of reading I've done so far suggests that I need to
> use spacers between each dipole element.
Not necessarily... though by fanning out the individual "band-wires"
you may help yourself feel better.

> I'm wondering if I really need to do that and if the twisted wire I have will
> have any kind of inductive coupling that makes the separate elements
> useless.
Well, you will have some inductive (and capacitive) coupling between
elements, but for a receiving antenna (you did say you were an SWL) it
is unlikely to be any bother at all.

*IF* you were trying to use the individual band-wires in the amateur
HF spectrum, the frequency multiple relationships between the bands,
would likely work *FOR* you, not against...

The impedance of *even* multiple wavelengths (7.0 MHz on a dipole cut
for 3.5 MHz) will be very high for the lower frequency element, and
hence the energy will be transported primarily through the wire cut
for the band of choice, although certainly some energy will be
contributed by the other wires.

With SWLing, I don't recall the frequency and band relationships, but
they are not so carefully maintained at exact multiple from 1.75 to
28.0 MHz like the ham bands are...

> Am I worrying about it too excessively?  Will a simple dipole be the
> easier/better solution?
Yes, you are worrying baout it too much. The idea of cutting several
wires to resonate on frequencies you listen to most is a *GOOD THING* (tm)
and should provide improved performance over a single dipole cut
somewhere as a compromise.

As for a "simple dipole" being easier and better: well, I always
thought cutting multiple wires, as you are considering doing, as being
a pretty simple and very effective solution to multi-band listening.

> Before I actually put this antenna up I thought I would check with
> the experts
Oh hell... guess you'd better disregard the above... I'm no expert,
just been doing this for 39 years and having a ball playing! ;^)
--
73, Jack - W4PPT/M

+--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--+
| Jack GF Hill        |Voice: [phone] -             Ham Call: W4PPT |
| P. O. Box 1685      |Modem: [phone] -  Bicycling and SCUBA Diving |
| Brentwood, TN  37024|Fax:   [phone] -          Life Member - ARRL |
| [e-mail]  - "Plus ca change, plus c'est la meme chose" |
+--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--+

From [e-mail] Mon 12 Jun 95 20:37:51
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF dipole question
Date: 12 Jun 1995 01:37:03 GMT
Organization: News & Observer Public Access
Lines: 39
Message-ID: <3rg5nv$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: vyger320.nando.net

[e-mail] (Robert Melchiorre) wrote:
>
> Hello all.
>
> I'm a shortwave listener and want to improve my current dipole antenna.
>
> I just picked up a considerable amount of 5 or 6 twisted conductor wire from
> the local trash bin thinking that I could make an excellent compound dipole
> antenna by cutting each conductor to a different size.
>
> The limited amount of reading I've done so far suggests that I need to
> use spacers between each dipole element.
>

Fan out the individual antennas as much as you can for the least
interaction between the elements.

> I'm wondering if I really need to do that and if the twisted wire I have will
> have any kind of inductive coupling that makes the separate elements
> useless.
>
> Am I worrying about it too excessively?  Will a simple dipole be the
> easier/better solution?

Yes you are worrying excessively.  The problem with parallel dipoles
is interaction, and it occurs most on even harmonicly related frequencies.
I had an impossible time once trying one of these parallel dipoles
on 40 and 20 meters.  Tuning for 40 was no problem, but 20 was very
frustrating.  I gave up due to a lack of time and spread the two by
about 60 degrees and had no problem.  But then I was using it for
transmitting as well as receiving, and I was trying to get multi-band
operation for a lightweight portable antenna that I could take camping
with me, your goals are different.  An antenna tuner may produce
better results for SWLing than a dipole for each band, but then
experimenting is fun and educational too, so try it if you like, if
it works, use it.

73,
Don W3FPR

From [e-mail] Mon 12 Jun 95 20:37:52
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!nntp.crl.com!usenet
From: [e-mail] (Jay Goldberg)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-pole antenna for mobile
Date: Sat, 10 Jun 1995 15:24:48 GMT
Organization: GCS
Lines: 57
Message-ID: <3rcjtj$[e-mail]>
References: <3r3pm7$[e-mail]>
NNTP-Posting-Host: crl4.crl.com
X-Newsreader: Forte Free Agent v0.55

[e-mail] (Park Youn Ok) wrote:


>Hi all!

>I made a J-pole antenna for car by simple method.
>Following is detail for J-pole antenna for car.
>The material is CB mobile antenna.
>The performance was very good with 3MHz flat SWR 1.2 or less.
>Especially, the performance of urban area(with amny
>building) was excellent.
>I made it conclusion, J-pole is more powerfull than
>5/8 Lamda antenna in urban area.


>                                                CB Antenna Mount     Mobile body

>                                                  ___________||       50Ohm cable
>                                                 /           ||      __________
> =============================================== --------------- ->()
>             gab is 1.5~ 2.5cm      ||           \___________||-+    +----------
>                                =============================|| |    |
>                                     ^                          |    |
>                                     |                         ---  ---
>                                     |                         ///  ///
>                                     +-- Insulator for matching bar
>                                         fixing

>                               |<-------- 1/4 Lambda ------->|
> |<-----------------------   3/4 Lambda -------------------->|



>Best 73! DS3ATF

>--
>       [e-mail]
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>+  Youn Ok Park, DS3ATF
>+  Computer Architecture Section, ETRI,
>+  P.O Box 106, Yusong,
>+  Taejon, 305-600, Korea
>+  http://puddle.etri.re.kr/~parkyo
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I just built a j-pole for the house....all copper...and I get 1.1:1 on
144mhz, 1.1:1 on 145mhz, 1.2:1 on 146mhz and 1.1:1 on 147mhz.

I could not believe my eyes when I fired up the 2mtr rig.
It is a really efficient antenna....or my construction :)
Anyhow..just wanted to put a good word in on the j-pole.

Cheap and easy to build.

Jay



From [e-mail] Mon 12 Jun 95 20:37:53
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!agate!library.ucla.edu!info.ucla.edu!news.bc.net!torn!news.unb.ca!coranto.ucs.mun.ca!dsmith
From: [e-mail] (David Smith)
Newsgroups: rec.radio.amateur.antenna
Subject: J-Pole Question
Date: 11 Jun 1995 18:51:15 GMT
Organization: NLnet
Lines: 27
Message-ID: <3rfdv3$[e-mail]>
NNTP-Posting-Host: terra.nlnet.nf.ca
X-Newsreader: TIN [version 1.2 PL2]

I am trying to build a j-pole antenna for 2 m using 450 ohm ladder line.
I am using an article in the September 1994 issue of QST.

Using the formula from the article, I get 57.02" for L 3/4 and 19.01" for
the matching stub (L 1/4).  The formula is L 3/4 = (8856 X V)/f, where:

L 3/4 = the length of the 3/4 wavelength radiator in inches,
    V = the velocity factor of the ladder line (which I am told is 0.94), and
    f = the design frequency in MHz.

However, I get confused when it comes to where to attach the coax to the
ladder line.

The article says to measure up 1 1/4" from the bottom for the 300 ohm TV
twin lead, but doesn't say what to do about other materials.  The 300 ohm
twin lead they used had a velocity factor of 0.83.

Whatever the distance for the ladder line, what is not clear from the
article is whether the distance up from the bottom of the antenna to the
attachment point for the coax is included in the calculated lengths or is
added on.  (In one spot in the article, the antenna is shown as 50 5/16"
long, and in another as approximately 52".  This 52" could be 50 5/16"
plus the 1 1/4".)

Any ideas?

David Smith, VO1DMS

From [e-mail] Mon 12 Jun 95 20:37:54
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!usc!howland.reston.ans.net!news.nic.surfnet.nl!sun4nl!baan.nl!daly.baan.nl!jmaas
From: [e-mail] (Johan Maas)
Subject: Re: Magnetic Loop Antenna
Sender: [e-mail] (The Daily News)
Message-ID: <[e-mail]>
Date: Mon, 12 Jun 1995 06:23:58 GMT
References:  <[e-mail]>
Nntp-Posting-Host: daly.baan.nl
Organization: Baan International b.v.
Lines: 27

In article <[e-mail]>, [e-mail] (Vorname Nachname) writes:
|> Since I own my shortwave license, I'am fascinated in magnetic loop antennans.
|> I build two such antennas, one loop for 80/40 m with a diameter of abt 2 m and
|> one for 20-10m with 0.8m diameter. Both antennas work quite well even under
|> the bad conditions they are mounted in my location.
|> But there is nothing, that could not be improved so I am searching for ANY
|> material, YOUR experiences with and whatever ist related to magnetic loops.
|> Escpecially I am searching some measurement results, radiations patters,
|> calculation formula theory of operation and so on.
|>
|> I've you can help, please email to [e-mail]
|>
|>
|> Thanks in advance, vy 73 de Bjoern Dingwerth.
|>
|>
|>
|> [e-mail]
|> AX.25 packet: DL2JBD@DK0MWX.#NRW.DEU.EU

Hello Bjoern,

I dont have extra info for you, but only a question where i can find info about these MAGN.
LOOPS.
Do you have a description /explanation of the types you have build.

Thanks vy 73 de Johan (PA3GSB)

From [e-mail] Mon 12 Jun 95 20:37:55
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Meter Questions
Date: 10 Jun 1995 03:01:09 GMT
Organization: News & Observer Public Access
Lines: 20
Message-ID: <3rb1tl$[e-mail]>
References: <3ral7e$[e-mail]>
NNTP-Posting-Host: grail705.nando.net

[e-mail] (Roy W Lewallen) wrote:

> There are apparently two "kinds" of S-Units, the one "defined" by "The
> Standard" and the other shown by the receiver meters. Nearly all receivers
> have an S-meter labeled "S-Units". Very few if any respond at 6 dB per
> "S-Unit", so these are obviously a different kind than the "standard"
> S-Unit. I suggest we follow the lead of the sub-atomic particle physicists
> and call the "Standard" S-Unit "charmed" S-Units, and the receiver S-Units
> "uncharmed". Any better ideas?
>
> 73,
> Roy Lewallen, W7EL

With the current confusion in what the S-meter reads as
opposed to the old fashioned 6 dB per unit scale, I think we may as
well paste S9+20 at every point on our S meters, and that way
everyone will be happy with our reports. ( BIG GRIN (:>) )

73,
Don W3FPR

From [e-mail] Mon 12 Jun 95 20:37:55
Path: grape.epix.net!news.sprintlink.net!newsie.dmc.com!news.iii.net!iii1.iii.net!not-for-mail
From: [e-mail] (Thomas C Sefranek)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Meter Questions
Date: 10 Jun 1995 18:31:54 -0400
Organization: iii.net
Lines: 10
Message-ID: <3rd6hd$[e-mail]>
References: <3ral7e$[e-mail]> <3rb1tl$[e-mail]>
NNTP-Posting-Host: iii1.iii.net

Ahhh Don,
         Don't we already do that?  "Your 5-9, but I missed your name, call,
location and grid square...  What meter reading?

:)

Tom

--
Thomas C. J. Sefranek  WA1RHP

From [e-mail] Mon 12 Jun 95 20:37:57
Path: grape.epix.net!news.sprintlink.net!pipex!demon!ifwtech.demon.co.uk!G3SEK
From: Ian G3SEK <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Meter Questions
Date: 11 Jun 1995 03:09:49 +0100
Organization: IFWtech
Lines: 59
Sender: [e-mail]
Message-ID: <[e-mail]>
References: <3ral7e$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: dispatch.demon.co.uk
X-Newsreader: Newswin Alpha 0.7
X-Posting-Host: ifwtech.demon.co.uk

In article: <3ral7e$[e-mail]>  [e-mail] (Roy W Lewallen) writes:
:
: [e-mail] (Gary Coffman):
:
: >. . .
:
: >There are standards, two of them, but none of the amateur manufacturers
: >seem to adhere to them. For HF receivers, the standard is that each
: >S unit represents a received signal level change of 6 dB, and that
: >a level of S9 represents a signal level at the antenna terminals of
: >50 microvolts. . .
:
: >The other standard is for VHF/UHF receivers. The definition is the
: >same for the S unit, but the reference level of S9 now represents
: >5 microvolts instead of 50. This was done to more nearly match the
: >realities of VHF/UHF signal levels.
:
: >. . .
:
: In my engineering world, a "standard" is a written document which is
: agreed to or endorsed by some organization or group of people.
:
: Who has defined and published these standards? Where can I get a copy?

IARU has, at least in Region 1 (Europe/Africa) and probably in Regions 2
and 3 also. Try ARRL if you really want a copy of the technical papers
and the minutes of the plenary meetings that endorsed them. But why
bother - it's pretty much as Gary said.

: There are apparently two "kinds" of S-Units, the one "defined" by "The
: Standard" and the other shown by the receiver meters.

Not so much "the other" as "all the others", because each rig is
different from the next one. Unlike a 'real' professional engineering
standard, there are no pass/fail criteria to say how closely a
given receiver's S-meter calibration should conform.

Most important of all, ham radio equipment is largely a seller's market
- the equipment manufacturers decide what they're going to offer, and
we can only take or leave it. Hence there's very little leverage to
enforce any 'standards' arising from within ham radio.

The good news is that you can always calibrate your own S-meter
using a signal generator and an attenuator. You might not hit the
'standard' target for S9, but you can usually adjust the meter
multiplier resistor to make the S-units correspond more closely to
6dB steps.

If the S-meter linearity is not very good, you can always draw up
an independent graph of signal level (dB) against one of the linear
auxiliary scales on the meter, such as Ic or Ip.


--
73 from Ian G3SEK            Editor, 'The VHF/UHF DX Book'
                            'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services       Clear technical English - anywhere.


From [e-mail] Mon 12 Jun 95 20:37:57
Path: grape.epix.net!news.sprintlink.net!psgrain!nntp.teleport.com!nntp.teleport.com!not-for-mail
From: [e-mail] (Dave Calhoun)
Newsgroups: rec.radio.amateur.antenna
Subject: Mixing antenna wires
Date: 12 Jun 1995 00:29:29 -0700
Organization: Teleport - Portland's Public Access [phone]
Lines: 8
Message-ID: <3rgqcp$[e-mail]>
NNTP-Posting-Host: linda.teleport.com
X-Newsreader: TIN [version 1.2 PL2]

I am moving into a new house and will be mounting a TV antenna, a 2m ham
antenna, and a FM radio antenna. Can any of these antenna wires be
joined together so that fewer wires will haqve to be run into the house?
I'm wondering about the TV and the FM radio especially. Thanks for the help,
dave
--
[e-mail]  Public Access User --- Not affiliated with Teleport
Public Access UNIX and Internet at [phone] (2400-14400, N81)

From [e-mail] Mon 12 Jun 95 20:37:58
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!news.telalink.net!uro!jackatak!root
From: [e-mail] (Jack GF Hill)
Subject: Re: NEED HELP!  Respond : Grounding 'Expert
Organization: Jack's Amazing CockRoach Capitalist Ventures
Date: Sun, 11 Jun 1995 14:38:38 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>
Sender: [e-mail] (Superuser)
Lines: 49

[e-mail] (Barry Kutner) writes:

> One question regarding all the grounding talk:
>
> Everybody talks about disconeecting antennas from the rig during
> thunderstorms. What do they do at commercial sites? Obviously they don't
> run and unplug antennas at the local TV and AM/FM stations?
And, what about your local repeaters?

I am not as well versed as several in the group (such as Gary Coffman,
who rides the camel at a commercial TV station) but I'll throw some
grist into the mill:

The antennas in use at these sites (and repeater sites, as well) are
usually "DC Ground" designs, where the antenna present a very low
impedance (DC continuity) to ground while at the same time radiating
RF.

> If the station is "well grounded" can I presume it is then unnecessary (and
> maybe even bad) to disconnect antenna from rig?
Well, let me answer this by saying that for a *commercial* enterprise
to go off the air when electrical storms are present, would result in
a VERY bad thing... to the shareholders/owners of that enterprise.
And, in this neck of the woods (and many others) would result in
pretty spotty TV from March until October! ;^) We have almost daily
lightning, and most of the TV towers are hit fairly often... with
normally no major outgae in service... due to proper grounding
designs.

Recopmmended reading:
"The Grounds for Lightning Protection" availble from PolyPhaser Corp
for about $22.00 -- best $22 you can spend on grounding!

PolyPhaser Corp
P. O. Box 9000
Minden, NV 89423-9000
[phone]

> What is the definition of this magic "well grounded" setup?
Ah, Gary?   ;^)
--
Jack - W4PPT/M

+--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--+
| Jack GF Hill        |Voice: [phone] -             Ham Call: W4PPT |
| P. O. Box 1685      |Modem: [phone] -  Bicycling and SCUBA Diving |
| Brentwood, TN  37024|Fax:   [phone] -          Life Member - ARRL |
| [e-mail]  - "Plus ca change, plus c'est la meme chose" |
+--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--+

From [e-mail] Mon 12 Jun 95 20:38:00
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Date: 10 Jun 1995 02:39:22 GMT
Organization: News & Observer Public Access
Lines: 41
Message-ID: <3rb0kq$[e-mail]>
References: <3r4qj0$[e-mail]> <3r8cvq$[e-mail]> <3r8tq4$[e-mail]>
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[e-mail] (Kein{nen Paul) wrote:
>
> I very much doubt that you can find a PC installation (computer, monitor,
> printer etc..) in which the circuitry floats respective to the chassis and
> thus also floats relative to the PE bar in the building (assuming 3 wire
> power cords).
>
It is not necessary that the DC common circuit actually float.  The
correct procedure is to connect DC common to the equipment ground
at only one point within any one machine.  In PC type computers
there is usually done inside the power supply.  In a properly
(read low noise) designed printed circuit board, the "ground" plane
is actually DC common, and should not be confused with earth ground.
In most IBM PC compatible motherboards, there is a mechanical mounting
stud near the keyboard connector that may be mistaken for a motherboard
grounding point - it is not = This mounting stud should have insulating
washers to keep it from grounding the DC common at that point.  This
one item has cured many cases of mysterious behavior in PCs.

Again, the rule of thumb for grounding digital circuits is to connect
DC common to equipment ground at only one point within a machine, and
to be connect any signal cable shields to the equipment chassis at
only one end.  I am aware that some terminal devices violate this
convention.  My cynical response is that it helped them pass the
tests required to get it to market, but caused many service headaches
in the field, but my practical response says that there are always
exceptions to any convention - just be aware, and if you experience a
problem maybe you can identify the root cause a bit faster.

Please re-read Gary Coffman's earlier post on grounding.  That is
something that could replace most of the words I have previously
read on grounding, and I checked the ARRL Handbooks section on
station grounding before placing my first post on this subject.
While it was somewhat informative, I found it woefully incomplete
in answering the all important WHY question that is so helpful
when the current conditions don't quite match the 'normal' and I
don't ever seem to encounter a totally 'normal' situation.

73,
Don W3FPR


From [e-mail] Mon 12 Jun 95 20:38:01
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!parsifal.nando.net!usenet
From: Don Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Date: 12 Jun 1995 19:05:47 GMT
Organization: News & Observer Public Access
Lines: 45
Message-ID: <3ri36b$[e-mail]>
References: <3r4qj0$[e-mail]> <3r8cvq$[e-mail]> <3r8tq4$[e-mail]> <3rb0kq$[e-mail]> <3rguc3$[e-mail]>
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[e-mail] (Kein{nen Paul) wrote:

;> Yes, this is good engineering practice, but look what happens when we look
;> at the situation at network level. If we have one computer and some
;> floating device at the other end, then we can apply principle b) above.
;> However, if you are trying to connect two computers, then principle b)
;> can no longer be applied due to the grounding in _each_ PC. This was
;> just the situation with a cumputer and multiple VT100/VT220 terminals,
;> which are connected just like PCs you described. It does not matter what
;> you do with pin 1 (protective ground), you will have circulating ground
;> currents through pin 7 anyway. In this case it might be better to connect
;> both ends of the cable shields for improved noise margin, but I do not
;> recommend it after having replaced line receivers on several terminals :-)
;> You should newer break the signal ground (pin 7) connection on RS-232 to
;> break the ground current, since you will end up with burnt receivers and
;> transmitters very quickly during normal operation.
;>
;> My recommendation is to ground equipment properly for electric safety
;> and use isolation (optoisolators, transformers etc.) to transfer the
;> signals.
;>
;> Sorry for this long ranting, but hope that someone might find something
;> useful, next time when someone is connecting together equipment in
;> different rooms or different buildings.
;>
;>         Paul OH3LWR
;>

These are very good points, and Paul's suggested isolation
techniques are good both in theory and practice.  The only
qualification I can add is to point out that a long distance
run (like to connect terminals to computers) has a
whole lot of considerations over and above connections
within the range of the RS232 specification.  The signals
used in computer to terminal operations will cause DC level
shifts due to accumulation of charge from the signal itself,
and must be dealt with in ways different from the normal
engineering practices involved in a single room or cluster of
rooms. Different signalling waveforms and protocols have been
developed to deal with just this problem.  That is not
to discount anything Paul has said, but only to paint it as
a "horse of a different color".

73,
Don W3FPR

From [e-mail] Mon 12 Jun 95 20:38:02
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!ix.netcom.com!netnews
From: [e-mail] (Bob)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Plans for 2m Ground plane?
Date: 10 Jun 1995 23:00:17 GMT
Organization: Netcom
Lines: 12
Distribution: world
Message-ID: <3rd861$[e-mail]>
References: <3r7bm9$[e-mail]> <3r7h2j$[e-mail]>
NNTP-Posting-Host: ix-dc9-10.ix.netcom.com


>Another equally easy, get a 1/4 wave magmount and set it on the
furnace
>ductwork in attic.
>
>
>
I have a question... Does this mean that it is not critical the ground
radials on a grounplane be cut to a specific length. I have been
experimenting with a groundplane and I am not sure how to calculate the
lenght of the radials.


From [e-mail] Mon 12 Jun 95 20:38:02
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Plans for 2m Ground plane?
Date: 12 Jun 1995 01:42:58 GMT
Organization: News & Observer Public Access
Lines: 17
Message-ID: <3rg632$[e-mail]>
References: <3r7bm9$[e-mail]> <3r7h2j$[e-mail]> <3rd861$[e-mail]>
NNTP-Posting-Host: vyger320.nando.net

[e-mail] (Bob) wrote:
> >
> I have a question... Does this mean that it is not critical the ground
> radials on a grounplane be cut to a specific length. I have been
> experimenting with a groundplane and I am not sure how to calculate the
> lenght of the radials.
>
The only thing critical that I know of is one of definition.  It is
not a *true* groundplane unless the radials are at a resonant length.
It will simply be another form of a vertical.

Which one will work better is anyone's guess until it is put up and
measured (particularly for an attic mounted one).  If it works,
don't worry about it.

73,
Don W3FPR

From [e-mail] Mon 12 Jun 95 20:38:03
Path: grape.epix.net!news.sprintlink.net!demon!plug.news.pipex.net!pipex!howland.reston.ans.net!news.cac.psu.edu!news.pop.psu.edu!hudson.lm.com!newsfeed.pitt.edu!dbisna.com!psinntp!psinntp!psinntp!news.nyc.pipeline.com!news
From: [e-mail] (Dave Santoro)
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna
Subject: Plans for an Eggbeater Antenna?
Date: Mon, 12 Jun 1995 14:41:24 GMT
Organization: HYY Inc.
Lines: 10
Message-ID: <3rhjn5$[e-mail]>
Reply-To: [e-mail]
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Xref: grape.epix.net rec.radio.amateur.homebrew:7731 rec.radio.amateur.antenna:11033

Hey folks,

I'm looking to homebrew an eggbeater antenna for 2M.  If anyone could
post plans or direct me to a publication that has them I would greatly
appreciate it.

73
Dave N2VYP



From [e-mail] Mon 12 Jun 95 20:38:04
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!Germany.EU.net!EU.net!uunet!mr.net!news.mr.net!inet-serv.com!n0jcf.com!not-for-mail
From: [e-mail] (Chris Elmquist)
Newsgroups: rec.radio.amateur.antenna
Subject: proper seperation when stacking multi-band vhf/uhf yagis ?
Date: 11 Jun 1995 22:30:22 -0500
Organization: The Basement of N0JCF
Lines: 17
Message-ID: <3rgcce$[e-mail]>
NNTP-Posting-Host: n0jcf.com

What is the rule of thumb for determining the proper vertical seperation
when mounting horizontally polarized yagis for *different* bands one above
another ?

I want to mount 6m, 2m, 222, 432, 902 and 1296 (the last two are
loop yagis on an H-frame) going up the mast.  How closely stacked can I
put them without affecting each other (generally) ?

I have 12' of mast sticking out of the tower.... how many antennas can
I have ?  :-)

Chris

--
Chris Elmquist, N0JCF
[e-mail]
[e-mail]

From [e-mail] Mon 12 Jun 95 20:38:05
Path: grape.epix.net!news.sprintlink.net!pipex!demon!ifwtech.demon.co.uk!G3SEK
From: Ian G3SEK <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: proper seperation when stacking multi-band vhf/uhf yagis ?
Date: 12 Jun 1995 12:59:22 +0100
Organization: IFWtech
Lines: 41
Sender: [e-mail]
Message-ID: <[e-mail]>
References: <3rgcce$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: dispatch.demon.co.uk
X-Newsreader: Newswin Alpha 0.7
X-Posting-Host: ifwtech.demon.co.uk

In article: <3rgcce$[e-mail]>  [e-mail] (Chris Elmquist) writes:
:
: What is the rule of thumb for determining the proper vertical seperation
: when mounting horizontally polarized yagis for *different* bands one above
: another ?
:
: I want to mount 6m, 2m, 222, 432, 902 and 1296 (the last two are
: loop yagis on an H-frame) going up the mast.  How closely stacked can I
: put them without affecting each other (generally) ?

Start with the 6m antenna at the bottom.

Determine the stacking distance for two identical 2m antennas like
the one you're going to use. If it's a commercial antenna, the
recommended stacking distance will probably be in the catalog. If not,
apply any reasonable rule of thumb - it isn't super-critical for this
particular purpose.

Stack your single 2m antenna at a *minimum* of *half* that distance
above the 6m one. That stacking distance places the larger, lower-
frequency antenna outside the capture area of the higher-frequency
antenna.

Following the same principle, continue on up the mast with the 222
antenna and the rest.


: I have 12' of mast sticking out of the tower.... how many antennas can
: I have ?

Since you didn't say exactly what kinds of antennas they are,
you'll have to work that out for yourself  :-)



--
73 from Ian G3SEK            Editor, 'The VHF/UHF DX Book'
                            'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services       Clear technical English - anywhere.


From [e-mail] Mon 12 Jun 95 20:38:06
Path: grape.epix.net!news.sprintlink.net!pipex!tcp.co.uk!usenet
From: [e-mail] (Darren)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: qsl info
Date: 11 Jun 1995 08:53:46 GMT
Organization: Sugar Radio DX group
Lines: 20
Message-ID: <3reauq$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: moonraker.tcp.co.uk
X-Newsreader: WinVN 0.92.6+

In article <[e-mail]>, wirenet![e-mail] (AA4LI) says:
>
>qslinfo
>bv2da
>su2mt
>ah1a

BV2DA - BOX 112-16 TAPEI, TAIWAN

SU2MT - MOHAMMED TARTAUSIEH, POB 1610, ALEXANDRIA, EGYPT

AH1A - *NOW VIA K1ER*

You would have been better posting the request in rec.radio.misc :-)

                                             Darren  G0TSM


                     http://www.tcp.co.uk/~moonraker/
           --.- .-. --..  -.. .  --. ----- - ... --  -.-     :-)

From [e-mail] Mon 12 Jun 95 20:38:07
Path: grape.epix.net!news.sprintlink.net!hookup!news.Direct.CA!news.cyberstore.ca!vanbc.wimsey.com!unixg.ubc.ca!news.bc.net!news.island.net!ham!rsmits
From: [e-mail] (Robert Smits)
Newsgroups: rec.radio.amateur.antenna
Subject: Quagi difficulties.
Message-ID: <[e-mail]>
Date: Sat, 10 Jun 1995 19:28:00 PST
Reply-To: [e-mail]
Distribution: world
Organization: The Curmudgeon's Cottage
X-Newsreader: Rnf 0.79b6
Lines: 37

Since I need a cheap but effective gain two meter antenna for a while, I
decided to roll my own quagi based on the dimensions suggested by N6NB in
the April '77 QST and subsequent Antenna Handbooks.

Upon actually building such an antenna I get very high SWR ratios. I think
I've tried a lot of possible solutions, but have obviously missed
something.

The quagi itself is rope supported, with the reflector and driven elements
mounted on wooden crosses that the rope goes through, and the director
elements taped to the rope (1/4 in poly line) at appropriate intervals.

The ropes are tied across my sun deck fence (wood), and the driven element
is fed at the bottom to make the quagi horizontally polarized. It is about
4 feet above the wooden deck.

The only change I made from the original was to use a small plexiglass
insulator with nuts and bolts to connect the RG-58 feedline (about 20
feet) to the antenna, instead of a chassis mount style PL-259 receptacle.

Changing the element material from 1/8 aluminum wire to No 12 insulated
copper wire has no effect. Changing the size of the driven loop - larger
and smaller has little effect. The feed line itself is new, in good
condition and checks OK with an ohm meter. Changing the spacing between
the driven element and the reflector, and the d.e. and directors does have
an effect, but I still can't get below about 3:1 SWR. Needless to say, my
IC-211 transmitter wouldn't like that at all.

My dip meter shows the antenna is resonant at about 144.5 MHz, which is
where it's supposed to be.

Anyone with suggestions where I should look next to improve this situation
will be welcome indeed.

--
[e-mail] (Robert Smits, VE7HS)


From [e-mail] Mon 12 Jun 95 20:38:08
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quagi difficulties.
Date: 12 Jun 1995 00:58:05 GMT
Organization: News & Observer Public Access
Lines: 34
Message-ID: <3rg3et$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: vyger320.nando.net

[e-mail] (Robert Smits) wrote:
> SNIP ...
> Changing the element material from 1/8 aluminum wire to No 12 insulated
> copper wire has no effect. Changing the size of the driven loop - larger
> and smaller has little effect. The feed line itself is new, in good
> condition and checks OK with an ohm meter. Changing the spacing between
> the driven element and the reflector, and the d.e. and directors does have
> an effect, but I still can't get below about 3:1 SWR. Needless to say, my
> IC-211 transmitter wouldn't like that at all.
>
> My dip meter shows the antenna is resonant at about 144.5 MHz, which is
> where it's supposed to be.
>
> Anyone with suggestions where I should look next to improve this situation
> will be welcome indeed.
>
You should be in the ballpark of 50 to 80 ohms at the feedpoint which
should give no more than a 1.6 VSWR, at the antenna input.  I haven't
done any calculations to see what say 80 ohms at the feedpoint will
yield in apparent VSWR at the transmitter end of 20 feet of RG58.

You might try putting your vswr meter right at the antenna terminals
to see what you get (staying out of the field yourself), or as an
better alternative use an antenna analyzer if you can get one.

I would suggest a quick test of your feedline, set up an inverted vee
at 144.5 and connect the feedline to it, then see what your VSWR is.
It should be no greater than 1.5.  If it also is very high, you can
suspect your feedline even though it is new and looks good.

Good luck with it.
73,
Don W3FPR


From [e-mail] Mon 12 Jun 95 20:38:09
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!jussieu.fr!oleane!pipex!swrinde!cs.utexas.edu!news.sprintlink.net!malgudi.oar.net!infinet!wvanho
From: [e-mail] (W. E. Van Horne)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quagi difficulties.
Date: 12 Jun 1995 11:11:50 GMT
Organization: InfiNet
Lines: 30
Distribution: world
Message-ID: <3rh7dm$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: rigel.infinet.com
X-Newsreader: TIN [version 1.2 PL2]

Robert Smits ([e-mail]) wrote:

: Upon actually building such an antenna I get very high SWR ratios. I think
: I've tried a lot of possible solutions, but have obviously missed
: something.

As you describe it, it should work.  Since it apparently does not, check
all aspects of what you are doing.  For example, how are you measuring
the SWR?

I have an MFJ-249 antenna analyzer, and had a problem with a simple HF
dipole.  I couldn't get the indicated SWR below 3:1, although there was a
clear dip at the resonant frequency (i.e. the SWR measured infinity away
from resonance, but no lower than 3:1 at resonance.)  The next issue of
QST that arrived a few days later contained the explanation.  The
instrument does not contain a high-pass filter in the input circuit, so
it responds to local broadcast signals.  The pickup of from a broadcast
band signal in my area, on a 20-meter dipole, was sufficient to drive the
meter to 3:1 indication on ALL frequencies throughout the HF spectrum!

Good luck, and 73,
Van - W8UOF
-------------------------------------------------------------------------
I have a spelling checker, it came with my PC.
It plainly marks four my revue mistakes I cannot sea.
I've run this poem threw it, I'm sure your please to no.
Its letter perfect in its weigh; my checker tolled me sew.
                                      (c) THE ROTARIAN
[e-mail]


From [e-mail] Mon 12 Jun 95 20:38:09
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!nntp.crl.com!pacbell.com!nntp-hub2.barrnet.net!news3.near.net!transfer.stratus.com!usenet
From: "J.Swenson" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Rohn 25, How many feet over last house bracket (un-guyed)
Date: 11 Jun 1995 16:51:03 GMT
Organization: Stratus Computer Inc, Marlboro MA
Lines: 4
Message-ID: <3rf6tn$[e-mail]>
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I would like to put up some Rohn-25 with a 6 element uagi without guys if
possible.  I have 2 house brackets.  Someone said 30' over the last one
is ok.  Is this right?


From [e-mail] Mon 12 Jun 95 20:38:10
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3rf6tn$[e-mail]>
Date: Mon, 12 Jun 1995 00:01:00 GMT
Lines: 16

In article <3rf6tn$[e-mail]> "J.Swenson" <[e-mail]> writes:
>I would like to put up some Rohn-25 with a 6 element uagi without guys if
>possible.  I have 2 house brackets.  Someone said 30' over the last one
>is ok.  Is this right?

No. Or rather it depends on the windloading of the antenna. If you're
talking about a little UHF yagi, then it's probably Ok, but if you are
talking about a 6 element 20 meter beam, not a chance.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Mon 12 Jun 95 20:38:11
Path: grape.epix.net!news.sprintlink.net!hookup!usenet.eel.ufl.edu!news-feed-1.peachnet.edu!hobbes.cc.uga.edu!cssun.mathcs.emory.edu!emory!swrinde!howland.reston.ans.net!agate!library.ucla.edu!info.ucla.edu!news.bc.net!news.island.net!ham!rsmits
From: [e-mail] (Robert Smits)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Message-ID: <[e-mail]>
Date: Sun, 11 Jun 1995 20:00:00 PST
References: <3rf6tn$[e-mail]>
Reply-To: [e-mail]
Distribution: world
Organization: The Curmudgeon's Cottage
X-Newsreader: Rnf 0.79b6
Lines: 17

"J.Swenson" <[e-mail]> writes:

>I would like to put up some Rohn-25 with a 6 element uagi without guys if
>possible.  I have 2 house brackets.  Someone said 30' over the last one
>is ok.  Is this right?
>

Absolutely NOT! Rohn 25G is designed to be guyed. It is rated to carry 30
lbs./sq foot Wind load, with 6 sq ft of allowable load, but only when
guyed. Even the 40 foot tower has two sets of guys in the plans, at 20
feet and at 40 feet. If the top set are left out, the load should be
derated by 50 %, which won't include any 6 el HF antenna.

This info is taken from the Unarco Rohn catalog.

--
[e-mail] (Robert Smits VE7HS)

From [e-mail] Mon 12 Jun 95 20:38:12
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!emory!news-feed-1.peachnet.edu!darwin.sura.net!babylon5.ccd.harris.com!not-for-email
From: [e-mail] (Doug Snowden)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Date: 12 Jun 1995 13:14:59 -0400
Organization: Harris Controls Division
Lines: 23
Distribution: world
Message-ID: <3rhsmj$[e-mail]>
References: <3rf6tn$[e-mail]> <[e-mail]>
NNTP-Posting-Host: rs2.ccd.harris.com
X-Newsreader: TIN [version 1.2 PL2]

: >I would like to put up some Rohn-25 with a 6 element uagi without guys if
: >possible.  I have 2 house brackets.  Someone said 30' over the last one
: >is ok.  Is this right?
: >

: Absolutely NOT! Rohn 25G is designed to be guyed. It is rated to carry 30
: lbs./sq foot Wind load, with 6 sq ft of allowable load, but only when
: guyed. Even the 40 foot tower has two sets of guys in the plans, at 20
: feet and at 40 feet. If the top set are left out, the load should be
: derated by 50 %, which won't include any 6 el HF antenna.

: This info is taken from the Unarco Rohn catalog.

I am not an authority on this subject, but I am sure I have seen somewhere
that a Rohn 25 will support some sort of load up to 40ft unguyed. Of
course with a good base.

--
Doug  Snowden
work: [phone]
home: (407) 98409360
[e-mail]


From [e-mail] Mon 12 Jun 95 20:38:13
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!ix.netcom.com!netcom.com!netcom11!faunt
From: [e-mail] (Doug Faunt N6TQS [phone])
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
In-Reply-To: [e-mail]'s message of 12 Jun 1995 13:14:59 -0400
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: at home, in Oakland
References: <3rf6tn$[e-mail]> <[e-mail]>
        <3rhsmj$[e-mail]>
Date: Mon, 12 Jun 1995 20:51:29 GMT
Lines: 27

I have a Rohn pamphlet in front of me that says "The Rohn 25G can be
used guyed, self-supporting, or bracketed"

Then there are various tables, such as this one, which is a partial:

25G bracketed tower

Tower   Bracket         Allowable antenna areas
Height  upper   lower   70mph   80mph   90mph
40      30      15      15.3    11.3    7.7
50      36      18      14.6    10.0    6.8
60      46      23      14.0    8.9     5.9
............

25G Self-supporting

Tower           Allowable antenna areas
height          70mph   80mph   90mph
10              19.7    14.3    10.5
20              14.2    9.0     6.9
............

All of this information is available from Rohn, for an inordinate
amount of money, or from their dealers, FOR FREE.  I had to push the
guys at my local HRO, with a letter in hand from Rohn stating the
above, but ended up with a complete technical manual for nothing.
73, doug

From [e-mail] Mon 12 Jun 95 20:38:14
Path: grape.epix.net!news.sprintlink.net!news.bluesky.net!solaris.cc.vt.edu!usenet
From: [e-mail] (jbmitch)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Date: 12 Jun 1995 20:38:29 GMT
Organization: Virginia Tech/Blacksburg Electronic Village
Lines: 14
Message-ID: <3ri8k5$[e-mail]>
References: <3rf6tn$[e-mail]>
NNTP-Posting-Host: jbmitch.beva.blacksburg.va.us
X-Newsreader: WinVN 0.92.1

In article <3rf6tn$[e-mail]>, "J.Swenson" <[e-mail]> says:
>
>I would like to put up some Rohn-25 with a 6 element uagi without guys if
>possible.  I have 2 house brackets.  Someone said 30' over the last one
>is ok.  Is this right?
>
quoting from the Rohn book: "The extra strength of the No. 25G allows it
to be self-supporting providing a house bracket is used, and under normal
conditions the 25G can rise 35 feet above this bracket."  Nonetheless, it
depends on the size of the antenna you're mounting. If it's 6 elements on
HF, like a TH6, or Pro-57, etc., I wouldn't be comfortable going more
than 10-15 feet above the highest house bracket.  Consult professionals
in your area, such as commercial tower installers. Good luck and be
careful.

From [e-mail] Mon 12 Jun 95 20:38:14
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news.moneng.mei.com!uwm.edu!math.ohio-state.edu!newsfeed.acns.nwu.edu!ftpbox!mothost!lmpsbbs!news
From: [e-mail] (Bruce Burke Redi)
Subject: Re: Rotating Antenna for Hidden Transmitte
Reply-To: [e-mail]
Organization: Motorola RPG  I.C. Technology Center
Date: Mon, 12 Jun 1995 16:00:55 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>
Sender: [e-mail] (LMPSBBS News Account)
Nntp-Posting-Host: 145.2.98.41
Lines: 34

In article [e-mail], [e-mail] (Robert Smits) writes:
}Brett Coningham <[e-mail]> writes:
}
}>I want to build an antenna system that rotates constantly at
}>about 3-5 rpm, for 2-meter transmitter hunts.  I actually have
}>built a lightweight 4-element 2-meter beam that would work well,
}>but need a rotating mechanism.  The hard part is finding a motor
}>that would run off twelve volts for, say, five or six hours, and
}>could handle a modest load, say one pound in a possible five
}>mph wind.
}>Has anyone else tried this?  What would you recommend for a
}>portable motor system?
}
}A dc stepping motor, probably. Copiers typically have lots of 12 and 24 V
}stepping motors, often with gears or belt drive sprockets attached.
}Perhaps you can scavenge some from copiers being scrapped at a local
}dealer.
}
}How, though are you planning to handle the transfer of signal from the
}antenna to the receiver while it is rotating?
}
}--
}[e-mail] (Robert Smits)
}

The easiest thing to do would be to rotate a passive reflector around a
monopole(1/4 wave vertical). The spacing would need to be such to give a cardiod
pattern. Getting really fancy, on the other side, you could add a director, thus
having a 3 element "yagi."

Bruce, WB4YUC




From [e-mail] Mon 12 Jun 95 20:38:16
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!news.bluesky.net!solaris.cc.vt.edu!news.netins.net!internet.spss.com!pagesat.net!sloth!news
From: Brett Coningham <[e-mail]>
Subject: Rotating Antenna for Hidden Transmitter
Content-Type: text/plain; charset=us-ascii
Message-ID: <[e-mail]>
Sender: [e-mail]
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Date: Sat, 10 Jun 1995 22:41:13 GMT
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I want to build an antenna system that rotates constantly at
about 3-5 rpm, for 2-meter transmitter hunts.  I actually have
built a lightweight 4-element 2-meter beam that would work well,
but need a rotating mechanism.  The hard part is finding a motor
that would run off twelve volts for, say, five or six hours, and
could handle a modest load, say one pound in a possible five
mph wind.
Has anyone else tried this?  What would you recommend for a
portable motor system?

73
Brett AB5P
[e-mail]


From [e-mail] Mon 12 Jun 95 20:38:17
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!agate!library.ucla.edu!info.ucla.edu!news.bc.net!news.island.net!ham!rsmits
From: [e-mail] (Robert Smits)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rotating Antenna for Hidden Transmitter
Message-ID: <[e-mail]>
Date: Sun, 11 Jun 1995 09:28:00 PST
References: <[e-mail]>
Reply-To: [e-mail]
Distribution: world
Organization: The Curmudgeon's Cottage
X-Newsreader: Rnf 0.79b6
Lines: 23

Brett Coningham <[e-mail]> writes:

>I want to build an antenna system that rotates constantly at
>about 3-5 rpm, for 2-meter transmitter hunts.  I actually have
>built a lightweight 4-element 2-meter beam that would work well,
>but need a rotating mechanism.  The hard part is finding a motor
>that would run off twelve volts for, say, five or six hours, and
>could handle a modest load, say one pound in a possible five
>mph wind.
>Has anyone else tried this?  What would you recommend for a
>portable motor system?

A dc stepping motor, probably. Copiers typically have lots of 12 and 24 V
stepping motors, often with gears or belt drive sprockets attached.
Perhaps you can scavenge some from copiers being scrapped at a local
dealer.

How, though are you planning to handle the transfer of signal from the
antenna to the receiver while it is rotating?

--
[e-mail] (Robert Smits)


From [e-mail] Mon 12 Jun 95 20:38:18
Path: grape.epix.net!mango.epix.net!gmfoster
From: Garry Foster <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rotating Antenna for Hidden Transmitter
Date: Sun, 11 Jun 1995 18:16:41 -0400
Organization: epix.net
Lines: 40
Message-ID: <[e-mail]>
References: <[e-mail]>
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Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
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In-Reply-To: <[e-mail]>



On Sat, 10 Jun 1995, Brett Coningham wrote:

> I want to build an antenna system that rotates constantly at
> about 3-5 rpm, for 2-meter transmitter hunts.  I actually have
> built a lightweight 4-element 2-meter beam that would work well,
> but need a rotating mechanism.  The hard part is finding a motor
> that would run off twelve volts for, say, five or six hours, and
> could handle a modest load, say one pound in a possible five
> mph wind.
> Has anyone else tried this?  What would you recommend for a
> portable motor system?
>
> 73
> Brett AB5P
> [e-mail]
>
>
>
Well I would suggust looking into stepper motors. You can get any speed
you want by changing the frequency of the pulses. And also there are many
available that could handle the load.  You could add a gear drive to use
smaller motors. Don Lancaster has written about people using car
alternators as high power steppers.( about $5.00 at my local junk yard)
However even eith half stepping you would still need some reduction to
get fine enough steps with something like this.

Normal 12 volt gear drive motors might do what you want. A starting place
might be a power window unit. One out of a rear window in a Blazer/Bronco
might hav e more power.

I haven't tried any of these just making suggustions. I guess you know
that the fiels can be rotated electrically by proper design.


Let us know how it turns out. Sounds like fun.
                                                Garry(WB0NNO)



From [e-mail] Mon 12 Jun 95 20:38:19
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!spool.mu.edu!bloom-beacon.mit.edu!gatech!newsjunkie.ans.net!interaccess!usenet
From: [e-mail] (Tom Geletka)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rotating Antenna for Hidden Transmitter
Date: Mon, 12 Jun 1995 04:41:23 GMT
Organization: InterAccess, Chicago's best Internet Service Provider
Lines: 43
Message-ID: <3rggjn$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: d131.he.interaccess.com
X-Newsreader: Forte Free Agent v0.55

Brett Coningham <[e-mail]> wrote:

>I want to build an antenna system that rotates constantly at
>about 3-5 rpm, for 2-meter transmitter hunts.  I actually have
>built a lightweight 4-element 2-meter beam that would work well,
>but need a rotating mechanism.  The hard part is finding a motor
>that would run off twelve volts for, say, five or six hours, and
>could handle a modest load, say one pound in a possible five
>mph wind.
>Has anyone else tried this?  What would you recommend for a
>portable motor system?

I know a hunter who used a car electric window motor with a series
resistance to reduce the speed. It worked well. He used a variable
resistance.
























Tom N9cba




From [e-mail] Mon 12 Jun 95 20:38:20
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!math.ohio-state.edu!hobbes.physics.uiowa.edu!cobra.uni.edu!fishern3485
From: [e-mail] (Nathan Fisher)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rotating Antenna for Hidden Transmitter
Message-ID: <[e-mail]>
Date: 12 Jun 95 08:12:46 -0500
References: <[e-mail]>
Organization: University of Northern Iowa
Lines: 54

> I want to build an antenna system that rotates constantly at
> about 3-5 rpm, for 2-meter transmitter hunts.  I actually have
> built a lightweight 4-element 2-meter beam that would work well,
> but need a rotating mechanism.  The hard part is finding a motor
> that would run off twelve volts for, say, five or six hours, and
> could handle a modest load, say one pound in a possible five
> mph wind.
> Has anyone else tried this?  What would you recommend for a
> portable motor system?

I just recently completed an extended project to build a Roanoke Dopplar
for 2m.  It simulates a rotating antenna, (i.e. no moving parts) and uses
the dopplar shift to electronicaly determine exact bearing, instantly.
The electronics are a bit rough to manage, (13 chips plus lots of resistors
and caps) but the electronics work for nay frequency.  With a scanner,
you only need change antennas to change bands.

I played my first official hunt yesterday with it, and it worked excellent.
I took about the shortest possible route to the fox, but had a bit 'o
trouble closing the last 100 yds due to massive reflections.  Still
caught 1st though.  Expect one week of construction time, with about
$75 in parts. (mostly chips)  Complete units are sold by Dopplar Systems,
at a high cost of $600+ for the box, and $100-200 for each antenna set.
Dopplar Systems has a very good antenna switching system, much smoother
than a Roanoke, but does not allow much adjustability, so is about equal
to the Roanoke.

Good plans are in a book called Transmitter Hunting, and I'm sorry I cannot
recall the author.  There are two errors on the schematic though.  Ask
me about them later if you decide to construct it. (two resistors of the
same number, and a missing "k" behind another resistor value!)


With the mechanical rotator, you will be fighting motor noise unless you
go brushless, and slip-rings to comminicate the antenna to the car are
a *pain*.  I tried it and gave up, although I know of at least one person
in my area that has made one successful unit in the past.  Consider an
AC inverter and a modified antenna rotor.  Also a problem I ran into was
the AGC in the radio caused an odd curve in the signal - it rose for about
1/4 sec after the bunny was keyed, and after they unkeyed, it took about
1/2 sec for the meter voltage to fall back to noise level.  Consider
disabling the AGC.

A commodore or apple computer makes a good assistant.  Feed it the signal
and hook it to an optical gate.  This way, it will know when a rotation is
completed, and can evenly plot the readings it has taken since the last
rotation.

Good luck!

--
Nathan Fisher
 N0ZYC
  [e-mail]

From [e-mail] Mon 12 Jun 95 20:38:21
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (Billcunn)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Searching for good Indoor Antenna 40-80m
Date: 10 Jun 1995 15:00:04 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 8
Sender: [e-mail]
Message-ID: <3rcq3k$[e-mail]>
References: <NOMSGID_77=3A7700=[e-mail]>
Reply-To: [e-mail] (Billcunn)
NNTP-Posting-Host: newsbf02.mail.aol.com

I operated out of an apartment for several years  I dipole antennas for
each band  I operated 2m-80m  you would do best by feeding each antenna
with it's own feed line  the 80m antenna may have to be bent around the
area to fit but it does work well   try to keep them as far from power
lines and other wiring in the area as you can


Bill    (KA2BBZ)

From [e-mail] Mon 12 Jun 95 20:38:22
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!pipex!sunic!sunic.sunet.se!mn5.swip.net!usenet
From: [e-mail] (Bo Sall)
Newsgroups: rec.radio.amateur.antenna
Subject: Software for designing logperodic HF antennas?
Date: 11 Jun 1995 18:16:23 GMT
Organization: SWIPnet AB
Lines: 5
Message-ID: <3rfbto$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: dialup124.swipnet.se
X-Newsreader: WinVN 0.92.2

Does someone know if there some kind of PC-software

how to design HF LP antennas ?

73 / SM7CKZ /Bob

From [e-mail] Mon 12 Jun 95 20:38:23
Path: grape.epix.net!news.sprintlink.net!hookup!usenet.eel.ufl.edu!news-feed-1.peachnet.edu!hobbes.cc.uga.edu!cssun.mathcs.emory.edu!emory!swrinde!howland.reston.ans.net!agate!library.ucla.edu!info.ucla.edu!news.bc.net!news.island.net!ham!rsmits
From: [e-mail] (Robert Smits)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Software for designing logperodic HF antennas?
Message-ID: <[e-mail]>
Date: Sun, 11 Jun 1995 20:07:00 PST
References: <3rfbto$[e-mail]>
Reply-To: [e-mail]
Distribution: world
Organization: The Curmudgeon's Cottage
X-Newsreader: Rnf 0.79b6
Lines: 19

[e-mail] (Bo Sall) writes:

>Does someone know if there some kind of PC-software
>
>how to design HF LP antennas ?
>
>73 / SM7CKZ /Bob

There was a basic program published in ARRL antenna books a few years ago,
I believe. And you can probably get it from the ARRL. Or I could email you
a copy uuencoded.



--
[e-mail] (Robert Smits)

I have no trouble with my enemies. But my goddam friends, they are the ones
that keep me walking the floor nights! Warren G Harding

From [e-mail] Mon 12 Jun 95 20:38:24
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: 12 Jun 1995 01:21:49 GMT
Organization: News & Observer Public Access
Lines: 21
Message-ID: <3rg4rd$[e-mail]>
References: <[e-mail]> <3qvfb2$[e-mail]> <[e-mail]> <3r7ofr$[e-mail]> <3r888k$[e-mail]> <[e-mail]>
NNTP-Posting-Host: vyger320.nando.net

[e-mail] (Gary Coffman) wrote:
> SNIP...
> For example, when the plate of a tube is at a voltage peak, it is
> at a current minimum, and vice versa. This should be apparent from
> looking at a loadline on a graph of characteristic curves. The
> *implications* of this may be lost on some, however. The *slope*
> of the line is the *reverse* of a resistance, in fact the principle
> of operation of the tube is that of a negative resistance. Thus the
> idea of using it as a *terminating* resistance for an unrelated
> reverse AC signal is absurd.
> SNIP...

Now, I recall a lot of discussion in this thread about whether the
tube is a source or not.  It just occurred to me that a negative
resistance is the mathematical equivalent of a generator. (just
mentioned for whatever it is worth)

73,
Don W3FPR



From [e-mail] Mon 12 Jun 95 20:38:24
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Vertically polarized noise question
Date: Sun, 11 Jun 95 01:29:03 -0500
Organization: Delphi ([e-mail] email, 800-695-4005 voice)
Lines: 18
Message-ID: <[e-mail]>
References: <3qqqsl$[e-mail]>
NNTP-Posting-Host: bos1f.delphi.com
X-To: Bob Bruhns <[e-mail]>

Bob Bruhns <[e-mail]> writes:

>  I have no sources to back this up, but I think the reason that "man
>made noise sources" are held to be vertically polarized is that they are
>local in nature and the noise propagates by ground wave.

 I would suggest that the antenna connected to most man made noise is the house
wiring, and that most of the radiating part of the antenna (wiring) is
vertically polarized.  The horizontal parts will tend to be so long as to
cancell or act as lon
g-wire antenna with deep side lobes.
best wishes.
Roger






From [e-mail] Mon 12 Jun 95 20:38:25
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!ix.netcom.com!netnews
From: [e-mail] (Bob)
Newsgroups: rec.radio.amateur.antenna
Subject: What effect do straight radials have on a groundplane?
Date: 10 Jun 1995 23:03:37 GMT
Organization: Netcom
Lines: 4
Distribution: world
Message-ID: <3rd8c9$[e-mail]>
References: <3r7h2j$[e-mail]> <3r8sa5$[e-mail]>
NNTP-Posting-Host: ix-dc9-10.ix.netcom.com

What is the effect on reception when the radials on a groundplane are
horizontal instead of drooping?

Bob

From [e-mail] Mon 12 Jun 95 20:38:26
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!cs.utexas.edu!news.tamu.edu!news.utdallas.edu!corpgate!bcarh189.bnr.ca!nott!cunews!freenet.carleton.ca!FreeNet.Carleton.CA!bk296
From: [e-mail] (Gordon Symonds)
Subject: WTB: Radio West Ferrite Loop
Message-ID: <[e-mail]>
Sender: [e-mail] (Gordon Symonds)
Reply-To: [e-mail]
Organization: The National Capital FreeNet, Ottawa, Ontario, Canada
Date: Mon, 12 Jun 1995 11:12:11 GMT
Lines: 6

(Gordon Symonds) References:
Organization: The National Capital FreeNet

I would like to find a large Radio West ferrite loop antenna (the multi-
band one) in operating condition. Please reply by email. Thanks.


From [e-mail] Thu 15 Jun 95 13:15:31
Path: grape.epix.net!news.sprintlink.net!uunet!in1.uu.net!news.inhouse.compuserve.com!news.production.compuserve.com!news
From: SpyKing <[e-mail]>
Newsgroups: misc.entrepreneurs,rec.aviation.ultralight,rec.models.rc,rec.pyrotechnics,rec.radio.amateur.antenna
Subject: ***Great New Web Site for Snoops***
Date: 13 Jun 1995 16:16:32 GMT
Organization: via CompuServe Information Service
Lines: 2
Message-ID: <3rkdl0$51t$[e-mail]>
Xref: grape.epix.net misc.entrepreneurs:45783 rec.models.rc:52744 rec.pyrotechnics:29757 rec.radio.amateur.antenna:11072

It's at http://www.interaccess.com/trc/tsa.html
It's still under construction...

From [e-mail] Thu 15 Jun 95 13:15:32
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!carbon!ouray!letrujil
From: [e-mail] (Hardwired)
Newsgroups: misc.entrepreneurs,rec.aviation.ultralight,rec.models.rc,rec.pyrotechnics,rec.radio.amateur.antenna
Subject: Re: ***Great New Web Site for Snoops***
Followup-To: misc.entrepreneurs,rec.aviation.ultralight,rec.models.rc,rec.pyrotechnics,rec.radio.amateur.antenna
Date: 14 Jun 1995 14:20:24 GMT
Organization: University of Colorado at Denver
Lines: 19
Message-ID: <3rmr78$[e-mail]>
References: <3rkdl0$51t$[e-mail]>
NNTP-Posting-Host: ouray.cudenver.edu
X-Newsreader: TIN [version 1.2 PL2]
Xref: grape.epix.net misc.entrepreneurs:45932 rec.models.rc:52857 rec.pyrotechnics:29794 rec.radio.amateur.antenna:11112

SpyKing ([e-mail]) wrote:
: It's at http://www.interaccess.com/trc/tsa.html
: It's still under construction...


And what the hell does spy stuff have to do with RC anything?  I checked
it out and its ok....nothing I care to see though.

--
    _/    _/                     _/  _/      _/                          _/
   _/    _/  _/_/   _/          _/  _/      _/  _/  _/      _/_/        _/
  _/_/_/_/ _/  _/  _/_/_/  _/_/_/  _/  _/  _/      _/_/_/ _/ _/_/  _/_/_/
 _/    _/ _/  _/  _/     _/   _/  _/ _/_/ _/  _/  _/     _/      _/   _/
_/    _/  _/_/_/ _/      _/_/_/  _/_/  _/_/  _/  _/      _/_/_/  _/_/_/


           Leroy [e-mail]
             Finger at this address for a PGP 2.6.2 key
             http://www.cudenver.edu/~ltrujill

From [e-mail] Thu 15 Jun 95 13:15:33
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!newsjunkie.ans.net!netnews.lightside.com!user52.lightside.com!user
From: [e-mail] (John Fay)
Newsgroups: rec.radio.amateur.antenna
Subject: **1ST EVER HAM OPINION POLL ON THE WEB**
Date: Tue, 13 Jun 1995 23:53:07 +0100
Organization: Elf. Ent.
Lines: 6
Message-ID: <[e-mail]>
NNTP-Posting-Host: user52.lightside.com
Mime-Version: 1.0
Content-Type: text/plain;charset=US-ASCII
Content-Transfer-Encoding: 7bit

I have estalished a WWW site that includes the 1st ever Ham opinion poll.
The question this month is "Do you support the new vanity call program,
about to go into effect in the US?" The poll takes into account license
class and the age of the voter. Your vote is tallied instintly and you see
the results on-line.
Check this site out at, http://www.csz.com/sarrio.html.

From [e-mail] Thu 15 Jun 95 13:15:34
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!uunet!in1.uu.net!moontower.com!nobody
From: [e-mail] (Randy Shields)
Newsgroups: rec.radio.swap,rec.radio.amateur.antenna
Subject: 12 GHz Satellite Dish--FS
Date: 14 Jun 1995 21:17:44 -0500
Organization: Austin Texas Internet
Lines: 18
Distribution: world
Message-ID: <3ro588$[e-mail]>
Xref: grape.epix.net rec.radio.swap:37373 rec.radio.amateur.antenna:11139

For Sale:  Satellite Receiver Reflector Dish

Approx. 63 X 68 cm, oval, aluminum.
Pole-mounting bracket included, mount is marked for elevation, 10 to 70 degrees.
Includes feed mount arm (feedhorn or LNB is NOT included): approx. 40 cm from
feed mounting collar to dish.  Feed mount arm is 25 mm diameter tubing.
4 cm dia. feed mount collar comes with w/20-25 mm reducer/adapter.

Used approx. 1 year, with PageSat data receiver.

Advertised specs:
frequency = 10.95 - 12.75 GHz
gain = 36.2 dB @ 11.7 GHz
offset angle = 22.5 degrees

$100 + shipping, USPS or UPS.

e-mail [e-mail]

From [e-mail] Thu 15 Jun 95 13:15:35
Path: grape.epix.net!news.sprintlink.net!news.ecrc.de!news.forth.gr!news-ath.forthnet.gr!helios.intranet.gr!demetre
From: [e-mail] (Demetre Koymanakos)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2m QUAD headaches....
Date: 9 Jun 1995 12:46:52 GMT
Organization: Intracom sa, GREECE
Lines: 16
Message-ID: <3r9frs$[e-mail]>
References: <[e-mail]> <3r1men$[e-mail]>
NNTP-Posting-Host: helios.intranet.gr
X-Newsreader: TIN [version 1.2 PL2]

: : I've just spent two days trying to make a good 2m quad, and am quite
: : frustrated!  I was told that no matching device was required when feeding
: : the driven element, and thatn a near 50 ohm impedance would develop if
: : I just opened the square on a side, spaced them, 1/2" apart, and hooked
: : on the braid and center to the two ends.  Nope.

I constructed a two band 2m, 70cm quad, the first with 3 elements, and the
second with 5, the antenna tunned like magic without any matching device, or
SWR over 1.1 in the center of the tunning band ! I even got a 15 Mhz spread !!
The only external device used was a dublexer in order to avoid two feed lines.
I followed the typical construction rules that are found in the ARRL antenna
handbook, and used aluminum wire, and pvc tubing for support.
The Handbook will most propably have most answers to your questions, give
it a try...

73's

From [e-mail] Thu 15 Jun 95 13:15:35
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!swrinde!ihnp4.ucsd.edu!network.ucsd.edu!news-mail-gateway
From: [e-mail] (Hansen, James K (FL40))
Newsgroups: rec.radio.amateur.antenna
Subject: RE: 5-band 4-el quad
Date: 14 Jun 95 01:01:00 GMT
Organization: ucsd usenet gateway
Lines: 20
Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]


>Anybody using commercial 4-el 5-band quad?
>I'm considering to buy Mike's autoelectric 4-el
>5-band quad. Is anybody using this antenna?
>What are Your experiences?
>
>I am particularly interested in mechanical structure,
>because conditions here in Finland can be very icy.
>

A quad antenna definitely does not stand up in bad weather as well as a
yagi.  I think the only people who would argue this fact are the
manufactures because they want to sell you something, or some of the quad
users who are too blinded with love for there antenna to recognize how much
more maintenance they require.  Otherwise, they can perform better than a
yagi of the same boom length and they don't need to be as high in the air.

Jim Hansen
WD0DIA
[e-mail]

From [e-mail] Thu 15 Jun 95 13:15:36
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news.moneng.mei.com!uwm.edu!rutgers!uwvax!newssinet!news.u-tokyo.ac.jp!wnoc-tyo-news!news.join.ad.jp!news.caren.net!sun330.snu.ac.kr!usenet
From: [e-mail] (Sangken Kauh)
Subject: [WTB]20m HF MONO YAGI
Message-ID: <[e-mail]>
Sender: [e-mail] (NEWS POSTER)
Nntp-Posting-Host: 147.46.34.43
Organization: SNU, Mech Engrg Dept
Date: Wed, 14 Jun 95 23:59:51 GMT
Lines:       19

I want to buy 20m HF mono yagi antenna.

There are so many multi band antenna.
For example, tri bander has 20, 15, and 10m bands.
The ad says 8dB of gain.
I want to know all of three bands has 8dB gain.


I am planning to buy 20m HF mono yagi antenna.
I want to obtain high gain on 20m.
I think the gain of mono bander is higher than multi bander on 20m.
Is this correct ??????

Please, let me know which model is suitable for me.

Thanks in advance !!!



From [e-mail] Thu 15 Jun 95 13:15:37
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: antenna for mustang
Date: 13 Jun 1995 02:57:25 GMT
Organization: News & Observer Public Access
Lines: 17
Message-ID: <3riuql$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: grail808.nando.net

[e-mail] (RANDY TRUE) wrote:
>
 > I have an 87 Mustang with a hatchback. I am currently using a Larsen
 > glass mount antenna. Not realy satisfied with the results as compared to
 > a mag mount, but I don't like what the mag mount does to the paint, and I
 > want something more permanent without drilling big holes. I've looked at
 > all the different mounts ( Comet, Diamond, Larsen, Hustler ) and nothing
 > will work because of the way the top lip of the hatch swings when it's
 > opened. Any thoughts?
 >
You can put a poly boot over a mag mount to minimize the paint
scratching, just take a plastic freezer bag, put the magnet inside it,
and secure it with a tightly wrapped rubber band.  Works fine, but
replace it often since the plastic does wear out.  May be worth a try.

73,
Don

From [e-mail] Thu 15 Jun 95 13:15:38
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!uunet!in1.uu.net!ftpbox!mothost!lmpsbbs!NewsWatcher!user
From: [e-mail] (Karl Beckman)
Subject: Re: antenna for mustang
Organization: Motorola LMPS - Pvt Data Sys
Date: Tue, 13 Jun 1995 09:38:49 -0400
Message-ID: <csle87-130695093850@145.39.1.10>
Followup-To: rec.radio.amateur.antenna
References: <[e-mail]> <3riuql$[e-mail]>
Sender: [e-mail] (LMPSBBS News Account)
Nntp-Posting-Host: 145.39.1.10
Lines: 32

In article <3riuql$[e-mail]>, DB Wilhelm <[e-mail]>
wrote:

> [e-mail] (RANDY TRUE) wrote:
> >
>  > I have an 87 Mustang with a hatchback. I am currently using a Larsen
>  > glass mount antenna. Not realy satisfied with the results as compared to
>  > a mag mount, but I don't like what the mag mount does to the paint, and I
>  > want something more permanent without drilling big holes. I've looked at
>  > all the different mounts ( Comet, Diamond, Larsen, Hustler ) and nothing
>  > will work because of the way the top lip of the hatch swings when it's
>  > opened. Any thoughts?
>  >
> You can put a poly boot over a mag mount to minimize the paint
> scratching, just take a plastic freezer bag, put the magnet inside it,
> and secure it with a tightly wrapped rubber band.  Works fine, but
> replace it often since the plastic does wear out.  May be worth a try.
>
> 73,
> Don

Also check the bag periodically and empty out the accumulated water.
(Remember that the top of the bag is open.  Rain will collect there and
rapidly destroy the metal base and loading coil if you forget to drain it
after every rain.  Winter salt slush is FAR more corrosive, eats coax too!)

--

Karl Beckman, P.E.  WA8NVW          <   The value of field experience   >
Motorola LMPS - Fixed Data          <  is directly proportional to the  >
                                    <  price of the equipment damaged.  >
If you agree with the opinions expressed, they're mine. If not, who cares?

From [e-mail] Thu 15 Jun 95 13:15:39
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!uunet!in1.uu.net!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (Foto67)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: antenna for mustang
Date: 13 Jun 1995 08:48:29 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 14
Sender: [e-mail]
Message-ID: <3rk1et$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: newsbf02.mail.aol.com

I have a Comet trunk mt on my T-bird. It's on the trunk lip near the back
window (as you'd expect).

My friend has a Diamond trunk mt. on his (older) T-bird. It's mounted in
relatively the same place.

They both work well and don't interfere with the open/close of the trunk.
What's the difference between this and your hacthback, given that the
hatchback hinges the same as any trunk? Is there more glass back there
than I imagine? Maybe the angles are different. I wish mine was more
verticle, but...

kd6pze


From [e-mail] Thu 15 Jun 95 13:15:40
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From: [e-mail] (N7QPX)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: antenna for mustang
Date: 14 Jun 1995 09:09:58 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 6
Sender: [e-mail]
Message-ID: <3rmn36$[e-mail]>
References: <[e-mail]>
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I just read an article in QST last week.  It said to use rubber baloons
over the mag mount,   The author said that he had been using baloons for a
while and had no problems and they protected the paint.


73 de Merv N7QPX

From [e-mail] Thu 15 Jun 95 13:15:41
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!lamarck.sura.net!dtix.dt.navy.mil!oasys.dt.navy.mil!not-for-mail
From: [e-mail] (Michael Jacobsen)
Newsgroups: rec.radio.amateur.antenna
Subject: Antenna Impedances?
Date: 15 Jun 1995 10:31:19 -0400
Organization: Annapolis Detachment, CARDEROCKDIV, NSWC
Lines: 43
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Michael Jacobsen)
NNTP-Posting-Host: oasys.dt.navy.mil

Recently I became interested in amateur radio and have
been reading various texts on the subject.  I am a bit
confused on a topic involving transmission line
impedances and antenna impedances.

If my understanding is correct, a dipole antenna has a
feed point impedance around 73 ohms when it is at least
1.5 wavelengths above ground.

Does a folded dipole antenna has a feed point impedance
of 300 ohms?  One text shows how to build a cheap
folded dipole to be used as a receiving antenna out of
ordinary 300 ohm flat antenna wire.  Both the antenna
and the feed wire are made from the same material.

It is important to match impedances of the radio, the
transmission line and the antenna.  If the above is
correct, then a dipole should be fed with 75 ohms
coaxial cable, and a folded dipole should be fed with
300 ohm flat antenna wire.  Also appropriate impedance
matching should be done at the radio as well as
transformation from balanced to unbalanced lines.

Now here is the heart of my question.  Applying this
knowledge to things more familiar to me, why do FM
stereo receivers come with dipole antennas that connect
to 300 ohm jacks on the receivers?  While these
antennas are not made with feed line of typical 300 ohm
wire (~1/2 inch separation of the conductors), they do
have parallel conductors (virtually no separation).
Would a folded dipole antenna be a more appropriate
choice for this application?  And if so, are the
manufactures just saving 10 cents or is the advantage
insignificant?  I realize that this topic is much more
critical when transmitting than when receiving.


    Learning But Puzzled,

    Mike Jacobsen    [e-mail]

--


From [e-mail] Thu 15 Jun 95 13:15:41
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!uunet!in1.uu.net!eskimo!usenet
From: [e-mail] (Bill Turner)
Subject: Re: Bare or insulated copper for wire antenna ?
X-Nntp-Posting-Host: tia1.eskimo.com
Message-ID: <[e-mail]>
Sender: [e-mail] (News User Id)
Organization: None
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Date: Tue, 13 Jun 1995 12:59:20 GMT
Lines: 23

In article <3rf5ht$[e-mail]>,
[e-mail] says...
>
>Someone recently said it was crazy to use insulated wire for an antenna.
>I have used insulated copper wire on inverted vee's and longwires for
>years and have had great results on both xmit/rcv.  Have I really been
>missing some great contacts ?  And I thought it was the old sunspot cycle

>all this time !  What do you think ?  Anyone ever do a side by side
>comparison ?
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
I would recommend insulated wire for one reason:  it slows down corrosion.
It does add a small amount of capacitance due to the dielectric effect, so
the resonant frequency will be slightly less, and of course, it is heavier.

Your observations are correct - it works fine.

73, Bill W7LZP
[e-mail]




From [e-mail] Thu 15 Jun 95 13:15:42
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!sdd.hp.com!hpscit.sc.hp.com!icon!hpbs3591.boi.hp.com!bblohm
From: [e-mail] (Bill Blohm)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Bare or insulated copper for wire antenna ?
Date: 13 Jun 1995 17:44:38 GMT
Organization: Hewlett Packard Boise Printer Division
Lines: 15
Message-ID: <3rkiq6$[e-mail]>
References: <3rf5ht$[e-mail]>
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X-Newsreader: TIN [version 1.2 021193BETA PL3]

J.Swenson ([e-mail]) wrote:
: Someone recently said it was crazy to use insulated wire for an antenna.
: I have used insulated copper wire on inverted vee's and longwires for
: years and have had great results on both xmit/rcv.  Have I really been
: missing some great contacts ?  And I thought it was the old sunspot cycle
: all this time !  What do you think ?  Anyone ever do a side by side
: comparison ?

Didn't do a side by side comparison.  But my first antenna I built I built
with transformer wire.  If you've ever tried to remove that insulation, you
know why I didn't.  This was for a 40m dipole antenna.  Seems to work just
fine.

Bill B.
KC7JSD

From [e-mail] Thu 15 Jun 95 13:15:43
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!simtel!harbinger.cc.monash.edu.au!newsserver.trl.OZ.AU!pcies4.trl.OZ.AU!ddiamond
From: [e-mail] (Drew Diamond)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Bare or insulated copper for wire antenna ?
Date: Wed, 14 Jun 1995 10:07:25
Organization: TRL
Lines: 27
Message-ID: <[e-mail]>
References: <3rf5ht$[e-mail]>
NNTP-Posting-Host: pcies4.trl.oz.au
Keywords: copper wire
X-Newsreader: Trumpet for Windows [Version 1.0 Rev Final Beta #7]

In article <3rf5ht$[e-mail]> "J.Swenson" <[e-mail]> writes:
>From: "J.Swenson" <[e-mail]>
>Subject: Bare or insulated copper for wire antenna ?
>Date: 11 Jun 1995 16:27:40 GMT

>Someone recently said it was crazy to use insulated wire for an antenna.
>I have used insulated copper wire on inverted vee's and longwires for
>years and have had great results on both xmit/rcv.  Have I really been
>missing some great contacts ?  And I thought it was the old sunspot cycle
>all this time !  What do you think ?  Anyone ever do a side by side
>comparison ?

Interesting thread. I recall a schoolfriend years ago who had got hold of some
silk covered wire for his antenna. He laboriously removed all the silk
covering, thinking "it would insulate the radio wave".

Anyway, some time ago I did an experiment- an open wire transmission line,
about 50' long of home-made 300 ohm open wire line. Hatfield transformer each
end to convert to 50 ohms for the test equipment. Overall loss, including
xfmrs was (from memory) about 1.5 dB at 100 MHz. Recorded results. Dismantled
transmission line, coiled it up and hung it up outside in the wx to oxidise
etc. About 6 months later did the same measurement. Loss? the same;  1.5 dB.
Conclusion; as far as bright copper vs. old tarnished copper for transmission
lines (and by inference, antennas), there is little or no difference in
performance.

73, Kind Regards, Drew, VK3XU   Telecom Australia Research Laboratories.

From [e-mail] Thu 15 Jun 95 13:15:44
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (WA8MSF)
Newsgroups: rec.radio.amateur.antenna
Subject: Best NMO Mobile Mount???
Date: 13 Jun 1995 14:30:24 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 13
Sender: [e-mail]
Message-ID: <3rklg0$[e-mail]>
Reply-To: [e-mail] (WA8MSF)
NNTP-Posting-Host: newsbf02.mail.aol.com

I am about to punch a 3/4" hole into the roof of an older, but
none-the-less expensive car for a mobile 2m/70cm antenna.  I plan on
having the car for a few more years and don't want the hole to quickly
start rusting.

Does anybody have a recommendation on what maker/style/configuration of
NMO mount would be the most watertight and least panel deforming for this
application?

Any and all practical hints will be gratefully accepted.

Mike
[e-mail]

From [e-mail] Thu 15 Jun 95 13:15:45
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Best NMO Mobile Mount???
Date: 14 Jun 1995 02:17:49 GMT
Organization: News & Observer Public Access
Lines: 24
Message-ID: <3rlgsd$[e-mail]>
References: <3rklg0$[e-mail]>
NNTP-Posting-Host: vyger212.nando.net

[e-mail] (WA8MSF) wrote:
>
> I am about to punch a 3/4" hole into the roof of an older, but
> none-the-less expensive car for a mobile 2m/70cm antenna.  I plan on
> having the car for a few more years and don't want the hole to quickly
> start rusting.
>
> Does anybody have a recommendation on what maker/style/configuration of
> NMO mount would be the most watertight and least panel deforming for this
> application?
>
> Any and all practical hints will be gratefully accepted.

Since rust and watertight seal seem to be your major concerns, you
could cut the hole with a punch or other device that will leave a
clean hole, then seal the cut surfaces with a good quality automotive
primer and paint.  When attaching the antenna, you might use silicone
sealer as a gasket on the exterior side for a weathertight seal.
Make certain that the grounding connection, which must expose the
metal surface, is tightly made on inside of the roof panel.

73,
Don W3FPR


From [e-mail] Thu 15 Jun 95 13:15:46
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From: [e-mail] (WA8MSF)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Best NMO Mobile Mount???
Date: 14 Jun 1995 12:09:06 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 18
Sender: [e-mail]
Message-ID: <3rn1j2$[e-mail]>
References: <3rlgsd$[e-mail]>
Reply-To: [e-mail] (WA8MSF)
NNTP-Posting-Host: newsbf02.mail.aol.com

Thanks for responding Don.

I had figured a chassis punch would leave a cleaner hole with less total
exposed surface area for oxygen to go after.  I'll do this if I can get
the headliner out without going to bodyshop extremes.

I'm under the general impression that NMOs have an O-ring seal under them
that SHOULD take care of the water ingress.  My question should have been
worded to ask if anyone knows of a particular manufacurer or part number
of NMO mount that has a superior construction or superior mechanical
detail for the purposes of minimizing water/rust problems while
maintaining superior electrical/RF function?

What does anybody think?

Gratefully,

Mike - [e-mail]

From [e-mail] Thu 15 Jun 95 13:15:47
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!emory!cssun.mathcs.emory.edu!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Best NMO Mobile Mount???
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3rklg0$[e-mail]>
Date: Wed, 14 Jun 1995 17:18:28 GMT
Lines: 28

In article <3rklg0$[e-mail]> [e-mail] (WA8MSF) writes:
>I am about to punch a 3/4" hole into the roof of an older, but
>none-the-less expensive car for a mobile 2m/70cm antenna.  I plan on
>having the car for a few more years and don't want the hole to quickly
>start rusting.
>
>Does anybody have a recommendation on what maker/style/configuration of
>NMO mount would be the most watertight and least panel deforming for this
>application?
>
>Any and all practical hints will be gratefully accepted.

Make the hole with a drill made for the purpose, radio shops have
them, or use a Greenlee punch. You want a clean hole with no
distortion of the panel. Now get a Larsen NMO mount and install
it according to directions. Remember to put a very light coat of
silicone grease on the O-ring before tightening everything down
snug. That's all you need to do. If you've cut the hole properly,
the NMO will seal properly, and it won't leak. Using goop like RTV
is just a crutch, and if you need it, it means you didn't do the
install right.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Thu 15 Jun 95 13:15:48
Path: grape.epix.net!news.sprintlink.net!pipex!sunic!sunic.sunet.se!seunet!news2.swip.net!news.algonet.se!usenet
From: [e-mail] (Jan Olof Bergsten)
Newsgroups: rec.radio.amateur.antenna
Subject: Broadband dipole, how do I make it ?
Date: Thu, 15 Jun 1995 00:02:13 GMT
Organization: SM7ETW
Lines: 25
Message-ID: <3rntrn$[e-mail]>
NNTP-Posting-Host: sophocles.algonet.se
X-Newsreader: Forte Free Agent v0.55

Hello Everybody

I want to build myself a broadband sw dipole. I know one design is a
folded dipole with a resistor and a balune. Like this...

I------------------------500ohm-------------------------I
I-------------------------I   I--------------------------------I
                          I   I    10:1 balune
                            I
                            I     50 OHM koax


But what should the distance be between the wires ?  And for how many
watts should the resistor be with a 100 Watt transmitter.

What bandwidth can you expect ? And any other useful data.

Or is there a simpler and better ??

73 DE SM7ETW  Jan  near Aneby on the South Swedish Highland

[e-mail]




From [e-mail] Thu 15 Jun 95 13:15:49
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Broadband dipole, how do I make it ?
Date: 15 Jun 1995 10:10:45 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 15
Sender: [e-mail]
Message-ID: <3rpf15$[e-mail]>
References: <3rntrn$[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com

Jan, I don't think the resistor will help at all in a receiving
application. It is the receiver that determines the feedline SWR on
receive. The antenna mismatch only causes a loss in coupling or energy
transfer from the antenna to the feedline.

Puting a resistor across the antenna will not aid in energy transfer at
all, it can only decrease the available signal. I would just use a regular
dipole, a fan dipole with elements for each main band of interest, a bow
tie for the lowest band, or a trap antenna.

In this day of good receivers, the S/N ratio should almost certainly be
established by the area surrounding the antenna, not by coupling of the
antenna to the feedline. I would not be overly concerned about SWR or
matching at the receive antenna, but I would use a good choke type balun
with the antenna.  73 Tom

From [e-mail] Thu 15 Jun 95 13:15:49
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Bruce W. Forsberg)
Subject: Re: Create CLP5130-1 log periodic
Organization: CTS Network Services (CTSNET), San Diego, CA
Date: Tue, 13 Jun 1995 04:16:53 GMT
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[e-mail] (Chris Elmquist) wrote:

>Looking for someone who's running this antenna...   I can't seem to
>find any ads or pictures of it anywhere anymore...  I'm curious if
>it must be mounted at the top of the mast or if it is possible to
>have the mast pass through it ??

I am running the 5130-2 model and have my mast going thru it as I have
a 2M/440 antenna above it. You can do it physically, whether or not it
hurts performance I would not know. I love my create log beam. I use
it to receive 1.2Ghz ATV and transmit 434 MHZ ATV and 2M audio all
with a triplexer at the same time. Works great.

    73's  and Good Luck.    WB6IZG   Bruce


From [e-mail] Thu 15 Jun 95 13:15:50
Newsgroups: rec.radio.amateur.antenna
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From: Brett Coningham <[e-mail]>
Subject: Re: Create CLP5130-1 log periodic
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Hi,
I have one of the Create antennas, and have found out the hard way
that you MUST have a non-metallic mast if you mount it vertically
polarized.  If you mount it horizontally polarized, I don't think
it matters, and yes, the mast can extend through the beam.

73 de Brett AB5P


From [e-mail] Thu 15 Jun 95 13:15:51
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From: [e-mail] (WA6UBE)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Create CLP5130-1 log periodic
Date: 13 Jun 1995 15:40:38 -0400
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I am using the CLP-5130-2 ( I believe )  it is the shortened version that
covers
from 105 to 1300 MHz ..

Great results as far as what I do with it >> see article on my comm
vehicle October 1993 issue of Popular Communications .. <<<

I dropped the thing once and bent the matching coil that is on the back
end of the
antenna, straightened it out as best as could be done in field conditions
and still
pleased with the gain and impedance match .. mine gives me about 1.8 to 1
on the 146, 220, and 440 bands ..   :-)

Patricia Gibbons - [e-mail]
73

From [e-mail] Thu 15 Jun 95 13:15:52
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From: [e-mail] (Jann Larsson)
Newsgroups: rec.radio.amateur.antenna
Subject: Create CLP5130-1 log periodic
Message-ID: <ftn_2.201.339$[e-mail]>
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 > I have one of the Create antennas, and have found out the hard way
 > that you MUST have a non-metallic mast if you mount it vertically
 > polarized.

Couldn't it be mounted on a bar sticking out from the mast? If so, how far from
the mast? Further more, how do I route the coax if it is monted on a
non-metallic mast?

Electronic greetings, Jann

( UUCP Dialup connection )


From [e-mail] Thu 15 Jun 95 13:15:53
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From: [e-mail] (Steve Stroh)
Newsgroups: rec.radio.amateur.antenna
Subject: Diamond vs Comet 2m/222/440 Omni?
Date: 14 Jun 1995 22:09:27 GMT
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I'm interested in buying either the Comet or the Diamond 2m/222/440
tri-band omni base station antennas.  Both seem to have their pros and cons.
I'd like to hear various experiences about both.

My interest is in putting it up and leaving it up for years- I don't mind
spending money up front for a reliable system- Type N connectors, 9913
coax, etc.  Antennas are NOT my thing.  The weather in the Seattle area
is "mostly gloomy"- it'll be wet a lot.

I plan (hope) to mount it on a 50' push up pole.

Comments?


Thanks,

Steve N8GNJ
--

Steve Stroh N8GNJ     [e-mail]
Amateur Radio TCP/IP  [e-mail]

From [e-mail] Thu 15 Jun 95 13:15:54
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From: [e-mail] (Bob Smith)
Newsgroups: rec.radio.amateur.antenna
Subject: G5RV Directional Characteristics
Date: 14 Jun 1995 11:24:58 GMT
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Can someone give me (and the world) a quick understanding of the
directional charactersitics of a G5RV @ various frequencies and @
various heights I figure these are all factors?

Thanks in advance.

--
Bob Smith, Atlanta, GA
[e-mail]
[e-mail]


From [e-mail] Thu 15 Jun 95 13:15:55
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: G5rv Mast material
Message-ID: <[e-mail]>
Date: 13 Jun 95 20:40:33 EST
References: <[e-mail]>
Distribution: world
Organization: LRL, Lilly Research Laboratories
Lines: 55

In article <[e-mail]>, [e-mail] (Claton Cadmus) writes:
> Hello Mike you wrote:
>
>
> MI>My question is what to use for mast material.  I'd rather not use lumber
>   >because the wind in West Jordan, Utah is bad.  I'd rather not use a metal
>   >mast because the ladder line radiates on certain frequencies and doesn't
>   >like to be near metal.
>
> MI>Has anybody ever tried Schedule 40 PVC pipe with wooden reinforcement
>   >inside?  I was at the lumber yard the other day and noticed that 1.25-inch
>   >doweling sold as stair railing is an almost perfect fit inside 1.25-inch PVC
>   >pipe.  Not too expensive.   Not very pretty either.  But it might work.
>
> Windy conditions and feedline radition are both valid concerns.  I have
> use PVC pipe and don't recommend it.  You don't say how high above the
> peak of the house roof you want to get the top of the "V".  For maderate
> heights I'd recommend you use 1x6 and 1x4 knotless wood glued and
> screwed in a "T" configuration.  See end view below.
>
>     _______________________
>    l       1x6             l
>    l_______________________l
>             l     l
>             l 1x4 l
>             l     l
>             l     l
>             l_____l
>
> Make sure you seal and paint this well.  It should last for many years.
>
> Hope this helps,
>
> 73 de  Claton Cadmus,  KA0GKC
>    ______________________________________________________________
>   |     FIDOnet= Claton Cadmus 1:282./100                        |
>   |    INTERnet= [e-mail]                    |
>   |   PACKETnet= KA0GKC@WB0GDB.#STP.MN.USA.NA                    |
>    --------------------------------------------------------------
>
>  * SLMR 2.1a * Is scientific progress suppose to smoke that way?

Another possible non-conducting mast material would be fiberglas reinforced
pipe (such as made by AO Smith or Fibercast). They are available in sizes up to
24 inch diameter. Most are made with continuous fiber thread diagonally
wrapped. Sionce corrosion resistance is not a factor here, you can buy the
cheapest resin pipe and likely get a lot of strength.
Since I have only used it for acid and corrosive piping and not for a mast, I
can't tell you the tensile strength or bending strength, but imagine the
manufacturer could... betcha no warranties when used in mast service.

Mel... KJ9C ([e-mail])

>
>

From [e-mail] Thu 15 Jun 95 13:15:56
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: G5RV mast material
Date: 15 Jun 1995 09:19:37 -0400
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>My question is what to use for mast material.  I'd rather not use lumber
>because the wind in West Jordan, Utah is bad.  I'd rather not use a metal
>mast because the ladder line radiates on certain frequencies and doesn't
>like to be near metal.

Mike,

The feedline does *not* radiate on any band (to any practical extent) with
that antenna unless you tie the feeders together or feed one feeder as a
long wire. In the normal balanced feed (using coax and a choke balun) the
feedline is non-radiating.

Even on 160 (when the antenna may be fed as a "T" and feedline radiation
is purposely created) it would not make any significant difference if the
mast were metal.

I would use a metal mast and simply space the ladder line feedline several
inches away.    73 Tom

From [e-mail] Thu 15 Jun 95 13:15:56
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From: Frank Donovan <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HD-73 rotators
Date: Tue, 13 Jun 1995 20:44:22 -0400
Organization: Southgate Internet Host
Lines: 11
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In-Reply-To: <3rcn0m$[e-mail]>

HD-73 rotators, parts and service are available from:
Norm's Rotor Service
H: 301-698-8168
W: 301-874-5885

On 10 Jun 1995, Billcunn wrote:

> I use to one one   I think the company went out of business  You might
> check AEmateur Electronic Supply co.  they can tell you more
>
>

From [e-mail] Thu 15 Jun 95 13:15:57
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Newsgroups: rec.radio.amateur.antenna
Subject: Hustler 2m collinear opinions
Message-ID: <[e-mail]>
From: [e-mail] (D. Larson)
Date: 14 Jun 95 07:51:18 MDT
Reply-To: [e-mail]
Distribution: world
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I am looking for a good mobile 2m antenna to use with my HTX-202.
I have no linear amplifier so my signal would be no more than 10W.
I am looking at a Hustler CGT144.  It's a collinear, phased 5/8 over
1/4 wave, that measures 7'1" tall (including the base).  It claims
gain of 5.2dB and Tucker is selling it for $45.  It sounds like what
I am looking for (except my better-half doesn't want a 7' antenna on
*HER* Subaru Justy).

My question is does anybody have comments on / experience with this
antenna?  Would it be better with a 6-10W HT to have just a 5/8 wave
whip rather than a collinear?

Thanks for any responses
73
---KC7EGB---
---Donald Larson---
---Laramie Wyoming---

From [e-mail] Thu 15 Jun 95 13:15:58
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Newsgroups: rec.radio.amateur.antenna
Subject: Re: Hustler 2m collinear opinions
Message-ID: <[e-mail]>
From: [e-mail] (D. Larson)
Date: 14 Jun 95 10:21:02 MDT
Reply-To: [e-mail]
References: <[e-mail]>
Distribution: world
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In article <[e-mail]>, [e-mail] (D. Larson) writes:
>I am looking for a good mobile 2m antenna to use with my HTX-202.
>I have no linear amplifier so my signal would be no more than 10W.
>I am looking at a Hustler CGT144.  It's a collinear, phased 5/8 over
>1/4 wave, that measures 7'1" tall (including the base).  It claims
>gain of 5.2dB and Tucker is selling it for $45.  It sounds like what
>I am looking for (except my better-half doesn't want a 7' antenna on
>*HER* Subaru Justy).
>
>My question is does anybody have comments on / experience with this
>antenna?  Would it be better with a 6-10W HT to have just a 5/8 wave
>whip rather than a collinear?
>
I forgot to ask another question...

Whatever antenna I get will likely have a PL-259 that I will replace with
a BNC so since I am already cutting coax, should I cut off the excess?
I won't need nearly 17 feet of it, even though it will be mounted at the rear
of the car.  Will this help reduce SWR or signal loss?

>Thanks for any responses
>73
>---KC7EGB---
>---Donald Larson---
>---Laramie Wyoming---

From [e-mail] Thu 15 Jun 95 13:15:59
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Newsgroups: rec.radio.amateur.antenna
Subject: Re: Hustler 2m collinear opinions
Message-ID: <[e-mail]>
From: [e-mail] (D. Larson)
Date: 15 Jun 95 08:24:18 MDT
Reply-To: [e-mail]
References: <[e-mail]>
 <[e-mail]> <3rnvms$[e-mail]>,<[e-mail]>
Distribution: world
Organization: University of Wyoming, Laramie
Nntp-Posting-Host: plains.uwyo.edu
Lines: 49

In article <[e-mail]>, [e-mail] (Ken Harrison) writes:
>In article <3rnvms$[e-mail]>, DB Wilhelm <[e-mail]> writes:
>> [e-mail] (D. Larson) wrote:
>>  > I forgot to ask another question...
>>  >
>>  > Whatever antenna I get will likely have a PL-259 that I will replace with
>>  > a BNC so since I am already cutting coax, should I cut off the excess?
>>  > I won't need nearly 17 feet of it, even though it will be mounted at the rear
>>  > of the car.  Will this help reduce SWR or signal loss?
>>  >
>> Cutting off any excess will not effect the SWR on the line, although
>> it may change the VSWR reading at the feed end of the line - due to
>> the old effect of "my feedline length tunes my antenna".  It will
>> however reduce your loss since loss comes in dB per foot, the fewer
>> the feet, the less the loss.
>
>But just how much loss are we looking at here?  Since the line is probably
>RG-58U @ 2 meters, with 10 feet lobbed off we would be looking at .6 dB
>(or thereabouts) less loss.  I don't believe that I would be worried about
>that extra .6 dB.  Rather than risk screwing up the VSWR, screwing up the
>BNC installation, etc., just use the stock length of coax.
>
>Oh, and as far as the CG144 goes, I've got one.  I used it on a jeep that
>already had a ball mount from a CB antenna.  That is the only reason I used it.
>I wanted something that would get up higher than the body of the vehicle using
>the existing mount.  I'd recommend a plain old 5/8 wave over the 7 foot tall
>CG144.  I'm planning on converting the CG144 for use as a base antenna with a
>ground plane.
>
>73,
>Ken
>
>---
>
>
>Ken Harrison                  [e-mail]                   Ham:  N6MHG
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>"Show me a man with both feet on the ground and I'll show you a man who can't
>put his pants on."                                          -- Arthur K. Watson
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>

Thanks to everyone who responded here and by e-mail.  I think I have
decided on a Hustler SF-2.  It's a simple 5/8 wave and 3 feet shorter.
I also think I'll leave the stock coax length.

73
---KC7EGB---

From [e-mail] Thu 15 Jun 95 13:16:00
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Rafael Solis)
Subject: Info on Diamond HF Verticals
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: zimmer.csufresno.edu
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Date: Tue, 13 Jun 1995 14:57:00 GMT
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I have the opportunity of buying a Diamond CP-4A HF antenna (10,17,20
and 40 meters).  I know that there is a CP-6 which covers 80 m. also.
Has anyone owned any of these.  I thought Diamond only made UHF/VHF
antennas.

Thanks and 73

Rafael (KE6JSR)



From [e-mail] Thu 15 Jun 95 13:16:01
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From: [e-mail] (Barry Kutner)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Keep Me from Frying My Acura with RF
Message-ID: <[e-mail]>
Date: Thu, 15 Jun 95 11:39:05 GMT
References: <3ro31i$[e-mail]>
Organization: W2UP, Newtown, PA
Lines: 14

I have a 92 Acura Legend, and have had no problems with RF using 25 W on
2 meters. I ran the power leads to the fuse panel (NOT the battery). The
coax runs along the drivers side, under the "edge thing" that you step on
when you enter. Then under the back seat, it goes into the trunk. I am
using a trunk lip mount in the center. Hope this helps...
73

--
=======================================================================
Barry N. Kutner, W2UP       Internet: [e-mail]
Newtown, PA                 Packet Radio: W2UP @ WB3JOE.#EPA.PA.USA.NA
                            Packet Cluster: W2UP >WB2R (FRC)
.......................................................................


From [e-mail] Thu 15 Jun 95 13:16:02
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From: Tony Smithson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Ladder Line Q
Date: 14 Jun 1995 22:56:00 GMT
Organization: Schlumberger
Lines: 19
Message-ID: <3rnpe0$[e-mail]>
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I have access to a >150' tower at my office. I am considering putting my
HF rig here at work.  I don't want to invest a lot of money in Hardline
for an infrequent operating site.

I thought about putting Ladder Line and using a BALUN to match my tuner.
If I use Ladder Line with a 6:1 BALUN should I use 2? One at the antenna
feed point and one at the Rig?

Will the missmatch at the antenna matter? I could see converting 50 to
300 on the LL then 300 back to 50 at the rig but not sure that's
necessary.  For some of you this probably sounds like a dumb question
but any help would be appreciated.  I want to know before I go to the
trouble of asking my boss about intalling the antenna.

Tony,
KN4TX
[e-mail]



From [e-mail] Thu 15 Jun 95 13:16:02
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From: [e-mail] (Gary V. Deutschmann Sr.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: looking for 6m antenna
Date: 14 Jun 1995 02:53:59 GMT
Organization: inlink
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References: <[e-mail]>
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X-Newsreader: TIN [version 1.2 PL2]

How close to St. Louiis do you live?

Gary - N0ZOI


From [e-mail] Thu 15 Jun 95 13:16:03
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From: Graeme Jury <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Loop antenna questions
Date: 13 Jun 1995 00:13:49 GMT
Organization: Taranaki Polytechnic
Lines: 14
Message-ID: <3ril7t$[e-mail]>
References: <3r7p0c$[e-mail]> <3r7qtb$[e-mail]>
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Joe,
I am using a vertical loop which is physically 1 wavelength on
80M. As it is counterpoised above ground it looks like 2 Wav on
80 and so up the bands. It is 50 Ft at one end and 20 ft at the
other and is fed at the 50 ft end. I have been over it with my
bridge and it is in the range 100 to 200 ohm J very little over
the bands 80 to 10. It worksd well I have worked USA England
and many other countries on 80M and regularly use 20 and 15. It
only requires 2 poles and no radials and has the rain static
advantages of loops. I like loops and built a quad on 15 with
circular elements once. This went like a rocket.

73 Graeme ZL2APV


From [e-mail] Thu 15 Jun 95 13:16:04
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Zack Lau (KH6CP))
Subject: Re: Loop antenna questions
References: <3r7p0c$[e-mail]> <3r7qtb$[e-mail]>
Organization: American Radio Relay League
Date: Wed, 14 Jun 1995 11:14:00 GMT
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N5WA wes ([e-mail]) wrote:
: Joe, a 280' horizontal loop antenna should work well on all bands from 80
: thru 10.  I have used one for several years, although mine is longer,
: 560', and higher, 70', yours should work well.  I recommend feeding it
: with open-wire line (ladder line).  Feed it in the center of one side if

Actually, this antenna is one of the best options for a simple
multibander fed with coax and an antenna tuner.  The SWR is often
low enough that additional losses from the signal traversing
back and forth isn't a big deal.  On the other hand, dipoles are
best fed with open wire when you run them on all bands, unless the
feedline is unusually short.  Here the extra losses do become
noticeable.

--
Zack Lau  KH6CP/1           2 way QRP WAS
                           8 States on 10 GHz
Internet: [e-mail]   10 grids on 2304 MHz

From [e-mail] Thu 15 Jun 95 13:16:05
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!news.oz.net!news.lei.net!news.pixi.com!eskimo!usenet
From: [e-mail] (Thomas Liang)
Subject: M2 Eggbeater Antennas
X-Nntp-Posting-Host: tia1.eskimo.com
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Lines: 4

I would any comments on the 2-meter and the 440 mhz M2 eggbeater antennas
on the PACSAT satellites.  Are the extra radial radial kits needed for
better performance?  Is the wave circularity allright?  Thanks.


From [e-mail] Thu 15 Jun 95 13:16:05
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Meter Questions
Date: 14 Jun 1995 09:11:56 -0400
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I'm sorry, I was trying to follow this thread but I couldn't. You guys are
all 45 dB over 9 here but I can't copy through the background noise.
Please repeat.

From [e-mail] Thu 15 Jun 95 13:16:06
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Mixing antenna wires
Date: 13 Jun 1995 02:50:21 GMT
Organization: News & Observer Public Access
Lines: 30
Message-ID: <3riudd$[e-mail]>
References: <3rgqcp$[e-mail]>
NNTP-Posting-Host: grail808.nando.net

[e-mail] (Dave Calhoun) wrote:
>
> I am moving into a new house and will be mounting a TV antenna, a 2m ham
> antenna, and a FM radio antenna. Can any of these antenna wires be
> joined together so that fewer wires will haqve to be run into the house?
> I'm wondering about the TV and the FM radio especially. Thanks for the help,
> dave
> --
> [e-mail]  Public Access User --- Not affiliated with Teleport
> Public Access UNIX and Internet at [phone] (2400-14400, N81)

Check your TV antenna specs to see if it covers the FM band as well.
Most log periodic types do since the FM band is in the middle of
the VHF TV channel set.  This will give you a single feedline for
both.

If you need a high-gain FM antenna (or TV or both) you would do well
to consider separate feedlines for the best performance.  Tying both
antennas together will reduce the performance somewhat.  I have done
this many times in the past, but always had good signal strength
in the areas where I tried it.

I'd suggest you not connect the ham antenna feedline to either antenna
unless you will be diligent to disconnect the TV and Tuner each and
every time you get on the air or you will turn the TV and tuner front
ends into a very crispy state.

73,
Don W3FPR


From [e-mail] Thu 15 Jun 95 13:16:07
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netcom.com!jmsmith
From: [e-mail] (Michael Smith)
Subject: NEC/ELNEC Loc?
Message-ID: <[e-mail]>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
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Date: Tue, 13 Jun 1995 14:21:29 GMT
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I'm looking for NEC/ELNEC or any variants on the net. Is this program
shareware? If so, where can I get it?

Thanks..

73
KE4RJQ
Mike


From [e-mail] Thu 15 Jun 95 13:16:08
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!news.cyberstore.ca!skypoint.com!news3.mr.net!mr.net!news.mr.net!dawn.mmm.com!news
From: US036470@  (Gary Hosler KN0Z)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: NEC/ELNEC Loc?
Date: 14 Jun 1995 21:36:36 GMT
Organization: 3M Company
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In <[e-mail]>, [e-mail] (Michael Smith) writes:
>I'm looking for NEC/ELNEC or any variants on the net. Is this program
>shareware? If so, where can I get it?
>
>Thanks..
>
>73
>KE4RJQ
>Mike
>
ELNEC is a (VERY GOOD) commercial product produced and maintained by
W7EL, Roy Lewallen.  Roy stops by here often and can be reached  at:
[e-mail]


From [e-mail] Thu 15 Jun 95 13:16:09
Path: grape.epix.net!news.sprintlink.net!psgrain!nntp.teleport.com!ip-pdx1-40.teleport.com!w7el
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: NEC/ELNEC Loc?
Date: Thu, 15 Jun 1995 02:10:32
Organization: Teleport - Portland's Public Access [phone]
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In article <[e-mail]> [e-mail] (Michael Smith) writes:

;I'm looking for NEC/ELNEC or any variants on the net. Is this
;program shareware? If so, where can I get it?

NEC is public domain. ELNEC and EZNEC are commercial, copyrighted products and
not shareware. You can get information about them from me.

Roy Lewallen, W7EL
[e-mail]


From [e-mail] Thu 15 Jun 95 13:16:10
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From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Date: 13 Jun 1995 02:18:09 GMT
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In the interest of home (and ham) safety, let me tell you about my
experience earlier tonight.

Funny what happens when you are talking about grounding.  During a
storm yesterday, one of the GFI circuits in the house was tripped.
Problem was that it wouldn't reset, so I went hunting for the cause.
I found a defective outlet, but along the way I also found some other
things that made me shudder - in the first receptacle along the
wiring path, I found an exposed neutral wire that broke when I
examined it.  Having repaired that, I was hoping I was done, but no
such luck, the next outlet on the string had 2 outbound wires from
the outlet box, and there was *no* safety ground wire connecting
to the duplex receptacle and the safety return wires were not
adequately connected together.  Correcting the open ground wire
condition finally lead me to the culprit receptacle on the rear
deck.

What is my point? Simply stated - trust nothing until you have
checked it out.  This is in a recently built house in a community
that *supposedly* has one of the toughest inspection teams in the
area for new structures.  You can be certain that I have a task
ahead of me, and I will not rest comfortably until I have checked
each and every connection point in the electrical system here.

I will also be communicating what I found to the town council and
the building inspection department.  This is the least I can do
for the protection of others as well as myself.

73,
Don W3FPR

From [e-mail] Thu 15 Jun 95 13:16:13
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!swrinde!emory!cssun.mathcs.emory.edu!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3r4qj0$[e-mail]> <[e-mail]> <[e-mail]>
Date: Tue, 13 Jun 1995 18:27:26 GMT
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Xref: grape.epix.net rec.radio.amateur.antenna:11069 rec.radio.amateur.homebrew:7753 rec.radio.amateur.misc:80706 rec.radio.amateur.digital.misc:8917

In article <[e-mail]> [e-mail] (L. M. Rappaport) writes:
>[e-mail] (Gary Coffman) wrote:
>... edited
>>Single point grounding is simple in concept, but often subtle in
>>execution.
>
>  Excellent article.  One question, however:  Assuming you bond
>everything properly like a reverse daisy chain to a single point gound
>at the meter entrance, is it ok to extend that gound by bonding
>multiple ground rods together?  Something like this
>
>     Ground Rod  --------+              +--------Stuff in shack
>                                           |               |
>     Ground Rod ---------+----------+--------Entrance Panel
>                                           |               |
>     Ground Rod ---------+              +--------Tower, etc

Daisy chaining of any sort is generally to be avoided. However,
this is not a daisy chain if I read the diagram correctly. What
you have is a star connected group of grounds (I'm assuming you
left out a couple of |'s in the drawing) that are connected to
a single entrance point. That's a perfectly acceptable way to
do it. IE

      G
      |
  G---x-------------------->house
      |
      G

That's fine. Now, if you were to do this;

G------G------G-----G------G--------->house

That would be Ok too, but not as desirable because of the accumulated
voltage drops in the daisy chain. What you want to avoid is this;


A----G----G----B-----G-----C----G->house
|              |           |--------->
|              |--------------------->
|------------------------------------>

with A, B, and C representing antennas or other external
equipment. Now you have a nasty ground loop through the
chain of G's and that's going to lead to trouble. If you
do this;

A-G    B-G    C-G              G-house
|      |      |------------------->
|      |-------------------------->
|--------------------------------->

This is *real* trouble. Now you're depending on the (poor) conductivity
of Earth to tie the grounds together, and they'll be at wildly different
potentials during a strike. Those potentials will be reflected on the
cables from A, B, and C, and will do big time damage to the station if
not shorted by a ground window.

Now the better way is to do this;

      A---------------------->
      G
      |
 BG===x====================>house
      |
      G
      C--------------------->

B's cable closely parallels the star ground run in the drawing. Since
A, B, and C's grounds are tied in star, they will be at nearly the
same potential. Best, however, would be individual ground runs from
A, B, and C's grounds back to a single common point at the house.
That avoids any ground loops.

Any of the situations that create external ground loops can be
shorted by a ground window at the station entrance. That will
protect the equipment *inside*, but equipment in the external
circuit, preamps, rotators, etc, can still be damaged by the
circulating ground currents. So it's best to avoid ground loops
in the external circuit and always use a star topology.

Remember, for lightning, just having good DC conductivity isn't
enough. In the first place, at 8,000+ amps of surge, even good
conductivity is rarely enough to prevent substantial voltage
drops. More important, however, is that lightning is RF, and
low *impedances*, including reactance, are important to keep
the potential differences at bay. It's always the *difference*
in potential that matters. It doesn't matter if everything
becomes elevated in potential, as long as everything is elevated
to the *same* potential. Star topology is important to make
this happen.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Thu 15 Jun 95 13:16:14
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From: [e-mail] (Bill Blohm)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Followup-To: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Date: 13 Jun 1995 17:23:44 GMT
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Gary Coffman ([e-mail]) wrote:

: A ground window is simple in concept, and simple in execution.
: Basically, it is a physically small conductive plate through
: which *every* cable that enters or leaves your station must
: pass. Every cable that is supposed to be at "ground" potential
: is bonded directly to this plate as it passes through. Every
: conductor that is not supposed to be at "ground" potential
: is bonded to the plate via an appropriate suppressor device.
: (A book could be written on that subject alone.) Then the
: plate is connected to your single point ground by a heavy
: low inductance strap conductor. Now any large potential
: difference that tries to express itself across cables
: connected to various cabinets in your shack will find itself
: shorted out at the ground window.

Question:  Does every cable have to pass _through_ this, or
could this ground window be, for example, a strip of aluminum
along the back of the table (protected from accidental touching,
of course) to which all grounds for all pieces of equipment are
connected?  All the power connections, serial cables, etc. such
as you mention would have their ground connection applied to
this aluminum strip, and that would be connected to the house
grounding system, probably via an outlet box as there are no
pipes in that area to connect to.

Workable?

Bill B.
KC7JSD

From [e-mail] Thu 15 Jun 95 13:16:15
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Path: grape.epix.net!news.sprintlink.net!mv!usenet
From: [e-mail] (L. M. Rappaport)
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Message-ID: <[e-mail]>
Nntp-Posting-Host: lmr.mv.com
Sender: [e-mail] (System Administrator)
Organization: MV Communications, Inc.
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[e-mail] (Gary Coffman) wrote:

...edited

>>     Ground Rod  --------+              +--------Stuff in shack
>>                                           |               |
>>     Ground Rod ---------+----------+--------Entrance Panel
>>                                           |               |
>>     Ground Rod ---------+              +--------Tower, etc

>Daisy chaining of any sort is generally to be avoided. However,
>this is not a daisy chain if I read the diagram correctly. What
>you have is a star connected group of grounds (I'm assuming you
>left out a couple of |'s in the drawing) that are connected to
>a single entrance point. That's a perfectly acceptable way to
>do it. IE

Yes, the idea is the entrance panel is connected to several ground
rods using individual cables and then not only regular house wiring
but also the tower and shack rf wiring goes to the same point.  Like a
big star.  (For some reason I can't draw that)

Where my scheme breaks down at the moment is that the tower has two
individual ground rods and there is one on each of three guy wires.
I'd guess that could cause a loop, eh?

Thanks,

Larry
--
Larry Rappaport W1HJF
[e-mail]
[e-mail]


From [e-mail] Thu 15 Jun 95 13:16:16
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!ihnp4.ucsd.edu!news1.ucsd.edu!nothing.ucsd.edu!brian
From: [e-mail] (Brian Kantor)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Date: 14 Jun 1995 20:34:37 GMT
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Current practice (i.e., what I've seen recently) on mountaintop radio
sites around here seems to be to have replaced the feedthrough ground
plate with a simple grounding bar to which all of the incoming coaxes
are bonded before they enter the building.

I can see that this is simpler and much less prone to water entrance
problems, and it seems to me this might be adequate.

Is this the new practice or did someone just get real lazy?
        - Brian

From [e-mail] Thu 15 Jun 95 13:16:17
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From: [e-mail] (Tovar)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Date: 15 Jun 1995 05:02:08 GMT
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In-reply-to: DB Wilhelm's message of 13 Jun 1995 02:18:09 GMT
Xref: grape.epix.net rec.radio.amateur.antenna:11124 rec.radio.amateur.homebrew:7777 rec.radio.amateur.misc:80806 rec.radio.amateur.digital.misc:8942

    I found a defective outlet, but along the way I also found some other
    things that made me shudder - in the first receptacle along the
    wiring path, I found an exposed neutral wire that broke when I
    examined it.  Having repaired that, I was hoping I was done, but no
    such luck, the next outlet on the string had 2 outbound wires from
    the outlet box, and there was *no* safety ground wire connecting
    to the duplex receptacle and the safety return wires were not
    adequately connected together.  Correcting the open ground wire
    condition finally lead me to the culprit receptacle on the rear
    deck.

    What is my point? Simply stated - trust nothing until you have
    checked it out.  ...

Right!  Folks, (if you haven't done so already) get yourself what some
of us in the computer business refer to as a "Win-Lose" box.  You plug
it into an outlet, and two out of three lights will light up at the same
intensity if things seem to be wired right.  It's not perfect (my own
apartment fails in an odd way, which i recognized by slightly dim light,
which i know is hard to fix, being old enough to be pre-conduit), but
at least you will know what you're up against.  Likewise, if you're
moving into a new building, do yourself a service and go around checking
every outlet so you find out while it's still easy to fix.

        -- KD6PAG  (who is happy not to have learned the hard way...)

From [e-mail] Thu 15 Jun 95 13:16:18
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!swrinde!emory!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3r4qj0$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 14 Jun 1995 14:43:31 GMT
Lines: 22
Xref: grape.epix.net rec.radio.amateur.antenna:11136 rec.radio.amateur.homebrew:7784 rec.radio.amateur.misc:80824 rec.radio.amateur.digital.misc:8949

In article <[e-mail]> [e-mail] (L. M. Rappaport) writes:
>
>Yes, the idea is the entrance panel is connected to several ground
>rods using individual cables and then not only regular house wiring
>but also the tower and shack rf wiring goes to the same point.  Like a
>big star.  (For some reason I can't draw that)
>
>Where my scheme breaks down at the moment is that the tower has two
>individual ground rods and there is one on each of three guy wires.
>I'd guess that could cause a loop, eh?

Connect them in a star at the tower base, and then connect that
point back to the star at the house. A star of stars is an acceptable
topology.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Thu 15 Jun 95 13:16:21
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!ihnp4.ucsd.edu!news.encore.com!psoper
From: [e-mail] (Pete Soper)
Subject: Re: NEED HELP! Respond : Grounding 'Expert
Organization: Encore Computer Corporation
Date: Tue, 13 Jun 1995 20:07:00 GMT
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]>
Sender: [e-mail] (Usenet News)
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[e-mail] (Gary Coffman) writes:

>Let me also address the idea of disconnecting the coax from a
>rig as a form of lightning protection. Now picture your antenna
>being struck by a bolt of lightning that has just travelled miles
>through the open air, do you really think that a few inches of
>air between the disconnected feeder and that nice grounded radio
>is going to stop it? Of course not. You've just brought Mr. Lightning
>into your home and told him to have fun jumping to your radio,
>your electrical outlets, your TV, your plumbing, and *you*.

But back in March:

>In article <[e-mail]> [e-mail] (Ken Schroder) writes:
>[snipped description]
>>When thunderstorms are predicted, I disconnect the coax and the ground
>>entrance cables from the tuner, as well as the coax to the rig and all
>>equipment grounds.  Also, I unplug my AC line surge suppressor from the wall

To which Gary replied Wed, 15 Mar 1995 16:35:10 GMT:

>Given the description of your system, and the fact that you disconnect
>antennas, power, and ground, I'd say you've done a good job. It would
>require a detailed site analysis to determine if your protective system
>would be sufficient to protect the equipment in a strike if it were to
>remain connected. My first cut would be to say it wouldn't because power
>ground isn't tightly coupled to system ground.

Ken again:

>>2) Given the grounding that I have described, how much lightning current is
>>likely to enter the shack on the coax and ground cables which come the wall,
>>assuming that they have been disconnected from everything inside the building?

And Gary:

>None. Disconnecting the cables opens the loop and doesn't offer a path
>for current. However, the *voltage* on the cables can be quite high.
>A ballpark guess would place it in the few thousand volts range. That
>shouldn't be able to arc more than an inch, so as long as you keep the
>cables at least an inch from a conductor, you should be Ok.

In March more than an inch seemed enough gap but more recently you feel
Mr. Lightning might be laughing at a gap of a few inches. Is there any gap
between an unconnected feedline and house wiring ground that is sufficient
to make the situation harmless? How about a near-horizontal gap of five feet
and a vertical gap (down) of 8-15 feet and the assumption that nobody is
between the feedline and the house wiring when the equipment is disconnected?

If the answer is that this would still flirt with a bolt connecting with
the house wiring, what if one more thing was added? This would be to
hook a lightning discharge device (like an Alpha Delta) outside the house
with a ground wire that goes straight down to a ground stake and have the
feedline pass through the discharge unit before going over into the house.
(In my case this is from a balanced antenna with no tower or metalic masts
involved) The feedline would still be disconnected when weather threatened
(and the stake would be bonded to the service entrance ground too). For those
of us who can't implement the "proper" setup you've so thoroughly described would
inside disconnection and an outside ground path be an adequate alternative
to outside disconnection/grounding (or hopefully equivalent from an
electrical standpoint)?

(House among tall trees, on a ridge, in the South. Mr. Lightning loves
 my neighborhood and visits nearby very often :-(  )

-------------------------------------------------------------------------
Pete Soper KS4XG  ([e-mail]) 919 481 3730/voice 919 481 3868/FAX
Encore Computer Corp    901 Kildaire Farm Rd       Cary, NC 27511     USA
                         Four months a ham.

From [e-mail] Thu 15 Jun 95 13:16:23
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: NEED HELP! Respond : Grounding 'Expert
Date: 14 Jun 1995 02:37:31 GMT
Organization: News & Observer Public Access
Lines: 40
Message-ID: <3rli1b$[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
NNTP-Posting-Host: vyger212.nando.net

[e-mail] (Pete Soper) wrote:
>

 > In March more than an inch seemed enough gap but more recently you feel
 > Mr. Lightning might be laughing at a gap of a few inches. Is there any gap
 > between an unconnected feedline and house wiring ground that is sufficient
 > to make the situation harmless? How about a near-horizontal gap of five feet
 > and a vertical gap (down) of 8-15 feet and the assumption that nobody is
 > between the feedline and the house wiring when the equipment is disconnected?
 >
 > If the answer is that this would still flirt with a bolt connecting with
 > the house wiring, what if one more thing was added? This would be to
 > hook a lightning discharge device (like an Alpha Delta) outside the house
 > with a ground wire that goes straight down to a ground stake and have the
 > feedline pass through the discharge unit before going over into the house.
 > (In my case this is from a balanced antenna with no tower or metalic masts
 > involved) The feedline would still be disconnected when weather threatened
 > (and the stake would be bonded to the service entrance ground too). For those
 > of us who can't implement the "proper" setup you've so thoroughly described would
 > inside disconnection and an outside ground path be an adequate alternative
 > to outside disconnection/grounding (or hopefully equivalent from an
 > electrical standpoint)?
 >
 > (House among tall trees, on a ridge, in the South. Mr. Lightning loves
 >  my neighborhood and visits nearby very often :-(  )

There are no easy answers to lightning, except that it is unpredictable.
I have personally seen the results of lightning jumping more than a
6 foot span to find another conductor.  This was on the rain gutter
system of a house - no antennas involved.  This may be an extreme
case, but for me the answer is to provide a low impedance path from
an object likely to be struck directly to ground (or as nearly so
as possible).  Look at good lightning rod installations, noting the
size and path of the conductor for an example of how to accomplish this.
Then after doing the best job you are able, you can still cross
your fingers and hope it is never tested by a direct strike.

73,
Don W3FPR


From [e-mail] Thu 15 Jun 95 13:16:26
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!emory!cssun.mathcs.emory.edu!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: NEED HELP! Respond : Grounding 'Expert
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 14 Jun 1995 17:02:45 GMT
Lines: 145

In article <[e-mail]> [e-mail] (Pete Soper) writes:
>[e-mail] (Gary Coffman) writes:
>>Let me also address the idea of disconnecting the coax from a
>>rig as a form of lightning protection. Now picture your antenna
>>being struck by a bolt of lightning that has just travelled miles
>>through the open air, do you really think that a few inches of
>>air between the disconnected feeder and that nice grounded radio
>>is going to stop it? Of course not. You've just brought Mr. Lightning
>>into your home and told him to have fun jumping to your radio,
>>your electrical outlets, your TV, your plumbing, and *you*.
>
>But back in March:
>
>>In article <[e-mail]> [e-mail] (Ken Schroder) writes:
>>[snipped description]
>>>When thunderstorms are predicted, I disconnect the coax and the ground
>>>entrance cables from the tuner, as well as the coax to the rig and all
>>>equipment grounds.  Also, I unplug my AC line surge suppressor from the wall
>
>To which Gary replied Wed, 15 Mar 1995 16:35:10 GMT:
>
>>Given the description of your system, and the fact that you disconnect
>>antennas, power, and ground, I'd say you've done a good job. It would
>>require a detailed site analysis to determine if your protective system
>>would be sufficient to protect the equipment in a strike if it were to
>>remain connected. My first cut would be to say it wouldn't because power
>>ground isn't tightly coupled to system ground.
>
>Ken again:
>
>>>2) Given the grounding that I have described, how much lightning current is
>>>likely to enter the shack on the coax and ground cables which come the wall,
>>>assuming that they have been disconnected from everything inside the building?
>
>And Gary:
>
>>None. Disconnecting the cables opens the loop and doesn't offer a path
>>for current. However, the *voltage* on the cables can be quite high.
>>A ballpark guess would place it in the few thousand volts range. That
>>shouldn't be able to arc more than an inch, so as long as you keep the
>>cables at least an inch from a conductor, you should be Ok.
>
>In March more than an inch seemed enough gap but more recently you feel
>Mr. Lightning might be laughing at a gap of a few inches. Is there any gap
>between an unconnected feedline and house wiring ground that is sufficient
>to make the situation harmless? How about a near-horizontal gap of five feet
>and a vertical gap (down) of 8-15 feet and the assumption that nobody is
>between the feedline and the house wiring when the equipment is disconnected?

I believe something is missing here.

If I recall correctly what Ken had, he had the coax shield tied to
ground outside, but didn't have a full ground window due to power
still being separate, and wanted to disconnect all the connections
to the rig inside, not just the coax. That way the radio wouldn't be
"grounded", and wouldn't offer a tempting target to which lightning
would want to arc.

With the shield well grounded just outside the shack, which is what
I understood Ken to be saying, only about 8,000 volts, the arc-over
voltage of RG-8, will be inside. But if the shield isn't well grounded
outside, then shield and center conductor can both rise to a large
fraction of the million plus volts of the bolt. Since that can jump
large distances, I don't think there is any practical safe spacing
inside the shack for that condition.

The NEC has recomendations for spacing potentially "live" conductors
inside a structure, but I believe they are far too lenient. I've seen
lightning jump very large distances inside industrial plants where
the NEC said the spacing was OK.

>If the answer is that this would still flirt with a bolt connecting with
>the house wiring, what if one more thing was added? This would be to
>hook a lightning discharge device (like an Alpha Delta) outside the house
>with a ground wire that goes straight down to a ground stake and have the
>feedline pass through the discharge unit before going over into the house.

Bingo! That's the idea, though I wouldn't recomend Alpha Delta as a
generally reliable suppressor due to its internal design (I'll address
why if anyone wants to know). It *will* serve as a shield ground connection,
but so will a barrel connector attached to the ground stake. Note, however,
my caution about *well grounded* in the previous article. During a strike,
a single rod will often saturate the Earth with which it is in contact,
and shield potential can still rise to a high value (at least some tens of
thousands of volts, likely more). You really do need a good ground field
to adequately spread the bolt current to Earth so that saturation won't
occur. (Or a full ground window to equalize potentials. In this latter
case, you don't care as much if the potential rises some tens of thousands
of volts as long as *everything* rises equally.)

>(In my case this is from a balanced antenna with no tower or metalic masts
>involved) The feedline would still be disconnected when weather threatened
>(and the stake would be bonded to the service entrance ground too). For those
>of us who can't implement the "proper" setup you've so thoroughly described would
>inside disconnection and an outside ground path be an adequate alternative
>to outside disconnection/grounding (or hopefully equivalent from an
>electrical standpoint)?

It's not exactly electrically equivalent due to the fact that a single
"ground" usually won't actually stay at a low potential during a strike
(tying that back to the service entrance ground can help, but often not
by much due to inductance in the run to the service entrance ground),
and you've still got a lightning connected conductor coming into the shack.
But it's a lot better than just disconnecting the coax inside *without*
that external ground connection.

>(House among tall trees, on a ridge, in the South. Mr. Lightning loves
> my neighborhood and visits nearby very often :-(  )

Fun isn't it? :-)

In general, you've got to offer lightning a relatively low impedance
alternative path to Earth in order to keep it from dancing a jig inside.
A disconnected *ungrounded* coax in the shack is a bad idea. Grounding
it *inside* isn't a great idea because there will still be large currents
flowing inside the shack, but its usually better than just leaving it loose
and live inside. Grounding it outside the shack is better still because the
large current flows, and their voltage drops, stay mostly outside. Grounding
it at the entrance point with a proper ground window that is tied to an
adequate ground field is much preferred, and with proper suppressors and
topology, can allow you to continue to operate through strikes, but requires
a fair amount of work on your part. It's all a matter of degree, and the
amount of risk you are willing to assume, as to where to stop.

Without a tower to offer an alternative path, your coax from your
dipole is going to be the primary path for lightning to take to
ground. You'd better make sure it has a *good* path outside the
shack. I'd be tempted to run the coax inside via a window so I
could just throw it out in the yard when a storm approached, and
I've operated that way in some places where I couldn't put in a
proper grounding system. The coax still represents a hazard to
people or animals wandering near it in a storm, but I had pretty
good control of that so I wasn't too concerned. I don't consider
that a good permanent solution, however, since I might not be
there when a storm approached, and I wouldn't want to throw the
coax out the window every time I left the house. Some of our
worst lightning storms pop up when the weather forecast calls
for a sunny day.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Thu 15 Jun 95 13:16:27
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (Med Stud)
Newsgroups: rec.radio.amateur.antenna
Subject: Outbacker Antennas
Date: 13 Jun 1995 19:30:16 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 6
Sender: [e-mail]
Message-ID: <3rl728$[e-mail]>
Reply-To: [e-mail] (Med Stud)
NNTP-Posting-Host: newsbf02.mail.aol.com

I'm thinking of getting an Outbacker antenna for my pathfinder.  What is
the general feeling about this antenna.  Is it worth the money?

Thanks in advance

Don, KB7JKA

From [e-mail] Thu 15 Jun 95 13:16:28
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!usc!nic-nac.CSU.net!csulb.edu!paris.ics.uci.edu!not-for-mail
From: [e-mail] (Clark Savage Turner)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Outbacker Antennas
Date: 14 Jun 1995 08:12:51 -0700
Organization: UC Irvine Department of ICS
Lines: 21
Message-ID: <3rmu9j$[e-mail]>
References: <3rl728$[e-mail]>
NNTP-Posting-Host: safety.ics.uci.edu

In <3rl728$[e-mail]> [e-mail] (Med Stud) writes:

>I'm thinking of getting an Outbacker antenna for my pathfinder.  What is
>the general feeling about this antenna.  Is it worth the money?

Hi Don:

Best to talk to guys on the air who mobile a lot.  Some of the truckers
on HF have been through several mobile HF antenna systems.  I know
that the Outbacker is very convenient and rugged.  It works.
However, every comparison I have heard made with the Bugcatcher
shows the Bugcatcher gets out more RF into the air.  It is far
uglier and more difficult to maintain.  My guess is that the tradeoff
is whether you want another couple of db into the air, or heat
dissipated into the better looking antenna :-) .

I use the simple little ham stick, which does fine and is even easier
and cheaper, though not very durable.  I am working on my own bugcatcher.

Clark
WA3JPG

From [e-mail] Thu 15 Jun 95 13:16:29
Path: grape.epix.net!news.sprintlink.net!uunet!solaris.cc.vt.edu!news.netins.net!mcrware.microware.com!dennisg
From: [e-mail] (Dennis Gabler)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Outbacker Antennas
Date: 15 Jun 1995 15:54:03 GMT
Organization: Microware Systems Corporation, Des Moines, Iowa
Lines: 9
Message-ID: <3rpl2r$[e-mail]>
References: <3rl728$[e-mail]>
NNTP-Posting-Host: wahz.microware.com
X-Newsreader: NN version 6.5.0 #5 (NOV)

In <3rl728$[e-mail]> [e-mail] (Med Stud) writes:

>I'm thinking of getting an Outbacker antenna for my pathfinder.  What is
>the general feeling about this antenna.  Is it worth the money?

I like mine.  It is rugged and convenient but of course is not as efficient
as a Bugcatcher.  Bugcatchers don't take well to Iowa winters so I went with
the Outbacker.  So far it performs well enough for my needs.


From [e-mail] Thu 15 Jun 95 13:16:30
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!EU.net!uunet!in1.uu.net!iglou!iglou.iglou.com!n4lq
From: [e-mail] (Steve Ellington)
Subject: PARALLEL 95 OHM COAX LOSS?
X-Nntp-Posting-Host: iglou.iglou.com
Message-ID: <[e-mail]>
Sender: [e-mail] (News Administrator)
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Date: Tue, 13 Jun 1995 00:58:10 GMT
Lines: 14

I plan on using a pair of RG62 (95 ohm) coax cables in parallel to obtain
50 ohms or at least close enough. The reason is because I have an
abundant supply of this stuff, being in the computer business.
Experimenting, I cut two 50ft lengths and fed my dummy load. The SWR was
near 1:1 on all frequencies therefore my theory was correct.

Now the question I have is this. Is my total feedline loss 1/2, twice or
the same as a single piece of coax? I don't have the equipment here to
measure it.
--
Steve Ellington
6900 Sunny Vale Way
Louisville, Ky 40272
E Mail   [e-mail]

From [e-mail] Thu 15 Jun 95 13:16:30
Path: grape.epix.net!news.sprintlink.net!ratty.wolfe.net!news.net99.net!news.rtd.com!news.azstarnet.com!usenet
From: Wes Stewart <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 13 Jun 1995 03:50:30 GMT
Organization: Arizona Daily Star - AZSTARNET
Lines: 15
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References: <[e-mail]>
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To: [e-mail]

[e-mail] (Steve Ellington) wrote:

stuff deleted

>Now the question I have is this. Is my total feedline loss 1/2, twice or
>the same as a single piece of coax? I don't have the equipment here to
>measure it.

To the first order, one-half. The losses are predominately due to center conductor resistance,
which is essentially halved by the parallel lines.

Have at it.

73, Wes, N7WS


From [e-mail] Thu 15 Jun 95 13:16:31
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!sdd.hp.com!hpscit.sc.hp.com!rkarlqu
From: [e-mail] (Richard Karlquist)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 13 Jun 1995 17:24:15 GMT
Organization: Hewlett-Packard
Lines: 29
Message-ID: <3rkhjv$[e-mail]>
References: <[e-mail]> <3rj1u6$[e-mail]>
NNTP-Posting-Host: hpscrj.scd.hp.com

In article <3rj1u6$[e-mail]>,
Wes Stewart  <[e-mail]> wrote:
>[e-mail] (Steve Ellington) wrote:
>
>stuff deleted
>
>>Now the question I have is this. Is my total feedline loss 1/2, twice or
>>the same as a single piece of coax? I don't have the equipment here to
>>measure it.
>
>To the first order, one-half. The losses are predominately due to center conductor resistance,
>which is essentially halved by the parallel lines.
>
>Have at it.
>
>73, Wes, N7WS
>

Wrong (clever "intuitive" argument though).

The db. loss of two 95 ohm lines in parallel in a 47.5 ohm system is
the same as the db. loss of one 95 ohm line in a 95 ohm system, which
is probably 10 or 20% higher than a 50 ohm coax of similar OD, depending
on dielectric.

Why is this?  Well, the resistance is halved, but the current increases
by root 2, because of halving Z-zero.  Same I^2*R losses.

Rick Karlquist, N6RK,  [e-mail]

From [e-mail] Thu 15 Jun 95 13:16:32
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 14 Jun 1995 13:42:25 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 15
Sender: [e-mail]
Message-ID: <3rn721$[e-mail]>
References: <3rkhjv$[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com

Perhaps another way of looking at this would help. If the HF loss in a
single cable of unit length is 3 dB , half the power is lost. If two such
cables are paralleled, the power applied to each cable is half as much so
each cable dissipates 1/4 of the total applied power, for a net
dissipation of half the applied power! So the losses are the same.

But the conductor arguement is true at very low frequencies where
conductor resistances dominate if the impedance of the load remains the
same.  At very low frequencies or dc, where the conductor losses dominate,
the losses are half as much when two conductors are paralleled when the
ratio of voltage to current remains the same. If the ratio of voltage to
current is adjusted to match the new parallel line impedance the losses
will remain the same.

Isn't this a confusing question?  73 Tom

From [e-mail] Thu 15 Jun 95 13:16:33
Path: grape.epix.net!news.sprintlink.net!psgrain!nntp.teleport.com!ip-pdx1-40.teleport.com!w7el
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: Thu, 15 Jun 1995 02:06:58
Organization: Teleport - Portland's Public Access [phone]
Lines: 21
Message-ID: <[e-mail]>
References: <3rkhjv$[e-mail]> <3rn721$[e-mail]>
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X-Newsreader: Trumpet for Windows [Version 1.0 Rev A]

In article <3rn721$[e-mail]> [e-mail] (W8JI  Tom) writes:
;From: [e-mail] (W8JI  Tom)
;Subject: Re: PARALLEL 95 OHM COAX LOSS?
;Date: 14 Jun 1995 13:42:25 -0400

;. . .

;But the conductor arguement is true at very low frequencies where
;conductor resistances dominate if the impedance of the load remains the
;same.  At very low frequencies or dc, where the conductor losses dominate,
;the losses are half as much when two conductors are paralleled when the
;ratio of voltage to current remains the same. . .

The conductor loss dominates not only at very low frequencies, but up to 1 GHz
or more for most types of coax.

My vote: The loss is 1/2 the loss of a single piece of the high-Z coax.

73,
Roy Lewallen, W7EL


From [e-mail] Thu 15 Jun 95 13:16:34
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From: [e-mail] (Bill Blohm)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Plans for 2m Ground plane?
Date: 13 Jun 1995 17:36:48 GMT
Organization: Hewlett Packard Boise Printer Division
Lines: 12
Message-ID: <3rkibg$[e-mail]>
References: <3r7h2j$[e-mail]> <3r8sa5$[e-mail]>
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Phil Rose ([e-mail]) wrote:
: With the one I built, I used brazing rods for the monopole and radials.
: However, it's not particularly waterproof as the connector is mounted
: exposing the works to  the sky. Therefore it's an ideal indoor antenna.

Brazing rod for the vertical, aluminum rods for the radials in mine.
For waterproofing, I put a mass of Silicone rubber on the exposed parts
of the connector.  The other end to which the feedline connects is under
an aluminum plate and so needs no protection.

Bill B.
KC7JSD

From [e-mail] Thu 15 Jun 95 13:16:35
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!news.sinet.slb.com!news
From: Tony Smithson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Power Lines and HF
Date: 14 Jun 1995 22:51:21 GMT
Organization: Schlumberger
Lines: 26
Message-ID: <3rnp59$[e-mail]>
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Thanks for reading this. I am considering buying a house not too far out
in the country but not in the city.  The house is new construction.
Next to the lot on which the house sits is a large high tension power
line. I don't know the voltage but there are 3 parallel poles with 6
pairs of wires (additional ground wires as well.)

The power line is about 300 feet from my potential antenna site and
about 75-100 feet tall.  I can put a 75' tower up and not fear it
falling on the power line.=0C

What I would like to know is, other than the potential line noise, what
will be the effects on reception?  Will the power line hurt me much on
HF? How much?

I'm sure someone out there has experience living near a power line such
as this and your input would be appreciated (before I buy a house that
puts me off the air.

You can post here or to my E-mail address:
[e-mail]

Tony, KN4TX

BTW - No response on R.R.A.Misc



From [e-mail] Thu 15 Jun 95 13:16:36
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From: [e-mail] (Gary Burchett)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Power Lines and HF
Date: Thu, 15 Jun 95 13:52:32 GMT
Organization: University of Alberta
Lines: 11
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References: <3rnp59$[e-mail]>
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>I'm sure someone out there has experience living near a power line such
>as this and your input would be appreciated (before I buy a house that
>puts me off the air.
>Tony, KN4TX

    I live beside a major power corridor into the city.  160 and 80 are solid
S9 noise, worse when it rains.  40 and up are not too bad, but arcing
insulators in high humidity sometimes affects them also.  I do my DX at a temp
location in the country, very quiet there.
Gary, VE6BBD

From [e-mail] Thu 15 Jun 95 13:16:37
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From: [e-mail] (Robert Smits)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quagi difficulties.
Message-ID: <[e-mail]>
Date: Mon, 12 Jun 1995 21:17:00 PST
References: <[e-mail]> <3rg3et$[e-mail]>
Reply-To: [e-mail]
Distribution: world
Organization: The Curmudgeon's Cottage
X-Newsreader: Rnf 0.79b6
Lines: 31

DB Wilhelm <[e-mail]> writes:

>You should be in the ballpark of 50 to 80 ohms at the feedpoint which
>should give no more than a 1.6 VSWR, at the antenna input.  I haven't
>done any calculations to see what say 80 ohms at the feedpoint will
>yield in apparent VSWR at the transmitter end of 20 feet of RG58.
>
>You might try putting your vswr meter right at the antenna terminals
>to see what you get (staying out of the field yourself), or as an
>better alternative use an antenna analyzer if you can get one.
>
>I would suggest a quick test of your feedline, set up an inverted vee
>at 144.5 and connect the feedline to it, then see what your VSWR is.
>It should be no greater than 1.5.  If it also is very high, you can
>suspect your feedline even though it is new and looks good.
>

Done it. Still high, although SWR came down with trimming the dipole.

On replacing the entire coax run from the antenna to the SWR meter, the
SWR came down VERY substantially - to about 1.8 to 1.

I'll look at it some more in the daylight tomorrow, but this seems to be
the problem, even though checking the original coax by terminating it with
a dummy load seemed to indicate it was fine.

Thanks, Bob.

--
[e-mail] (Robert Smits)


From [e-mail] Thu 15 Jun 95 13:16:38
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!usc!math.ohio-state.edu!news.cyberstore.ca!vanbc.wimsey.com!unixg.ubc.ca!news.bc.net!news.island.net!ham!rsmits
From: [e-mail] (Robert Smits)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quagi difficulties.
Message-ID: <[e-mail]>
Date: Mon, 12 Jun 1995 21:22:00 PST
References: <[e-mail]> <3rh7dm$[e-mail]>
Reply-To: [e-mail]
Distribution: world
Organization: The Curmudgeon's Cottage
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[e-mail] (W. E. Van Horne) writes:

>Robert Smits ([e-mail]) wrote:
>
>: Upon actually building such an antenna I get very high SWR ratios. I think
>: I've tried a lot of possible solutions, but have obviously missed
>: something.
>
>As you describe it, it should work.  Since it apparently does not, check
>all aspects of what you are doing.  For example, how are you measuring
>the SWR?
>
>I have an MFJ-249 antenna analyzer, and had a problem with a simple HF
>dipole.  I couldn't get the indicated SWR below 3:1, although there was a
>clear dip at the resonant frequency (i.e. the SWR measured infinity away
>from resonance, but no lower than 3:1 at resonance.)  The next issue of
>QST that arrived a few days later contained the explanation.  The
>instrument does not contain a high-pass filter in the input circuit, so
>it responds to local broadcast signals.  The pickup of from a broadcast
>band signal in my area, on a 20-meter dipole, was sufficient to drive the
>meter to 3:1 indication on ALL frequencies throughout the HF spectrum!

Thanks for the advice, Van. It does seem to be related to the coax feed I
used, since replacing it with a run of RG-8 saw the SWR drop immediately
to about 1.8:1. The original coax was new, had good silver PL-259s,
measured OK with an ohmmeter, AND when using it to feed a dummy load.

Live and learn, I guess.

73, Bob, VE7HS

--
[e-mail] (Robert Smits)

THOSE WHO KNOW

Those who always
know what's best
are
a universal pest.

   - Piet Hein

From [e-mail] Thu 15 Jun 95 13:16:39
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!uunet!in1.uu.net!pgh!cliff
From: [e-mail] (Cliff Frescura)
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Message-ID: <[e-mail]>
Date: Tue, 13 Jun 1995 02:26:31 GMT
References: <3rf6tn$[e-mail]> <3ri8k5$[e-mail]>
Organization: Nauticom - Internet Access Provider
Lines: 57

In article <3ri8k5$[e-mail]> [e-mail] (jbmitch) writes:
>In article <3rf6tn$[e-mail]>, "J.Swenson" <[e-mail]> says:
>>
>>I would like to put up some Rohn-25 with a 6 element uagi without guys if
>>possible.  I have 2 house brackets.  Someone said 30' over the last one
>>is ok.  Is this right?
>>
>quoting from the Rohn book: "The extra strength of the No. 25G allows it
>to be self-supporting providing a house bracket is used, and under normal
>conditions the 25G can rise 35 feet above this bracket."  Nonetheless, it
>depends on the size of the antenna you're mounting. If it's 6 elements on
>HF, like a TH6, or Pro-57, etc., I wouldn't be comfortable going more
>than 10-15 feet above the highest house bracket.  Consult professionals
>in your area, such as commercial tower installers. Good luck and be
>careful.

Here's what I know works:

Dig a hole in the ground, approx 1.5ft x 1.5ft x 6ft deep.
Fill the bottom 6 inches with pea gravel.
Insert one 25G straight section into the hole
   (there is a top and bottom to each section ;-) )
Call the "mud" truck.  You'll need about one yard.
Jog section in wet mud until it is vertical.
Wait about 1-2 weeks.
Add two straight sections and top section.
You now have a 35' tower (+/-).

I have a three element tribander on the top of this tower with no guys.
This installation survived hurricane Hugo (100mph winds).  Though I could
see the tower sway a bit!

When I moved from NC to PA I disassembled the tower and hacksawed off
the bottom 5 feet.  The base looked fine, both inside of the legs and
outside of the legs.

I put up a second tower using this same method and thought I would try
three staight sections and one top section.  At the top of the 3rd
straight section I felt there was too much sway to think about adding the
top section and removed the third straight section.

This seems to fit the data in the Rohn Handbook.

Caveat Emptor:
I would not put any antenna on the tower that was more than a 3 element
tribander (A3S variety).  I would never go higher than 35 feet.  I would
only use NEW tower sections.  The soil composition will determine what
you can do.  The last two feet of the hole are the hardest.  Don't stop.
Enter at your own risk.

73,
Cliff K3LL
--

+--------------------------------------------------------------------------+
|[e-mail]                      K3LL @ W3UDX.#WPA.PA.USA.NOAM |
| [e-mail]                      "Adapt, Migrate, or Die."     |

From [e-mail] Thu 15 Jun 95 13:16:40
Path: grape.epix.net!news.sprintlink.net!nwfocus1.wa.com!nwfocus.wa.com!krel.iea.com!comtch!n0dh
From: [e-mail] (D.C. Henderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Date: 13 Jun 1995 15:59:57 GMT
Organization: CompuTech, Spokane WA
Lines: 26
Message-ID: <3rkclu$[e-mail]>
References: <3rf6tn$[e-mail]>
NNTP-Posting-Host: comtch.iea.com
X-Newsreader: TIN [version 1.2 PL1]

J.Swenson ([e-mail]) wrote:
: I would like to put up some Rohn-25 with a 6 element uagi without guys if
: possible.  I have 2 house brackets.  Someone said 30' over the last one
: is ok.  Is this right?

I'm no0t sure what a "6 element uagi" is?? How many square feet of wind
loading???  I ran 40 feet of Rohn 25 unguyed with a house bracket at the
9' point, 3'x3'x5' concrete base, for over 10 years in Melbourne, FL.
Antenna was Cushcraft A4 tribander and a 7 element 2 meter beam. Survived
gusts estimated to 70 mph in heavy rain. I did put temporary guys on it
whenever a real hurricane came to town however. My guess is as long as
you stay below about 6 square feet of antenna you should be ok. By the way
you should always use temporary guys when working and climbing on the
thing !!!!!!

Contrary to an earlier posting Rohn does (or used too) rate the 25 series
to 30' without guys and to 40' with a house bracket and no guys. I don't
remember what the antenna wind loading was but it was less than 6 sq ft
I'm sure. If this 6 element uagi is a 6 element HF yagi then guy it or
get some rohn 45 (which is rated to 50' unguyed with a house bracket.)

Once the winds get above 75 MPH all bets are off! Guyed, unguyyed, laying
on the ground! Been there done that!

Dave
N0DH/7

From [e-mail] Thu 15 Jun 95 13:16:41
Path: grape.epix.net!news.sprintlink.net!uunet!in1.uu.net!holmes.sgate.com!holmes.sgate.com!donovanf
From: Frank Donovan <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Date: Thu, 15 Jun 1995 06:20:26 -0400
Organization: Southgate Internet Host
Lines: 32
Message-ID: <[e-mail]>
References: <3rf6tn$[e-mail]>
NNTP-Posting-Host: holmes.sgate.com
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
In-Reply-To: <3rf6tn$[e-mail]>


U failed to mention what band this six element Yagi is for!
It makes a big difference if its a 20 meter 6 element Yagi!

The 1991 Rohn Catalog says "the Rohn 25G can rise 35 feet above this
bracket."  This assumes u follow the requirementss in the Rohn drawing
for installation of bracketed towers and do not exceed the allowable
antenna area.  In the example cited above, the allowable antnna area is only
1.7 sq ft at 70 mph  (very few areas of the country are safe for only 70 mph
designs).  If u reduce the tower height to 24 feet above the bracket u shud
be good for 6.8 sq ft at 70 mph, but only 4.9 sq ft at 80 mph.  At 14 feet
above the bracket u start to be able to safely handle small HF tribanders:
13.5 sq ft at 70 mph, 8.3 sq ft at 80 mph and 5.5 sq ft at 90 mph.  If
u reduce the height above the bracket to 10 feet, the antenna areas increase
to 15.3, 11.3 and 7.7 sq ft at 70,80 and 90 mph.

I strongly suggest u get urself a current Rohn catalog!

73!
Frank
W3LPL



On 11 Jun 1995, J.Swenson wrote:

> I would like to put up some Rohn-25 with a 6 element uagi without guys if
> possible.  I have 2 house brackets.  Someone said 30' over the last one
> is ok.  Is this right?
>
>
>

From [e-mail] Thu 15 Jun 95 13:16:43
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!EU.net!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!ncar!uchinews!internet.spss.com!pagesat.net!sloth!news
From: Brett Coningham <[e-mail]>
Subject: Re: Rotating Antenna for Hidden Transmitter
Content-Type: text/plain; charset=us-ascii
Message-ID: <[e-mail]>
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Lines: 25

To those who've asked about how I plan to feed this antenna while
it's rotating, here's what I've built so far.
I took the driven element from a Cushcraft 147-4 4-element beam;
this element is 1/2" in diameter, with a 3/8" inner diameter. I
mounted it vertically into a wooden tripod, which is drilled
through the center with a 3/8" hole, except for the top 3/4"
which is 1/2" wide.  The element sits very snugly in the top
part of the hole.  Now, I built the rest of the three elements
from light aluminum wire (clothsline wire), and HUNG them from
a light 1/2" x 1/2" wood strip, at the same element spacing as
the original beam. This strip is supported by a thin fiberglass
rod which runs down THROUGH the driven element to the ground,
or baseplate.  The result is a four-element beam with the same
ele. spacing as the original beam, but the non-driven elements
can rotate around the driven element.  Pretty neat, eh?   One
devious characteristic of this is that the elements tend to
swing in the breeze, changing the signal strength at random,
which should make it even harder for the hunters to get a
steady signal to home in on.
Everything is ready for some kind of motor to drive it.
Thanks for all the suggestions so far, you've given me some
ideas to go looking for motors with.
73 de Brett AB5P
[e-mail]


From [e-mail] Thu 15 Jun 95 13:16:43
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!nntp.crl.com!pacbell.com!pb2esac!jaminge
From: [e-mail] (John Minger)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rotating Antenna for Hidden Transmitter
Date: 14 Jun 1995 22:39:51 GMT
Organization: Pacific Bell, ESAC
Lines: 17
Message-ID: <3rnofn$[e-mail]>
References: <[e-mail]> <[e-mail]>
NNTP-Posting-Host: pb2esac.esac.pacbell.com
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In article <[e-mail]>, Brett Coningham  <[e-mail]> wrote:
>To those who've asked about how I plan to feed this antenna while
>it's rotating, here's what I've built so far.
>
(edited..)

Isn't it interesting to note how many folks thought this antenna
was for the T-Hunting receiver, and not the "Fox".
Nasty little idea though....

-John


--
John Minger  KE6DTC                        "Society is like a stew.  If you
Glendale, CA                            don't keep it stirred up, you get a
<[e-mail]>                   lot of scum on top."  -Edward Abbey

From [e-mail] Thu 15 Jun 95 13:16:44
Path: grape.epix.net!news.sprintlink.net!nntp.sunbelt.net!udel!rochester!casaba.srv.cs.cmu.edu!fore.com!not-for-mail
From: [e-mail] (Ed Bathgate)
Newsgroups: rec.radio.amateur.antenna
Subject: Rotator wire multiband antenna
Date: 15 Jun 1995 10:21:55 -0400
Organization: FORE Systems, Inc.
Lines: 19
Message-ID: <3rpfm3$[e-mail]>
NNTP-Posting-Host: baleen.fore.com
X-newsreader: xrn 7.03



A while back somebody posted a design of a multiband dipole made of
flat 5 wire rotator cable.  Does this design work?  What were the lengths
of the sides?

73

Ed  N3SDO

--------------------------------------------------------------------------
Ed Bathgate                                   Email: [e-mail]
Senior Test Technician                        Ham: N3SDO
FORE Systems Inc                              N3SDO@W3IXR.#WPA.USA.NOAM
Pittsburgh PA USA                             R/C pilot nickname "Crasher"

The opinion expressed above is mine, and should not reflect the policy
of my employer.
-------------------------------------------------------------------------

From [e-mail] Thu 15 Jun 95 13:16:45
Path: grape.epix.net!news.sprintlink.net!news.clark.net!usenet
From: [e-mail] (Richard Todd Perry)
Newsgroups: rec.radio.amateur.antenna
Subject: RS discone
Date: 13 Jun 1995 04:08:05 GMT
Organization: Clark Internet Services, Inc.
Lines: 14
Message-ID: <3rj2v5$[e-mail]>
NNTP-Posting-Host: perryrt.clark.net
Mime-Version: 1.0
X-Newsreader: WinVN 0.93.11

Has anyone used the Radio Shack Discone? I'm thinking about getting it for my
dual bander (2m/440) FM rig, since my old J-pole is falling apart
(literally!). I'm interested if anyone has comments for or against. Is it
worth the $60? Thanks!


--
                        Regards,
                        R. T. Perry
                        KB2JAC
                        GMOO
- The world is divided into two groups of people: Those that own HP's
and those that yell "HEY! Where's the equals sign?"


From [e-mail] Thu 15 Jun 95 13:16:46
Path: grape.epix.net!news.sprintlink.net!pipex!howland.reston.ans.net!news.starnet.net!wupost!news.inlink.com!vulcan.inlink.com!raiar
From: [e-mail] (Gary V. Deutschmann Sr.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: RS discone
Date: 14 Jun 1995 02:57:17 GMT
Organization: inlink
Lines: 16
Message-ID: <3rlj6d$[e-mail]>
References: <3rj2v5$[e-mail]>
NNTP-Posting-Host: vulcan.inlink.com
X-Newsreader: TIN [version 1.2 PL2]

I have one, it's OK, but not really great.  A J-Pole outshines it by a mile.
It's a great scanner antenna thouugh!

If you want to hook RG-8 or better up to it, it may suffice on 440, but
el-zilcho using anything less.

Since it only costs about 7 bucks to build a new J-Ple and only takes about
2 hours including wireing, I'd go that route.

Gary - N0ZOI

If you need plans, e-mail me and I will get them to you, for a multi-band
J-Pole.

Gary


From [e-mail] Thu 15 Jun 95 13:16:47
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!news.ti.com!goldengate!nlb1
From: nlb1@goldengate (Nicholas L. Barbieri)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: RS discone
Date: 15 Jun 1995 17:06:49 GMT
Organization: Texas Instruments
Lines: 20
Message-ID: <3rppb9$[e-mail]>
References: <3rj2v5$[e-mail]> <3rlj6d$[e-mail]>
NNTP-Posting-Host: sanjose.rtc.sc.ti.com
X-Newsreader: TIN [version 1.2 PL2]

I've had one up for a few years now.  I feed it with RG8X, and it works
satisfactorily on 2m and 440.  I also use it occasionally with my Bearcat
handheld scanner.  My main reason for choosing it was that I only needed
one antenna for all my VHF/UHF rigs (I have 5).  The gain is not that
great, though.  It is up about 35 feet, so I don't have many problems
hitting the local packet nodes up to 60 miles away.  I bought a dual
band Cushcraft vertical some time back, and eventually plan to replace
the discone with it.  My only complaint is that the coax connector is
in the center of an 8 inch tube in the middle of the antenna, making it
impossible to remove the coax without removing three tiny screws and
the tube.  Otherwise, it is reasonalbly well built, and I may leave it
up as an alternate antenna when I finally put up the vertical.

BTW, the SWR is flat on 2m and 440.  I run 50 watts on both bands.

--
Nicholas L. Barbieri                            Amateur Radio: KB6QI
Texas Instruments
San Jose, CA, USA
email: [e-mail]

From [e-mail] Thu 15 Jun 95 13:16:48
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!uunet!in1.uu.net!news.ssd.intel.com!chnews!vegas.ch.intel.com!cmoore
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: SGC-230 auto tuner
Date: 13 Jun 1995 05:40:25 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 30
Distribution: world
Message-ID: <3rj8c9$[e-mail]>
NNTP-Posting-Host: vegas.ch.intel.com
Originator: [e-mail]

There is a review of the SGC-230 automatic antenna tuner
in the June 73 written by Gordon West, WB6NOA. He pretty
much says the SGC-230 is not good for mobile work. I must
take issue with his statements. It is true that the SGC-
230 would not work well in the trunk of a car. But since
it is weatherproof, there is absolutely no reason to put
it in the trunk. It is true that the SGC-230 doesn't work
well with coax on the output so just don't use coax on
the output. If it hurts to do that, then don't do that.

I have the SGC-230 mounted on a 5/8 inch rod that is
grounded through the trailer hitch hole in my S10 rear
bumper. A standard mobile antenna mount sits atop the
grounded rod. A 2 inch piece of RG-8 inner conductor (no
braid) runs from the SGC-230 to the 13 ft whip which is
close to a resonant quarter-wave on 17m. It works great
on 20m and has gain over a resonant quarter-wave on 15m,
12m, and 10m. If you don't have a trailer hitch, the rod
can be clamped and grounded to the bumper of a car.

The SGC-230 makes a darn good mobile antenna tuner. Loading
into that 13 ft whip, it is only one 'S' unit down from a
bugcatcher on *40m*. Saying the SGC-230 is not a good mobile
antenna tuner is throwing out the baby with the bath water.

Gordon, I hope you are listening. We're hams - we make things
work. Please don't dismiss the SGC-230 out of hand - It is
a great mobile antenna tuner.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)

From [e-mail] Thu 15 Jun 95 13:16:49
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!news.cyberstore.ca!vanbc.wimsey.com!unixg.ubc.ca!news.bc.net!rover.ucs.ualberta.ca!alberta!adec23!mark
From: [e-mail] (Mark G. Salyzyn)
Subject: Re: SGC-230 auto tuner
Organization: Mr Bill Show
Date: Tue, 13 Jun 95 23:22:37 GMT
Message-ID: <[e-mail]>
Lines: 23
References: <3rj8c9$[e-mail]>

[e-mail] writes:

>There is a review of the SGC-230 automatic antenna tuner
>in the June 73 written by Gordon West, WB6NOA. He pretty
>much says the SGC-230 is not good for mobile work.

Which of course, you and I know is bull.

Gordon West has lost a lot of credibility with this obviously false statement!

>It is true that the SGC-230 doesn't work well with coax on the output so just
>don't use coax on the output.

At 100W, I have yet to have much trouble with the 12 feet of RG58 I use ...

>Gordon, I hope you are listening. We're hams - we make things
>work. Please don't dismiss the SGC-230 out of hand - It is
>a great mobile antenna tuner.

Gordon, you also have *this* HAMs voice to add to the list of disappointed
readers.

Ciao, 73 de VE6MGS/Mark -sk-

From [e-mail] Thu 15 Jun 95 13:16:50
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!spool.mu.edu!bloom-beacon.mit.edu!news.kei.com!ub!galileo.cc.rochester.edu!uhura.cc.rochester.edu!rdewan
From: [e-mail] (Rajiv Dewan)
Subject: Re: SGC-230 auto tuner
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: uhura.cc.rochester.edu
Organization: University of Rochester - Rochester, New York
References: <3rj8c9$[e-mail]> <[e-mail]>
Date: Wed, 14 Jun 95 13:13:23 GMT
Lines: 41

In <[e-mail]> [e-mail] (Mark G. Salyzyn) writes:

>[e-mail] writes:

>>There is a review of the SGC-230 automatic antenna tuner
>>in the June 73 written by Gordon West, WB6NOA. He pretty
>>much says the SGC-230 is not good for mobile work.

>Which of course, you and I know is bull.

>Gordon West has lost a lot of credibility with this obviously false statement!

Your faithfulness to SGC and your vitriol for some one who does not agree
with your rosy opinion of the SGC seems boundless.  While, admittedly, we do
not know everything about antennas and propagation, there is still a science
to them.

It is quite well known that base loaded short verticals (SGC) are outperformed,
with regards to field strength, by mid-point loaded short verticals with
top hats (Bugcatcher).  The latter have higher radiation resistance and
lower losses.  This fits right in with my experience with ICOM AH2 system
that is quite identical to the SGC system.  I found that a bug catcher was
far more effective an antenna than the AH2 system ever was.  However, the AH2
won out in flexibility.

>>It is true that the SGC-230 doesn't work well with coax on the output so just
>>don't use coax on the output.

>At 100W, I have yet to have much trouble with the 12 feet of RG58 I use ...

>>Gordon, I hope you are listening. We're hams - we make things
>>work. Please don't dismiss the SGC-230 out of hand - It is
>>a great mobile antenna tuner.

>Gordon, you also have *this* HAMs voice to add to the list of disappointed
>readers.


Best regards,
Rajiv
aa2ui

From [e-mail] Thu 15 Jun 95 13:16:51
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!uunet!in1.uu.net!DIALix!adelaide.DIALix.oz.au!not-for-mail
From: [e-mail] (Rob Silva)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SGC-230 auto tuner
Date: 14 Jun 1995 21:40:35 +0930
Organization: DIALix Services, Adelaide, Australia.
Lines: 50
Sender: [e-mail]
Message-ID: <3rmjjr$r85$[e-mail]>
References: <3rj8c9$[e-mail]>
NNTP-Posting-Host: adelaide.dialix.oz.au
NNTP-Posting-User: rsilva

[e-mail] writes:

>There is a review of the SGC-230 automatic antenna tuner
>in the June 73 written by Gordon West, WB6NOA. He pretty
>much says the SGC-230 is not good for mobile work. I must
>take issue with his statements. It is true that the SGC-
>230 would not work well in the trunk of a car. But since
>it is weatherproof, there is absolutely no reason to put
>it in the trunk. It is true that the SGC-230 doesn't work
>well with coax on the output so just don't use coax on
>the output. If it hurts to do that, then don't do that.

>I have the SGC-230 mounted on a 5/8 inch rod that is
>grounded through the trailer hitch hole in my S10 rear
>bumper. A standard mobile antenna mount sits atop the
>grounded rod. A 2 inch piece of RG-8 inner conductor (no
>braid) runs from the SGC-230 to the 13 ft whip which is
>close to a resonant quarter-wave on 17m. It works great
>on 20m and has gain over a resonant quarter-wave on 15m,
>12m, and 10m. If you don't have a trailer hitch, the rod
>can be clamped and grounded to the bumper of a car.

>The SGC-230 makes a darn good mobile antenna tuner. Loading
>into that 13 ft whip, it is only one 'S' unit down from a
>bugcatcher on *40m*. Saying the SGC-230 is not a good mobile
>antenna tuner is throwing out the baby with the bath water.

>Gordon, I hope you are listening. We're hams - we make things
>work. Please don't dismiss the SGC-230 out of hand - It is
>a great mobile antenna tuner.

There is certainly no denying that the SGC-230 is a good little tuner. You do
need to be careful about how and where you mount it (in relation to your whip)
and if you're using a stainless-steel whip you might find it re-tuning if you
use it while actually mobile. SGC in fact publish a little blurb on their QMS
antenna system (which has a -230 inside it) which talks about a "20dB advantage"
over what presumably is a poorly installed in-board SGC-230.

There are at least 2 other companies manufacturing what appear to be identical
(circuit-wise) tuners (don't ask me who licenses it from whom) and many
others who badge the SGC-230.




--
-----------------------------+------------------------------------------------
Rob Silva                    |     The sooner you fall behind, the more
                             |          time you have to catch up
[e-mail] |

From [e-mail] Thu 15 Jun 95 13:16:52
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!not-for-mail
From: [e-mail] ("Anthony R. Gold")
Newsgroups: rec.radio.amateur.antenna
Subject: SGC-230 auto tuner
Date: 14 Jun 1995 13:43:29 -0500
Organization: Microvest Limited, London
Lines: 17
Sender: [e-mail]
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: news.cs.utexas.edu

In article <[e-mail]>
           [e-mail] "Rajiv Dewan" writes:

 > It is quite well known that base loaded short verticals (SGC) are outperformed,
 > with regards to field strength, by mid-point loaded short verticals with
 > top hats (Bugcatcher).  The latter have higher radiation resistance and
 > lower losses.  This fits right in with my experience with ICOM AH2 system
 > that is quite identical to the SGC system.  I found that a bug catcher was
 > far more effective an antenna than the AH2 system ever was.  However, the AH2
 > won out in flexibility.

I vote for a Bug Catcher fed by a Smart Tuner.

Regards,
--
   Tony - G3SKR / AA2PM                  email:  [e-mail]
                                        packet: g3skr@n0ary.#nocal.ca.usa.na

From [e-mail] Thu 15 Jun 95 13:16:53
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SGC-230 auto tuner
Date: 15 Jun 1995 10:01:45 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 17
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References: <[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com

>How can the SGC unit be one 'S' unit down from a Bugcatcher when in the
>SGC literature it states, "you can get more than 20 dB of gain by simply
>using an SGC compared with any other 1.8 to 30 MHz system." You must, of
>course, be in error with your statement.

Get used to it. That's advertising. GAP eliminates ground loss, Uni-Hat
increases radiation resistance, and everything is the best in the world.

The truth is that Cecil is correct. Properly located the SGC is comparable
to a base or center loaded antenna on the higher bands, but it certainly
is *not* better.
I doubt that the SGC is very close to a resonant antenna on 160 or 80
though.
It's not the poorest system, and not the best.(There is no *best* system.)
But it surely is one of the most convenient to use!

73 Tom

From [e-mail] Thu 15 Jun 95 13:16:54
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (WA6UBE)
Newsgroups: rec.radio.amateur.antenna
Subject: SIG for: nvis antennas
Date: 13 Jun 1995 15:29:31 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Message-ID: <3rkour$[e-mail]>
Reply-To: [e-mail] (WA6UBE)
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Greetings!

     I have been experimenting with various forms of Near Vertical
Incident Skywave (NVIS) since June of 1990.   -  ( See write up on NVIS in
World Radio News & also the Jan 1995 Issue of QST) ..

     I would be interested in establising a special interest group around
the subject of NVIS, and perhaps we can all share notes and information on
the different methods we have found that work reliably for HF high-angle
skywave ..Perhaps we can also start a discussion thread here on NVIS ..

     For Field Day this year I will be using a military AS2259/GR  NVIS
system on 40 and 80 meters
from the Santa Clara Valley Section - fed with a Sunair GSB900DX military
HF radio..

Thanx  &  73

Patricia Gibbons - [e-mail]
or at: City of San Jose/ GSA-Communications Div: 1-408-277-4082 for
voice-mail messages..

From [e-mail] Thu 15 Jun 95 13:16:55
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: 13 Jun 1995 12:34:04 -0400
Organization: America Online, Inc. (1-800-827-6364)
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>Tom,

>Let me first apologize for any nastiness in previous posts.  I am
>sorry, and I hope you will accept my apologies.

>Sincerely,

>Jeff

Accepted Jeff. None of us are expert in all areas or without error. This
is only a technical discussion, not a personal scoreboard. Personal
insults have no place here. Things work the way they work, and it isn't
any body's fault!

>>The formula should have been :
>>
>>R load=  (Ep sqrd over Po) over 4
>>For a class B amplifier it is over 2
>>For a class A amplifier it is over 1
>>
>>That would be roughly at conduction angles of  90, 180 and 360
>>degrees respectively. The number gets larger as the conduction
>>angle drops.
>>Ep is the maximum plate voltage swing. PO is power output with a
>>lossless tank.

>Hmmm...
<snip>

>Now, equation 3 looks suspiciously like your equation "Ep sqrd over
>Po", at least in form, but I'm having difficulty equating a term called
>"maximum plate voltage swing" to my Vrms.  They just don't *sound*
>the same.  I'd equate "maximum plate voltage swing" to Vpeak (peak
>voltage), but then the equations don't match up.

>Help me out here, Tom.

Ahh, you are indeed correct. It is the RMS voltage swing, not the peak
voltage! Sorry. I'm sure that another error is buried in this formula
because it does not allow for the shape of the anode resistance. That is
why I referred to it as a crude approximation. The correct formula
would employ a Fourier Analysis done at enough points to accurately
represent the complex wave shape.

>>On the other hand, if you thought that Ep (V in yours) was the dc
>>anode voltage, your formula is totally wrong for any class other than
>>"A".

>As I stated when defining the formula, V is the "peak" rf voltage.
>And the formula holds for all classes, as long as the output is a sine
>wave.

Then you and I (and all the books I have) are in total agreement Jeff!
The match is to the effective E/I at the desired frequency. That is the
point I have always tried to make.

The huge flywheel of the tank is what allows this point to be measured
with a reverse generator (as long as the generator does not modify the
operating point of the tube).

Incidentally, RCA sold an AM BC transmitter that used a class C
triode that produced better that 90% plate efficiency. It had third
harmonic parallel tuned circuits in series with the grid and anode
connections. The circuits squared the waveform and allowed the tube
to switch faster.

Peak power output and maximum efficiency with that PA occurred at
the same point of tuning! Think of that, over 90% efficiency at
maximum power output, how does that fit the 50% efficiency rule?

73 Tom

From [e-mail] Thu 15 Jun 95 13:17:00
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: 13 Jun 1995 12:34:04 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 213
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Message-ID: <3rkels$[e-mail]>
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Gary wrote,

>That's the problem, you're measuring system efficiency from DC input
>to AC output.

How do we measure the efficiency of a PA then, if not from dc input to
ac output? If I measure the efficiency of a generator, it is by
horsepower input to electrical power output. Is that wrong also?

>You can't speak reasonably about conjugate matching between DC
>and AC, apples and oranges.  The matching theorem only applies
>with energy of the same form, in our case AC at a particular
>frequency.

Then why do you use it that way? I keep saying the  Thevenin model
does not apply because it is a non-linear power limited
*CONVERTER*. Read the past posts, *you* keep using some  50%
rule that is allegedly supported by a model that doesn't even apply to
the circuit.

>Your load pull tests *did* show increasing output power with
>lowered load impedances below your maximum efficiency point, just
>as theory predicts they should.

Not really Gary.

The 50% efficiency point was at considerably *less* power than the
point of maximum output power. The point of maximum efficiency was
the point that showed zero reflected power from the reverse generator.

data: Max efficiency was 78% (includes tank losses) and 144 watts
PO.

Maximum power was 172 watts at 63% eff (includes tank losses).

If tank losses are deducted the plate efficiency at 172 watts was at least

70-73%, since the tank losses would drop a little by the lower loaded
(operating) Q.  That certainly does not confirm the model you (and the
new ARRL Handbook) are using.

Furthermore, these points move much closer together in an amplifier
that has a better tank circuit (by actual measurement). And with a very
good tank occur at or almost at the same point, where efficiency can be
well over 50%.

>Because you keep insisting on claiming you're conjugate matching.
>A *consequence* of a conjugate match between a source and a load
>is 50% efficiency. It's not some rule you can just dismiss. It's
>at the heart of the equations from which the matching theorem
>is derived.

I don't find that in text in my books, with the exception of the new
ARRL  Handbook.

>You seem to treat these "rules" as if they came from some authority
>figure and not derived from basic physical reality.

When they disagree with reality, I must disregard them.

>I suppose you try to say the "rule" that says things fall down in
>a gravity field can just be ignored when convenient as well.

I would if something fell up in front of me. Let's take that sarcastic
reply further. I can have a helium balloon. It will fall upwards and seem
to break the rule you gave. The reason is the rule had some specific
guidelines, and the exclude the rule from that application.

>You're the one trying to extend the idea of matching back through a
>non-linear DC to AC converter. You can't do that. It's nonsense to
>attempt to conjugate match DC to AC. You can't do it. The DC is like
>a stopped (24 hr) clock that's only right once a day.

I must not have been very clear. I always meant to say the Thevenin
model (and Norton) can not be applied to a non-linear power converter,
especially to determine anything about the source. I wanted to be
absolutely clear about that (but apparently I haven't). I also want to
distance myself *totally* and completely from the use of a Thevenin or
Norton equivalent, and that 50% efficiency rule as far as possible when
dealing with a power limited, non-linear power converter like a PA
stage.

I also hold to my statements that the Maximum Power Transfer
Theorem does apply to all devices in this discussion, and that
maximum power transfer (from the source to the load) occurs when a
conjugate match is presented at the output connector for the load.

>>Why do we insist the tube is a source, when it is a variable
>>resistance that is completely out of circuit for a period of time in any

>>amplifier beyond class A. i.e. class AB through end?

>I should be asking you a similar question. Why do you insist on
>claiming you are matching to a static E/I when in fact the tube is a
>*negative* resistance with a slope opposite a resistor.

But I've never said that, or intended to say that. What I've always
maintained is that we match to the available RMS fundamental voltage
and current available at the plate to tank junction. That all the tube
does in a conventional PA is give the tank a *tug* at the right instant.

>IE at maximum plate voltage, minimum current flows, and vice versa,
>as looking at a loadline on any characteristic curve chart will show.
>Like the stopped clock, you're only right once per cycle.

So Gary. If I place a variable resistance from a source containing a
series fixed impedance to ground, and increase the resistance the
current will drop but the voltage will increase (exactly like the across
tube). Is that a *negative* resistance?

You have confused terms, Gary. A negative resistance exhibits a series
current increase as the voltage applied across that particular component
is reduced from the external source. It does not mean that the lower
resistor in a two resistor voltage divider is a *negative* resistance
because as the resistance is lowered the current goes up and the
voltage goes down. The tube is *not* a negative resistance in this
application, it is a simple variable resistance.

>I call the tube the source because there is no source of AC power
>being input to it equal to the AC current pulses coming out of it.
>Tetrode equation again. Nowhere else in the circuit can you find a
>component that outputs AC in greater amounts than it takes in, thus
>it is the source of AC power in the circuit. That it runs off DC
>is irrelevant to the matching issue since you can't conjugately
>match DC and AC.

>You keep tangling up issues of DC->AC conversion efficiency, which
>the matching theorem says *nothing* about, with the issue of
>maximum AC power transfer from the source to the load, which the
>theorem addresses. A consequence of that transfer is the 50%
>efficiency at conjugate match.

The  Maximum Power Transfer Theorem *NEVER* says that the
maximum efficiency is 50%. As a matter of fact, while nothing is
mentioned in the original Theorem (as with Norton's and Thevenin's
original theorems), others that have written about the application of the
Maximum Power Transfer Theorem have stated the maximum available
power transferred is 100% with a conjugate match (5-44 equation 5.90
Two Terminal Circuits (Signal Sources) by Giacoletto).

Of course I'm sure someone will say that *must* be wrong and go back
to the standard misuse of the Thevenin or Norton models in a non-
linear power limited circuits!

>Since you *can't* be conjugate matching the way you say you are,
>because of the negative slope of the E/I line, I've been using the
>*fact* that you get 50% transfer at conjugate match to show you are
>*not* conjugate matching to the source.

There's that 50% rule for a Thevenin or Norton linear perfect source
limited only by a dissipating resistance that you accused me of using
being wrongly applied by you again Gary. Please read your earlier
statements. You tell me *I* apply the rule when you are the one doing
it over and over and over again.  The ONLY ARGUMENT YOU CAN
OFFER IS THAT 50% THING derived from misuse of a model!

>>Why do we fix on one point of the plate resistance (and sometimes
>>even one point of the variational plate resistance) as some point of
>>conjugate match?

In statement that I was referring to *Gary's use* of one point in a tube's

"load map" as the point of conjugate match. I could understand why he
selected one value  out of an entire non-linear time varying resistance
as the match point. Here's how he explains how he selected that
point.....

>A *very* good question. As explained above, that's the *only* point
>where you can be conjugately matched to the source if you calculate
>source impedance as a ratio of E/I. To analyze what's happening, you
>have to look at every instant around the cycle. That's what I've done
>with the Ik equation. When you *integrate* those snapshots, you get
>an average value for interesting things like current and voltage,
>but you only get a value for E/I that's valid for an instant in time.
>You can match to that *at that instant* and say you are conjugately
>matched, but at any other instant *you cannot say you are conjugately
>matched to E/I* unless your transforming network dynamically alters
>it's transformation ratio in step with the signal's dance up and
>down the *negative* E/I slope, which passive LC networks do not.
>SNIP<

Please re-read (or read) my examples about the "mechanical" tank (the
flywheel pulled by a lever) and/or the power generator (limited by field
strength or shaft power, take your pick).

I think if the circuit is considered in it's entirety, it is easy to
understand
how it works. I say again... we can not match to any static value of the
plate resistance, or especially to the variation plate resistance of the
tube. The tube must be treated as a non-linear resistance that gives the
tank a *pull* at the correct instant. We actually match to the "huge
electrical flywheel" established by the tube pulling on the tank voltage.
In other words, it is the E/I produced at maximum desired-frequency
power transfer that we match to.

The voltage and current at the junction of the tank and the anode
represents a non-time varying impedance because of the flywheel of
the tank. It is a well defined E/I that we match to. If the voltage is
1000
volts RMS at one ampere RMS the power is 1 kW and the impedance
is 1000 ohms. It is this impedance that we conjugately match to!

The tank does *NOT* set this value. The value of RF current and
voltage available is determined by the slope of the resistance of the
tube, the conduction angle, the plate voltage, and the current available
from the supply. (If the dc current available exceeds the dc current
required, it can be ignored)

Trying to work the 50% efficiency "thing" into ANY non-linear or
power limited source is futile. It will only lead to confusion and
bewilderment in analyzing a very simple circuit.

73 Tom

From [e-mail] Thu 15 Jun 95 13:17:00
Path: grape.epix.net!news.sprintlink.net!pipex!sunsite.doc.ic.ac.uk!nntp0.brunel.ac.uk!strath-cs!clyde.open.ac.uk!adminmbx
From: "Fraser Robertson (G4BJM)" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Tonna 2m/70cm beam
Date: 15 Jun 1995 14:17:43 GMT
Organization: The Open University
Lines: 11
Message-ID: <3rpfe7$[e-mail]>
NNTP-Posting-Host: adder.open.ac.uk

Hi all, we have just aquired a Tonna beam for satellite use.
It's a 9 ele on 2m and 19 on 70cm.  It's not assembled yet.

I thought it was a crossed yagi on both bands, but it only has
one driven element per band, so I presumably it is just straight
vertical or horizontal polarasation on each band?

Can anyone explain exactly what this antenna is, and is it any good
for satellite work.

Thanks in advance, Fraser G4BJM

From [e-mail] Thu 15 Jun 95 13:17:01
Path: grape.epix.net!news.sprintlink.net!newsfeed.internetmci.com!news.internetmci.com!news-admin
From: [e-mail] (Bob Smith)
Newsgroups: rec.radio.amateur.antenna
Subject: vertical antenna advice
Date: 13 Jun 1995 18:51:29 GMT
Organization: InternetMCI
Lines: 19
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NNTP-Posting-Host: dialup766.losangeles.mci.net
Mime-Version: 1.0
X-Newsreader: WinVN 0.93.14

Interested in putting up a HF vertical in my backyard - her's the
situation:

1.  It is a rather severe slope - about 45 degrees
2.  Lots of trees

Do you think the slope will affect the gain in a particular
direction?

Is there a radial pattern suggested that will nullify and
directional gain?

Thanks in advance for any responses.

--
Bob Smith
[e-mail]
[e-mail]


From [e-mail] Thu 15 Jun 95 13:17:02
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!uunet!in1.uu.net!eskimo!usenet
From: [e-mail] (Bill Turner)
Subject: Re: Vertically polarized noise question
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Date: Tue, 13 Jun 1995 12:55:44 GMT
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In article <[e-mail]>, [e-mail] says...
>
>Bob Bruhns <[e-mail]> writes:
>
>>  I have no sources to back this up, but I think the reason that "man
>>made noise sources" are held to be vertically polarized is that they are
>>local in nature and the noise propagates by ground wave.
>
> I would suggest that the antenna connected to most man made noise is the
house
>wiring, and that most of the radiating part of the antenna (wiring) is
>vertically polarized.  The horizontal parts will tend to be so long as to
>cancell or act as lon
>g-wire antenna with deep side lobes.
>best wishes.
>Roger
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
My understanding of why verticals are "noisy" is that man-made noise may be
either horizontally or vertically polarized when generated, but horizontally
polarized signals are "shorted out" by ground wave travel over the earth.
The horizontal component is the electric field.  Conversely, on a vertical
the horizontal component is the magnetic field and is essentially unaffected
by the earth's conductivity.  Thus, vertical noise propagates by ground wave
and horizontal doesn't.

This may be an oversimplification, but it does make sense.

73, Bill W7LZP
[e-mail]






From [e-mail] Thu 15 Jun 95 13:17:03
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From: [e-mail] (Your Name)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.misc
Subject: Re: Voyager/Caravan antenna mounting?
Date: 13 Jun 1995 01:33:43 GMT
Organization: Whatever you want
Lines: 8
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Xref: grape.epix.net rec.radio.amateur.antenna:11047 rec.radio.amateur.misc:80661

In article <[e-mail]>, [e-mail] (Wayne Day) says:
>
>We've got a new Plymouth Voyager (same-same as Dodge Caravan) in the family.

Wayne, mount it at the back, on the roof. We have a few people in our
club with Voyagers and this seems to be the best spot, far away from
the computer.
Dave VE7BBV

From [e-mail] Thu 15 Jun 95 13:17:04
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!simtel!news.kei.com!ub!netfs.dnd.ca!dgbt!clark.dgim.doc.ca!news
From: [e-mail] (Jim Cummings)
Subject: Webster Band Spanners?
Message-ID: <[e-mail]>
Sender: [e-mail] (#Usenet News)
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Hello:

Does anyone still make the Webster Band Spanner? I realize that it is
most likely a company called Webster, but does any one have any current
information on them?  I seem to recall that years ago CQ had done a
magazine article on the company, does anyone recall this also?

On a more technical note....

I am using an ICOM AH-2 to tune a CB stainless steel whip while mobiling
in my Ford Ranger.  Recently I read that because of the nature of
stainless steel, there are greater losses of the transmitting signal due
to heat loss than would be otherwise experienced with a copper whip (it
may be a rather academic exercise in that the efficiency is so low on the
40 and 80 meter bands, what's the big deal with another 3 db loss).
However, I considered replacing the whip with a Webster Band Spanner,
fully extending the adjustable whip and letting the AH-2 continue to do
its thing.

Another amateur advised against this as he explained that since the Band
Spanner is helically wound and would not be as effective as just the
straight whip.

Are there others who have thoughts on this?

73 and live better digitally
Jim, VE3XJ



From [e-mail] Thu 15 Jun 95 13:17:05
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!newsjunkie.ans.net!Rezonet.net!altitude!interso.hip.cam.org!user
From: [e-mail] (Archibald d'Arsenic)
Newsgroups: rec.radio.amateur.antenna
Subject: What about the AL 800 antenna 2M/70Cm
Date: Wed, 14 Jun 1995 13:39:08 -0400
Organization: Communications Accessibles Montreal, Quebec Canada
Lines: 9
Message-ID: <[e-mail]>
NNTP-Posting-Host: interso.hip.cam.org

Who have more info concerning the AL800 Antenna (ANLI) for 2M/70CM, in
term of improvement in Rx and Tx.

Also, what about the small rubber antenna which is coming with it.

73,
VE2 SDZ

you can reply to [e-mail]

From [e-mail] Thu 15 Jun 95 13:17:06
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!swrinde!ihnp4.ucsd.edu!network.ucsd.edu!news-mail-gateway
From: [e-mail] (Muenzler, Kevin)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What effect do straight radials have
Date: 15 Jun 95 15:38:00 GMT
Organization: ucsd usenet gateway
Lines: 20
Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]



Bob ([e-mail]) writes:
> What is the effect on reception when the radials on a groundplane are
> horizontal instead of drooping?
>
> Bob

The effect on the radiation pattern is minimal.  However the feedpoint
impedance is changed (raised) as you lower the radials.  At horizontal
the impedance is around 36 ohms and is around 50 ohms at 45 degrees.
You can compensate for the lower feedpoint by shortening the radiator
or lowering the radials.  A dipole is just a groundplane with the "radials"
180 degrees from the radiator.

Kevin Muenzler, WB5RUE
[e-mail]
"I am Voltohm of Borg!  Resistance is E/I, Power is EI, you will be
attenuated!"
 ------------------------------

From [e-mail] Thu 15 Jun 95 13:17:07
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From: [e-mail] (WA6UBE)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What effect do straight radials have on a
Date: 13 Jun 1995 15:35:38 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Sender: [e-mail]
Message-ID: <3rkpaa$[e-mail]>
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The textbook reply is that the impedance at resonance will be lower than
with "drooping" radials -- with radials at 90 deg to the direction of the
vertical element,
Z- may be from 30 to 50 ohms depending on interaction from the ground
itself,
i.e. height of feedpoint from earth, roof, etc ..

drooping a radial will tend to raise the Z of  the antenna feedpoint, with
all other factors being equal ..

73
Patricia Gibbons - City of San Jose Communications Div
[e-mail]

From [e-mail] Thu 15 Jun 95 13:17:07
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news.starnet.net!wupost!news.utdallas.edu!corpgate!bcarh189.bnr.ca!nott!cunews!freenet.carleton.ca!FreeNet.Carleton.CA!ae517
From: [e-mail] (Russ Renaud)
Subject: Re: What effect do straight radials have on a groundplane?
Message-ID: <[e-mail]>
Sender: [e-mail] (Russ Renaud)
Reply-To: [e-mail] (Russ Renaud)
Organization: The National Capital FreeNet
References: <3rd8c9$[e-mail]> <3r7h2j$[e-mail]> <3r8sa5$[e-mail]>
Date: Tue, 13 Jun 1995 14:40:42 GMT
Lines: 15


Bob ([e-mail]) writes:
> What is the effect on reception when the radials on a groundplane are
> horizontal instead of drooping?
>
> Bob

It will lower your feedpoint impedance to around 36 ohms, if I recall
correctly.  I'm not sure how much effect it will have on your pattern.

Just a sec, now.

I just checked EZNEC; it doesn't look to have any effect on your pattern.

Russ, va3rr/aa8lu

From [e-mail] Thu 15 Jun 95 13:17:08
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What effect do straight radials have on a groundplane?
Date: 13 Jun 1995 15:05:23 -0400
Organization: America Online, Inc. (1-800-827-6364)
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I don't have any direct experience with that question Bob, but I expect
any effect on rececption would be minimal. The main effect is a change in
impedance at the feedpoint. I'm sure there would be some small changes in
the pattern, because there is a slightly deeper null below each radial,
but the change is probably not enough to worry about.

73 Tom

From [e-mail] Thu 15 Jun 95 13:17:09
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netnews
From: [e-mail] (Glenn Sparks)
Newsgroups: rec.radio.amateur.antenna
Subject: Wire antenna in Saltwater Beach house environment
Date: 15 Jun 1995 14:12:17 GMT
Organization: Netcom
Lines: 26
Distribution: world
Message-ID: <3rpf41$[e-mail]>
NNTP-Posting-Host: ix-hou6-04.ix.netcom.com

I have a beachhouse on the Gulf that I use on weekends year round.  I
have an Old Heathkit there with a full lenght 80m and 40m dipole up
about 40 foot.  Every year I have to rebuild it, the guy wires break,
the antenna wire break, the ropes to raise the antenna rot, etc.

Any ideas for a more reliable mechanical setup.  I use the heavy
galvanized guy wire, and the copperweld antenna wire.

I am considering solid insulated wire, but all I can find is soft drawn,
I have been told if you will tie the soft drawn to your car, and a tree
and stretch it about 10% and leave it streched overnight it will work OK
without a support strand.

Also what is the plastic/poly stuff they use on ships, and how expensive
is it.

Thanks for any advice, at first I thought it was cheap enough to ignore,
but it is getting tiresome.

I do enjoy the signals I get with the salt marsh ground and the full
lenght antenna though.  I have 4 - 10' copper tubes in a 1 meter square
all braized together with the tubing running up the wall of the beach
house, then braid from RG-8 for a ground.

Thanks in advance
Glenn Sparks

From [e-mail] Mon 19 Jun 95 16:41:00
Path: grape.epix.net!news.sprintlink.net!roch3.eznet.net!usenet
From: [e-mail],  ARS AA2IZ
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 160m FULL SIZE HORI LOOP QUESTIONS
Date: 17 Jun 1995 14:19:11 GMT
Organization: E-Znet Inc. Rochester N.Y. 14623 (716)-262-2485
Lines: 50
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X-Newsreader: AIR News 3.X (SPRY, Inc.)

>  loop length about 550 feet
>  wire size:  18 awg copper weld
>  DC resistance around the loop is 12 ohms
>  loop height is 30 feet above very rocky soil (poor ground).
>  feed point is in the corner of the diamond, above my house
>
>  I saw articles indicating that 80m loops work pretty good on other bands.  I
>  wanted to go down to 160, therefore I opted for the 160m loop.  I still wanted
>  to work all bands, however.
>
>  The results:  mixed.   Recieving is great, it is a very quiet antenna.
>  However, after having tried a two different noise bridges, the data gathered
>  tends to indicate that the input impedance is around 12 - 20 ohms on most
>  bands, with very low reactance.  On 160 meters, it is closer to 50  ohms, 0
>  Xl/Xc .  On 10 meters however, the reactance goes very capacitive (> 50 ohms
>  Xc).

>  Anybody have any experience and or suggestions about this setup.  I think my
>  next test should be to measure the antenna directly at the feedpoint.
>
>  Please let me know what you all think.
>
>  Tracy
>
Hi.   I have a 160m full wave loop almost identical to your's.  The main difference is that I used #12 awg wire
and only have about 3 or 4 ohms resistance around the loop.  If anything, my loop is a couple of feet
closer to the ground than your's.

My experience with this antenna has been tremendous.  Obviously it's a cloud warmer kind of antenna.  For
stateside contacts, especially for up to 5 or 6 hundred miles or so, it's unbeatable.  At long ranges, some
of my other antennas work better of course.  It's a super sweepstankes antenna.

I use it on all bands.  It works even better on the higher bands.  Of course the impedance is all over the place
on the higher bands, but that is irrelevent to me.  I use VERY low loss feedline, and an efficient tuner (for
the sake of the radio's finals!) and I can load it up anywhere I want.

As you say, it is wonderfully quiet.  Just the thing for this summer weather.

My advice....use good feedline, an effective tuner, and don't sweat the SWR.


73 de Gary, AA2IZ


>>>>
Gary P. Hoffman
[e-mail]
ARO AA2IZ



From [e-mail] Mon 19 Jun 95 16:41:01
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!library.ucla.edu!news.bc.net!unixg.ubc.ca!news!cln.etc.bc.ca!gcarlisl
From: [e-mail] (Gale Carlisle)
Subject: 6 METER YAGI
X-Nntp-Posting-Host: cln.etc.bc.ca
Message-ID: <[e-mail]>
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Date: Sun, 18 Jun 1995 22:46:59 GMT
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        Need plans and info on high gain 6 meter yagi design. Any input
        would be greatly appreciated.

                                        Steve Carlisle  VE7AHL

From [e-mail] Mon 19 Jun 95 16:41:02
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!news.ti.com!sislnews.csc.ti.com!usenet
From: [e-mail] (Mitchell Carson)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Advice wanted: Calculating SWR from fwd vs. reflected pwr readings
Date: 18 Jun 1995 18:49:36 GMT
Organization: Texas Instruments
Lines: 25
Message-ID: <3s1sg0$[e-mail]>
Reply-To: [e-mail] (Mitchell Carson)
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Xref: grape.epix.net rec.radio.amateur.antenna:11265 rec.radio.amateur.homebrew:7845

Someone please give this poor boy (me) some advice.

I'm currently working on a homebrew J-pole antenna for 2m and 70cm use.
Unfortunately, I do not own a SWR meter for the 70cm bands (none of my
local amateur friends do either).  However, one of my friends has a
forward/reflected power meter with a 2m & 70cm slug in it.

I realize that I have to position the coax feedpoints to the J-pole radials in
order to tune the SWR's to an acceptable level.  I have access to a MFJ-249
antenna analyzer but it will only work from 1.8 to 170 MHz.  I plan on using
this instrument to tune the 2m portion of the J-pole.

I'm presuming that SWR's can be calculated from forward vs. reflected power
measurements.  The problem is that I can't locate any references to this
subject in any of the local libraries.  If it is possible to derive SWR's from
this type of measurement, would someone be kind enough to provide me with
a suitable formula?

Thanks in advance and 73,
Mitchell
KC5MKW

[e-mail]

Std. disclaimer:  I speak only for myself.

From [e-mail] Mon 19 Jun 95 16:41:03
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: Advice wanted: Calculating SWR from fwd vs. reflected pwr readings
Date: 19 Jun 1995 00:05:08 GMT
Organization: News & Observer Public Access
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Xref: grape.epix.net rec.radio.amateur.antenna:11277 rec.radio.amateur.homebrew:7848

[e-mail] (Mitchell Carson) wrote:
>
> Someone please give this poor boy (me) some advice.
> I'm presuming that SWR's can be calculated from forward vs. reflected power
> measurements.  The problem is that I can't locate any references to this
> subject in any of the local libraries.  If it is possible to derive SWR's from
> this type of measurement, would someone be kind enough to provide me with
> a suitable formula?
>
Certainly SWR can be calculated from forward power and reflected
power.  Check the Transmission Line section of an ARRL Handbook
for the formulas,  Or in case you don't have access to a handbook,

  SWR = (1 + rho)/(1 - rho)
    my *rho* is usually written as the lower case greek letter rho.
and
  rho = the square root of (Pr/Pf)
         where Pf = power in the forward wave
               Pr = power in the reflected wave

Now that all that is done, there is usually an easier way to tune
antennas, Just tune for minimum reflected power.  If you get to
zero reflected, the SWR is 1.
I have been doing this for years with good success since it is usually
not impoortant to me just what the SWR is, but I want it at a minimum.

73,
Don W3FPR


From [e-mail] Mon 19 Jun 95 16:41:03
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From: [e-mail] (Foto67)
Newsgroups: rec.radio.amateur.antenna
Subject: Antenna drawings???
Date: 19 Jun 1995 01:24:55 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 13
Sender: [e-mail]
Message-ID: <3s31n7$[e-mail]>
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Has anyone ever posted antenna drawings in this newsgrp?
It seems to me a person could draw plans for friends, general public in
the ham world, and post them here using Window's Draw ( for example just
because it's common ) and then we'd be able to visualize the plans more
clearly.

How to do this? Well we all need a uuencode/uudecode program to turns the
drawings into text to be posted and then the individual turns the text
back to the drawing at home to view. Wincode works well and is "freeware."

For discussion...



From [e-mail] Mon 19 Jun 95 16:41:04
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!news.ti.com!magic
From: [e-mail] (BV/N0IAT)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: antenna for mustang
Date: Mon, 19 Jun 1995 18:17:44 GMT
Organization: Texas Instruments
Lines: 14
Message-ID: <3s3irg$[e-mail]>
References: <[e-mail]> <3riuql$[e-mail]>
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NNTP-Posting-Host: 137.167.36.115

My friend had a 8? mustang and mounted a 1.5" wide piece of metal to the
frame just under the bumper.  He had previously drilled a hole in the
metal to attach a 3/8" x 24 mount.  He used a hustler 5/8 wave over 1/4
wave colinear antenna, 50 watts, and had a very effective mobile
station.  When he went to sell the car, he simply unbolted the metal
strip from under the bumper and presto...no more antenna.  He also used
this bracket with an HF rig and it worked well...very effective ground.

Though this might hinder performance by not placing the antenna at the
highest point on the car, it does work.

73 de BV/N0IAT   Joe in Taipei, Taiwan Republic of China



From [e-mail] Mon 19 Jun 95 16:41:05
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netcom.com!jassing
From: [e-mail] (Josh Assing)
Subject: Antenna Help Please... (900MHZ)
Message-ID: <[e-mail]>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
X-Newsreader: TIN [version 1.2 PL1]
Date: Mon, 19 Jun 1995 20:09:35 GMT
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Sender: [e-mail]


This is off topic; but someone pointed me here for some
advice/experiments to try.

History:
I live in the middle of nowhere in the Santa Cruz Mountains.  The nature
preserve (which surrounds my property) won't let us string phone lines
in.  We've been using cellular; but it's too expensive to continue using
it as our main phone.

We have neighbors that will let us put a phone line in & run a
transmition device from there.

I think I'm going to give the 900 Mhz cordless phones a try.  We'll be
pushing the signal (hopefully) about 1 - 1.5 miles (More???)

Question:
Is there a directional antenna that I can attach to the base unit AND the
'hand held' unit (possibly running up a tree or on top of the house?)

The hand unit won't be used as a true 'cordless' -- i.e.: I won't need to
roam around with it; just use it in the house, or in one kitchen.

It was suggested that perhaps a reflector at the base unit might be the
best bet.

Does anyone know anything about 'boosting' the signal?

Thanks; Post here; or reply to: [e-mail]

Thanks!
...josh!


From [e-mail] Mon 19 Jun 95 16:41:06
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.cac.psu.edu!news.pop.psu.edu!hudson.lm.com!netline-fddi.jpl.nasa.gov!nntp.et.byu.edu!news.kei.com!world!uunet!iglou!iglou.iglou.com!n4lq
From: [e-mail] (Steve Ellington)
Subject: Re: Antenna HF operation ideas
X-Nntp-Posting-Host: iglou.iglou.com
Message-ID: <[e-mail]>
Sender: [e-mail] (News Administrator)
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Date: Sat, 17 Jun 1995 02:03:20 GMT
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Jason Hanson ([e-mail]) wrote:
: I am a poor college student who would like to get active on HF fromy my
: apartment.  I need suggestions...

: One thought was a tuner with random-wire.  But I have a few questions:  WIll
: the elcheapo MFJ tuner work okay?  What kind of wire should I use?  How much?
: (I was thinking about 1/4 wavelength on the band, but I don't know if I am
: right.)  Will it work if not perfectly straight?

: Any help at all would be appreciated!
: --
: Jason J. Hanson            |    1013 Milton St. #203      |  [phone]
: University of Wisconsin    |     Madison, WI 53715        |  Ham: N9LEA (Extra)
: --  [e-mail]   =*++*=   Proud Democrat, Badger fan, speeder  --
: --
: Jason J. Hanson            |    1013 Milton St. #203      |  [phone]
: University of Wisconsin    |     Madison, WI 53715        |  Ham: N9LEA (Extra)
: --  [e-mail]   =*++*=   Proud Democrat, Badger fan, speeder  --
In the second story bedroom of my house, I ran a piece of hookup wire to
the window screen and loaded it up with my Century 21 (30watts) and
elcheapo MFJ tuner. I worked a station 700 miles away on 40 meters with
no problem. Is this a good antenna? Naw! but at least it worked. So give
it a try Jason.Just don't run much power and don't expect very long solid
qsos.
--
  Steve
[e-mail]



From [e-mail] Mon 19 Jun 95 16:41:07
Path: grape.epix.net!news.sprintlink.net!nuclear.microserve.net!pinetree
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Impedances?
Date: Sun, 18 Jun 95 06:14:45 GMT
Organization: Microserve Information Systems (800)-380-INET
Lines: 12
Distribution: world
Message-ID: <3s0gjo$[e-mail]>
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X-Newsreader: News Xpress Version 1.0 Beta #3

In article <[e-mail]>,
   [e-mail] (Michael Jacobsen) wrote:
>Now here is the heart of my question.  Applying this
>knowledge to things more familiar to me, why do FM
>stereo receivers come with dipole antennas that connect
>to 300 ohm jacks on the receivers?

The proper antenna for this use is, in fact, a folded dipole
fed with 300 ohm line.  Antennas supplied by *most* reputable
tuner/receiver manufacturers are of this type.

73,  Jack  WB3U

From [e-mail] Mon 19 Jun 95 16:41:07
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Impedances?
Date: 18 Jun 1995 06:50:17 -0400
Organization: America Online, Inc. (1-800-827-6364)
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NNTP-Posting-Host: newsbf02.mail.aol.com

Ooops. Did I say current OVER power. Beat me with a stick and turn the
formula over ;-) . 73 Tom

From [e-mail] Mon 19 Jun 95 16:41:08
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 18 Jun 1995 23:40:32 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 24
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>Why are most antenna tuners set up in a 'T' configuration (capacitors
in series, inductor in parallel) instead of a 'pi' with caps in
parallel and inductor in series?  Wouldn't a pi setup give better
attenuation of harmonics?

73...Jim  N2VNO<

Jim
Mostly because the component values are more liveable with a T network.
The Pi requires huge capacitors on the lower bands, and the stray
capacitance would be so high that they wouldn't work on 10 meters.

Some tuners that are advertised as Pi-networks are really L networks! They
have a meaningless additional capacitor across one end of the network. The
part is there, but if a circuit analysis is done, it becomes plain the
network is functionally *not* a pi!

Remember the capacitors are the most expensive part of a tuner, cutting
down on the number of plates reduces the cost dramatically.

73 Tom


From [e-mail] Mon 19 Jun 95 16:41:09
Path: grape.epix.net!news.sprintlink.net!newsie.dmc.com!news.iii.net!iii1.iii.net!not-for-mail
From: [e-mail] (Thomas C Sefranek)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 19 Jun 1995 07:37:37 -0400
Organization: iii.net
Lines: 23
Message-ID: <3s3nik$[e-mail]>
References: <[e-mail]> <3s2rjg$[e-mail]>
NNTP-Posting-Host: iii1.iii.net

Ahhh Tom!
         ALL I build are Pi Tuners!  I have YET to find them impractical
or unworkable at even 160 meters.  I have 750 pf 15,000 volt caps, and
a large roller inductor.  It works great on 10 meters too.
Stray capacitance? Sure!  But the stray inductance is worse!
All in all, I find I need a "bit" of capacitor in the circuit to match
a 50 ohm dummy load with no inductance (Minimum).

I have been at field days when several T tuners failed to match a longwire.

And the Pi lets me have 2 grounded shafts, so I have less insulation to
install.

And I find the low-pass characteristics to be superior to the T.

Have you actually used a Pi?  Or are you guessing?

Check it out!

Tom

--
Thomas C. J. Sefranek  WA1RHP

From [e-mail] Mon 19 Jun 95 16:41:10
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 19 Jun 1995 16:09:07 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 56
Sender: [e-mail]
Message-ID: <3s4lh3$[e-mail]>
References: <3s3nik$[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com

>Ahhh Tom!
>        ALL I build are Pi Tuners!  I have YET to find them impractical
>or unworkable at even 160 meters.  I have 750 pf 15,000 volt caps,
>and a large roller inductor.  It works great on 10 meters too.
>Stray capacitance? Sure!  But the stray inductance is worse!
>All in all, I find I need a "bit" of capacitor in the circuit to match
>a 50 ohm dummy load with no inductance (Minimum).

>Have you actually used a Pi?  Or are you guessing?

Tom,
I was talking about a real pi, and *not* guessing! Putting an extra cap
at the other end of an L network does not make it a pi network.

The tuner you described is a good example of this. If it only has 750 pF
of capacitance the "Pi" appearing circuit is not a pi by both definition
and operation...unless the load impedance is above 300 ohms on 160
AND has no equivalent shunt inductive reactance!

With 300 ohm load R the Q of the network in any "Pi" tuner with only
750 pF of capacitance is just over 2 on 160 meters. That is not a very
selective pi, but it does electrically behave as a pi. The Q available
will
increase if the load resistance increases.

But if the load Z is less than 300 ohms the network electrically
performs as an "L", even if you draw it on paper and it "looks" like a
pi. It also won't act like (or electrically be ) a pi if the load has the
equivalent of even a very high value of shunt inductive reactance at 300
ohms equivalent parallel R, and at higher impedances if the equivalent
shunt reactance exists.

A network with only 750 pF of shunt C available acts like a pi on 160
through 40 under very restricted load conditions. If the load resistance
is 20 ohms, 750 pF capacitors allow the network to be a pi only on 7
MHz!

The following values are for a pi with 20 ohms load R:
160 meters 2800 pF, 80 meters 1500 pF.

 40 ohms:
160 2000 pF, 80 1100 pF.

So what I said is very true. The problem manufacturers face is:

1.) They can't use vacuum caps because the parts must be purchased
new.

2.) The stray capacitance of the capacitor and layout kills a pi on 28
MHz.  Especially when the caps are big enough to *really* be a pi at
low load impedances on 160 through 40.

3.) Networks can look like a pi when they don't work like one, because
the values are incorrect.

73 Tom

From [e-mail] Mon 19 Jun 95 16:41:11
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!cc.iu.net!news
From: [e-mail]   (Bill Newkirk)
Newsgroups: rec.radio.amateur.antenna
Subject: Any opinions on tri-band (2/220/440) antennas?
Date: 16 Jun 1995 03:29:07 GMT
Organization: Space Coast Amateur Technical Group
Lines: 17
Message-ID: <3rqtq3$[e-mail]>
Reply-To: [e-mail] (Bill Newkirk)
NNTP-Posting-Host: netport-6.iu.net
X-Newsreader: IBM NewsReader/2 v1.09

got a school station to set up - and have only one run of coax to the roof
available for VHF/UHF.  was thinking along the lines of something like
a comet cx-333 or a discone.

would like it to be able to take a salt environment pretty well (it's on the
beach).

would like to include these three bands since that's the 3 big ones for people
to use and don't have any 6m gear coming up in the future...

needs to be mechanically well built.

i'm open for suggestions...tnx es 73

Bill Newkirk WB9IVR                  The Space Coast Amateur Technical Group
Melbourne, FL                       duty now for the future of amateur radio


From [e-mail] Mon 19 Jun 95 16:41:12
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (RFAcres)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Any opinions on tri-band (2/220/440) antennas?
Date: 18 Jun 1995 10:37:11 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 18
Sender: [e-mail]
Message-ID: <3s1dmn$[e-mail]>
References: <3rqtq3$[e-mail]>
NNTP-Posting-Host: newsbf02.mail.aol.com

In regards to the CX-333: When it was still a new model I knew of one
where the owner was less than pleased with its overall perfomance.
Recently I bought a CX-333 and put it on a remote base for 144/220/440. I
works better than the compromise of two separate antennas that I had
before and takes only one run of hardline. On 222 it works just as well if
not better than the Comet 220 mono band base antenna. On the 144 side the
remote base does a bit better than the 220 repeater at the same site that
is 30 feet further up the tower (not terribly surprising, but the triband
antenna does do well.)

I can't give a more scientific answer, but I have been pleased with my
CX-333. Please make sure that you use a good grade of coax for that single
run in your project.

Have fun!

Brian McCarthy, NX9O
[e-mail], [e-mail] or Packet: NX9O@N4NIA

From [e-mail] Mon 19 Jun 95 16:41:13
Path: grape.epix.net!news.sprintlink.net!hookup!news.kei.com!nntp.et.byu.edu!news.byu.edu!hamblin.math.byu.edu!yvax.byu.edu!sandersm
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Best NMO Mobile Mount???
Message-ID: <[e-mail]>
Date: 14 Jun 95 21:32:19 -0700
References: <3rlgsd$[e-mail]> <3rn1j2$[e-mail]>
Distribution: usa
Organization: Brigham Young University
Lines: 28

Maybe I am all wet, but I have a Larson NMO mount that is a mag mount mount and
does not require any holes in the car.  Perhaps it is called NMO because I can
unscrew the portion of the whip base and replace it with different sizes of
"tuned" whips.  The unscrewable part uses a rubber washer to keep moisture out
of the connection, and it has worked very well for me for 3 1/2 years.  My car
is garaged at night, but sits outside all day in sun, rain, and snow.

Milt

In article <3rn1j2$[e-mail]>, [e-mail] (WA8MSF) writes:
> Thanks for responding Don.
>
> I had figured a chassis punch would leave a cleaner hole with less total
> exposed surface area for oxygen to go after.  I'll do this if I can get
> the headliner out without going to bodyshop extremes.
>
> I'm under the general impression that NMOs have an O-ring seal under them
> that SHOULD take care of the water ingress.  My question should have been
> worded to ask if anyone knows of a particular manufacurer or part number
> of NMO mount that has a superior construction or superior mechanical
> detail for the purposes of minimizing water/rust problems while
> maintaining superior electrical/RF function?
>
> What does anybody think?
>
> Gratefully,
>
> Mike - [e-mail]

From [e-mail] Mon 19 Jun 95 16:41:14
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!news.cyberstore.ca!skypoint.com!umn.edu!news
From: "Dave Quick" <[e-mail]>
Subject: Re: Best NMO Mobile Mount???
To: [e-mail]
Message-ID: <[e-mail]>
X-Minuet-Version: Minuet1.0_Beta_17A
Sender: [e-mail] (Usenet News Administration)
Nntp-Posting-Host: dialup-5-125.gw.umn.edu
X-Popmail-Charset: English
Reply-To: <[e-mail]>
Organization: University of Minnesota, Twin Cities
Date: Fri, 16 Jun 1995 22:52:46 GMT
Lines: 35

On 14 Jun 1995 02:17:49 GMT,
DB Wilhelm  <[e-mail]> wrote:

>[e-mail] (WA8MSF) wrote:
>>
>> I am about to punch a 3/4" hole into the roof of an older, but
>> none-the-less expensive car for a mobile 2m/70cm antenna.  I plan on
>> having the car for a few more years and don't want the hole to quickly
>> start rusting.
>>
>> Does anybody have a recommendation on what maker/style/configuration of
>> NMO mount would be the most watertight and least panel deforming for this
>> application?
>>
>> Any and all practical hints will be gratefully accepted.
>
>Since rust and watertight seal seem to be your major concerns, you
>could cut the hole with a punch or other device that will leave a
>clean hole, then seal the cut surfaces with a good quality automotive
>primer and paint.  When attaching the antenna, you might use silicone
>sealer as a gasket on the exterior side for a weathertight seal.
>Make certain that the grounding connection, which must expose the
>metal surface, is tightly made on inside of the roof panel.
>
>73,
>Don W3FPR
>
>
I had a Larson NMO in the middle of my car's roof for a while. Seem'd fine,
and didn't leak at all. As for drilling the hole, I used a drill bit
called a "Uni-Bit". It's a stepped device capable of drilling several
different hole sizes. They work great on sheet metal, and a nice new sharp
Uni-Bit will produce a perfectly smooth perfectly round hole with no
distortion of the surface.


From [e-mail] Mon 19 Jun 95 16:41:16
Path: grape.epix.net!news.sprintlink.net!news.primenet.com!ctrask
From: [e-mail] (Christopher Trask)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Broadband Dipole
Date: 19 Jun 1995 04:43:01 GMT
Organization: Primenet [phone]
Lines: 65
Message-ID: <3s2v8l$[e-mail]>
NNTP-Posting-Host: usr4.primenet.com
X-Newsreader: TIN [version 1.2 PL2]

W8JI  Tom ([e-mail]) wrote:
: Tom, I have seen some design like the one I described, I think it was
: >called T2FD, but I don┤t have any desription left of it.
X-Newsreader: TIN [version 1.2 PL2]

: >I have also seen a antenna from Barker and Williamsson that look like
: the one I described that they say works from 3.5-30 Mhz.

: >The antenna is to be used in the Ham bands, but also in between them
: for MARS type traffic.

: >73 Jan

: Jan

: Yes, but the difference is that your application is for receiving. The
: receiver establishes the line SWR, not the antenna. So while the resistor
: may help satisfy a transmitter, it will not help satisfy the receiver. The
: only effect it can possibly have is to *decrease* the signal.

: IMHO  I think adding a lossy feedpoint termination resistance is a
: worthless addition to a receiving installation, and that is all the
: antennas you mentioned do.

: 73 Tom

Gentlemen:
        I need to point out the <FACT> that the resistor in the antenna
is <NOT> a lossy termination.  It functions in exactly the same manner as
does the terminating resistor in a rhomboid antenna, which is to force the
current in the antenna arms, resulting in the directivity of the radiation
pattern.  But rather than argue the point, I strongly suggest that ELNEC
or MININEC be brought into the picture.  These are very simple antennas to
model.  Having used AMP (the great-grandfather of the present antenna mod-
elling programmes) and NEC (the real thing), I have a great appreciation of
the simplicity and ease of ELNEC, although I would like to see patches and
transmission lines added to the geometry.
        Furthermore, it is <ESSENTIAL> that a receiving antenna be matched
to the receiver for exactly the same purpose as matching an antenna to a
transmitter, which is to enable the best transfer of energy from the anten-
na to the receiver.  Mismatching the receiver/antenna has exactly the same
effect on VSWR, and can be measured as an increase in the effective antenna
noise temperature.
        A simpler example of this effect is to replace the mismatched an-
tenna with an ideal antenna and an attenuator pad.  The net result is a
decrease in the receiver gain and a subsequent increase in noise figure,
which, alnog with dynamic range, is an essentially important factor in
receiver system performance.
        I once got into this same argument with a VP of engineering (10
years my younger) who insisted that the mismatch resulted in the reflect-
ed energy reing reradiated into space and did not affect the antenna pat-
tern.  He also stated emphatically that attenuators would not affect noise
figure if they were made out of transformers.  His previous job experience
had been, among other things, making sleeping bags in New York state.

        I don't work for him anymore.

        Questions?

-------------------------------------------------------------------------------
Chris Trask / N7ZWY
ATG Design Services                       __  __     ____  ___       ___ ____
[e-mail]       _~_            /__)/__) / / / / /_  /\  / /_    /
                         (@ @)          /   / \  / / / / /__ /  \/ /___  /
----------------------ooO~(_)~Ooo----------------------------------------------

From [e-mail] Mon 19 Jun 95 16:41:17
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!vixen.cso.uiuc.edu!news.uoregon.edu!news.algonet.se!usenet
From: [e-mail] (Jan Olof Bergsten)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Broadband dipole, how do I make it ?
Date: Sun, 18 Jun 1995 19:01:46 GMT
Organization: SM7ETW
Lines: 30
Message-ID: <3s1tsa$[e-mail]>
References: <3rntrn$[e-mail]> <3rpf15$[e-mail]>
NNTP-Posting-Host: sophocles.algonet.se
X-Newsreader: Forte Free Agent v0.55

[e-mail] (W8JI  Tom) wrote:

>Jan, I don't think the resistor will help at all in a receiving
>application. It is the receiver that determines the feedline SWR on
>receive. The antenna mismatch only causes a loss in coupling or energy
>transfer from the antenna to the feedline.

>Puting a resistor across the antenna will not aid in energy transfer at
>all, it can only decrease the available signal. I would just use a regular
>dipole, a fan dipole with elements for each main band of interest, a bow
>tie for the lowest band, or a trap antenna.

>In this day of good receivers, the S/N ratio should almost certainly be
>established by the area surrounding the antenna, not by coupling of the
>antenna to the feedline. I would not be overly concerned about SWR or
>matching at the receive antenna, but I would use a good choke type balun
>with the antenna.  73 Tom

Tom, I have seen some design like the one I described, I think it was
called T2FD, but I don┤t have any desription left of it.

I have also seen a antenna from Barker and Williamsson that look like
the one I described that they say works from 3.5-30 Mhz.

The antenna is to be used in the Ham bands, but also in between them
for MARS type traffic.

73 Jan



From [e-mail] Mon 19 Jun 95 16:41:18
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Broadband dipole, how do I make it ?
Date: 18 Jun 1995 23:33:07 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 23
Sender: [e-mail]
Message-ID: <3s2r5j$[e-mail]>
References: <3s1tsa$[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com

Tom, I have seen some design like the one I described, I think it was
>called T2FD, but I don┤t have any desription left of it.

>I have also seen a antenna from Barker and Williamsson that look like
the one I described that they say works from 3.5-30 Mhz.

>The antenna is to be used in the Ham bands, but also in between them
for MARS type traffic.

>73 Jan

Jan

Yes, but the difference is that your application is for receiving. The
receiver establishes the line SWR, not the antenna. So while the resistor
may help satisfy a transmitter, it will not help satisfy the receiver. The
only effect it can possibly have is to *decrease* the signal.

IMHO  I think adding a lossy feedpoint termination resistance is a
worthless addition to a receiving installation, and that is all the
antennas you mentioned do.

73 Tom

From [e-mail] Mon 19 Jun 95 16:41:19
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!usc!nic-nac.CSU.net!vax.sonoma.edu!harrisok
From: [e-mail] (Ken Harrison)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Can you ID this Antenna?
Date: 16 Jun 95 23:11:13 -0800
Organization: Sonoma State University
Lines: 28
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: vax.sonoma.edu

In article <[e-mail]>, [e-mail] (Ken Harrison) writes:
> My father-in-law picked up a used 2 meter ground plane from an estate sale
> about 10 years ago and recently gave it to me.  I saw an ad for one of these
> particularly antennas about 10 years ago but don't remember the brand or
> specs.  Can someone help me ID this thing?
>
> The radiator is about 15.5 feet tall.  It has four radials that come straight
> out at the bottom and they are 1/4 wave length.  There is a tubular gamma
> match at the bottom where the coax attaches.  The main identifying
> feature about this antenna is the two J sections held off the radiator by
> insulating material.  They are not electrically connected.
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Oops...  Actually the are connected-- right at the top of the small section
of the "J"...

And I have been informed that this antenna is a Butternut.

73,
Ken



Ken Harrison                  [e-mail]                   Ham:  N6MHG
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Show me a man with both feet on the ground and I'll show you a man who can't
put his pants on."                                          -- Arthur K. Watson
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


From [e-mail] Mon 19 Jun 95 16:41:20
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!parsifal.nando.net!eweaver
From: Eric Weaver <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.swap
Subject: Cheap HT Antennas
Date: Mon, 19 Jun 1995 13:25:19 -0400
Organization: News & Observer Public Access
Lines: 23
Message-ID: <[e-mail]>
NNTP-Posting-Host: parsifal.nando.net
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Xref: grape.epix.net rec.radio.amateur.antenna:11299 rec.radio.swap:37632


ORA Electronics has some HT antennas on sale that have BNC connectors,
and may be used in amateur applications. They also have many others that
would be more suitable for commercial applications. They are having a
"close-out" sort of sale, and have a lot of cellular/CB/commercial
antennas, among other cheap goodies.

Part number AV0102      - 4" VHF Rubber Duckie w/BNC    $2.00
Part number AX0101      - 6" UHF Rubber Duckie w/BNC    $2.00
Part Number CMS-MT-100  - Motorola type through hole mount
                          for antenna, 10 ft RG-58, TNC
                          connector (put your own BNC/PL259 on it)
                                                        $3.80

I do not have any connection to them, I just thought others might want to
get some of this stuff. Their number is 818-772-2700.

----------------------------------------------------------------------
 73 de ke4zer  /  [e-mail]  /  [e-mail]
----------------------------------------------------------------------
 Eric Weaver - Data/FAX [phone] - PO BOX 12741 RTP, NC 27709-2741
----------------------------------------------------------------------


From [e-mail] Mon 19 Jun 95 16:41:20
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!netline-fddi.jpl.nasa.gov!nntp-server.caltech.edu!news.claremont.edu!kaiwan.kaiwan.com!ledge!bob.albert
From: [e-mail] (BOB ALBERT)
Newsgroups: rec.radio.amateur.antenna
Subject: Coax wanted
Message-ID: <[e-mail]>
Date: Fri, 16 Jun 95 21:30:00 -0800
Distribution: world
Organization: The Ledge PCBoard: Lake View Terrace, CA: USA: 818-896-2007
Reply-To: [e-mail] (BOB ALBERT)
X-Newsreader: PCBoard Version 15.21
X-Mailer: PCBoard/UUOUT Version 1.10
Lines: 6

I am looking for about 100 feet of 50 Ohm coaxial cable.  The size
isn't critical; I need it for feeders for a 40m dipole at about 100
Watts.  It's for a nine year old who is getting his ticket, and I want
to make him an antenna.  I have the wire and insulators but lack the
feed line.  Anyone have such laying around and want to sell?
818-894-2887.  73 DE K6DDX

From [e-mail] Mon 19 Jun 95 16:41:21
Newsgroups: rec.radio.amateur.antenna,rec.radio.swap
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!nntp.crl.com!pacbell.com!amdahl.com!juts.ccc.amdahl.com!arl00
From: [e-mail] (Arlan R Levitan)
Subject: Computer Controlled Rotor War Stories
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Arlan R Levitan)
Organization: Amdahl Corporation, Sunnyvale CA
Date: Mon, 19 Jun 1995 18:43:55 GMT
Lines: 14
Xref: grape.epix.net rec.radio.amateur.antenna:11301 rec.radio.swap:37640

My logging program (AEA's LogWindows 2.0) supports several brands of
rotor control boxes with RS-232 interfaces. Most of them are three to five
hundred bucks, the notable exception being the Heath IntelliRotor.

I know this is a discontinued product which Heath will no longer service,
but at $170 or so, it's a tempting alternative to pricey boxes like the
DCU-01.

I'm thinking of getting the Heath controller and a compatabile rotor for
my first HF beam (a Cushcraft A3S replacing an R7) which goes up soon.

Any experiences with this beastie, or any other non-satellite computerized
rotor/control system would be greatly appreciated. Please reply here
rather than via mail.

From [e-mail] Mon 19 Jun 95 16:41:22
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (Dvitale2)
Newsgroups: rec.radio.amateur.antenna
Subject: Daiwa rotator help
Date: 17 Jun 1995 23:48:21 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 15
Sender: [e-mail]
Message-ID: <3s07m5$[e-mail]>
Reply-To: [e-mail] (Dvitale2)
NNTP-Posting-Host: newsbf02.mail.aol.com

I have a Daiwa MR-750PE multi torque rotator. I need another
motor for it. Daiwa evidently does not make it anymore and I
can't find anyone in the U.S. that sells parts or supports that
rotator. I have called many ham equipment distributors, like
A.E.S and H.R.O. ect....
If anyone knows where I can find a distributor in the states or
perhaps if anyone has a whole rotator system that they are not
using, I may be interested it purchasing it from you.
It's a super rotator. I don't know why Daiwa stopped
manufacturing it. With all four motors mounted on the housing it
will support up to 36 sq. ft of antenna. I just have one motor
mounted on the unit and in strong wind storms it will slip.
If anyone has info, either post on net or e-mail me.

Thanks, Dan Vitale  KD6P......73.

From [e-mail] Mon 19 Jun 95 16:41:22
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (Foto67)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Diamond vs Comet 2m/222/440 Omni?
Date: 19 Jun 1995 01:24:27 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 11
Sender: [e-mail]
Message-ID: <3s31mb$[e-mail]>
References: <3rnmmn$[e-mail]>
NNTP-Posting-Host: newsbf02.mail.aol.com

I have a Diamond, it's been up there for about 2 yrs. I live near Palm
Springs, so it gets its share of sun/heat in the sum - well most of the
year. I notice the looks are deteriorating, but haven't noticed drop in
performance. My buddy across town has the same in 144/220 version. He says
he's always sprayed coats of clear laquer on before putting up an antenna.
As to the brand I don't know, but one of the major brands. He says it'll
add ten yrs to the life.

The short of it is - so far we both like the Diamonds fine...
kd6pze


From [e-mail] Mon 19 Jun 95 16:41:23
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!demon!codesmth.demon.co.uk!dingbat
From: Andy Dingley <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: DIY discone for scanning
Date: 17 Jun 1995 03:19:16 +0100
Organization: Codesmiths, UK
Lines: 18
Sender: [e-mail]
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: dispatch.demon.co.uk
X-Newsreader: Newswin Alpha 0.7
X-Posting-Host: codesmth.demon.co.uk

I'm interested in building a discone for scanning (maybe 100-1000 MHz).
I'm not after massive gain, but as this is probably going to be my only
mast-mounted antenna, I'd like decent broadband coverage.

Any advice ? Any ftp-able plans ?

I'm a pretty competent machinist/welder/physicist, so manufacture
shoudln't be a problem.

Should I go for a discone, or would some sort of dipole nest /
collinear winding in a grp tube be better ?


Thanks

--
Andy Dingley                                      [e-mail]


From [e-mail] Mon 19 Jun 95 16:41:24
Path: grape.epix.net!news.sprintlink.net!uunet!news.inhouse.compuserve.com!news.production.compuserve.com!news
From: Tom Genereux <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: electric screwdriver tuned mobile a
Date: 16 Jun 1995 18:20:09 GMT
Organization: Priviate individual
Lines: 5
Message-ID: <3rsi0p$m3s$[e-mail]>

Has anyone had any experience with the HF 10-80m mobile antennas
that I see advertised as assembled or kit form, do they work
well? are they suitable for marine mobile use? does anyone have
any articles on how to build one.
                                  Tom KF2ST

From [e-mail] Mon 19 Jun 95 16:41:25
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!usc!news.service.uci.edu!dialin33658.slip.nts.uci.edu!user
From: [e-mail] (Rich Barron)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,alt.radio.scanner,alt.radio.digital,in.ham-radio,sci.electronics
Subject: Re: HELP me find this PART - NEWBIE (X K band trans)
Date: Sat, 17 Jun 1995 02:32:04 -0800
Organization: University of California, Irvine
Lines: 30
Message-ID: <[e-mail]>
References: <3rq4pm$[e-mail]>
NNTP-Posting-Host: dialin33658.slip.nts.uci.edu
Xref: grape.epix.net rec.radio.amateur.antenna:11218 rec.radio.amateur.equipment:13269 alt.radio.scanner:18956 alt.radio.digital:903 sci.electronics:131372

In article <3rq4pm$[e-mail]>, "Darin C. Ginther"
<[e-mail]> wrote:

> I am interested in building a device that will transmit microwaves
> at 10.525 Ghz (X band) and/or 22 Ghz (K band).  I need about 10 kilowatts
> of power.


OK, I think we've pretty much determined that you are looking for a 10
milliwatt device rather than 10 kilowatts. I also assume you are looking
for "The Zapper" which is an amature radio transmitter used to practice
call signs and morse code at the 10 GHz range. These are available in
plans (book with 30 other kits as well is $15, or $10 with kit purchase),
kit form (about $40), or fully built (about $50) from a place called
Electronic Rainbow. (317-291-7262) The hard part you are trying to find is
probably a GaAs FET made by a company called Avantek, which was bought by
HP a while back. The Avantek part number is AFT 26884-STR, and Electronic
Rainbow has them for $13 each.

You need to be careful when constructing this practice code transmitter
because if it is not properly tuned, it will set of peoples radar
detectors for about half a mile or so. If you are getting one of the kits,
it is a surface mount project which is a little harder to deal with than
normal kits due to the small parts and relative dificulty in getting
componants - not that it can't be done.

I've heard of K band devices, but don't know how they differ in
construction from the X band ones.

Ham radio swap meets usually have a person or two there selling such devices.

From [e-mail] Mon 19 Jun 95 16:41:25
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!news.alpha.net!earth!n9yjz
From: [e-mail] (Joseph Moschella)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,sci.electronics
Subject: Re: HELP me find this PART - NEWBIE (X K band trans)
Followup-To: rec.radio.amateur.antenna,rec.radio.amateur.equipment,sci.electronics
Date: 16 Jun 1995 04:48:40 GMT
Organization: Exec-PC
Lines: 5
Message-ID: <3rr2f8$[e-mail]>
References: <3rq4pm$[e-mail]> <3rqhjo$[e-mail]> <3rr0am$[e-mail]>
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: I just hope he's nowhere nearby when he turns this thing on.......

I just hope I'm in another hemisphere!

Joe, N9YJZ

From [e-mail] Mon 19 Jun 95 16:41:26
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (RFAcres)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HELP me find this PART - NEWBIE (X K band trans)
Date: 18 Jun 1995 10:37:11 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 26
Sender: [e-mail]
Message-ID: <3s1dmn$[e-mail]>
References: <3rq4pm$[e-mail]>
NNTP-Posting-Host: newsbf02.mail.aol.com

Dear Darin,

I think your quest for a 10.525 GHz, 10KW continuous duty transmitter may
be flawed in many ways.  Have you created a budget for this?  Have you
applied for a mondo gov't grant and have the $$ already? Are you one of
the filthy rich that can afford the lawsuits that would result from the
use of such a device?

Now once you do get this birdie zapper off the ground, please coordinate
with your local EPA office. You may have to declare a no-fault statement
regarding any holes that you may create in the ozone layer.

You aren't near an FCC office are you?

Please tell me you are not in the states of Georgia, Oregon, Washington,
Illinios and Maine.  We have family and friends in these and other states
that we would miss terribly.

Now if you're setting up your work shop in California or Texas, please
don't point it near a major fault or oil line.

Above all, please tell us you're kidding.  But if you're not, good luck!

anna of RFAcres ([e-mail], [e-mail], Packet: N9KHC@N4NIA)
                         "When the going gets tough, the tough go
shopping!"

From [e-mail] Mon 19 Jun 95 16:41:27
Path: grape.epix.net!news.sprintlink.net!demon!newbrain.demon.co.uk!Ian
From: Ian Robert Walker <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,sci.electronics
Subject: Re: HELP me find this PART - NEWBIE (X K band trans)
Date: 18 Jun 1995 20:22:47 +0100
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In article <3rr2f8$[e-mail]>
           [e-mail] "Joseph Moschella" writes:

> : I just hope he's nowhere nearby when he turns this thing on.......
>
> I just hope I'm in another hemisphere!

If you arn't you soon will be!

--
Ian G8ILZ
I have an IQ of 6 million, or was it 6?

From [e-mail] Mon 19 Jun 95 16:41:28
Path: grape.epix.net!news.sprintlink.net!cioeserv.cioe.com!jabbott
From: [e-mail] (john abbott)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,alt.radio.scanner,alt.radio.digital,in.ham-radio,sci.electronics
Subject: Re: HELP me find this PART - NEWBIE (X K band trans)
Date: 18 Jun 1995 23:34:41 GMT
Organization: CIOE Corporation
Lines: 14
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References: <3rrerb$[e-mail]>
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Lacroix Marc ([e-mail]) wrote:
: Darin C. Ginther ([e-mail]) wrote:
: : I am interested in building a device that will transmit microwaves
: : at 10.525 Ghz (X band) and/or 22 Ghz (K band).  I need about 10 kilowatts
: : of power.
: : This device must be able to create "harmful" interference on X and
: : K bands...Of course, this will only be used in a lab setting (HA!)..

: Hmmm, HARMFUL did you say ... That's the right word.

Looks like the laddie has had one traffic ticket too many or possibly believes
he has a hot product for 18-wheeler jockies.  Not too shabby until you begin to
realize it has to radiate in a 360 degree pattern to block ol' smokey, and the
driver sits in that 360 degree pattern.  Ugly sight - bar-b-qued 18wheeler!

From [e-mail] Mon 19 Jun 95 16:41:29
Path: grape.epix.net!news.sprintlink.net!news.infi.net!usenet
From: atanner <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,alt.radio.scanner,alt.radio.digital,in.ham-radio,sci.electronics
Subject: Re: HELP me find this PART - NEWBIE (X K band trans)
Date: 19 Jun 1995 03:30:27 GMT
Organization: InfiNet
Lines: 15
Message-ID: <3s2r0j$[e-mail]>
References: <3rrerb$[e-mail]> <3s2d6h$[e-mail]>
NNTP-Posting-Host: h-narnia.infi.net
Xref: grape.epix.net rec.radio.amateur.antenna:11282 rec.radio.amateur.equipment:13347 alt.radio.scanner:19018 alt.radio.digital:907 sci.electronics:131614

> : : I am interested in building a device that will transmit microwaves
> : : at 10.525 Ghz (X band) and/or 22 Ghz (K band).  I need about 10 kilowatts
> : : of power.

I think they sell a kit at Rat Shack that puts out about 20 pounds.
If that is too much for your application just put one of those
resistor thingies in series with the power supply. About a 1K-Ohm
one would probably work, if you are using 12 volts or use a lower
voltage battery.

Also, you can connect the power in the reverse direction on many
radar detectors and they will actually radiate instead of receive.
If you use 6 to 12 volts of AC, then, you can make a pretty good
radar, except you'll have to hook up to an oscilloscope modified
for circular scan.

From [e-mail] Mon 19 Jun 95 16:41:29
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (Runrobin)
Newsgroups: rec.radio.amateur.antenna
Subject: Help: Butternut minibeam
Date: 17 Jun 1995 17:41:05 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 8
Sender: [e-mail]
Message-ID: <3rvi5h$[e-mail]>
Reply-To: [e-mail] (Runrobin)
NNTP-Posting-Host: newsbf02.mail.aol.com

I would like to hear from anyone having knowledge or even an opinion re:
the Butternut 'butterfly' minibeam for 20, 17, 15, 12, and 10 mtrs. I need
aq 'clandistine' antenna, but I can put it up about 50 feet among the
trees in some woods. A larger beam or antenna would not be possible.
Comments pro and con would be appreciated. Please provide some data on teh
configuration, e.g. height above ground, etc, that you are commenting on.

Thanks.. Stan Schretter  W4MFZ

From [e-mail] Mon 19 Jun 95 16:41:30
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!netcom.com!dgf
From: [e-mail] (David Feldman)
Subject: HF on Jeep Cherokee
Message-ID: <[e-mail]>
Organization: Organization? Me?
Date: Sun, 18 Jun 1995 19:28:55 GMT
Lines: 25
Sender: [e-mail]

I succumbed to the Jeep Grand Cherokee lease deal and ended up with one,
replacing my old 84 AMC. Anyway, I'd like to mount a HF antenna (hustler
type) and could use some words of wisdom.

Options I can think of:

  1. Mag mount on roof. I had this on the AMC. Worked great but hard to
  avoid damaging the finish, and this is a lease car and will go back in
  2 years.

  2. Trailer hitch mount. I got a class-3 trailer hitch, but it seems that
  putting so much of the mast down that low will hurt efficiency. WOuld it
  be worth extending the mast another foot or two? The hustler is only
  7 feet long or so but I could accomodate much higher overall length.

  3. One of those SGC type antennas. 13' whip would be nice, but I don't
  want to drop the $$. Also the rig is FT900/AT and has it's own tuner.

  4. Lip mount, but not sure where to mount it. Car doesn't have a rear
  trunk per se.

Any other thoughts?

73 Dave WB0GAZ [e-mail]


From [e-mail] Mon 19 Jun 95 16:41:31
Path: grape.epix.net!news.sprintlink.net!news.clark.net!ronald
From: [e-mail] (Ron C.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF on Jeep Cherokee
Date: 19 Jun 1995 13:39:15 GMT
Organization: Clark Internet Services, Inc., Ellicott City, MD USA
Lines: 30
Message-ID: <3s3um3$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: clark.net
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Newsreader: TIN [version 1.2 PL2]

I have the 93 Jeep Grand Cherokee, FT900AT and use the Hustler mounted on
the trailer hitch using a foldover mount. It works great, probably
because I have it grounded in three placesunder the jeep. Grounding is
the key to success in mobile HF I believe. Good luck, 73 KM4VX RonDavid
Feldman ([e-mail]) wrote:
: I succumbed to the Jeep Grand Cherokee lease deal and ended up with one,
: replacing my old 84 AMC. Anyway, I'd like to mount a HF antenna (hustler
: type) and could use some words of wisdom.

: Options I can think of:

:   1. Mag mount on roof. I had this on the AMC. Worked great but hard to
:   avoid damaging the finish, and this is a lease car and will go back in
:   2 years.

:   2. Trailer hitch mount. I got a class-3 trailer hitch, but it seems that
:   putting so much of the mast down that low will hurt efficiency. WOuld it
:   be worth extending the mast another foot or two? The hustler is only
:   7 feet long or so but I could accomodate much higher overall length.

:   3. One of those SGC type antennas. 13' whip would be nice, but I don't
:   want to drop the $$. Also the rig is FT900/AT and has it's own tuner.

:   4. Lip mount, but not sure where to mount it. Car doesn't have a rear
:   trunk per se.

: Any other thoughts?

: 73 Dave WB0GAZ [e-mail]


From [e-mail] Mon 19 Jun 95 16:41:32
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!usc!nic-nac.CSU.net!vax.sonoma.edu!harrisok
From: [e-mail] (Ken Harrison)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Hustler 2m collinear opinions
Date: 14 Jun 95 20:46:27 -0800
Organization: Sonoma State University
Lines: 41
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <3rnvms$[e-mail]>
NNTP-Posting-Host: vax.sonoma.edu

In article <3rnvms$[e-mail]>, DB Wilhelm <[e-mail]> writes:
> [e-mail] (D. Larson) wrote:
>  > I forgot to ask another question...
>  >
>  > Whatever antenna I get will likely have a PL-259 that I will replace with
>  > a BNC so since I am already cutting coax, should I cut off the excess?
>  > I won't need nearly 17 feet of it, even though it will be mounted at the rear
>  > of the car.  Will this help reduce SWR or signal loss?
>  >
> Cutting off any excess will not effect the SWR on the line, although
> it may change the VSWR reading at the feed end of the line - due to
> the old effect of "my feedline length tunes my antenna".  It will
> however reduce your loss since loss comes in dB per foot, the fewer
> the feet, the less the loss.

But just how much loss are we looking at here?  Since the line is probably
RG-58U @ 2 meters, with 10 feet lobbed off we would be looking at .6 dB
(or thereabouts) less loss.  I don't believe that I would be worried about
that extra .6 dB.  Rather than risk screwing up the VSWR, screwing up the
BNC installation, etc., just use the stock length of coax.

Oh, and as far as the CG144 goes, I've got one.  I used it on a jeep that
already had a ball mount from a CB antenna.  That is the only reason I used it.
I wanted something that would get up higher than the body of the vehicle using
the existing mount.  I'd recommend a plain old 5/8 wave over the 7 foot tall
CG144.  I'm planning on converting the CG144 for use as a base antenna with a
ground plane.

73,
Ken

---


Ken Harrison                  [e-mail]                   Ham:  N6MHG
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Show me a man with both feet on the ground and I'll show you a man who can't
put his pants on."                                          -- Arthur K. Watson
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



From [e-mail] Mon 19 Jun 95 16:41:33
Path: grape.epix.net!news.sprintlink.net!news.ns.net!usenet
From: Chris Choulos <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Iso-loop Antenna
Date: 18 Jun 1995 01:32:12 GMT
Organization: NextGen Systems Internet Services
Lines: 3
Message-ID: <3rvvms$[e-mail]>
NNTP-Posting-Host: ppp16.ns.net

I'm thinking about getting an iso-loop antenna. I need something that will fit in my attic. Is there anyone out there that has used one and can give me an
I'll be using about 100 Watts from an ICOM 738.


From [e-mail] Mon 19 Jun 95 16:41:33
Path: grape.epix.net!news.sprintlink.net!nwfocus1.wa.com!news.halcyon.com!usenet
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Iso-loop Antenna
Date: Sun, 18 Jun 95 11:21:13 PDT
Organization: Northwest Nexus Inc.
Lines: 21
Message-ID: <[e-mail]>
References: <3rvvms$[e-mail]>
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In article <3rvvms$[e-mail]>, <[e-mail]> writes:

> I'm thinking about getting an iso-loop antenna. I need something that will
fit in my attic. Is there anyone out there that has used one and can give me
any comments on its performance.
> I'll be using about 100 Watts from an ICOM 738.


I am using a IsoLoop and it works very well.  I've had no problems and have
worked a lot of DX using it.  I have mine mounted 15 feet off the ground on
two 2 x 4s.

I have a friend who has his mounted in his attic.  We have never seen much of
a difference in performance.  Both seem to work equally well.

Bill





From [e-mail] Mon 19 Jun 95 16:41:34
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!uwm.edu!reuter.cse.ogi.edu!news.ssd.intel.com!chnews!vegas.ch.intel.com!cmoore
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ladder Line Q
Date: 17 Jun 1995 19:11:24 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 13
Distribution: world
Message-ID: <3rv9cs$[e-mail]>
References: <3rnpe0$[e-mail]>
NNTP-Posting-Host: vegas.ch.intel.com
Originator: [e-mail]

In article <3rnpe0$[e-mail]>,
Tony Smithson  <[e-mail]> wrote:
>I have access to a >150' tower at my office. I am considering putting my
>HF rig here at work.  I don't want to invest a lot of money in Hardline
>for an infrequent operating site.

Hi Tony, I assume from your posting that it is a single-band 50 ohm
antenna. Here's the solution: Feed it with ladder-line which is an
exact number of *electrical* half-wavelengths. Connect it to a 1:1
choke balun at the transmitter end. You will probably need to trim
or add some ladder-line to get the best SWR. Good luck.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)

From [e-mail] Mon 19 Jun 95 16:41:35
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netcom.com!jsoohoo
From: [e-mail] (John Soo-Hoo)
Subject: Re: Magnesium's Conductivity?
Message-ID: <[e-mail]>
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
References: <[e-mail]> <thomas.g.booth-080695161813@160.205.101.24>
Distribution: usa
Date: Mon, 19 Jun 1995 17:45:11 GMT
Lines: 30
Sender: [e-mail]

In article <thomas.g.booth-080695161813@160.205.101.24> [e-mail] (Booth, Thomas G) writes:
>In article <[e-mail]>, [e-mail] (Michael
>K. Davis) wrote:
>>
>> Does anyone know how well Magnesium tubing would perform in the construction
>> of a VHF or UHF yagi?   I'm looking to save weight, for backpacking, but have
>> no information about it's conductivity....
>>
>> Please reply by mail to [e-mail]
>>
>> Thanks,  AB6SL
>
>Well, my CRC book sez magnesium in the polycrystalline form has a
>resistivity of 4.45 microohm-cm, compared w/ 1.67 microhm-cm for copper,
>and 2.65 microhm-cm for aluminum (I rounded off the values for Al & Cu to
>the same number of significant digits as given for Mg).  I think you ought
>to get a feel for conductivity from these figures.
>
>I don't have any experience using Mg in antennas, so I really can't share
>any experience...
>

From what I can remember about magnesium, it will rust and it will burn.
I suggest sticking to copper or aluminum or a aluminum-magnesium alloy (if
you must have mangesium).


It's also kinda expensive.



From [e-mail] Mon 19 Jun 95 16:41:36
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!asuvax!news.asu.edu!aztec.asu.edu!hamop
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Matching 75 ohm hardline???
Date: 17 Jun 1995 03:30:54 GMT
Organization: Arizona State University
Lines: 9
Message-ID: <3rti9e$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


Use a "series section transformer" which consists of a section of
line having Zo either greater or lesser than the Zo of the main
line inserted in series with the main line .  Formulas are available
for calculation of length to be inserted and distance from end of
the main line.
Charlie, W7XC
--


From [e-mail] Mon 19 Jun 95 16:41:36
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Path: grape.epix.net!news.sprintlink.net!mv!usenet
From: [e-mail] (L. M. Rappaport)
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Message-ID: <[e-mail]>
Nntp-Posting-Host: lmr.mv.com
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Date: Sat, 17 Jun 1995 18:41:31 GMT
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[e-mail] (Gary Coffman) wrote:

>In article <[e-mail]> [e-mail] (L. M. Rappaport) writes:

>>Where my scheme breaks down at the moment is that the tower has two
>>individual ground rods and there is one on each of three guy wires.
>>I'd guess that could cause a loop, eh?

>Connect them in a star at the tower base, and then connect that
>point back to the star at the house. A star of stars is an acceptable
>topology.

The guys are steel and not insulated from the tower.   In addition,
the tower base is also grounded.  I can connect all those grounds as a
star which then connects to the star at the house, but doesn't the
tower + grounds constitute 3 loops in the tower star?

IE, if the tower is grounded, a guy wire is grounded, and connecting
each of those to another, common, star create a loop?

Thanks, Gary,

Larry


--
Larry Rappaport W1HJF
[e-mail]
[e-mail]


From [e-mail] Mon 19 Jun 95 16:41:38
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.digital.misc
Path: grape.epix.net!news.sprintlink.net!mv!usenet
From: [e-mail] (L. M. Rappaport)
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
Message-ID: <[e-mail]>
Nntp-Posting-Host: lmr.mv.com
Sender: [e-mail] (System Administrator)
Organization: MV Communications, Inc.
Date: Sun, 18 Jun 1995 17:49:55 GMT
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[e-mail] (Gary Coffman) wrote:

...edited

>It's a circle, but it's not a ground loop.

>A ground loop occurs when two current meshes share a common
>element.

>If we eliminate the shared impedance by collapsing the buss to
>a star, the ground loop goes away.

>The guy wires don't represent a ground loop because there aren't
>two current meshes.

>                 x-------------(SL1)
>               / | \             |
>              /  |  \            |
>             /   |   \           |
>            /    |    \          |
>           /     |     \         |
>           x-/\/-x-/\/--x--------x
>           |Rg1  |  Rg2 |
>           |_____*______|
>                star

>Where Rg1 and Rg2 are the impedances of the individual strips
>of Earth connecting the guy anchors with the tower base. These
>are shorted by the star connection and can be ignored. The
>current source is SL1 which represents a lightning bolt flowing
>current to Earth. The current will divide at the tower top, with
>some flowing down the tower, some flowing down one guy, and some
>flowing down another. The guys are in *parallel* with the tower
>between Earth and sky. There's only one current mesh, and no
>ground loop. The tower looks like the common element of our
>ground loop example above, but it isn't because all the currents
>are flowing in one mesh.

>Now if the star were missing, and some piece of equipment's
>current mesh bridged a guy anchor and the tower base across
>Rg1 or Rg2, *then* you'd have a ground loop. Currents flowing
>across Rg1 would induce a potential that would be seen in
>the equipment current mesh, and alter the current flowing
>through that mesh. By starring the grounds, we short circuit
>that possibility.

Ok, now I understand.  It's the common point obtained by tying the
bottom of the guys and tower together in a star which changes the
configuration from a loop to a "mesh".  In turn by tying the mesh into
a the star at the house entrance panel eliminates the loop which might
be formed between the two stars were they not connected.

Thanks for the help, Gary.

73, Larry
--
Larry Rappaport W1HJF
[e-mail]
[e-mail]


From [e-mail] Mon 19 Jun 95 16:41:39
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From: [e-mail] (L. M. Rappaport)
Subject: Re: NEED HELP!  Respond : Grounding 'Experts' !
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In any case, by effectively shorting (bridgeing to a common point) the
tower base and the three guy wires, eliminates the possiblity for
ground loops, correct?  Bascially, all grounds go to a common point
(by the utility meter) and are starred out from there.

I'm going to have to do a little rework this summer.  I've been lucky
so far!

Larry
--
Larry Rappaport W1HJF
[e-mail]
[e-mail]


From [e-mail] Mon 19 Jun 95 16:41:39
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From: [e-mail] (KC6ZCR)
Newsgroups: rec.radio.amateur.antenna
Subject: Oubacker differences
Date: 17 Jun 1995 01:34:58 -0400
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Is there a difference in performance between the Outbacker Antennas OB
series?

Thank you in advance and please E-mail me directly at:
[e-mail]

73, Dominic

From [e-mail] Mon 19 Jun 95 16:41:41
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Outbacker Antennas
Date: 17 Jun 1995 17:55:17 GMT
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In article <3rl728$[e-mail]>,
Med Stud <[e-mail]> wrote:
>I'm thinking of getting an Outbacker antenna for my pathfinder.  What is
>the general feeling about this antenna.  Is it worth the money?

Hi Don, IMO the Outbacker is too much money for too little performance.
A bugcatcher with a top hat seems to beat them all. The screwdriver
antennas are a close second. Hamsticks came in last in the contest
reported by Worldradio. Outbackers did not compete in the contest
but IMO would rank about the same as Hamsticks (somebody please
correct me if I'm wrong).

The mobile antenna problem is different if you don't work the low
bands, i.e. below 14 MHz. I use an SGC-230 and a 13 ft whip to
cover 10m-20m. It has low-angle gain over any shorter antennas
on 10m-15m. For 75m, I use a bugcatcher. For 40m, I use a Hamstick
mounted on top of a 4.5 ft Hustler bottom section. This 13 ft.
configuration slightly outperforms the 8 ft. bugcatcher on 40m
and doesn't have as much wind resistance.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)



From [e-mail] Mon 19 Jun 95 16:41:41
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From: [e-mail] (Larry Fisher)
Newsgroups: rec.radio.amateur.antenna
Subject: Outbacker on 80 mtrs
Date: 18 Jun 1995 06:38:48 GMT
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I got my Outbacker to work quite well on all the bands but it won't
cooperate on 80.  The SWR is way too high to put any power into it, and I
don't know if there was supposed to be another stinger for that band or
not.  I've only got the one stinger that's about 6" long or so.  The SWR
indicates that I need to extend my stinger more to lower the resonant
freq.  At present it is somewhere off band.  If someone has had
experience with this antenna on 80 mtrs I could sure use some input.

[e-mail]


--
--- Larry Fisher RPT, Portland Metro's Authority on PianoDisc Systems
        For more information call [phone] in Vancouver, Wa.

From [e-mail] Mon 19 Jun 95 16:41:42
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: Don Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 17 Jun 1995 16:10:24 GMT
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[e-mail] (W8JI  Tom) wrote:
>
> I think perhaps we are all leaving something out of this!
>
I think what is being left out is the fact that the 95 ohm coax
is not running with a 1:1 SWR.  While the SWR at each end of the
paralleled lines can be close to 1:1 for a 50 ohm source and load,
each line not running with a 1:1 SWR, off the top of my head, I
feel like it should be 2:1 (haven't done the math) so the actual
loss on each line is higher.  My feeling is that the final result
should be close to the loss of the single line running with a
flat SWR.

73,
Don W3FPR

From [e-mail] Mon 19 Jun 95 16:41:43
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 16 Jun 1995 16:18:13 -0400
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Hello Again,

Someone help me out here, this is a great question!

First issue:
The original response and my response appear generally correct. The loss
is
the same if two lines are paralleled as in one line by itself if the line
SWR
is 1:1 in both circumstances.

The reason is that the current in each line remains the same when they
remain
"matched", so the losses are the same.

Roy's answer appears to be correct if the load impedance was constant at
50
ohms.

If the line loss is dominated by the conductor resistance, losses should
also
be non-symmetrical with electrically short lines. If the voltage is
increased
while current is decreased the losses should go down. That is contrary to
common opinion, but may certainly be true.

Secondly, look at the case of the 450 ohm line. It would carry one ampere
at
450 watts, a 50 ohm line would have three amperes. I*I / R losses are 9
times
worse (the same loss ratio as the impedance ratio).

The conductor radius in a custom RG-58 PTFE type 50 ohm line I have is the
same size as the conductor in the ladder line. The braid normally has
around
three times the loss resistance of a smooth conductor, but the shield much
larger diameter than the center conductor and this cable has an inner
layer
of copper foil. So the total copper path RF resistance in the coax should
be
around half the 450 ohm line (using two equal size wires) resistance. So
with
nine times the "current caused" power loss (three times the current) the
loss
should be around 4.5 times the loss in the 450 ohm line, or about 6 or
seven
dB worse.

At 30 MHz the loss in the 50 ohm cable is 5.8 dB per c feet. The ladder
line
loss is .05 dB per c feet. The difference is around 6 dB!

That seemed to work pretty good, didn't it!

Now my puzzlement.

This means cable loss charts and fromulas are incorrect or incomplete
doesn't
it? They show the same additional loss for an equal SWR caused by an
increased or decreased load impedance! Increased load impedance, even if
it
causes a higher SWR, should lower the loss of a short line.

73 Tom

From [e-mail] Mon 19 Jun 95 16:41:44
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From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: Sat, 17 Jun 1995 01:16:46 GMT
Organization: Ericsson
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[e-mail] (Gary Coffman) wrote:

> [snip]                                         It would
>seem highly coincidental if copper losses and dielectric
>losses were equal for all frequencies. We know that Rd must
>be significant because air dielectric lines have much less
>loss than poly dielectric lines with the same size conductors.
>OTOH, we also know Rc is significant since cables with smaller
>conductors have greater losses. But can we prove Rd=Rc for
>any cable?

>I'll leave that as an exercise to the reader. :-)


No, but we can sure calculate loss for any coax at any frequency.  The
proper formula for doing so involves too many variables and constants
that need to be explained or presented in table form for each type of
material used.  I could not come up with a simple way of presenting it
here.  But...  today only, for those of you following this thread,
I'll let you in on a how to get a GREAT 45 page reference that has all
the M17 (military screened) and RG coaxial cables listed with all
their specifications.  It also has many formulas and application notes
involving things like resistance to the envoronment, cross-talk,
physical strength, self-generating cable noise (measured more than
500mV of electrical noise on an RG cable), attenuation stability and
uniformity, and on and on.

So how much you ask?  I got mine free for the asking about 18 months
ago from:

     Times Microwave Systems (formerly known as Times Wire and Cable)
     a Division of Smiths Industries
     P.O Box 5039
     Wallingford, Connecticut 06492
     [phone]

The catalog munber is TL-13 and is entitled:
     COAXIAL CABLE
     THE COMPLETE CATALOG AND HANDBOOK

They make a very good product too for those interested.
Now don't go posting this around or anything, just IF you are
interested, you might politely ask if they have any more booklets
available.  And don't mention my name (unless you're going to buy 100K
feet or so.)  ;-)

=====================================================================
Now, as far as the thread goes...
I would be MORE concerned with a greater risk of impedance spikes
(those who have ever swept coax on a network analyzer know what I
mean) by nailing the 2 coaxs in parallel, than I would with a couple
of dB more or less loss.  I personally would not want to use this for
anything other than HF.  Besides, ever try to stuff two cables at one
time into one of those PL-259s???  <grin>

Mike KD6PKJ


From [e-mail] Mon 19 Jun 95 16:41:45
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From: [e-mail] (Richard Karlquist)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 18 Jun 1995 03:04:41 GMT
Organization: Hewlett-Packard
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In article <3ruupg$[e-mail]>,
Don Wilhelm  <[e-mail]> wrote:
>[e-mail] (W8JI  Tom) wrote:
>>
>> I think perhaps we are all leaving something out of this!
>>
>I think what is being left out is the fact that the 95 ohm coax
>is not running with a 1:1 SWR.  While the SWR at each end of the
>paralleled lines can be close to 1:1 for a 50 ohm source and load,
>each line not running with a 1:1 SWR, off the top of my head, I
>feel like it should be 2:1 (haven't done the math) so the actual
>loss on each line is higher.  My feeling is that the final result
>should be close to the loss of the single line running with a
>flat SWR.
>
>73,
>Don W3FPR

Another clever intuitive argument that happens to be wrong.
Two paralleled 100 ohm lines between 50 ohm source and load
is a perfectly matched system (i.e., there is no reflection
at the point where the line splits or the point where it
recombines.)  Hence the only mismatch with the two 95 ohm lines
is the mismatch due to having 95 ohms instead of 100 ohms
(which amounts to a 1.05 to 1 VSWR )  We should all be so
lucky as to have an antenna that is matched that well (at
more than a single frequency.)


Rick Karlquist N6RK
[e-mail]

From [e-mail] Mon 19 Jun 95 16:41:46
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From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: Sat, 17 Jun 1995 01:22:10 GMT
Organization: Ericsson
Lines: 5
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References: <[e-mail]> <3rtadu$[e-mail]>
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X-Newsreader: Forte Free Agent v0.55

Oops, I gave you the fax number.
The phone number is [phone].

Mike


From [e-mail] Mon 19 Jun 95 16:41:47
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 18 Jun 1995 06:46:12 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 20
Sender: [e-mail]
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Mike,

>No, but we can sure calculate loss for any coax at any frequency.  The
proper formula for doing so involves too many variables and constants
that need to be explained or presented in table form for each type of
material used.  I could not come up with a simple way of presenting it
here.<

I can find the long formulas using conductor and dielectric losses and so
on to calculate losses in reference engineering textbooks but right along
with it are formulas and nomographs that show the loss for increased SWR.
They give consideration to conductor losses but then simplify it to a VSWR
problem.

I'm still having a difficult time believing all these books are
overlooking something so important, but that has been known to happen (see
meaning of matched ;-) ).

73  Tom


From [e-mail] Mon 19 Jun 95 16:41:47
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From: [e-mail] (Jeff DePolo)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 18 Jun 1995 19:18:17 GMT
Organization: University of Pennsylvania
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References: <[e-mail]> <3rtadu$[e-mail]>
NNTP-Posting-Host: red.seas.upenn.edu

In article <3rtadu$[e-mail]>,
Mike Groves <[e-mail]> wrote:
>Now, as far as the thread goes...
>I would be MORE concerned with a greater risk of impedance spikes
>(those who have ever swept coax on a network analyzer know what I
>mean) by nailing the 2 coaxs in parallel, than I would with a couple
>of dB more or less loss.  I personally would not want to use this for
>anything other than HF.  Besides, ever try to stuff two cables at one
>time into one of those PL-259s???  <grin>

There shouldn't be any impedance anomalies along the lengths of the
cables unless there is actually something physically wrong with them.

BTW, KLM routinely sticks two cables into a single PL-259.  Their 40m
monobanders use two parallel pieces of RG58-sized RG400 Teflon cable
as a transformer, and they share a common PL259 at each end.

                                                        --- Jeff
--
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 Jeff DePolo  WN3A            Twisted Pair: H:610-337-7383  W:215-387-3059 x300
 [e-mail]  RF: 442.1 442.2 442.4 443.8 444.15 link system
 Claim to Fame: I got the first speeding ticket on the information superhighway

From [e-mail] Mon 19 Jun 95 16:41:48
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!ix.netcom.com!netnews
From: [e-mail] (Ted Viens)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 18 Jun 1995 21:24:44 GMT
Organization: Netcom
Lines: 32
Distribution: world
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In <3ruupg$[e-mail]> Don Wilhelm <[e-mail]> writes:
>
>[e-mail] (W8JI  Tom) wrote:
>>
>> I think perhaps we are all leaving something out of this!
>>
>I think what is being left out is the fact that the 95 ohm coax
>is not running with a 1:1 SWR.  While the SWR at each end of the
>paralleled lines can be close to 1:1 for a 50 ohm source and load,
>each line not running with a 1:1 SWR, off the top of my head, I
>feel like it should be 2:1 (haven't done the math) so the actual
>loss on each line is higher.  My feeling is that the final result
>should be close to the loss of the single line running with a
>flat SWR.
>
>73,
>Don W3FPR

What I think is left out is the suggestion that the dual leads be used
in a shielded balanced line configuration.  I am too lazy to dig out my
Handbook, but I think the shielded balanced line configuration would
give you the greatest efficiency in getting signal to and from your
antenna.  It would also demand some study and experimentation in
matching techniques at the antenna and transmitter and allow you to
take advantage of the balanced output of your antenna tuner.  It may be
arcane of me to suggest that experimentation has been one of the
foundation principles of amateur radio but it is not arcane at all to
suggest that we try to get the most bang for our buck or available
resources.
--
Bye...  Ted..
Deep in the Heart of the Armpits of Houston, Texas...

From [e-mail] Mon 19 Jun 95 16:41:49
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 18 Jun 1995 23:27:17 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 32
Sender: [e-mail]
Message-ID: <3s2qql$[e-mail]>
References: <3s25is$[e-mail]>
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NNTP-Posting-Host: newsbf02.mail.aol.com

Here's what I think we are doing with the look at purely the conductor
resistance. We can not treat the line like it is operating at dc, nor can
we ignore the reactance changes as we move along the line.

For example, if I have two 95 ohm lines the same length and terminated
in the same 95 ohm load. One has low conductor resistance-and one
has high conductor resistance. If the input impedance is the same, each
line will receive exactly equal amounts of current at the generator. The
only difference is the one with higher resistance will supply less power
to the load!

Second, doesn't the VAR (volt amperes reactive) increase in the
mismatched line, whether the load is lower Z or higher Z? I think that
may be the thing we are ignoring.

If the VAR wasn't the problem, and the loss was all from I sqrd R loss
in the conductors, there would be no difference at all in the loss with a
high load Z or SWR or a low load Z or SWR if the line was 1/4 wl
long. Because as much as the current increased at one end of the line, it
would decrease the same amount at the other end!

I think the lower loss with a higher load resistance argument is
seriously flawed unless the line is *very* short in wavelengths or
operated with dc.

I believe the problem is the VAR increase in the mis-terminated line of
any significant length. It causes the apparent current to increase no
matter which way the load Z goes. The reactive component causes the
apparent current to be higher than the real current we extract at the
load.

73 Tom

From [e-mail] Mon 19 Jun 95 16:41:50
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!agate!holonet!colossus.holonet.net!cencore!forrest.gehrke
Distribution: world
Newsgroups: rec.radio.amateur.antenna
Subject: PARALLEL 95 OHM COAX
From: [e-mail] (Forrest Gehrke)
Message-ID: <[e-mail]>
References: <[e-mail]>
Date: Fri, 16 Jun 1995 11:34:00 -0500
Organization: Central Core BBS   201.575.8991
Lines: 29



RL> My vote: The loss is 1/2 the loss of a single piece of the high-Z
RL> coax.

Roy, Why wouldn't the loss be the same?
Assume each RG-62 line is 100 feet long and has a
loss of 3dB per 100 feet at the frequency of
interest.

We parallel two such lines and we start out with
100 watts.  But we are now dividing that power
to 50 watts per line.  We lose 25 watts in each
line.  But we lose a total of 50 watts--the same as if
we had only used one line.

(Maybe it's just semantics--you may be meaning that
each line would sustain 1/2 of the loss when paralleled
that single line would dissapate?)

No one mentioned it, but we have 47.5 ohms on 95 ohm
characteristic Z line, so we have VSWR of 2:1 on
each line and there will be a small additional loss
due to VSWR.  (This comment assumes that with a
single line we had 95 ohm load--obviously if the
load were 47.5 ohms in each case, there would
be no difference).
73, --k2bt
 * RM 1.3 02583 * I found the source code for life!  But I can't read it :(

From [e-mail] Mon 19 Jun 95 16:41:51
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!convex!darwin.sura.net!fconvx.ncifcrf.gov!mack
From: [e-mail] (Joe Mack)
Subject: Re: PL-259's and 9913
Message-ID: <[e-mail]>
Organization: Frederick Cancer Research and Development Center
References: <3rsd8h$[e-mail]>
Date: Fri, 16 Jun 1995 17:50:58 GMT
Lines: 22
Xref: grape.epix.net rec.radio.amateur.antenna:11212 rec.radio.amateur.equipment:13267

In article <3rsd8h$[e-mail]> [e-mail] (Steve Bertsch) writes:
>When using PL-259's with Belden 9913, is there any trick to dealing with the
>braid and foil inner shield? Do I just take my x-acto and slice the whole
>works down to the center conductor, and hope nothing shorts out?
>
>PS If you're going to say "Use N connectors," don't. The rig, antenna switch,
>SWR meter, etc. have UHF connectors, and I'm too lazy to change everything.

I put adapters etc onto the SWR meter and then I can do everything with N.
It can be done.

Friends don't let friends use PL-259's..

        Joe Mack NA3T
        [e-mail]


>
>Thanks,
>Steve N8KWV



From [e-mail] Mon 19 Jun 95 16:41:52
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From: [e-mail] (Mark A. Garrett)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PL-259's and 9913
Date: 16 Jun 1995 19:30:13 GMT
Organization: University of Illinois at Urbana
Lines: 29
Message-ID: <3rsm45$[e-mail]>
References: <3rsd8h$[e-mail]>
Reply-To: [e-mail] (Mark A. Garrett)
NNTP-Posting-Host: firefly.prairienet.org


In a previous article, [e-mail] (Steve Bertsch) says:

>When using PL-259's with Belden 9913, is there any trick to dealing with the
>braid and foil inner shield? Do I just take my x-acto and slice the whole
>works down to the center conductor, and hope nothing shorts out?
>
>PS If you're going to say "Use N connectors," don't. The rig, antenna switch,
>SWR meter, etc. have UHF connectors, and I'm too lazy to change everything.
>
>Thanks,
>Steve N8KWV

There is no real trick to using UHF connectors on 9913.  I use UHF
connectors on the solid center conductor 9913 with very good results. I
usually trim back the foil and braid so that if it is pulled forward before
the connector is attached, it will not make contact with the center
conductor.  I then go ahead and prep the connector just like any other RG-8
style coax.  I did use N connectors on this run but was constantly having
problems with the braid working loose from the connector and causing the
connector to spin.  I have had no problems with using the UHF connectors
since the braid is soldered directly to the connector and even before
soldering it has a strong mechanical bond since it is threaded on to the
coax.  I now prefer using UHF over N for this reason.
I do recommend that you use a good quality UHF connector for this coax.>

--
Mark Garrett   [e-mail]
               KA9SZX @ N9LNQ.#ECIL.IL.USA.NOAM

From [e-mail] Mon 19 Jun 95 16:41:53
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!gatech!bloom-beacon.mit.edu!crl.dec.com!crl.dec.com!lead.zk3.dec.com!usenet
From: Jim McHale - NM1W <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Re: PL-259's and 9913
Date: 19 Jun 1995 19:05:32 GMT
Organization: WHATX
Lines: 9
Message-ID: <3s4hps$[e-mail]>
References: <3rsd8h$[e-mail]> <3rsm7e$[e-mail]>
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X-URL: news:3rsm7e$[e-mail]
Xref: grape.epix.net rec.radio.amateur.antenna:11302 rec.radio.amateur.equipment:13373

Solderable N connectors are available and avoid the hassles of cable twisting
and coming out;
I prefer the soldered connections.
--
=======================================================================
Jim McHale,NM1W                First Strike Software Inc   [e-mail]
    Mac/OSF/Unix consulting                603-329-7885
=======================================================================


From [e-mail] Mon 19 Jun 95 16:41:53
Path: grape.epix.net!news.sprintlink.net!cam.news.pipex.net!pipex!soap.news.pipex.net!pipex!edi.news.pipex.net!pipex!sunic!sunic.sunet.se!seunet!news2.swip.net!news.algonet.se!usenet
From: [e-mail] (Jan Olof Bergsten)
Newsgroups: rec.radio.amateur.antenna
Subject: Plans for T2FD ??
Date: Sun, 18 Jun 1995 21:31:03 GMT
Organization: SM7ETW
Lines: 5
Message-ID: <3s26k6$[e-mail]>
NNTP-Posting-Host: sophocles.algonet.se
X-Newsreader: Forte Free Agent v0.55

Does anybody have plans for a T2FD antenna ?

73 SM7ETW Jan



From [e-mail] Mon 19 Jun 95 16:41:54
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netnews
From: [e-mail] (Ron Klein)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Date: 18 Jun 1995 13:44:23 GMT
Organization: Netcom
Lines: 43
Distribution: world
Message-ID: <3s1ajn$[e-mail]>
References: <3rf6tn$[e-mail]> <[e-mail]> <3rhsmj$[e-mail]>
NNTP-Posting-Host: ix-ftc-co1-23.ix.netcom.com

In <3rhsmj$[e-mail]> [e-mail] (Doug Snowden)
writes:

>
>: >I would like to put up some Rohn-25 with a 6 element uagi without guys if

>: >possible.  I have 2 house brackets.  Someone said 30' over the last one
>: >is ok.  Is this right?
>: >
>
>: Absolutely NOT! Rohn 25G is designed to be guyed. It is rated to carry 30
>: lbs./sq foot Wind load, with 6 sq ft of allowable load, but only when
>: guyed. Even the 40 foot tower has two sets of guys in the plans, at 20
>: feet and at 40 feet. If the top set are left out, the load should be
>: derated by 50 %, which won't include any 6 el HF antenna.
>
>: This info is taken from the Unarco Rohn catalog.
>
>I am not an authority on this subject, but I am sure I have seen somewhere
>that a Rohn 25 will support some sort of load up to 40ft unguyed. Of
>course with a good base.
>
>--
>Doug  Snowden
>work: [phone]
>home: (407) 98409360
>[e-mail]
>
>

The Rohn 25 is NOT designed to be unguyed - if you meen as a freestanding
tower with no house bracket to support it.

I recently testified as an expert witness (I hold a PE license) in a case
involving just that question.

--
Ron Klein - W0OSK
-----------------
[e-mail]




From [e-mail] Mon 19 Jun 95 16:41:55
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rotator wire multiband antenna
Date: 18 Jun 1995 00:51:23 GMT
Organization: News & Observer Public Access
Lines: 37
Message-ID: <3rvtab$[e-mail]>
References: <3rpfm3$[e-mail]>
NNTP-Posting-Host: grail913.nando.net

[e-mail] (Ed Bathgate) wrote:
>
>
>
> A while back somebody posted a design of a multiband dipole made of
> flat 5 wire rotator cable.  Does this design work?  What were the lengths
> of the sides?
>
Great idea, and it can be made to work, but is not the best way to
set up parallel dipoles.  Using the 5 conductor wire is probably the
most economical, easily obtainable source of wire for this type of
antenna,

Problem is, the lowest frequency antenna can be easily tuned, but
when you try to cut the length of the second harmonic of the
lower frequency, you may find yourself with a real chore.  The last
time I tried it (for a portable inverted vee, I gave up.  I cut the
lowest frequency for 40 mtrs, no problem, then I tried to cut the
second set for 20 mtrs.  I finally stripped the 20 mtr conductors
away from the 40 mtr portion, and positioned them at right angles
to the 40 mtr wires.  After adding a bit of length to my prevoiusly
cut 40 mtr dipole, I was able to get the 20 mtr wires tuned.  15
mtrs runs parallel to the 20 mtr dipole, and 10 mtrs is parallel
to the 40 mtr one.  I was able to tune them all in this way,
It is a lot of cut and try, and you can get it to work, but if
your patience limit is anything like mine, you might give up and
spread them from the start.

Sorry, I don't have convenient lengths, I start with about 5% longer
than the standard formula of 468/f(MHz) and prune from there.
I will prune for either resonance or 1:1 VSWR depending on what my
goal is at the moment.  (resonance and 1:1 VSWR are not usually
at the same length for a coax fed dipole or inverted vee).

73,
Don W3FPR


From [e-mail] Mon 19 Jun 95 16:41:56
Path: grape.epix.net!news.sprintlink.net!news.bluesky.net!solaris.cc.vt.edu!swiss.ans.net!prodigy.com!usenet
From: [e-mail] (Jason Smith)
Newsgroups: rec.radio.amateur.antenna
Subject: Scanner Antenna?
Date: 18 Jun 1995 15:36:52 GMT
Organization: Prodigy Services Company  1-800-PRODIGY
Lines: 3
Distribution: world
Message-ID: <3s1h6k$[e-mail]>
NNTP-Posting-Host: inugap1.news.prodigy.com
X-Newsreader: Version 1.2

Could anyone recommend a good scanner costing under 75$'s for a Uniden
Bearcat BC700A that has 800\900mhz frequencys?


From [e-mail] Mon 19 Jun 95 16:41:56
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!ix.netcom.com!netnews
From: [e-mail] (William Rice)
Newsgroups: rec.radio.amateur.antenna
Subject: RE: SGC 230
Date: 17 Jun 1995 12:15:08 GMT
Organization: Netcom
Lines: 7
Distribution: world
Message-ID: <3ruh0c$[e-mail]>
NNTP-Posting-Host: ix-atl8-27.ix.netcom.com



    Reference the postings about vehcle mounted antennas: The SGC 230
makes a great random/long wire tuner.

        David Panek, KE4MLV


From [e-mail] Mon 19 Jun 95 16:41:57
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!uwm.edu!reuter.cse.ogi.edu!news.ssd.intel.com!chnews!vegas.ch.intel.com!cmoore
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SGC-230 auto tuner
Date: 17 Jun 1995 18:14:24 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 22
Distribution: world
Message-ID: <3rv620$[e-mail]>
References: <3rj8c9$[e-mail]> <[e-mail]> <[e-mail]>
NNTP-Posting-Host: vegas.ch.intel.com
Originator: [e-mail]

In article <[e-mail]>,
Rajiv Dewan <[e-mail]> wrote:
>
>It is quite well known that base loaded short verticals (SGC) are
>outperformed, with regards to field strength, by mid-point loaded
>short verticals with top hats (Bugcatcher).

Hi Rajiv, nobody is saying that the SGC with a 102 inch whip will
outperform a bugcatcher on 40m. Even with my 13 ft whip, the SGC
comes in about one 'S' unit down from my bugcatcher. The key word
in your posting is "short".

On 17m, my SGC-230 plus 13 ft whip very slightly outperforms the
bugcatcher. On 12m, there is no contest. The SGC-230 plus 13 ft
whip is about one 'S' unit *better than the bugcatcher*.

The moral is, given whatever boundary conditions, what is the best
configuration? For my boundary conditions, The SGC-230 plus 13 ft.
whip is the best choice. Your milage may vary. Just don't dismiss
something without thinking about it first.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)

From [e-mail] Mon 19 Jun 95 16:41:58
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!reuter.cse.ogi.edu!news.ssd.intel.com!chnews!vegas.ch.intel.com!cmoore
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SGC-230 auto tuner
Date: 17 Jun 1995 19:04:00 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 42
Distribution: world
Message-ID: <3rv8v0$[e-mail]>
References: <3rj8c9$[e-mail]> <[e-mail]>
NNTP-Posting-Host: vegas.ch.intel.com
Originator: [e-mail]

In article <[e-mail]>,  <[e-mail]> wrote:

>How can the SGC unit be one 'S' unit down from a Bugcatcher when in the
>SGC literature it states, "you can get more than 20 dB of gain by simply
>using an SGC compared with any other 1.8 to 30 MHz system." You must, of
>course, be in error with your statement.

Hi Armond, I have my doubts about that quote of yours. Here's the
exact quote from the SGC advertisment:

"But once you use it, you'll find an almost unbelievable jump in
reception and transmitting range (3-20db)."

It does not say *compared with _any_ other 1.8 to 30 MHz system*.
I inferred they were comparing it to a 102 inch whip tuned by a
mobile antenna tuner located at the transceiver. If you assume
that, then their db figures make sense. The SGC-230 manual clearly
explains how they arrived at that 20 db figure and it certainly
wasn't by comparing it to a bugcatcher. Of course, you haven't
bothered to RTFM.

The SGC system will not perform as well as a bugcatcher below
17m. My SGC-230 with a 13 ft whip is equal to an 8 ft. bugcatcher
on 17m and BETTER than the bugcatcher on 15m, 12m, and 10m. I
rarely work any bands mobile below 18MHz. I can switch
bands on the fly and achieve results superior to a bugcatcher
for which I would have to stop the truck. Now you tell me, which
is the better choice for my type of operation? I *have* a bugcatcher
and I choose to use the SGC-230 and the 13 ft. whip because it
PERFORMS BETTER _AND_ is more convenient to operate.

Your problem is, you cast everything in the worst possible light.
You have never said anything good about the SGC-230 but it is
the best possible solution to _some_ problems; not all
problems, and maybe not most problems, but _some_ problems.
There are probably hams who have passed over the SGC solution
even though it would be their best solution (like mine) because
of the mis-directed "information" in "Aerials" and now "CQ".

I have no connection with SGC except as a super satisfied customer.

73, Cecil, KG7BK, OOTC, xIRE  (not speaking for my employer)

From [e-mail] Mon 19 Jun 95 16:41:59
Path: grape.epix.net!news.sprintlink.net!uunet!george.inhouse.compuserve.com!news.inhouse.compuserve.com!news.production.compuserve.com!news
From: Randy Williams <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SGC-230 auto tuner
Date: 19 Jun 1995 01:04:41 GMT
Organization: via CompuServe Information Service
Lines: 22
Message-ID: <3s2if9$gr5$[e-mail]>
References: <[e-mail]>

I'm wondering: Does Pierre at SGC in Redmond, WA peruse this
group?  Anyway, I am a very satisfied user of the sgc230 tuner.
I have used it with a number of rigs in MARITIME mobile use.

I have used it initially to feed a 25ft marine HF antenna.
Later, I switched to the backstay.  I will admit I did prefer the
backstay configuration.  One of the reasons that I chose this
auto tuner over most others was that I was not stuck with
matching rig to tuner. No seperate control cable.  I liked this
extra bit of flexability.

When matched with the QMS mount system by SGC, The SG-2000 xcvr
is an outstanding mobile rig.  This configuration was designed
primarily for commercial/industrial application. I know of a
number of them in use by geological firms contracting with the
oil biz in Saudi Arabia, for example.

But its HAM RADIO!!!  Its a hobby. Have fun...experimentation is
one of the main reasons we have this hobby. Invent something new.

Randy, N7CJE
Key Largo, FL

From [e-mail] Mon 19 Jun 95 16:42:00
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!library.ucla.edu!info.ucla.edu!csulb.edu!csus.edu!netcom.com!netcom16!faunt
From: [e-mail] (Doug Faunt N6TQS [phone])
Subject: Re: SGC-230 auto tuner
In-Reply-To: Randy Williams's message of 19 Jun 1995 01:04:41 GMT
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: at home, in Oakland
References: <[e-mail]>
        <3s2if9$gr5$[e-mail]>
Date: Mon, 19 Jun 1995 07:05:45 GMT
Lines: 6

I will point out that the ICOM AH-2 can quite successfully be used
with any rig, not just the matching ICOM 735.  It seems to work just
fine, if you're willing to do the setup by hand for tuneup.
It's a lot cheaper than the SGC, especially when found used.  Look
around your local yacht harbor.  I got one for $125.
73, doug

From [e-mail] Mon 19 Jun 95 16:42:01
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news.moneng.mei.com!uwm.edu!reuter.cse.ogi.edu!news.ssd.intel.com!chnews!vegas.ch.intel.com!cmoore
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SGC-230 auto tuner
Date: 18 Jun 1995 19:14:48 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 59
Distribution: world
Message-ID: <3s1tv8$[e-mail]>
References: <3rj8c9$[e-mail]> <[e-mail]>
NNTP-Posting-Host: vegas.ch.intel.com
Originator: [e-mail]

In article <[e-mail]>,  <[e-mail]> wrote:

>How can the SGC unit be one 'S' unit down from a Bugcatcher when in the
>SGC literature it states, "you can get more than 20 dB of gain by simply
>using an SGC compared with any other 1.8 to 30 MHz system." You must, of
>course, be in error with your statement.

Unlike "Aerials" in "Worldradio", people are equal here and in a
position to defend the truth. I have not been able to verify your
quote. Would you mind telling us where it came from?

I dug up the SGC advertisment entitled, "Why the QMS works so well -
the 20 dB Advantage." What they are comparing the QMS system to is
a composite of six generic mobile antennas. The six entries are:

1. Most mobile HF antennas are so heavy they must be bumper-mounted,
close to only a foot from the ground. Moving the antenna to the top
of the vehicle can gain 3-6 dB by reducing ground losses.

2. Bumper mounting leaves the vehicle as a shield in one direction.
Moving the antenna to the top of the vehicle can gain 3-6 dB in that
previously shielded direction.

3. A lot of automatic antenna tuners are mounted inside the trunk.
Moving the auto-tuner to the base of the antenna can gain 3-6 dB.

4. A lot of resonant type mobile antennas are wound with #22 wire.
The SG-303 is wound with a 3 mm tape/wire strap, equivalent to #4
wire. Going from #22 to #4 wire can gain 3-6 dB.

5. The SG-303 is two antennas in a single casing, resonant at about
22 MHz AND 10 MHz. It will outperform a conventional 9 foot whip on
the lower frequency HF bands - a 3-6 dB gain.

6. Many hams use the built-in auto-tuners in their transceivers
to tune their mobile antennas. If the antenna is non-resonant, a
high SWR exists causing feed-line losses. Putting the tuner at
the base of the antenna can save 3-6 dB.

What they are saying is, if you have any of these conditions that
can be remedied by the QMS system, then you can gain 3 dB. If you
have 4 or more of these conditions, you might gain 20 dB. Is it
all 100% true? I doubt it, but I have trouble shooting down any
one of the above six statements. If you want to argue with any
of these statements, please feel free.

Will the QMS system outperform a bugcatcher? It just might on 15m
with a bumper-mounted bugcatcher. Will it outperform a bugcatcher
on 75m? Of course not, but if operation on 75m is a rarity for
an individual, he must put up with the bulk of a 75m bugcatcher
even though he rarely uses it. There is room for more than one
kind of mobile antenna in this world. IMO, a properly installed
QMS antenna system would outperform bumper-mounted Hamsticks on
some or most bands. And I agree that's a lot of money to pay for
never getting wet.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)

PS - If you're K6EA, I can say hi to a fellow OOTC member.

From [e-mail] Mon 19 Jun 95 16:42:02
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!gatech!bloom-beacon.mit.edu!news.kei.com!ub!galileo.cc.rochester.edu!uhura.cc.rochester.edu!rdewan
From: [e-mail] (Rajiv Dewan)
Subject: Re: SGC-230 auto tuner
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: uhura.cc.rochester.edu
Organization: University of Rochester - Rochester, New York
References: <3rj8c9$[e-mail]> <[e-mail]> <3rv8v0$[e-mail]>
Date: Mon, 19 Jun 95 14:33:59 GMT
Lines: 38

In <3rv8v0$[e-mail]> [e-mail] writes:
>The SGC system will not perform as well as a bugcatcher below
>17m. My SGC-230 with a 13 ft whip is equal to an 8 ft. bugcatcher
>on 17m and BETTER than the bugcatcher on 15m, 12m, and 10m. I

This improvement results primarily from the longer whip sported by the
SGC system.  I am not comfortable with assigning all the benefit to the
miraculous nature of the SGC Tuner.

A true test of a mobile system, in my opinion, is on the 30 thru 80m
bands where the antenna is really very short.  It is in these bands
that high Q, higher radiation resistance for the length,
etc., become crucially important.  Getting the antenna to have reasonable
efficiency and put a good signal (field strength) on these bands is
what the Bugcatcher does well.

>rarely work any bands mobile below 18MHz. I can switch
>bands on the fly and achieve results superior to a bugcatcher
>for which I would have to stop the truck. Now you tell me, which
>is the better choice for my type of operation? I *have* a bugcatcher
>and I choose to use the SGC-230 and the 13 ft. whip because it
>PERFORMS BETTER _AND_ is more convenient to operate.

Well, I almost never stray above 30m on mobile operation.  And I
prefer the bugcathcer system.  However, I do see why you might
prefer the SGC system for the higher frequency bands.  The combination
of a longer whip and the flexibility would be nice to have.


>I have no connection with SGC except as a super satisfied customer.

I have no connection with any one except my family.

>73, Cecil, KG7BK, OOTC, xIRE  (not speaking for my employer)

Regards,
Rajiv
aa2ui

From [e-mail] Mon 19 Jun 95 16:42:03
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!gatech!bloom-beacon.mit.edu!news.kei.com!ub!galileo.cc.rochester.edu!uhura.cc.rochester.edu!rdewan
From: [e-mail] (Rajiv Dewan)
Subject: Re: SGC-230 auto tuner
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: uhura.cc.rochester.edu
Organization: University of Rochester - Rochester, New York
References: <3rj8c9$[e-mail]> <[e-mail]> <3s1tv8$[e-mail]>
Date: Mon, 19 Jun 95 14:39:50 GMT
Lines: 19

In <3s1tv8$[e-mail]> [e-mail]
commenting on the virutes of the SGC system, writes:


>3. A lot of automatic antenna tuners are mounted inside the trunk.
>Moving the auto-tuner to the base of the antenna can gain 3-6 dB.

While I agree that  it would be better to mount the tuner right at
the base of the whip,  3 to 6 db gain seems high.

So when the tuner is in the trunk, the couple of feet of coax or wire
is dissipating 50 to 75 Watts and yet does not even get hot to touch
after extended operation?


Rajiv
aa2ui



From [e-mail] Mon 19 Jun 95 16:42:04
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!not-for-mail
From: [e-mail] ("Anthony R. Gold")
Newsgroups: rec.radio.amateur.antenna
Subject: SGC-230 auto tuner
Date: 19 Jun 1995 12:24:34 -0500
Organization: Microvest Limited, London
Lines: 21
Sender: [e-mail]
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: news.cs.utexas.edu

In article <[e-mail]>
           [e-mail] "Rajiv Dewan" writes:

 > While I agree that  it would be better to mount the tuner right at
 > the base of the whip,  3 to 6 db gain seems high.
 >
 > So when the tuner is in the trunk, the couple of feet of coax or wire
 > is dissipating 50 to 75 Watts and yet does not even get hot to touch
 > after extended operation?

1) The lost power may be radiated into the car's body or wiring and raise
the temperature of those to a minimal extent.

2) It is tough to get an average power over an "extended operation" equal
to the PEAK rating of the tuner.  Perhaps K1MAN would make a broadcast of
his news bulletin on FM from his driveway just to to test your theory.
And Fred Maia could hold the wire to see if it (or he) gets warm.

--
   Tony - G3SKR / AA2PM                  email:  [e-mail]
                                        packet: g3skr@n0ary.#nocal.ca.usa.na

From [e-mail] Mon 19 Jun 95 16:42:05
Path: grape.epix.net!news.sprintlink.net!demon!uknet!trog.dra.hmg.gb!taz.dra.hmg.gb!WAGRAY
From: [e-mail] (Walter Gray)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,alt.radio.scanner,alt.radio.digital,in.ham-radio,sci.electronics
Subject: Re: TAMU Idiots; was HELP me find this PART - NEWBIE (X K band trans)
Date: 19 Jun 1995 09:35:05 GMT
Organization: Defence Research Agency
Lines: 51
Message-ID: <3s3gc9$[e-mail]>
References: <3rq4pm$[e-mail]> <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: taz.dra.hmg.gb
Xref: grape.epix.net rec.radio.amateur.antenna:11286 rec.radio.amateur.equipment:13350 alt.radio.scanner:19019 alt.radio.digital:908 sci.electronics:131622

In article <[e-mail]>, [e-mail] (Steve Sampson) writes:
>In article <3rq4pm$[e-mail]> "Darin C. Ginther" <[e-mail]> writes:
>
>>I am interested in building a device that will transmit microwaves
>>at 10.525 Ghz (X band) and/or 22 Ghz (K band).  I need about 10 kilowatts
>>of power.
>
>OK
>
>>Does anyone know where to buy such a transmitter?  I understand you
>>can buy a nifty little semi-conductor such as a Gunn diode, but these
>>damn things are difficult to tune correctly in an enclosure.  They
>>also require special equipment that I do not have available.
>
>So you want 10 kilowatts, but you don't know how to tune anything.
>
>>I have heard that a person can purchase a device called a Gunnplexer,
>>which is used to activate intruder alarms and automatic doors - it
>>transmitts on 10.525 Ghz and is really the first step of what I need.
>
>Gunn diodes don't do much beyond 200 milliwatts.  At this power level
>they are unaffordable by consumers.
>
>>This device must be able to create "harmful" interference on X and
>>K bands...Of course, this will only be used in a lab setting (HA!)..
>
>>Any advise, comments?
>
>Get a life?  Find Love?  How about volunteering at school to help the
>disadvantaged students get ready for high school?  Teach someone
>to read?
>
>Advise is actually spelled advice.
>
>>--
>>Darin. C Ginther
>>Personal homepage - http://acs.tamu.edu/~dcg9381/
>
>Is everyone at TAMU this stupid?
>--
>Steve
>


I heard once; "you can always tell an Aggie, but you caint tell him much".

walter



- - - - - - - - - - - - - - disclaimers - - - - - - - - - - - - - - -

From [e-mail] Mon 19 Jun 95 16:42:06
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netnews
From: [e-mail] (Ted Viens)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: test msg
Date: 18 Jun 1995 20:56:37 GMT
Organization: Netcom
Lines: 27
Distribution: world
Message-ID: <3s23u5$[e-mail]>
References: <3rprnp$[e-mail]>
NNTP-Posting-Host: ix-hou5-05.ix.netcom.com

In <3rprnp$[e-mail]> [e-mail] (Gary Metzler)
writes:
>
>hi all,
>just trying to put a message
>onto the system to see if it works. thanks,gary
>
>
>... Catch the Blue Wave!
>___ Blue Wave/QWK v2.12
>

Yes, it did work...
But UNFORTUNATELY, Gary...   The "Gary" quota for this group,
rec.radio.amateur.antenna, and several other groups has already been
exceeded and newsgroup servers around the world have already been
programmed to filter out contributions from "Gary's" not already on the
approved list.  Perhaps if you would make your contributions using a
psuedonym you will be able to thwart the function of these filters...

(This is a joke, dammit...  A little tongue in cheek tirade.  I have
just never been very fond of smileys or other terminal iconography.  I
am, however, awestruck at the high percentage of "Gary's" contributing
to these newsgroups...)
--
Bye...  Ted..
Deep in the Heart of the Armpits of Houston, Texas...

From [e-mail] Mon 19 Jun 95 16:42:07
Path: grape.epix.net!news.sprintlink.net!hookup!uwm.edu!news.alpha.net!pacifier!usenet.eel.ufl.edu!brutus.bright.net!infoserv.illinois.net!ddsw1!redstone.interpath.net!cphillips
From: [e-mail] (Curt Phillips)
Newsgroups: rec.radio.amateur.antenna
Subject: TH7DXX Info Wanted
Date: Thu, 15 Jun 95 23:09:28 GMT
Organization: North Carolina Division of Energy
Lines: 20
Distribution: world
Message-ID: <3rqf1n$[e-mail]>
NNTP-Posting-Host: cphillips.pdial.interpath.net
Keywords: Hygain TH7DXX yagi beam
X-Newsreader: News Xpress Version 1.0 Beta #2

  I'm interested in some input on how well a HyGain TH7DXX performs as
compared to other triband antennas.  I've used a Mosley TA-33 in the past
and would expect the HyGain to be better than that. I've used a 5 element
20 meter monobander and would expect the TH7 to be not nearly as good as
that (harumph... I'd guess the TH7 would do better on 10 and 15 meters,
to head off you "wise-guys" :-)
  But, how does the TH7DXX rate compared to other triband antennas in
it's size class?
What do you think is a fair price for a used one in good condition?
Thanks for your input...

==========Opinions expressed are solely those of the author============
Curt Phillips KD4YU (ex-WB4LHI)      |"I don't want to gain immortality
Chairman, Tarheel Scanner/SWL Group  | through my work.  I want to gain
[e-mail]  | immortality through NOT DYING."
ARRL Life; QCWA; Raleigh Am Radio Soc|                 --Woody Allen
=====Compu$erve:73167,2050===MCIMail:WCPHILLIP===GEnie:C.PHILLIPS======




From [e-mail] Mon 19 Jun 95 16:42:07
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!asuvax!news.asu.edu!aztec.asu.edu!hamop
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: 17 Jun 1995 00:09:05 GMT
Organization: Arizona State University
Lines: 9
Message-ID: <3rt6f1$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


Might this be germain to the question?  When a wave excites a
receiving antenna half of the energy may be delivered to a matched
load but the other half is reradiated.  The current in the antenna
caused by the received wave is no different from a current sourced
by a transmitter, so it radiates.
Charlie,  W7XC
--


From [e-mail] Mon 19 Jun 95 16:42:08
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!asuvax!news.asu.edu!aztec.asu.edu!hamop
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The meaning of 'matched'
Date: 17 Jun 1995 03:56:08 GMT
Organization: Arizona State University
Lines: 7
Message-ID: <3rtjoo$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


Line need not be very long if loss factor is high enough to make
reflection below level of detection and hence z in appears equal
to Zc of line.
Charlie,  W7XC
--


From [e-mail] Mon 19 Jun 95 16:42:09
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!ix.netcom.com!netcom.com!netcom8!faunt
From: [e-mail] (Doug Faunt N6TQS [phone])
Subject: Was, Re: SGC-230 auto tuner, now more about mobile antennas and SGC
In-Reply-To: [e-mail]'s message of Fri, 16 Jun 1995 11:49:16 GMT
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: at home, in Oakland
References: <3rpeg9$[e-mail]> <[e-mail]>
Date: Fri, 16 Jun 1995 19:37:01 GMT
Lines: 25


In article <[e-mail]> [e-mail] (David Stockton) writes:
<much text deleted>
                                        Remote control of
   centre and top loading ought to make an interesting challenge!  so
<much text deleted>
       Cheers
             David  GM4ZNX

The W6AAQ "screwriver" antenna is a remotely controlled center (or
centre) loaded antenna, and works very well, according to the Visalia
mobile antenna tests, written up in WorldRadio this month.

There's also an article in the ARRL 4th Antenna Compendium from KE2QJ
showing less than 6db between a center loaded whip and a whip using an
antenna coupler.  One variable here was that his test rig had the
coupler mounted externally, above the bumper.  Most people seem to
mount the coupler in the trunk, further from the base of the antenna.
I wonder if he works for SGC.
73, doug






From [e-mail] Mon 19 Jun 95 16:42:10
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!newsxfer.itd.umich.edu!gatech!bloom-beacon.mit.edu!news.kei.com!ub!netfs.dnd.ca!dgbt!clark.dgim.doc.ca!news
From: [e-mail] (Jim Cummings)
Subject: Re: Webster Band Spanners?
Message-ID: <[e-mail]>
Sender: [e-mail] (#Usenet News)
Organization: Communications Canada
X-Newsreader: TIN [version 1.1 PL8]
References: <3ro0t8$[e-mail]>
Date: Mon, 19 Jun 95 15:47:45 GMT
Lines:       35

DB Wilhelm ([e-mail]) wrote:
: [e-mail] (Jim Cummings) wrote:
:  >  SNIP ...
:  > Another amateur advised against this as he explained that since the Band
:  > Spanner is helically wound and would not be as effective as just the
:  > straight whip.
:  >
:  > Are there others who have thoughts on this?
:  >
: I don't know what other parameters are involved in your installation,
: but helically wound antennas are electrically longer than a straight
: whip of the same length, and for this reason *should* be a more
: efficient radiator.  There are many other factors that will determine
: the final radiated signal strength.  If you can, try it out and see
: what you get.

: 73,
: Don W3FPR

Hello Don:

I did a little test the other evening.  With my 102 inch CB whip, with
the AH-2, CHU on 7335 was coming in at 20 db over S9 on my IC735.
However, when the whip was replaced by the WBS, the signal dropped down
to S6.

Subsequent to this test, I realized that I may not have had the rod down
far enough to contact the coil in the tube.  So I will fool around a
little bit more and see and try to let you know.

73 and live better digitally
Jim, VE3XJ



From [e-mail] Mon 19 Jun 95 16:42:10
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!usc!crash!jadpc!cg57.esnet.com!lasernet.com!ej_johnson
Newsgroups: rec.radio.amateur.antenna
Message-ID: <50619005841$[e-mail]>
X-Gateway: Act-Up 4.6  19 Jun 95 00:58:41  Laser*Point Mail Node 466-8026
Lines: 10
Date: Sat, 17 Jun 95 19:48:00 LOC
Organization: East County Repeater Association BBS (52:1000/205)
From: Ej Johnson <[e-mail]>
In-Reply-To: [e-mail] (Ian Thurston)
Subject: What`s the gain of a 2M

IT::--- Maximus 2.02
IT:: * Origin: East County Repeater Association BBS (52:1000/205)
hi Ian!   I sent in a address change to act-up to change my address to
[e-mail]

I hope It works!
                73's
                        EJ!

 * OLX 2.1 TD * Elvis is dead,and I don't feel so good myself!

From [e-mail] Mon 19 Jun 95 16:42:11
From: [e-mail] (Claton Cadmus)
Path: grape.epix.net!news.sprintlink.net!mn.state.net!nic.dot.state.mn.us!news.state.mn.us!news3.mr.net!mr.net!medtronic.com!rosevax!hamlink!fredmail
Newsgroups: rec.radio.amateur.antenna
Subject: What`s The gain of a 2m j
Message-ID: <[e-mail]>
Date: Fri, 16 Jun 1995 09:47:21
X-FTN-To: All
Lines: 21

Pierre wrote:

CO>asking about a usual J-pole like the one presented in this month QST in
  >the Hints

A j-pole is simply an end feed verticle dipole.  A dipole has a gain of
2.18 dbi.  However, a J-pole due to the matching sectio has a gain on
1.89 dbi slightly less then the dipole.  A quarter wave verticle is
about 0dbi so the j-poles do better by 2db.
Hope this Helps

73 de  Claton Cadmus,  KA0GKC
   ______________________________________________________________
  |     FIDOnet= Claton Cadmus 1:282./100                        |
  |    INTERnet= [e-mail]                    |
  |   PACKETnet= KA0GKC@WB0GDB.#STP.MN.USA.NA                    |
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   If anything I have written makes any cents, I claim copyright!
 * SLMR 2.1a * I'm insufficiently knowledgable on too many subjects.



From [e-mail] Mon 19 Jun 95 16:42:12
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Wire antenna in Saltwater Beach house environment
Date: 18 Jun 1995 00:32:42 GMT
Organization: News & Observer Public Access
Lines: 30
Message-ID: <3rvs7a$[e-mail]>
References: <3rpf41$[e-mail]>
NNTP-Posting-Host: grail913.nando.net

[e-mail] (Glenn Sparks) wrote:
>
> I have a beachhouse on the Gulf that I use on weekends year round.  I
> have an Old Heathkit there with a full lenght 80m and 40m dipole up
> about 40 foot.  Every year I have to rebuild it, the guy wires break,
> the antenna wire break, the ropes to raise the antenna rot, etc.
>
> Any ideas for a more reliable mechanical setup.  I use the heavy
> galvanized guy wire, and the copperweld antenna wire.
>
Snip ...

From my experiences with beaches, I would guess that there are
quite a few beach houses there that regularly fly flags and other
stuff.  Take a good look at their masts, and ask the owners how
long they stay up, then use that information to determine what
would be best for your needs.

I would suggest that you use insulated wire to keep the salt away
from the copper a little longer, or paint the wire to do the same
thing.  You might try an inverted vee configuration so that you
do not have to put much tension on the wire trying to hold the
feedline (and balun if you use one).  Leting the wires of an
inverted vee sag will not usually alter the radiation, and allows
you to use most any type of wire that will carry RF.

73,

Don W3FPR


From [e-mail] Fri 23 Jun 95 21:02:12
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!dg-rtp!teton!mead
From: [e-mail] (Glenn Mead)
Subject: 2m Marine antenna
Message-ID: <[e-mail]>
Sender: mead@teton (Glenn Mead)
Date: Fri, 23 Jun 95 15:07:26 GMT
Organization: Data General Corp.
Lines: 29

I am trying to install a 2m (144-148) antenna on my boat.
The Shakespear VHF/FM antenna was only $29, but is tuned
for the marine bands (158-164 ?). The swr is unacceptable
on the ham bands. The antenna is an 8' long tapered fiberglass
tube with a ferrul on the base to mount to a std marine mount.
I took the antenna apart, and found what appears to be a
j-pole coax antenna inside. I would like to replace the
existing j-pole with a coax j-pole tuned for the ham bands.
Any help on building such an animal would be greatly
appreciated.

The existing antenna (measurements are at home)

         |
         |
         |
         |
         | <---- Single , straight wire
         |
         |
        |||  <---- coax (sheild and center not connected)
        |||
        |||
        |||///  <---- short coax, end crimped and connected to center
         *      <---- everything seems to be soldered to here
         |
         |      <---- coax feed line from radio

Thanks.

From [e-mail] Fri 23 Jun 95 21:02:13
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!wanda.pond.com!kd3bj!shark.pond.com!bbs
From: [e-mail] (General BBS user login)
Subject: Re: Antenna HF operation ideas
Sender: [e-mail] (News Posting Phantom User)
Nntp-Posting-Host: jupiter.kd3bj.ampr.org
Organization: The KD3BJ Usenet BBS
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]>
Date: Tue, 20 Jun 1995 22:54:48 GMT
Lines: 10

When it comes to improvised antennas, try this one:
Scene:  Band barracks at U.S. Naval Schools Command, Great Lakes Naval
Station.  Steel double-decker cots.
Remove mattress.  Attach clip lead from coax to steel cot.  Load up
Galaxy 500.  Transmit.  Work Santa Rosa, California.  The tune switch and
a fluorescent tube taped inside the locker containing the radio
transmitter made for easy-to see what you're doing after taps.  As Kurt
N. Sterba affirms:  If you can load it, it will radiate.



From [e-mail] Fri 23 Jun 95 21:02:14
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!purdue!haven.umd.edu!news.umbc.edu!hookup!gatech!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 21 Jun 1995 07:16:35 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 15
Sender: [e-mail]
Message-ID: <3s8v2j$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com

>Tom
I agree fully that many so called PI tuners work as "L's" so what do you
think of an L tunner?

                                                                Garry
(WB0NNO)<

Gary,

They work great because they provide maximum BW, maximum efficiency,
smooth tuning, and harmonic supression. The only draw back is a little
tougher time matching reactive loads and very low impedance
transformations, but it can all be handled.

73 Tom

From [e-mail] Fri 23 Jun 95 21:02:14
Path: grape.epix.net!mango.epix.net!gmfoster
From: Garry Foster <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: Wed, 21 Jun 1995 18:52:43 -0400
Organization: epix.net
Lines: 32
Message-ID: <[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]>
NNTP-Posting-Host: mango.epix.net
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-Sender: [e-mail]
In-Reply-To: <3s8v2j$[e-mail]>



On 21 Jun 1995, W8JI Tom wrote:

> >Tom
> I agree fully that many so called PI tuners work as "L's" so what do you
> think of an L tunner?
>
>                                                               Garry
> (WB0NNO)<
>
> Gary,
>
> They work great because they provide maximum BW, maximum efficiency,
> smooth tuning, and harmonic supression. The only draw back is a little
> tougher time matching reactive loads and very low impedance
> transformations, but it can all be handled.
>
> 73 Tom
>
>
While looking at the drawing for the Icom AH3 (I think) that was
published in CQ a few years ago I noticed that it was an  "L" even though
the Icom rep at Datton was insisting that it was a PI. What it  had was a
serries inductor and a bank of capicators that could be either from the
input side of the inductor to ground or the output side to ground. The
thing that interested me was there  are 3 low value capicators to ground on
the output side that wern't switched.  I'm guessing that yhese are to help
with resonant lenghts of antenna. Any ideas on this.

                                                                Garry(WB0NNO)


From [e-mail] Fri 23 Jun 95 21:02:15
Path: grape.epix.net!news2.sprintlink.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!uunet!news.iii.net!iii1.iii.net!not-for-mail
From: [e-mail] (Thomas C Sefranek)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 22 Jun 1995 18:18:37 -0400
Organization: iii.net
Lines: 17
Message-ID: <3scq8g$[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]> <[e-mail]>
NNTP-Posting-Host: iii1.iii.net

HI,
        I can tell you what Tom would say (If he hasn't lready),
He has offered to eat any tuner that actually makes the specs,
and I'll join him!  (I may require sauce with the unit though!)

It's gfunny how MFJ made all the fixes I published years ago,
WITHOUT even a note of recognition.  But I'm NOT saying FMJ
F*** Magic tuners are the only ones that are deficient.

I say, BUILD your own!  It's just not that difficult.

Have a good field day!
Tom
(From the radio shack store in pa.)

--
Thomas C. J. Sefranek  WA1RHP

From [e-mail] Fri 23 Jun 95 21:02:16
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: SCOTT DOUGLAS <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Bare or insulated copper for wire antenna ?
Date: Wed, 21 Jun 95 03:46:02 -0500
Organization: Delphi ([e-mail] email, 800-695-4005 voice)
Lines: 12
Message-ID: <[e-mail]>
References: <3rf5ht$[e-mail]> <3rg35f$[e-mail]>
NNTP-Posting-Host: bos1a.delphi.com
X-To: George J. Molnar <[e-mail]>

George J. Molnar <[e-mail]> writes:

>>Someone recently said it was crazy to use insulated wire for an antenna.

Crazy?  I've heard that the insultation may detune the antenna slightly.  But,
who cares...what's the cheapest way to go...if you have to cut throught leaves,
etc. the insulation will save the shorting to the trees, ice, whatever.  This
is a hobby of innovation.  I've loaded fences before...if you get a good match
and your hear signals, you can surely work them...try it, you might save time
and more importantly, money for more toys!

GL OM, 73 de wb5pbj

From [e-mail] Fri 23 Jun 95 21:02:17
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netcom.com!selwitz
From: [e-mail] (Jay Selwitz)
Subject: Re: Bare or insulated copper for wire antenna ?
Message-ID: <[e-mail]>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
References: <3rf5ht$[e-mail]> <3rg35f$[e-mail]> <[e-mail]>
Date: Thu, 22 Jun 1995 17:39:21 GMT
Lines: 7
Sender: [e-mail]

Regarding bare copper, aside from detuning problems, what are the risks
if the wire touches tree limbs and leaves?  At what power levels does
this become a fire hazard?

Jay Selwitz, KB6LYO
--
                                             [e-mail]

From [e-mail] Fri 23 Jun 95 21:02:17
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!sdd.hp.com!hpscit.sc.hp.com!icon!greg
From: [e-mail] (Greg Dolkas)
Subject: Re: Best NMO Mobile Mount???
Sender: [e-mail] (News Administrator)
Message-ID: <[e-mail]>
Date: Tue, 20 Jun 1995 23:53:20 GMT
References: <[e-mail]>
Organization: HP - Information Networks Division
X-Newsreader: TIN [version 1.1.8 PL6]
Lines: 15

Cliff Frescura ([e-mail]) wrote:
: I've installed two Larsen NMO mounts with no problems during or after
: installation.  I would recommend spending the extra bucks and getting
: a Greenlee chassis punch.  May seem like an unnecessary expense, but
: I think it's worth it.  You might try to talk your local club into
: buying one for the membership to use ;-).

Ok, but the one thing *really* worrying me is *where* to punch that hole.
How do I know that an antenna in that position will work properly, and not
have a warped pattern, or kill the car's electronics?  This isn't an exact
science, yet you'd better be very happy with the very first attempt.

Would a mag-mount be worth trying first?

Greg  KO6TH

From [e-mail] Fri 23 Jun 95 21:02:18
Path: grape.epix.net!news2.sprintlink.net!news.sprintlink.net!gatech!howland.reston.ans.net!agate!boulder!tali.hsc.colorado.edu!mnemosyne.cs.du.edu!nyx10.cs.du.edu!not-for-mail
From: [e-mail] (bill davidson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Best NMO Mobile Mount???
Date: 21 Jun 1995 23:25:34 -0600
Organization: University of Denver, Math/CS Dept.
Lines: 21
Message-ID: <3sause$[e-mail]>
References: <[e-mail]> <[e-mail]
NNTP-Posting-Host: nyx10.cs.du.edu

Sender:
Followup-To:
Distribution:
Organization: /usr/lib/news/organi[sz]ation
Keywords:
Cc:


The drill is much much better than a punch.  It includes a "grinder" to
strip paint to bare metal for the edge of the NMO to contact, and that
makes ALL the difference.  An NMO mount that doesn't make excellent ground
to the metal it is drilled through is a bad deal.  An NMO that goes to
metal all the way around the edge (look closely at the arrangement of
metal and O rings) is the best you can do for a given location for a local
ground plane.

A punch doesn't strip the paint - which you really want inside the O ring
on a good NMO mount.

 /s Bill


From [e-mail] Fri 23 Jun 95 21:02:19
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news.starnet.net!wupost!news.inlink.com!vulcan.inlink.com!raiar
From: [e-mail] (Gary V. Deutschmann Sr.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Can you ID this Antenna?
Date: 20 Jun 1995 23:45:46 GMT
Organization: inlink
Lines: 4
Message-ID: <3s7mja$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: vulcan.inlink.com
X-Newsreader: TIN [version 1.2 PL2]

Looks like an old Cushcraft I had years ago, but can't say for sure.

Gary - N0ZOI


From [e-mail] Fri 23 Jun 95 21:02:20
Path: grape.epix.net!news.sprintlink.net!nexus.coast.net!news.kei.com!ddsw1!usenet
From: John Fleming <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Comments on GAP Antennas, Anyone?
Date: 22 Jun 1995 17:46:46 GMT
Organization: MCSNet Services
Lines: 28
Message-ID: <3scaa6$[e-mail]>
References: <[e-mail]> <3s5bh5$[e-mail]>
NNTP-Posting-Host: johnflem.pr.mcs.net

All I can say is,
 "Don't it always seem to go,
  that you don't know what you've got
  till it's gone?"

I used to have a GAP Challenger, and I got out almost
every day, in Chicago area, QRP!

Now, I hardly ever make a contact.

But, as they say, your mileage may vary....

John N9NDH

[e-mail] (Runrobin) wrote:
>
> I did not have a great deal of good results with my GAP (80-10) antenna.
> While it did match the feedline with a reasonable SWR, it was consistently
> outperformed by a R5 vertical  at the higher bands and by a 40 mtr dipole
> (30 feet up) on 40/80 mtrs - I used open wire and a tuner.
>
> I was not able to mount it very much in the clear - as some articles
> recommend. My situation required that it be mounted in some woods and
> possibly too close to some trees. I hear that it performs better in an
> open field type of environment.
>
> Bottom line - I would not recommend one, based upon my experience!


From [e-mail] Fri 23 Jun 95 21:02:21
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!nntp.crl.com!news.fibrcom.com!news.txdirect.net!news
From: [e-mail] (Rick Blank)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Comments on GAP Antennas, Anyone?
Date: Fri, 23 Jun 1995 09:53:26 GMT
Organization: Internet Direct, Inc., San Antonio, Texas
Lines: 55
Message-ID: <3sdgvu$[e-mail]>
References: <[e-mail]> <3s5bh5$[e-mail]> <3scaa6$[e-mail]>
NNTP-Posting-Host: link087.txdirect.net
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
X-Newsreader: Forte Free Agent v0.55

John Fleming <[e-mail]> wrote:

>All I can say is,
> "Don't it always seem to go,
>  that you don't know what you've got
>  till it's gone?"

>I used to have a GAP Challenger, and I got out almost
>every day, in Chicago area, QRP!

>Now, I hardly ever make a contact.

>But, as they say, your mileage may vary....

>John N9NDH

>[e-mail] (Runrobin) wrote:
>>
>> I did not have a great deal of good results with my GAP (80-10) antenna.
>> While it did match the feedline with a reasonable SWR, it was consistently
>> outperformed by a R5 vertical  at the higher bands and by a 40 mtr dipole
>> (30 feet up) on 40/80 mtrs - I used open wire and a tuner.
>>
>> I was not able to mount it very much in the clear - as some articles
>> recommend. My situation required that it be mounted in some woods and
>> possibly too close to some trees. I hear that it performs better in an
>> open field type of environment.
>>
>> Bottom line - I would not recommend one, based upon my experience!
I have had a Gap Challenger for almost 4 years now and while it is not
as good as some antennas mounted higher on bands higher than 20m ,
i.e., an R-7 at 50 feet, it is definately a decent antenna...if I can
hear them, I can work them....

20meters is a good band with it, DX and stateside contacts work well,
40m DX is great, 75m not-so-great.  On 40 meters, the Gap is better
to Las Vegas than the 40/75m Unadilla trapped dipole, anything closer
and the dipole is better.  I worked a bunch of European DX right after
I installed the antenna and running 100 watts got excellent reports
with at least an S-9 signal into Spain and Sweeden.....

I really consider the antenna a really GOOD 20 and 40 meter antenna
for working DX or long distance steside contacts,and it is a great SWL
antenna to boot.  If you are interested in 75 and 40m contacts in
close, then a dipole or full wave loop will outperform the GAP but
they lose when compared to the low angle of radiation the GAP exhibits
on longer paths.....

Just my 2cents worth,

Rick, KI5SL





From [e-mail] Fri 23 Jun 95 21:02:22
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!nexus.coast.net!zombie.ncsc.mil!news.duke.edu!godot.cc.duq.edu!newsfeed.pitt.edu!dbisna.com!psinntp!psinntp!psinntp!psinntp!ncrgw2.ncr.com!ncrhub6!daynews!ranger!news
From: Greg Smith <[e-mail]>
Subject: Comments please on a few antennas
X-Nntp-Posting-Host: 149.25.48.52
Content-Type: text/plain; charset=us-ascii
Message-ID: <[e-mail]>
Sender: [e-mail] (News Administrative Login)
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Xref: grape.epix.net rec.radio.amateur.equipment:13541 rec.radio.amateur.antenna:11409

Please excuse this repeat posting if you have already read
this.  I accidentally posted without a subject.

I plan to buy one or two antennas and I'd like to hear comments
from those who have used the following:

MFJ 1730  Pocket Roll-up 2m antenna
I do quite a bit of wilderness canoeing and backpacking.  I
take the HT along for emergencies.  The duck is worthless
over long distances and the telescoping antennas are usually
too long, even when collapsed. Is this J-pole going to give me
comparable performance to a telescoping antenna such as the AEA
Hot Rod?

Comet SH-55 and Diamond RH-77CA
For everyday use.  I'm hope I could do much better with these
than my standard duck.  Are these antennas worth $32 or is the
gain increase from a factory duck negligible?

(Curiosity only)
Comet CH-32 Miracle Baby
Says it can handle 10W but I'd be worried about burning up my
radio with this.  Do they work?  Are they safe?  Nothing like
having the entire antenna 2 inches from your eyes.

Please share any info or experiences you may have with these
antennas.  E-mail appreciated but I will also check here
periodically for replies.  Thank you very much.



--
Greg Smith, KB8YBS
AT&T Global Information Solutions



From [e-mail] Fri 23 Jun 95 21:02:22
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!xlink.net!rz.uni-karlsruhe.de!news.uni-stuttgart.de!moritz
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Convert a 1/4 wave to 5/8 wave
Date: 21 Jun 1995 09:08:38 GMT
Organization: Comp.Center (RUS), U of Stuttgart, FRG
Lines: 13
Message-ID: <3s8nim$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: ipers1.e-technik.uni-stuttgart.de

In article <[e-mail]>,  <[e-mail]> wrote:
>I bought a 1/4 wave mag-mount to use with my HT recently and
>thought I would experiment a little.

Tim,

If you really want to improve anything get rid of the mag mount first.
You can tune a 5/8 by adding a T-piece and a stub in the feed line.

73, Moritz DL5UH




From [e-mail] Fri 23 Jun 95 21:02:23
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Convert a 1/4 wave to 5/8 wave
Date: 22 Jun 1995 01:03:11 GMT
Organization: News & Observer Public Access
Lines: 25
Message-ID: <3safgf$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: grail809.nando.net

[e-mail] wrote:
>
> I bought a 1/4 wave mag-mount to use with my HT recently and
> thought I would experiment a little. I bought a 5/8 whip and
> replaced the orginal 1/4 wave and it seems to work fine even
> though I'm told you out to match the impedence when you make
> such a change. The rig only puts out 5W so does it really
> matter that much? Does anyone have any ideas as to how I could
> match this attenna inexpensively?
>
If it were my 5 Watt rig, I would want to make sure as much power
as possible is getting delivered to the antenna for max signal out.
A typical 5/8 wave antenna has a feedpoint impedance of about 50 -j150
ohms.  This means that the resistive portion of the impedance is a
good match for 50 ohm line and transceivers, but the -j150 term
indicates that the antenna is also capacitive.  This capacitive
portion can be easily tuned out by placing an inductor in series
with the feedline.  The inductor size should be about +j150 ohms at
the center operating frequency.  Start with a coil with too much
inductance and tune it for minimum SWR.
You can also check the Antenna projects section of the  ARRL
handbook or most any good antenna handbook for additional information.

73,
Don W3FPR

From [e-mail] Fri 23 Jun 95 21:02:25
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!agate!library.ucla.edu!unixg.ubc.ca!news.bc.net!rover.ucs.ualberta.ca!alberta!adec23!mark
From: [e-mail] (Mark G. Salyzyn)
Subject: Re: Convert a 1/4 wave to 5/8 wave
Organization: Mr Bill Show
Date: Fri, 23 Jun 95 15:04:43 GMT
Message-ID: <[e-mail]>
Lines: 38
References: <[e-mail]> <3safgf$[e-mail]>

DB Wilhelm <[e-mail]> writes:

>A typical 5/8 wave antenna has a feedpoint impedance of about 50 -j150 ohms.

Yet the theory and practice I have been involved with tells us that the 5/8
wave is 100-j120 ohms. Maybe *that* is the reason all 5/8 wave antennas are
fed with a 2:1 slightly inductive autotransformer ... (A *real* 5/8 wave
is 0.64 Lambda, some commercial variants are 0.55 and 0.625, I do not have
any extensive experience with the shorter lower gain units and their
impedances).

I have used two 5/8 wave back to back as a vertical dipole, and fed it with
a 1/4 wave hairpin (not supposed to be inductive, but when folded to bring
the center point near the feed point to act as a 4:1 balun, it requires
100 ohms of series capacitance to cancel the inductance of the fold). This was
published in March 1993(?) in rec.radio.amateur.misc (should be in the archives
and on the CDROMs). I believe the fact I got a 1:1 match on the unit also
proves that the 5/8 wave is 100 ohms (being that the dipole is 200 ohms and a
4:1 tamed it). I built the antenna totally out of 1/2" copper pipe and elbows.

>You can also check the Antenna projects section of the  ARRL
>handbook or most any good antenna handbook for additional information.

The ARRL handbook has a 2M 5/8 wave with a 2:1 autotransformer at the base.
10 turns, tapped at the 7th turn. I have built this `project' as well, and
it worked *great*. Side by side with a quarter wave, the field strength
meters around my antenna test site were dramatically different once a 1:1
match was achieved. I also experimented with the number and length of the
ground radials on both the 1/4 wave and the 5/8 wave and found four 1/4 wave
length ground radials achieved the optimum balance between gain and
convenience (The Signal strength meters did not improve much with 100 radials,
up to a wavelength in length). I used some half round acrylic, glued together,
to captivate the feed, the antenna wire (with a screw passing through one of
the halves to the autotransformer to make that link) and the N connector I
placed at the base. Radials and antenna consisted of spring wire, with a brass
coupling soldered to increase the length and allow for adjustments.

Ciao -- Mark Salyzyn/VE6MGS

From [e-mail] Fri 23 Jun 95 21:02:25
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!news.cyberstore.ca!skypoint.com!news3.mr.net!mr.net!news.mr.net!chrisepc!chrise
From: [e-mail] (Chris Elmquist)
Newsgroups: rec.radio.amateur.antenna
Subject: Cushcraft 729 432 boomer crooked feedpoint ?
Date: Thu, 22 Jun 1995 09:00:39
Organization: Comtrol Corporation
Lines: 28
Message-ID: <[e-mail]>
NNTP-Posting-Host: ws30.comtrol.com
Summary: the "redi-match" stubs are not parallel to the driven element
Keywords: Cushcraft 729 boomer
X-Newsreader: Trumpet for Windows [Version 1.0 Rev A]

Has anyone assembled a new Cushcraft 729 432 boomer ?  We have built
two around here and if their instructions are followed to the letter--
you end up with the two redi-match stubs going off at an extremely
steep angle in reference to the driven element.  The clamps that
tie the redi-match stubs to the driven element are not clamping
well because of what appears to be an incorrect measurement.

I have spoken to Cushcraft and they say it is fine this way.  But I'm
not sure I agree-- because if they had intended for this angle to
exist, they would have had to design the clamps differently.

A friend has assembled his and bent the balun end of the redi-match
stubs to allow them to run parallel to the driven element.  But the
result of this is that the clamps now end up at just about the end
of the redi-match before he can get a 1.2:1 match.  Bending doesn't
seem like the right solution either-- firstly, because there is no
mention of it in the instructions and secondly because the tuning
dimensions are all incorrect then.

I *think* they are shipping the wrong clamps with the kit and don't
know it yet.

Any ideas ?

Chris
--
Chris Elmquist, N0JCF    Comtrol Corporation    voice: (800)GO-ROCKET
[e-mail]                              fax:   [phone]

From [e-mail] Fri 23 Jun 95 21:02:26
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: SCOTT DOUGLAS <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Cushcraft R7 vs GAP
Date: Wed, 21 Jun 95 03:29:17 -0500
Organization: Delphi ([e-mail] email, 800-695-4005 voice)
Lines: 18
Message-ID: <[e-mail]>
References: <3r79ug$[e-mail]>
NNTP-Posting-Host: bos1a.delphi.com
X-To: Stanley L. Flegler <[e-mail]>

Stanley L. Flegler <[e-mail]> writes:

>like the GAP Challenger work on 40 and 80 when it is only 31.5 feet tall and

It's adequate on 80 meters but I'd consider dipoles strung high (I have both).
The Gap is not best performance especially in summer when the noise level is
unbearable.  Experiment with both and keep the one that suits you best.

The Gap seems to be designed for hams like me who dont want to spend a bunch of
time tuning their vertical (like my hustler).  SWR-wise it IS wide banded but
not really adjustable.  Surrounding structures also have much to do with it.
The ground radials are essential (but only 3 are needed).  I have worked much
DX with it (yet I got a great deal on mine) and it survived a tree fall on top
of one of the guy wires.

It's a matter of personal taste.  Try them both.

73 de wb5pbj

From [e-mail] Fri 23 Jun 95 21:02:27
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: SCOTT DOUGLAS <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Cushcraft R7 vs GAP
Date: Wed, 21 Jun 95 03:37:09 -0500
Organization: Delphi ([e-mail] email, 800-695-4005 voice)
Lines: 5
Message-ID: <[e-mail]>
References: <3r79ug$[e-mail]>
NNTP-Posting-Host: bos1a.delphi.com
X-To: Stanley L. Flegler <[e-mail]>

Re:  Gap...

Forgot to mention that I have worked much DX with the GAP...different modes
and all with just 100 watts.


From [e-mail] Fri 23 Jun 95 21:02:29
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!agate!darkstar.UCSC.EDU!news.scruz.net!cruzio!davew
From: [e-mail]
Subject: Re: Daiwa rotator help
Reply-To: [e-mail]
Organization: Cruzio Community Networking System, Santa Cruz, CA
Date: Thu, 22 Jun 1995 14:53:26 GMT
Message-ID: <[e-mail]>
References: <3s07m5$[e-mail]>
Sender: [e-mail] (David Wells)
Lines: 10

Give it to me and buy a Yeasu!
.



--
Dave Wells KD6TO INTERNET: [e-mail]
Packet:KD6TO@K6LY.#NOCAL.CA.USA.NOAM;  COMPUSERVE:74067,1755
(WA4UQQ Worldwide Amateur Radio Directory III KD6TO)
.

From [e-mail] Fri 23 Jun 95 21:02:30
Path: grape.epix.net!news.sprintlink.net!warp.cris.com!usenet
From: mpblaze <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Directional Antenna
Date: 23 Jun 1995 15:32:37 GMT
Organization: Concentric Internet Services
Lines: 7
Message-ID: <3semql$[e-mail]>
NNTP-Posting-Host: crc1.cris.com

Can anyone recommend a GOOD directional antenna for use with a scanner
at 46-49 mhz?  One that can pinpoint well would be nice, but of course,
without the price of a satellite dish antenna.  Possible base, possible
handheld ideas...

Mark


From [e-mail] Fri 23 Jun 95 21:02:30
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!msunews!news
From: Philippe Perreault <perreaul>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: E-mail address for FAIR RADIO SALES?
Date: 22 Jun 1995 12:53:06 GMT
Organization: Michigan State University, College of Engineering
Lines: 11
Message-ID: <3sbp3i$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: oak.egr.msu.edu
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.1N (X11; I; SunOS 5.3 sun4c)
X-URL: news:[e-mail]

That was a great question...if you get their E-Mail adrs, would you
forward it to me???

Thanks

Send to:: [e-mail]

Thanks.

Phil


From [e-mail] Fri 23 Jun 95 21:02:31
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!lll-winken.llnl.gov!venus.sun.com!news2me.EBay.Sun.COM!engnews2.Eng.Sun.COM!usenet
From: [e-mail] (Ray Anderson)
Newsgroups: rec.radio.amateur.antenna
Subject: EZNEC antenna description files now available via ftp
Date: 23 Jun 1995 21:18:58 GMT
Organization: Sun Microsystems Inc.
Lines: 41
Message-ID: <3sfb42$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: radium.eng.sun.com


A small group of contributed EZNEC input files (*.ez) are now stored on
ftp.netcom.com in the /pub/ra/rander/NEC/EZNEC_FILES directory.

Presently there are only 3 files, however we expect the number to grow
over time. Thanks to Russ Renaud  VA3RR/AA8LU ( [e-mail]) for
assisting in gathering input for the archive.

There are also a considerable number of NEC and mininec related files
(executables, source code, and utilities) in /pub/ra/rander/NEC .

Anyone wanting to contribute to the collection either upload to
ftp.netcom.com /pub/ra/rander/uploads, or e-mail to [e-mail].

At present the directory EZNEC_FILES contains:

qha.ez
 describes a half turn quadrafilar helix antenna with equal size loops
with a lens/diameter ratio of 1.5 (W2DU type but without
self-phasing)
(from Russ Renaud [e-mail])


bobtailc.ez
 describes a bobtail curtain for 7MHz
(from Russ Renaud [e-mail])

eggb_rec.ez
describes a rectangular eggbeater-type antenna with width/length ratio to
provide approx 100 ohms impedance at resonance so the two in parallel would
be near 50 ohms.
(from Russ Renaud [e-mail])



73 de WB6TPU
Ray Anderson
[e-mail]




From [e-mail] Fri 23 Jun 95 21:02:32
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!gatech!bloom-beacon.mit.edu!news.kei.com!travelers.mail.cornell.edu!cornellcs!rochester!rocksanne!news
From: [e-mail] (John Sotack)
Subject: FAQ:  Where can I find it???
Message-ID: <[e-mail]>
Keywords: FAQ
Sender: [e-mail]
Reply-To: [e-mail]
Organization: Xerox Corporation, Webster NY
Date: Wed, 21 Jun 1995 14:57:09 GMT
Lines: 5

Whre can I find the FAQ for this news group.  Please reply to [e-mail].  I can not recieve mail on my Unix account from which I am posting.

John Sotack



From [e-mail] Fri 23 Jun 95 21:02:32
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!magma.Mines.Colorado.EDU!not-for-mail
From: [e-mail] (Dynamite Kid)
Newsgroups: rec.radio.amateur.antenna
Subject: FS: 10/11 M Base Antennae
Date: 22 Jun 1995 14:40:39 -0600
Organization: Colorado School of Mines - Test News Server
Lines: 14
Message-ID: <3sckg7$[e-mail]>
NNTP-Posting-Host: moran.mines.colorado.edu
X-Newsreader: TIN [version 1.2 PL2]

Hey Guys,
        I have the following two base antennae for sale that can be used for 10
or 11 M operation:

        1) The Maco V 5/8 aluminum ground plane  antenna.  Asking $50.

        2) Super Scanner tri-directional antenna.  Asking $100.

Buyer pays for shipping for both.  Will take best offer.  Please E-mail me at
[e-mail] with your offers.  Thanks!

Steven M Packard
314 "The Dynamite Kid"
Saline Michigan

From [e-mail] Fri 23 Jun 95 21:02:33
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!ix.netcom.com!netnews
From: [e-mail] (William Rice)
Newsgroups: rec.radio.amateur.antenna
Subject: FS: 30 foot whip
Date: 22 Jun 1995 18:44:53 GMT
Organization: Netcom
Lines: 3
Distribution: world
Message-ID: <3scdn5$[e-mail]>
NNTP-Posting-Host: ix-tf2-04.ix.netcom.com

For sale: Military AB1011 30 foot fiberglass whip with base. usable as
a 15 foot mobile or 30 foot fixed whip. $100 David Panek ke4mlv
404-331-7211

From [e-mail] Fri 23 Jun 95 21:02:34
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!purdue!haven.umd.edu!cville-srv.wam.umd.edu!jei.umd.edu!gevans
From: [e-mail] (Gary Evans)
Newsgroups: rec.radio.amateur.antenna
Subject: good ant for school?
Date: 20 Jun 1995 15:13:08 GMT
Organization: University of Maryland College Park
Lines: 1
Message-ID: <3s6oi4$[e-mail]>
NNTP-Posting-Host: jei.umd.edu
X-Newsreader: TIN [version 1.2 PL1]



From [e-mail] Fri 23 Jun 95 21:02:34
Path: grape.epix.net!news.sprintlink.net!cc.iu.net!news
From: [e-mail]   (Bill Newkirk)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: good ant for school?
Date: 21 Jun 1995 17:58:22 GMT
Organization: Space Coast Amateur Technical Group
Lines: 21
Message-ID: <3s9mju$[e-mail]>
References: <3s6oi4$[e-mail]>
Reply-To: [e-mail] (Bill Newkirk)
NNTP-Posting-Host: netport-24.iu.net
X-Newsreader: IBM NewsReader/2 v1.09

In <3s6oi4$[e-mail]>, [e-mail] (Gary Evans) writes:
(nothing came thru if there was supposed to be something)

for a start, something along the lines of a vertical is a good start if you don't
have the places to hang up some wires for the HF bands and/or no support
for something like a yagi for higher HF bands.

the antenna that's been the yeoman service antenna at the junior high where
we have a station set up has been an old Hy-gain 14AVQ (20/15/10 vertical).

we put up an R-7 a short while ago, the coupler box didn't take the weather
very well and that was recently replaced (different design box it appears).

we'll be putting in a new VHF/UHF antenna shortly (the previous discone only
made it for a couple of years in the salt air. the new one will be in a radome
to help protect it).


Bill Newkirk WB9IVR                  The Space Coast Amateur Technical Group
Melbourne, FL                       duty now for the future of amateur radio


From [e-mail] Fri 23 Jun 95 21:02:35
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From: [e-mail] (Terry Calof)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: good ant for school?
Date: Thu, 22 Jun 1995 16:41:35 +0800
Organization: The University of Manitoba
Lines: 7
Message-ID: <[e-mail]>
References: <3s6oi4$[e-mail]> <3s9mju$[e-mail]>
NNTP-Posting-Host: dial071.mbnet.mb.ca

If you want a reliable 2m antenna, I suggest an AEA Isopole 144. I've had
no problems for 3 years with one on our school roof. The good thing about
that antenna is that the feedline passes inside the mast, and the UHF
connector is protected from the elements. Our roof is tar, so I used a Rad
Shack tripod, bolted to 3 large and heavy patio blocks, which in turn
rested on 2" blue styrofoam pads to prevent sinking of the blocks into the
tar. 73/Terry VE4UC

From [e-mail] Fri 23 Jun 95 21:02:36
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From: [e-mail] (Terry Hubbard)
Newsgroups: rec.radio.amateur.antenna
Subject: Ground using polyphaser?
Date: 22 Jun 1995 13:34:47 -0500
Organization: Exec-PC
Lines: 12
Distribution: usa
Message-ID: <3scd47$[e-mail]>
NNTP-Posting-Host: earth.execpc.com

I am trying to implement a ground system using the ground window concent
and have to get the ac power to go thru the window. Ployphaser makes
a 15 amp and a 20 amp surge surpressor that I don't currently have the
modem number for. Will these devices when mounted to the ground panel provide
the desired effect. I saw these devices at Dayton and the instructions said
that in order for proper safe operation the unit must be grounded. Will the
nertral be coupled to the ground panel thru this device?

Any help appreciated.

73s Terry KF9HI


From [e-mail] Fri 23 Jun 95 21:02:37
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From: Ken Mason <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Help, Construction/Tuning of Parallel Dipole
Date: 20 Jun 1995 17:59:24 GMT
Organization: Intel Corporation, Folsom CA, USA
Lines: 24
Message-ID: <3s729s$[e-mail]>
NNTP-Posting-Host: kmasonpc.fm.intel.com

Hello,

 I have built a two band dipole, 80M and 40M. This antenna is a full
size 40M dipole with a loading coil (about 120uH) at the end to add
the 80M band. Total length is about 73 feet. This antenna works great
for 80M and 40M but the antenna can't work on 15M. I would like to
add the other novice bands to the antenna (15M and 10M). It would be
easy for me to add the bands using parallel dipoles.

 My questions are, do I need to space the dipoles so that the 15M
and 10M dipoles will tune? If the dipoles need to be spaced how much
spacing is needed? When tuning the antenna should I start tuning the
80M/40M first then the 15M then lastly the 10M or should I start with
the highest frequency and work down. Do the length of the dipoles
need to be modified because of the parallel configuration?

 I would like to add the dipoles to the antenna by taping them all
together. This would be the easiest thing for me to do.


                    Thanks,
                     Ken
                    KC6TEU
            [e-mail]

From [e-mail] Fri 23 Jun 95 21:02:43
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help, Construction/Tuning of Parallel Dipole
Date: 21 Jun 1995 07:02:47 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 12
Sender: [e-mail]
Message-ID: <3s8u8n$[e-mail]>
References: <3s729s$[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com


> I would like to add the dipoles to the antenna by taping them all
together. This would be the easiest thing for me to do.


                    Thanks,
                     Ken<

Ken, You have to have some spacing in the elements for it to work. The
results using parallel dipoles seem to vary, but my results have always
been that I needed a few inches inches at the minimum of separation. Start
with the low bands and work your way up with tuning. 73 Tom

From [e-mail] Fri 23 Jun 95 21:02:44
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help, Construction/Tuning of Parallel Dipole
Date: 22 Jun 1995 01:13:38 GMT
Organization: News & Observer Public Access
Lines: 33
Message-ID: <3sag42$[e-mail]>
References: <3s729s$[e-mail]>
NNTP-Posting-Host: grail809.nando.net

Ken Mason <[e-mail]> wrote:
SNIP...
> easy for me to add the bands using parallel dipoles.
>
>  My questions are, do I need to space the dipoles so that the 15M
> and 10M dipoles will tune? If the dipoles need to be spaced how much
> spacing is needed? When tuning the antenna should I start tuning the
> 80M/40M first then the 15M then lastly the 10M or should I start with
> the highest frequency and work down. Do the length of the dipoles
> need to be modified because of the parallel configuration?
>
>  I would like to add the dipoles to the antenna by taping them all
> together. This would be the easiest thing for me to do.
>
Ken, parallel dipoles do work just fine if you spread them apart.
The lower frequencies do have an influence on the tuning of the
higher frequencies (the other way around is true too, but the effect
is not much).  The mutual influence is much less the farther apart
you spread them.  At 90 degrees apart, there is hardly any effect
at all.  Spread them if you are able, and I suggest you do not tape
them together if you have any other alternative.

To tune them, start at the lowest band and work upwards.  After you
get round once it would be a good idea to go around a second time
just to make sure you have compensated for any mutual tuning effects.

Good luck, it's not really as hard as it sounds (unless you do not
spread them).

73,
Don W3FPR



From [e-mail] Fri 23 Jun 95 21:02:45
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From: [e-mail] (Dick Hughes)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF on Jeep Cherokee
Date: Wed, 21 Jun 1995 20:24:17 GMT
Organization: Oregon Public Networking
Lines: 49
Message-ID: <3s9v5p$[e-mail]>
References: <[e-mail]>
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X-Newsreader: Forte Free Agent v0.55

[e-mail] (David Feldman) wrote:

>I succumbed to the Jeep Grand Cherokee lease deal and ended up with one,
>replacing my old 84 AMC. Anyway, I'd like to mount a HF antenna (hustler
>type) and could use some words of wisdom.

>Options I can think of:

>  1. Mag mount on roof. I had this on the AMC. Worked great but hard to
>  avoid damaging the finish, and this is a lease car and will go back in
>  2 years.

>  2. Trailer hitch mount. I got a class-3 trailer hitch, but it seems that
>  putting so much of the mast down that low will hurt efficiency. WOuld it
>  be worth extending the mast another foot or two? The hustler is only
>  7 feet long or so but I could accomodate much higher overall length.

>  3. One of those SGC type antennas. 13' whip would be nice, but I don't
>  want to drop the $$. Also the rig is FT900/AT and has it's own tuner.

>  4. Lip mount, but not sure where to mount it. Car doesn't have a rear
>  trunk per se.

>Any other thoughts?

>73 Dave WB0GAZ [e-mail]

Dave, my vote would be for the hitch mount.  We have a Grand Cherokee
and that is the only place I would consider placing a large antenna.

Go for the DK3 (SGC and others) type antenna.  Have one on our
motorhome and can't see how I ever got along without it.  I can get
the SWR down to 1:1 in just seconds.  Be sure and use a cross-needle
SWR bridge like the CN-410 so you don't have to fool with meter
adjustments while in the car.  You can get a DK3 for under $200 and it
is well worth it.

Don't get misled by the fact that your radio has a built-in tuner.
The ANTENNA has to be tuned to resonance, not the feed line.  That can
only be done at the antenna.  Also, the very low impedance at the base
of your shortened antenna has to be matched to the feedline.  The DK3
takes care of both of these problems (opportunities?)  AFTER you have
taken care of antenna resonance and feed-point matching THEN you can
use the internal tuner for final touch up if you want, but there will
be no need if the first two have been taken care of.

73, Dick W7LVA  [e-mail]



From [e-mail] Fri 23 Jun 95 21:02:47
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From: [e-mail] (Dick Hughes)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF on Jeep Cherokee
Date: Thu, 22 Jun 1995 02:13:23 GMT
Organization: Oregon Public Networking
Lines: 48
Message-ID: <3sajkb$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: dynip46.efn.org
X-Newsreader: Forte Free Agent v0.55

[e-mail] (David Feldman) wrote:

>I succumbed to the Jeep Grand Cherokee lease deal and ended up with one,
>replacing my old 84 AMC. Anyway, I'd like to mount a HF antenna (hustler
>type) and could use some words of wisdom.

>Options I can think of:

>  1. Mag mount on roof. I had this on the AMC. Worked great but hard to
>  avoid damaging the finish, and this is a lease car and will go back in
>  2 years.

>  2. Trailer hitch mount. I got a class-3 trailer hitch, but it seems that
>  putting so much of the mast down that low will hurt efficiency. WOuld it
>  be worth extending the mast another foot or two? The hustler is only
>  7 feet long or so but I could accomodate much higher overall length.

>  3. One of those SGC type antennas. 13' whip would be nice, but I don't
>  want to drop the $$. Also the rig is FT900/AT and has it's own tuner.

>  4. Lip mount, but not sure where to mount it. Car doesn't have a rear
>  trunk per se.

>Any other thoughts?

>73 Dave WB0GAZ [e-mail]

Dave:
I can't find the response I sent to you earlier today.  Will try again
with abbreviated version.

Go for the trailer hitch mount.  Have Grand Cherokee and don't see any
other practical way to do it without butchering the car.

Go for the DK3 type antenna (screwdriver type.)  Can't beat it.  Use
cross-needle SWR meter that does not require adjustment.  DK3's can be
purchased for under $200.  You can increase the length of the lower
mast on the DK3 to get the coil above the roof, but will affect your
ability to tune 10 meters when using decent length top section.  Need
to compromise here (Unless no interest in 10 meters.)

Forget the internal tuner.  Doesn't do any good.  Have to tune the
antenna at the antenna, and match the base impedance at the antenna.
DK3 does both.  73 and good luck with your project

Dick Hughes - W7LVA



From [e-mail] Fri 23 Jun 95 21:02:48
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From: [e-mail] (Daniel Senie)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF on Jeep Cherokee
Date: 22 Jun 1995 02:20:22 GMT
Organization: Daniel Senie Consulting
Lines: 53
Message-ID: <3sak1p$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: peanut.iii.net

In article <[e-mail]>, David Feldman <[e-mail]> wrote:
)I succumbed to the Jeep Grand Cherokee lease deal and ended up with one,
)replacing my old 84 AMC. Anyway, I'd like to mount a HF antenna (hustler
)type) and could use some words of wisdom.
)
)Options I can think of:
)
)  1. Mag mount on roof. I had this on the AMC. Worked great but hard to
)  avoid damaging the finish, and this is a lease car and will go back in
)  2 years.

Reread your lease provisions to be sure it's going to be that picky. Have
the car somewhat dirty upon return so that any scuffing cannot be seen.

I use a large H shaped 4 magnet system on my Pathfinder. Works great. I had
to remove it the other day and work on the feedpoint. First time it'd been
off in a year. No serious markings (just cleaner under the magnets).
)
)  2. Trailer hitch mount. I got a class-3 trailer hitch, but it seems that
)  putting so much of the mast down that low will hurt efficiency. WOuld it
)  be worth extending the mast another foot or two? The hustler is only
)  7 feet long or so but I could accomodate much higher overall length.

I used to use one of these. If it is a receiver-type hitch, be sure you run a
separate ground braid from the base of the antenna to the part of the
trailer hitch that is permanently mounted, or to SOMETHING that's really
attached to the truck. Having the receiver sliding around in the hitch
made things bad for me when I was using this approack (with a "Tenna Hitch"
mechanism).
)
)  3. One of those SGC type antennas. 13' whip would be nice, but I don't
)  want to drop the $$. Also the rig is FT900/AT and has it's own tuner.
)
)  4. Lip mount, but not sure where to mount it. Car doesn't have a rear
)  trunk per se.

Nearly impossible on a Pathfinder. Probably as bad on a Jeep.

)
)Any other thoughts?

Have someone attach a piece of steel to the edge of the trailer hitch
bracketing, and extend it out the left side of the truck, just far enough
for a mount and mast to clear and go up. The GM folks at Dayton had one of
these that was very nicely done.

Dan

--
---------------------------------------------------------------
Daniel Senie                 Internet:     [e-mail],
Daniel Senie Consulting                    [e-mail]
http://www.senie.com         Packet Radio: [e-mail]

From [e-mail] Fri 23 Jun 95 21:02:49
Path: grape.epix.net!news.sprintlink.net!hookup!news.umbc.edu!haven.umd.edu!cville-srv.wam.umd.edu!ham
From: [e-mail] (Scott Richard Rosenfeld)
Newsgroups: rec.radio.swap,rec.radio.amateur.antenna
Subject: Hustler resonators for sale
Followup-To: poster
Date: 22 Jun 1995 13:27:54 GMT
Organization: University of Maryland College Park
Lines: 28
Message-ID: <3sbr4q$[e-mail]>
NNTP-Posting-Host: rac5.wam.umd.edu
Xref: grape.epix.net rec.radio.swap:37824 rec.radio.amateur.antenna:11379

Through a variety of trades, I have managed to acquire
the following Hustler resonators I consider to be
somewhat extraneous:

Two RM-40, $25 new, asking $14
One RM-40S (super resonator, 1 kW), $36 new, asking $20
Three RM-20, $22 new, asking $12
Two RM-15, $16 new, asking $9

Note that these are used; some are the older gray-coated
models and some are the newer white-coated ones.  They're
all in pretty good shape, prices are negotiable, and I'd
like shipping to be added although anything is possible.

Build your mobile setup!

I am also looking for the 75/80/30/17 meter resonators.
Will consider trades.

Thanx!

Scott NF3I  301-549-1022 (h) or 301-982-1015 (w)

--
72 and 73!                                     _________   _________  The
301-549-1022 Talk to me eves&weekends, else lv. message \ /  Long   Original
Scott Rosenfeld  Amateur Radio NF3I  Burtonsville, MD    |   Live    $5.00
  WAC-CW/SSB  WAS  DXCC - 136 QSLed on dipoles __________| Dipoles! Antenna!

From [e-mail] Fri 23 Jun 95 21:02:49
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!roper.uwyo.edu!roper.uwyo.edu!nntp
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Magnesium's Conductivity?
Message-ID: <[e-mail]>
From: [e-mail] (D. Larson)
Date: 21 Jun 95 11:20:51 MDT
Reply-To: [e-mail]
References: <thomas.g.booth-080695161813@160.205.101.24> <[e-mail]>
 <3s5k9h$[e-mail]>,<[e-mail]>
Distribution: world
Organization: University of Wyoming, Laramie
Nntp-Posting-Host: plains.uwyo.edu
Lines: 23

In article <[e-mail]>, [e-mail] (John Soo-Hoo) writes:
>In article <3s5k9h$[e-mail]> [e-mail] (WB3U) writes:
>>In article <[e-mail]>,
>>   [e-mail] (John Soo-Hoo) wrote:
>>>From what I can remember about magnesium, it will rust and it will burn.
>>>I suggest sticking to copper or aluminum or a aluminum-magnesium alloy (if
>>>you must have mangesium).
>>
>>On of my cars used to have real magnesium wheels.  They never rusted and they
>>never burned.  Cast magnesium is presently being used for reflectors on MMDS
>>(2.5 GHz) receive antennas.
>>
>It is more than likily your wheels were an alloy not pure magnesium.
>
Agreed, probably an alloy.

My experience with magnesium is that as a large solid piece, it will NOT
burn but as little shavings it burns very hot.  Don't know about rust or
RF conductivity.
73
KC7EGB
---Donald Larson---
---Laramie Wyoming---

From [e-mail] Fri 23 Jun 95 21:02:50
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From: [e-mail] (Ross Alexander)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Magnesium's Conductivity?
Date: 21 Jun 1995 21:10:26 GMT
Organization: Athabasca University
Lines: 21
Message-ID: <3sa1s2$[e-mail]>
References: <thomas.g.booth-080695161813@160.205.101.24> <[e-mail]>   <3s5k9h$[e-mail]>,<[e-mail]> <[e-mail]>
NNTP-Posting-Host: aupair.cs.athabascau.ca
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[e-mail] (D. Larson) writes:
>My experience with magnesium is that as a large solid piece, it will NOT
>burn but as little shavings it burns very hot.  Don't know about rust or
>RF conductivity.
>73
>KC7EGB

I used a certain magnesium chassis lawnmower for twenty years.  Never
rusted, never caught fire, and it was thoroughly thrashed and abused
for the duration.

On the other hand, I expect electrolytic corrosion could be a problem
under the right circumstances.  Magnesium's well up there on the
electromotive series.

regards,
Ross ve6pdq


--
Ross Alexander, ve6pdq  --  [phone]  --  [e-mail]

From [e-mail] Fri 23 Jun 95 21:02:51
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From: [e-mail] (Daniel Meyer)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Magnesium's Conductivity?
Date: 23 Jun 1995 17:16:42 GMT
Organization: Project GLUE, University of Maryland, College Park, MD
Lines: 41
Distribution: usa
Message-ID: <3sestq$[e-mail]>
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John Soo-Hoo ([e-mail]) wrote:
: In article <thomas.g.booth-080695161813@160.205.101.24> [e-mail] (Booth, Thomas G) writes:
: >In article <[e-mail]>, [e-mail] (Michael
: >K. Davis) wrote:
: >>
: >> Does anyone know how well Magnesium tubing would perform in the construction
: >> of a VHF or UHF yagi?   I'm looking to save weight, for backpacking, but have
: >> no information about it's conductivity....
: >>
: >> Please reply by mail to [e-mail]
: >>
: >> Thanks,  AB6SL
: >
: >Well, my CRC book sez magnesium in the polycrystalline form has a
: >resistivity of 4.45 microohm-cm, compared w/ 1.67 microhm-cm for copper,
: >and 2.65 microhm-cm for aluminum (I rounded off the values for Al & Cu to
: >the same number of significant digits as given for Mg).  I think you ought
: >to get a feel for conductivity from these figures.
: >
: >I don't have any experience using Mg in antennas, so I really can't share
: >any experience...
: >

: From what I can remember about magnesium, it will rust and it will burn.
: I suggest sticking to copper or aluminum or a aluminum-magnesium alloy (if
: you must have mangesium).

The reason magnesium is so expensive is that it is very reactive
(aluminum is also pretty expensive compared to steel for the same
reason).  Since they both oxidize so well (magnesium oxidizes better than
alluminum actually), they will form a coating of rust along the edge.
The rust actually protects the rest of the magnesium from oxidation.  So,
with either aluminum or magnesium you will get a very fine layer of rust
on the edge but the internal portions will not rust.  As for burning...
Yeah it can, but a big chunk of it is not likely to burn to easily, and
magnesium certainly will not burn spontaneously.  However, yes, it burns
VERY hot.

dan



From [e-mail] Fri 23 Jun 95 21:02:52
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!hookup!remus.wat.hookup.net!noc.tor.hookup.net!ve3ied!gts!feline!gray
From: [e-mail] (Kelly Gray)
Subject: Re: Mixing antenna wires
Message-ID: <[e-mail]>
Organization: Humber College Academic Computing Dept.
References: <3rgqcp$[e-mail]>
Date: Tue, 20 Jun 1995 15:23:39 GMT
Lines: 23

In article <3rgqcp$[e-mail]>,
Dave Calhoun <[e-mail]> wrote:
>I am moving into a new house and will be mounting a TV antenna, a 2m ham
>antenna, and a FM radio antenna. Can any of these antenna wires be
>joined together so that fewer wires will haqve to be run into the house?
>I'm wondering about the TV and the FM radio especially. Thanks for the help,
>dave
>--

As long as they are for receive only, the TV and FM radio antenna wires can
be combined. If you can tolerate only recieving FM signals from the same
direction as the TV, you can simply use a splitter to allow the TV and FM
radio to share the same antenna. The TV antenna can be used to receive FM
radio signals just as well as it receives TV signals.

The one thing that you do NOT want to do is connect the 2M antenna to either
the TV or the FM radio. If you do, the first time you transmit more than a
fraction of a watt, you risk blowing the front end on the receivers. The only
way to prevent this is with some sort of duplexer arrangement, which tends to
be much more expensive than the additional cable.




From [e-mail] Fri 23 Jun 95 21:02:53
Path: grape.epix.net!news2.sprintlink.net!news.sprintlink.net!howland.reston.ans.net!news.cac.psu.edu!psuvm!tjh112
Organization: Penn State University
Date: Thu, 22 Jun 1995 16:06:46 EDT
From: tyler harpster <[e-mail]>
Message-ID: <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: more gain: 1/2 wave whip or j-pole for 2m?
Lines: 2

I'm curious,  Which gives more gain on 2 meters?  I have an ht and I want to
 know if I would get more umph from a 1/2 wave hot rod whip, or a j-pole?
anybody know the facts?  I'd appreciate any answers... Tyler.  N3SPD

From [e-mail] Fri 23 Jun 95 21:02:53
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From: Tom Genereux <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,alt.sailing.asa
Subject: MOTOR TUNED MOBILE ANTENNAS:
Date: 20 Jun 1995 11:23:41 GMT
Organization: Priviate individual
Lines: 7
Message-ID: <3s6b3t$fjf$[e-mail]>
Xref: grape.epix.net rec.radio.amateur.antenna:11348 rec.radio.amateur.equipment:13440 rec.radio.amateur.homebrew:7881 rec.radio.amateur.misc:81249

Does anyone have any experence with the motor tuned (electric
screwdriver) mobile antennas like the High Sierra type antennas?

Do they work well? any problems with mounting? Do you think they
would work in a Marine mobile situation?

                                Tom KF2ST

From [e-mail] Fri 23 Jun 95 21:02:54
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna,alt.sailing.asa
Subject: Re: MOTOR TUNED MOBILE ANTENNAS:
Date: 21 Jun 1995 15:32:14 GMT
Organization: Intel Corporation, Chandler, AZ
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In article <3s6b3t$fjf$[e-mail]>,
Tom Genereux  <[e-mail]> wrote:
>Does anyone have any experence with the motor tuned (electric
>screwdriver) mobile antennas like the High Sierra type antennas?
>Do they work well? any problems with mounting? Do you think they
>would work in a Marine mobile situation?

Hi Tom, The latest Worldradio reported very close to the same results
with bugcatchers and screwdrivers, i.e. very good.

Locating an unbalanced antenna at the top of a marine mast has the
same problems as an elevated vertical on land, i.e. where's the ground?

73, Cecil, KG7BK, OOTC  (not speaking for my employer)

From [e-mail] Fri 23 Jun 95 21:02:55
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Steve Ellington)
Subject: Re: PARALLEL 95 OHM COAX LOSS?
X-Nntp-Posting-Host: iglou.iglou.com
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Sender: [e-mail] (News Administrator)
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Date: Tue, 20 Jun 1995 14:04:42 GMT
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W8JI  Tom ([e-mail]) wrote:
: Roy,

: >The conductor loss dominates not only at very low frequencies, but up to
: 1 GHz
: >or more for most types of coax.

: >My vote: The loss is 1/2 the loss of a single piece of the high-Z coax.

: So let me understand this. If I have 50% loss in a cable, I parallel two
: cables and each one has half the power, the loss is now only 25%?

: Hummmm. 50 watts divided by 2 is 25 watts per cable. In one cable I would
: have 25 watts of loss, in two cables I would have 12.5 watts per cable for
: 25 watts total.

: I think perhaps we are all leaving something out of this!

: 73 Tom
Yes we are. Well, if we were dealing with regular old house current, it
would be obvious that if we paralleled two wires, we would have less
loss. Why? Because there is less resistance. The fact that the current is
equally divided between the wires is not relevant to the point. Now, I
know at RF we have skin effect and dielectric loss and all that bunk but
the principle is still the same, the bigger the wire or the more of them
we parallel, the less loss.

Now am I thinking straight or not? By the way, I tried this on my R7
vertical and got a great impedance match using two rg62 cables. Also, I
put a dummy load on the other end and the swr was 1:1 so the z comes out
just right. For those of us who can get free rg62, this is a real deal!

I applied 50 watts to 150ft of this stuff and got 30 watts at the other
end using 28mhz. Seems kinda high to me.
--
  Steve
[e-mail]



From [e-mail] Fri 23 Jun 95 21:02:56
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Gary Coffman)
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
Date: Tue, 20 Jun 1995 15:47:14 GMT
Lines: 19

In article  [e-mail] (Steve Ellington) writes:
>YEABUT you are doubling the amount of coax you are sending signal
>through. If the published loss says 3db per 100ft, It doesn't matter how
>many watts you put in, you still loose 3db per 100ft so If I double the
>length of the cable, I loose 6db per 100ft of paralleled cable. Don'tyasee.

Nope. The distance the signal travels down the cable doesn't change
for *paralleled* cables. It's still 100 feet from source to load. It's
just that now half of the signal goes down one path, and the other
half goes down the other path, but each only travels 100 feet. If the
*same* bit of signal had to traverse both paths in *series*, then your
argument would be correct.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Fri 23 Jun 95 21:02:57
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Gary Coffman)
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3rtadu$[e-mail]> <3s105k$[e-mail]>
Date: Tue, 20 Jun 1995 15:57:36 GMT
Lines: 27

In article <3s105k$[e-mail]> [e-mail] (W8JI  Tom) writes:
>I can find the long formulas using conductor and dielectric losses and so
>on to calculate losses in reference engineering textbooks but right along
>with it are formulas and nomographs that show the loss for increased SWR.
>They give consideration to conductor losses but then simplify it to a VSWR
>problem.
>
>I'm still having a difficult time believing all these books are
>overlooking something so important, but that has been known to happen (see
>meaning of matched ;-) ).

It's just looking at different parts of the elephant. If you collapse
the vectors, as you must to get net power, you'll find that a line
has constant power along its length (minus attenuation), and always
flows from source to load. However, it's the current peaks that contribute
most strongly to that attenuation because power loss is I*I*R, so loss is
non-linearly related to current. That means that if you don't collapse the
vectors (which is what we want for cable attenuation rather than for net
power), losses will be proportionate to ISWR because the loss is dominated
by the value of *peak* current, not average current.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |

From [e-mail] Fri 23 Jun 95 21:02:58
Path: grape.epix.net!news.sprintlink.net!hookup!news.kei.com!ddsw1!news.rtd.com!news.azstarnet.com!usenet
From: Wes Stewart <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 20 Jun 1995 04:58:51 GMT
Organization: Arizona Daily Star - AZSTARNET
Lines: 45
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References: <3s2drr$[e-mail]>
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[e-mail] (CHARLES J. MICHAELS) wrote:
>
>Right on Rick,
>       Another way to look at it is that (assuming same loss per
>foot rate in all the lines) half the pwr goes down each of the
>paralleled lines and each loses the same percentage of pwr so when
>added together power loss is the same.
>Charlie,  W7XC
>--
>

As the guy whose (incorrect) reply started this discussion I guess it's my responsibility to
keep the fun going:-)

How about looking at it this way.  If we parallel two identical lines, we effectively divide
the inductance and series resistance per unit length in half and double the effective
capacitance per unit length.  Because under ideal conditions Z0=(L/C)^.5, we have divided the
original Z0 by 2.

Everybody seems to pretty much agree with my original premise that the series resistance is
the predominant loss factor.

For those that don't agree, I offer the equation from "Reference Data for Radio Engineers"
4th edition, p. 574, that states:

A(db/100') 4.34 * (Rt/Z0) + 2.78 * f * (e^.5) * pf

where Rt = the total line resistance,
      f = the frequency in MHz,
      e = the effictive dielectric constant,
and   pf = the power factor of the dielectric at frequency f

For the case at hand and most high quality lines at HF, the power factor will be very small so
the terms to the right of the plus sign become realitively insignificant.  This leaves the
left hand side with the loss being proportional to the ratio of the series R and the Z0.
Clearly, dividing both by two changes nothing.

So, we have a new transmission line with half the Z0 of the old but with the same loss per
unit length.

Another crazy intuitive argument, eh?


73, Wes


From [e-mail] Fri 23 Jun 95 21:02:59
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Bob)
Subject: Parts needed
Sender: [e-mail] (Usenet login)
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Date: Thu, 22 Jun 1995 17:39:23 GMT
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I would like the addresses and phone numbers of suppliers of aluminum
tubing and plexiglass.

Thanks,

Bob

From [e-mail] Fri 23 Jun 95 21:03:00
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From: SCOTT DOUGLAS <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Q: Where to buy coax waterproofing ?
Date: Wed, 21 Jun 95 03:52:07 -0500
Organization: Delphi ([e-mail] email, 800-695-4005 voice)
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References: <3rsaa6$[e-mail]>
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X-To: john 015 <[e-mail]>

john 015 <[e-mail]> writes:

>I need to make a positively waterproof seal where an RG-8A/U enter a
>sealed aluminium compartment (submergible).  I'm looking for a place
>which sells (retail, I only need two) "things" that will form such a
>seal.
>(SealCon and Heyco are two names I have for manufactureres of above.)
>
>Second, is PVC the jacket of choice for buriable cable  ?

PVC is great because you can always run new cable thru the chase as you need
to.  I would check with a salt-water fish tank company for reliable sealer.
Pack in in the caulk and them spray paint with a silicone spray, several coats.
And, go for it!  It's simple and always served me well with no noticable coro-
sion.

73 de wb5pbj

From [e-mail] Fri 23 Jun 95 21:03:01
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From: Ken Mason <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quagi difficulties.
Date: 21 Jun 1995 17:36:18 GMT
Organization: Intel Corporation, Folsom CA, USA
Lines: 26
Message-ID: <3s9lai$[e-mail]>
References: <[e-mail]> <3rg3et$[e-mail]> <[e-mail]>
NNTP-Posting-Host: kmasonpc.fm.intel.com

[e-mail] (Robert Smits) wrote:

>
> On replacing the entire coax run from the antenna to the SWR meter, the
> SWR came down VERY substantially - to about 1.8 to 1.
>
> I'll look at it some more in the daylight tomorrow, but this seems to be
> the problem, even though checking the original coax by terminating it with
> a dummy load seemed to indicate it was fine.
>
> Thanks, Bob.
>
> --
> [e-mail] (Robert Smits)
>

Bob,

 Was the length the same for each coax? You could be
running into a 1/2 wave multiple in which the SWR meter
will show 1:1. Add a foot or so of coax to the "GOOD" coax
and see if it is still 1:1.

                          Ken
                        KC6TEU
            [e-mail]

From [e-mail] Fri 23 Jun 95 21:03:01
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Steve Ellington)
Subject: Re: R7 Ques
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Sender: [e-mail] (News Administrator)
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[e-mail] wrote:
: Has anyone ever tried to add radials to the Cuscrafft R7?
No and don't try. Cushcraft disalows it. This is resonant as a 1/2 wave
antenna and if you add any metal to the radials it will detune it. Adding
radials to the mast would change the ground reference. The only thing
that might enhance the R7 would be to put a gound screen on the ground
beneath it to help reduce ground losses. These would not be resonant.
Someting like chicken wire would work. Just be sure to keep and eye on
the chickens.
--
  Steve
[e-mail]



From [e-mail] Fri 23 Jun 95 21:03:02
Path: grape.epix.net!news.sprintlink.net!msc.edu!bweinman
From: bweinman@@mutt.hamline.edu (Bruce Weinman)
Newsgroups: rec.radio.amateur.antenna
Subject: Repeater antennas?
Date: 22 Jun 1995 14:59:38 GMT
Organization:
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Message-ID: <3sc0gq$[e-mail]>
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X-Newsreader: TIN [version 1.2 PL0]

Can someone point me to some reading on what's necessary to run a 2m
repeater through a single antenna?  The term "duplexer" has been
mentioned, but my redearch has stalled there.
Bruce N0NUN

--
_____________________________________________________________________________
There are four kinds of homicide:             [e-mail]
felonious, excusable, justifiable             [e-mail]
and praiseworthy.
                -Ambrose Bierce

From [e-mail] Fri 23 Jun 95 21:03:03
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rotator wire multiband antenna
Date: 21 Jun 1995 07:10:47 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 8
Sender: [e-mail]
Message-ID: <3s8unn$[e-mail]>
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>Problem is, the lowest frequency antenna can be easily tuned, but
when you try to cut the length of the second harmonic of the
lower frequency, you may find yourself with a real chore.  The last
time I tried it (for a portable inverted vee, I gave up.<

Don's experience agrees with mine. If the wires are close, the thing won't
work. There needs to be some physical separation in the wires, or the
antenna will put you in a basket weaving class. 73 Tom

From [e-mail] Fri 23 Jun 95 21:03:04
Path: grape.epix.net!news.sprintlink.net!redstone.interpath.net!cphillips
From: [e-mail] (Curt Phillips)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Scanner Antenna?
Date: Wed, 21 Jun 95 19:24:24 GMT
Organization: North Carolina Division of Energy
Lines: 23
Distribution: world
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References: <3s1h6k$[e-mail]>
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X-Newsreader: News Xpress Version 1.0 Beta #2

[e-mail] (Jason Smith) wrote:
>Could anyone recommend a good scanner costing under 75$'s for a Uniden
>Bearcat BC700A that has 800\900mhz frequencys?
>

   The Channelmaster "Monitenna" is a very good, but large (over 8' tall)
fixed station antenna that is used by several of our club members.  It is
given very high marks by all of our members that use it.  I have one that
doesn't work very well... of course, it's still in the box, as I haven't
had time to install it yet :-).
   Typically you can purchase one for about $30-$35.  We did a group
purchase through a distributor and got them for a little less than that.
   BTW,  the "Monitenna" is manufactured in Smithfield, NC about 30 miles
south of here, but I nor any of my club members work there or have any
financial interest in the company.

==========Opinions expressed are solely those of the author============
Curt Phillips KD4YU (ex-WB4LHI)      |"I don't want to gain immortality
Chairman, Tarheel Scanner/SWL Group  | through my work.  I want to gain
[e-mail]  | immortality through NOT DYING."
Triangle TeleComputer BBS919-772-9745|                 --Woody Allen
=====Compu$erve:73167,2050===MCIMail:WCPHILLIP===GEnie:C.PHILLIPS======


From [e-mail] Fri 23 Jun 95 21:03:04
Path: grape.epix.net!news.sprintlink.net!psgrain!qiclab.scn.rain.com!europa.com!spider.europa.com!user
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: SGC 230 for Base Station
Date: Thu, 22 Jun 1995 20:08:03 -0800
Organization: Europa Communications, Inc, Portland Oregon USA
Lines: 4
Message-ID: <[e-mail]>
NNTP-Posting-Host: spider.europa.com

I'm interested in experiences using this tuner for base station use where
hidden or low profile antennas are a must.  How might it work to tune a
vertical wire up a tree if some type of ground plane or ground radials
might be employed?

From [e-mail] Fri 23 Jun 95 21:03:07
Path: grape.epix.net!news.sprintlink.net!newsie.dmc.com!news.iii.net!dts
From: [e-mail] (Daniel Senie)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SGC-230 auto tuner
Date: 21 Jun 1995 14:13:28 GMT
Organization: Daniel Senie Consulting
Lines: 130
Message-ID: <3s99er$[e-mail]>
References: <3rj8c9$[e-mail]> <[e-mail]> <3s1tv8$[e-mail]>
NNTP-Posting-Host: peanut.iii.net

In article <3s1tv8$[e-mail]>,  <[e-mail]> wrote:
)In article <[e-mail]>,  <[e-mail]> wrote:
)
)>How can the SGC unit be one 'S' unit down from a Bugcatcher when in the
)>SGC literature it states, "you can get more than 20 dB of gain by simply
)>using an SGC compared with any other 1.8 to 30 MHz system." You must, of
)>course, be in error with your statement.
)
)Unlike "Aerials" in "Worldradio", people are equal here and in a
)position to defend the truth. I have not been able to verify your
)quote. Would you mind telling us where it came from?

Thanks for digging this up, I must have missed this advert. Where did
you find it? I'd love to read the original.

)
)I dug up the SGC advertisment entitled, "Why the QMS works so well -
)the 20 dB Advantage." What they are comparing the QMS system to is
)a composite of six generic mobile antennas. The six entries are:
)
)1. Most mobile HF antennas are so heavy they must be bumper-mounted,
)close to only a foot from the ground. Moving the antenna to the top
)of the vehicle can gain 3-6 dB by reducing ground losses.

I'll attest to top mounting. I have a bugcatcher (of the carolina - wd4bum
of hamstick fame) mounted on the center of the roof of my Pathfinder. It's
about 7 feet tall, so I still clear bridges which have 13 foot clearance.
Roof mounting makes a good bit of difference. I don't see where this is a
particular advantage for the QMS, but a good suggestion for all antennas.

Interesting that in their ads, they picture the QMS on trunk lids and on
the side of sport/utility trucks. I wonder why they don't top mount them in
their ads?

)
)2. Bumper mounting leaves the vehicle as a shield in one direction.
)Moving the antenna to the top of the vehicle can gain 3-6 dB in that
)previously shielded direction.

Again, agreed. Still don't see the QMS advantage, though. Any antenna
can be rigged anywhere, given some ingenuity.

)
)3. A lot of automatic antenna tuners are mounted inside the trunk.
)Moving the auto-tuner to the base of the antenna can gain 3-6 dB.

Use a resonant antenna...

)
)4. A lot of resonant type mobile antennas are wound with #22 wire.
)The SG-303 is wound with a 3 mm tape/wire strap, equivalent to #4
)wire. Going from #22 to #4 wire can gain 3-6 dB.

By "a lot" I guess they are refering to hustlers, and perhaps the
75 meter hamstick. You gotta put all that wire somewhere... Perhaps
one of the antenna experts here could comment on the efficiencies of
using a coil of #4 (or equivalent) wire at the base of an antenna, at a
high current point, versus using a coil of #22 wire at the center of the
antenna. I suspect there are some tradeoffs to be had here.

)
)5. The SG-303 is two antennas in a single casing, resonant at about
)22 MHz AND 10 MHz. It will outperform a conventional 9 foot whip on
)the lower frequency HF bands - a 3-6 dB gain.

Ok, so it's a nice antenna for a couple of bands. Why would one use
a 9 foot whip on the lower freqnecy bands without loading? Sure you could
put a bedspring on your roof and load that up too, but it seems inefficient.
)
)6. Many hams use the built-in auto-tuners in their transceivers
)to tune their mobile antennas. If the antenna is non-resonant, a
)high SWR exists causing feed-line losses. Putting the tuner at
)the base of the antenna can save 3-6 dB.

If the antenna is nonresonant on the low bands, and you're trying to use
a tuner to compensate, you'll get mediocre results no matter what. What
I use a tuner for in my HF mobile setup is to allow operating the rig
with an SWR (at the rig's output spiggot) of 2:1 or 3:1 when it becomes
necessary to broaden the usable range of a given tap on the bugcatcher.

Using a tuner to cover every band with one antenna will result in signals.
Were the efficiencies received worth the expense of the equipment?
)
)What they are saying is, if you have any of these conditions that
)can be remedied by the QMS system, then you can gain 3 dB. If you
)have 4 or more of these conditions, you might gain 20 dB. Is it
)all 100% true? I doubt it, but I have trouble shooting down any
)one of the above six statements. If you want to argue with any
)of these statements, please feel free.

Most interesting to see how they derived it all... With all the text, they
can certainly make the argument without false advertising claims against
them. I've certainly seen equivalent hype in other industries.

)
)Will the QMS system outperform a bugcatcher? It just might on 15m
)with a bumper-mounted bugcatcher. Will it outperform a bugcatcher
)on 75m? Of course not, but if operation on 75m is a rarity for
)an individual, he must put up with the bulk of a 75m bugcatcher
)even though he rarely uses it. There is room for more than one

I'll offer an alternative for the occasional 75 meter user. I run a
40m-10m bug catcher (carolina, though the texas bug catcher is available
this way too). With the smaller bugcatcher, it's possible to build an
un-guyed antenna.

For the occasional 75 meter use (for me, this consists of checking in to
the Section ARES net on Sunday mornings if I happen to be mobile) I have
a 75 meter hamstick which mounts in place of the bugcatcher. Both are on
quick disconnects.

)kind of mobile antenna in this world. IMO, a properly installed
)QMS antenna system would outperform bumper-mounted Hamsticks on
)some or most bands. And I agree that's a lot of money to pay for
)never getting wet.

In the end, I think Cecil and I pretty much agree on all of this. There's
nothing wrong with the SGC tuner. I think their hype on the QMS is
excessive, and the price tag is not worth the money.

Never getting wet comes at a high cost, both in Dollars and in reduced
performance on most of the bands (especially now, when the higher bands
are mostly useless).

Dan
--
---------------------------------------------------------------
Daniel Senie                 Internet:     [e-mail],
Daniel Senie Consulting                    [e-mail]
http://www.senie.com         Packet Radio: [e-mail]

From [e-mail] Fri 23 Jun 95 21:03:08
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!usc!sdd.hp.com!col.hp.com!fc.hp.com!jayk
From: [e-mail] (Jay Kesterson K0GU)
Newsgroups: rec.radio.amateur.antenna
Subject: Six meter quad results
Date: 23 Jun 1995 16:32:21 GMT
Organization: Morris is a cat, Morse is a code
Lines: 83
Message-ID: <3seqal$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: hpxxxa.fc.hp.com
X-Newsreader: TIN [version 1.2 PL2]


When I asked for help designing a six meter quad several people ask that I
post the results. So here it is, FWIW. The quad was partially designed using
AO with a bit of tweaking by me. Results seem near predicted on F/B (on NEC2)
but the driven element (.5 inch copper tubing) was a bit long. As shown below
the SWR was 1.7:1 on 50.125 and 1.5:1 on 50.0. I plan to take about five
inches out of the driven element.

If you have both NEC and MiniNEC this is a good antenna file to use to see
the problem MiniNEC seems to have with quads. The results are different by
about five percent.

73, Jay  K0GU                  [e-mail]

==========================================================================

If your not familiar with the format below:

DL = .125 driven element length
RL = .125 reflector  "      "
D1 = .125 director#1 "      "
D2 = .125 director#2 "      "

Spacing:

R                    D                  D                  D
E--------------------R------------------#------------------#
F                    V                  1                  2
 <-------54"-------->
 <---------------107.9"---------------->
 <--------------------------163"-------------------------->


==========================================================================

K0GU Four Element Six Meter Quad 14' Boom
average ground
50.125 MHz
16 copper wires, inches

H = 360

RL = 31.4
RLT = H+RL
RLB = H-RL

DL = 30.4
DLT = H+DL
DLB = H-DL

D1 = 30.0
D1T = H+D1
D1B = H-D1

D2 = 29.3
D2T = H+D2
D2B = H-D2

SPACE = 54
SPACE2 = 107.9

4       0      -RL     RLT             0     RL    RLT         #14
4       0      -RL     RLT             0    -RL    RLB         #14
4       0      -RL     RLB             0     RL    RLB         #14
4       0       RL     RLB             0     RL    RLT         #14

4   SPACE      -DL     DLT         SPACE     DL    DLT         .5"
4   SPACE      -DL     DLT         SPACE    -DL    DLB         .5"
4   SPACE      -DL     DLB         SPACE     DL    DLB         .5"
4   SPACE       DL     DLB         SPACE     DL    DLT         .5"

4  SPACE2      -D1     D1T        SPACE2     D1    D1T         #14
4  SPACE2      -D1     D1T        SPACE2    -D1    D1B         #14
4  SPACE2      -D1     D1B        SPACE2     D1    D1B         #14
4  SPACE2       D1     D1B        SPACE2     D1    D1T         #14

4     163      -D2     D2T           163     D2    D2T         #14
4     163      -D2     D2T           163    -D2    D2B         #14
4     163      -D2     D2B           163     D2    D2B         #14
4     163       D2     D2B           163     D2    D2T         #14

1 source
Wire 7, center

From [e-mail] Fri 23 Jun 95 21:03:09
Path: grape.epix.net!news2.sprintlink.net!news.sprintlink.net!psgrain!news.tek.com!emerald.cse.tek.com!royle
From: [e-mail] (Roy W Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The PARALLEL 95 OHM COAX that wouldn't die!
Date: 23 Jun 1995 00:53:57 GMT
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 31
Distribution: world
Message-ID: <3sd3b5$[e-mail]>
NNTP-Posting-Host: emerald.cse.tek.com

[e-mail] (Forrest Gehrke):

>RL> My vote: The loss is 1/2 the loss of a single piece of the high-Z
>RL> coax.

>Roy, Why wouldn't the loss be the same?
>Assume each RG-62 line is 100 feet long and has a
>loss of 3dB per 100 feet at the frequency of
>interest. . .

Hm, this thread really has a life of its own.

Permit me to use 100 ohms for convenience.

Neglecting additional loss due to SWR, the loss with two parallel 100-ohm
cables driving a 50-ohm load will be 1/2 that of a single 100-ohm coax
driving a 50-ohm load.

The loss with two parallel 100-ohm cables driving a 50-ohm load will be
the same as with one 100-ohm cable driving a 100-ohm load.

This is for HF, where dielectric loss is negligible compared to resistive
conductor loss.

If anyone disagrees after the qualifications, I'll do some calculations,
but several folks already have.

73,
Roy Lewallen, W7EL
[e-mail]


From [e-mail] Fri 23 Jun 95 21:03:10
Path: grape.epix.net!news.sprintlink.net!demon!pacsat.demon.co.uk!slewis
From: Simon Lewis <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Tonna 2m/70cm beam
Date: Fri, 23 Jun 1995 20:59:10 GMT
Organization: None
Lines: 32
Message-ID: <[e-mail]>
References: <3rpfe7$[e-mail]>
Reply-To: [e-mail]
X-NNTP-Posting-Host: pacsat.demon.co.uk
X-Broken-Date: Saturday, Jun 17, 1995 21.30.24
X-Newsreader: Newswin Alpha 0.7

In article: <3rpfe7$[e-mail]>  "Fraser Robertson (G4BJM)" > From: "Fraser
Robertson (G4BJM)" <[e-mail]>

> Hi all, we have just aquired a Tonna beam for satellite use.
> It's a 9 ele on 2m and 19 on 70cm.  It's not assembled yet.
>
> I thought it was a crossed yagi on both bands, but it only has
> one driven element per band, so I presumably it is just straight
> vertical or horizontal polarasation on each band?
>
> Can anyone explain exactly what this antenna is, and is it any good
> for satellite work.
>
> Thanks in advance, Fraser G4BJM
>
>


Yes! Its a simple 9 ele 2m beam and 19 ele 70cm beam on the same boom.
Linear polarised - to make a cross yagi you need two! plus phasing harnesses and mounts
read the satellite experimenters handbook to see how they mount!

Its not that simple if you have not played with phasing before!

--
+-------------------------------------------------------------------------+
|  73 From:  Simon Lewis GM4PLM - Helensburgh - Strathclyde - Scotland    |
| Packet: GM4PLM @ GB7SAN.#78.GBR.EU   Email: [e-mail]   |
| AMSAT - UK Member 4282     **** SUPPORT YOUR LOCAL AMSAT GROUP ****     |
+-------------------------------------------------------------------------+


From [e-mail] Fri 23 Jun 95 21:03:11
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (ABLACKBELT)
Newsgroups: rec.radio.amateur.antenna
Subject: Tower/Coax Routing Question?
Date: 23 Jun 1995 12:32:28 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 29
Sender: [e-mail]
Message-ID: <3seqas$[e-mail]>
Reply-To: [e-mail] (ABLACKBELT)
NNTP-Posting-Host: newsbf02.mail.aol.com

Hi,
I have an ez way 50 ft tower which telescopes and tilts with the pivot of
the
tilt about ten feet above the ground. My problem is that I run my coax to
the
ground level and along the side of my house to the shack. I have replaced
the
coax and rotator cable three times due to my dogs biting or otherwise
compromising the cable. I wonder if I ran the coax down the side of the
tower
to a point approximately ten feet from the ground (the pivot pt) and over
to
the eves of the house (approximately 18') if I would be inviting a direct
lightning strike to the house. Somehow I have it in my mind that running
along the ground will dissipate some bit of a strike (which I did have a
year
ago and blew off a corner of concrete at ground level) if not all.  I am a
bit apprehensive about doing the overhead thing. Any comments would be
greatly appreciated. Also the run under the eves in 35 feet before it gets
to
the shack.
Thanks
 A.R.S. KD4NAV
 MICHAEL RUBIN
   E-mail directly to:    [e-mail]

  73 TU CU SK DE KD4NAV



From [e-mail] Fri 23 Jun 95 21:03:12
Path: grape.epix.net!news.sprintlink.net!cc.iu.net!news
From: [e-mail]   (Bill Newkirk)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: TV antenna using electrical wiring
Date: 21 Jun 1995 18:10:39 GMT
Organization: Space Coast Amateur Technical Group
Lines: 15
Message-ID: <3s9nav$[e-mail]>
References: <3s5eo3$[e-mail]>
Reply-To: [e-mail] (Bill Newkirk)
NNTP-Posting-Host: netport-24.iu.net
X-Newsreader: IBM NewsReader/2 v1.09

In <3s5eo3$[e-mail]>, [e-mail] (Scott M Weaston) writes:
>     I know this really doesn't apply to this group but does anyone know
>anything about those antennas that claim to give better reception for
>televisions?  I am trying to find some info on it...let me know what you know

besides that they don't work very well?  (gotta love those rabbit ears that
use "Proven TV Dish RF Technology!" y'know...that set of rabbit ears that had
the decorative dish in the middle?).

i guess it would beat nothing at all...the house wiring things should be some sort
of coupler that blocks the line current while passing the radio signals.

Bill Newkirk WB9IVR                  The Space Coast Amateur Technical Group
Melbourne, FL                       duty now for the future of amateur radio


From [e-mail] Fri 23 Jun 95 21:03:12
Path: grape.epix.net!news.sprintlink.net!cc.iu.net!news
From: [e-mail]   (Bill Newkirk)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: VHF Ant Help
Date: 21 Jun 1995 18:13:59 GMT
Organization: Space Coast Amateur Technical Group
Lines: 21
Message-ID: <3s9nh7$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (Bill Newkirk)
NNTP-Posting-Host: netport-24.iu.net
X-Newsreader: IBM NewsReader/2 v1.09

In <[e-mail]>, [e-mail] writes:
>Do I need to use special quality of cable to run to an outdoor ant that covers
>6m, 2m and 440 ???  The ant is a Comet triband mobile whip that I have
>mounted on a 15 ft fiberglass pole that is set on the back of the house on a
>2nd story deck.  Do I need special connectors too? THANKS. The ant will be
>used only for FM work.

i would think regular old RG-213/RG-8 would do.  heck even RG-58 if the
run is only like 30 feet or so would work.

you're going to need whatever connector the antenna has on it or you'll have
to modify the antenna to take a different connector -- offhand i'd guess it's
got an SO-239 on it (mates with the standard PL-259 plug) or an N connector.
get one with whatever reducers you need for the cable you're running and
assemble per the directions.

hook it up, check it out, weatherproof if ok and enjoy.

Bill Newkirk WB9IVR                  The Space Coast Amateur Technical Group
Melbourne, FL                       duty now for the future of amateur radio


From [e-mail] Fri 23 Jun 95 21:03:13
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!sdd.hp.com!col.hp.com!jwc
From: [e-mail] (John Chapman)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: VHF Ant Help
Date: 21 Jun 1995 18:34:43 GMT
Organization: HP Colorado Springs Division
Lines: 5
Message-ID: <3s9oo3$[e-mail]>
References: <[e-mail]> <3s9nh7$[e-mail]>
NNTP-Posting-Host: mssjwc.col.hp.com
X-Newsreader: TIN [version 1.2 PL2]

   I f you havn't allready you may want to put some radials under
that comet to simulate a car body.

 John, N0KIC


From [e-mail] Fri 23 Jun 95 21:03:14
Path: grape.epix.net!news.sprintlink.net!matlock.mindspring.com!sco.mindspring.com!sco
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: VHF Ant Help
Date: Tue, 20 Jun 1995 20:08:36 -0400
Organization: MindSpring Enterprises, Inc.
Lines: 5
Message-ID: <[e-mail]>
NNTP-Posting-Host: sco.mindspring.com
X-Newsreader: Trumpet for Windows [Version 1.0 Rev B]

Do I need to use special quality of cable to run to an outdoor ant that covers
6m, 2m and 440 ???  The ant is a Comet triband mobile whip that I have
mounted on a 15 ft fiberglass pole that is set on the back of the house on a
2nd story deck.  Do I need special connectors too? THANKS. The ant will be
used only for FM work.

From [e-mail] Fri 23 Jun 95 21:03:15
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: W8JK Uni-directional
Date: 21 Jun 1995 06:58:22 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 37
Sender: [e-mail]
Message-ID: <3s8u0e$[e-mail]>
References: <3s2ugd$qdd$[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com


>In his book "Wire Antenna Handbook", Dave Ingram (K4TWJ) desribes
a modification of Dr. John Kraus's phased dipole array that
provides a unidirectional pattern. The phasing looks OK because
it is 225 degrees but I am not so sure about current balancing.
He uses 450 Ohm ladder line for connecting the dipoles and
building a matching feeder section. This would work out to 1/4
wavelength if I assume a velocity factor of .64. If any of you
has experience with this antenna or can provide some sort of
analysis, I would appreciate it. I have a small antenna range and
do computer modelling of antenna response patters. I would be
pleased to share further results with participants in this group.

Regards,
GK.<

Thank's Don,

I re-read that and I see I needed my bi-focals on that one!

Yes, GK has a good point. If the phase is not 180 or  0 degrees, the
currents are not equal in the driven elements. The correct pasing delay
for a cross fire array is equal to the element spacing for a
uni-directional pattern. In other words, if I have two dipole 180 degrees
shifted because of transposing the feedline spaced 90 degrees apart the
correct phasing delay is also 90 degrees.

That works beautifully because the array is uni-directional firing in the
direction of the non-phasing line delayed element over octaves of BW (as
the frequency is decreased below the 90 degree spacing frequency). But GK
is exactly correct, no allowance was made for the feedpoint impedance
shift in the two elements, and that limits the directivity.

So the correct phasing line length in electrical degrees is equal to the
element spacing in electrical degrees, did he do that?

73 Tom

From [e-mail] Fri 23 Jun 95 21:03:15
Path: grape.epix.net!news2.sprintlink.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: W8JK Uni-directional
Date: 21 Jun 1995 03:05:57 GMT
Organization: News & Observer Public Access
Lines: 15
Message-ID: <3s82al$[e-mail]>
References: <3s2ugd$qdd$[e-mail]> <3s7beh$[e-mail]>
NNTP-Posting-Host: grail1411.nando.net

[e-mail] (W8JI  Tom) wrote:
>
> GK,
>
 > I don't have that book, but how the heck do you make an 8JK
 > non-directional???
 > That sounds weird. Do you mean bi-directional? If so, it is bi-directional
 > as designed by John Kraus. Please explain what Ingram said. 73 Tom

Tom, I read "uni-directional" - that is "one-directional" which is
an adaptation of the 8JK beam.  The pattern fed at 90 degrees out of
phase should be some a cardiod.

73,
Don

From [e-mail] Fri 23 Jun 95 21:03:16
Path: grape.epix.net!news.sprintlink.net!holonet!colossus.holonet.net!tippy!mike.cotterman
From: [e-mail] (MIKE COTTERMAN)
Newsgroups: rec.radio.amateur.antenna
Subject: was: NEC/ELNEC Loc? EZNE
Message-ID: <[e-mail]>
Date: Wed, 21 Jun 95 13:05:00 -0500
Distribution: world
Organization: Tippecanoe Information System - Lake Tippecanoe
Reply-To: [e-mail] (MIKE COTTERMAN)
X-Newsreader: PCBoard Version 15.21
X-Mailer: PCBoard/UUOUT Version 1.10
Lines: 24


RR>While we're on the subject, would anyone on the newsgroup be interested
RR>sharing EZNEC .ez input files?

        Great idea Russ.  What's the best way to do this?


RR>I've only had the application for 2 weeks, but I've modelled some
RR>interesting antennas, including a bobtail curtain, a Lindenblad, a
RR>Quadrafilar Helix and a square loop eggbeater.  The QHA took a few hour
RR>at the keyboard, to say the least.

        My most ambitious effort to date has been the Bruce and Sterba
arrays (vertical and horizontal) from the ARRL Antenna Book.  I'd be happy
to share these and any others as I get 'em punched in.
        I was confined to bed after a recent surgery so I'm not pumping 'em
out too fast.  I wait for my wife to leave the house, then make my way out
to the computer...I just can't leave that darn program alone!

                                        Mike


---
 * WR 1.31 [NR] * UNREGISTERED EVALUATION COPY

From [e-mail] Fri 23 Jun 95 21:03:17
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!sdd.hp.com!hp-pcd!hp-cv!reuter.cse.ogi.edu!news.ssd.intel.com!chnews!vegas.ch.intel.com!cmoore
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: was: NEC/ELNEC Loc? EZNE
Date: 22 Jun 1995 18:44:54 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 11
Distribution: world
Message-ID: <3scdn6$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: vegas.ch.intel.com
Originator: [e-mail]

In article <[e-mail]>,
MIKE COTTERMAN <[e-mail]> wrote:
>
>       My most ambitious effort to date has been the Bruce and Sterba
>arrays (vertical and horizontal) from the ARRL Antenna Book.  I'd be happy
>to share these and any others as I get 'em punched in.

Has anyone modeled an automobile? I've been using a rectangular grid
approximately the size of my S10 positioned 1.5 ft. above real ground.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)

From [e-mail] Fri 23 Jun 95 21:03:17
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news2.sprintlink.net!news.sprintlink.net!cs.utexas.edu!utnut!nott!cunews!freenet.carleton.ca!FreeNet.Carleton.CA!ae517
From: [e-mail] (Russ Renaud)
Subject: Re: was: NEC/ELNEC Loc? EZNE
Message-ID: <[e-mail]>
Sender: [e-mail] (Russ Renaud)
Reply-To: [e-mail] (Russ Renaud)
Organization: The National Capital FreeNet
References: <[e-mail]> <3scdn6$[e-mail]>
Date: Fri, 23 Jun 1995 12:13:10 GMT
Lines: 11

 ([e-mail]) writes:
>
> Has anyone modeled an automobile? I've been using a rectangular grid
> approximately the size of my S10 positioned 1.5 ft. above real ground.
>
> 73, Cecil, KG7BK, OOTC  (not speaking for my employer)

There's an impressive NEC-2 input file on ftp.netcom.com (if you can get in).
It's a very extensive model of a car.

73 de Russ, va3rr/aa8lu

From [e-mail] Fri 23 Jun 95 21:03:18
Path: grape.epix.net!news2.sprintlink.net!news.sprintlink.net!demon!boltons.demon.co.uk!Al
From: Al Bolton <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: What's a Bugcatcher?
Date: Fri, 23 Jun 95 08:41:12 GMT
Lines: 16
Message-ID: <[e-mail]>
Reply-To: [e-mail]
X-NNTP-Posting-Host: boltons.demon.co.uk
X-Newsreader: Demon Internet Simple News v1.29

Hello,

Excuse my ignorance, but what is a "Bugcatcher" type of mobile aerial? I have
noticed many references to it in this newsgroup and it would seem to be a good
efficient mobile aerial. I operate almost exclusively mobile so any info would
be much appreciated!

Regards, 73/72,

________________
Al Bolton.
OK8VSQ/OM/G4VSQ.
Caversham, UK.
G-QRP 8741.
----------------

From [e-mail] Fri 23 Jun 95 21:03:19
Path: grape.epix.net!news2.sprintlink.net!news.sprintlink.net!psgrain!news.tek.com!emerald.cse.tek.com!royle
From: [e-mail] (Roy W Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What's the gain of a 2m j
Date: 23 Jun 1995 00:51:59 GMT
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 17
Distribution: world
Message-ID: <3sd37f$[e-mail]>
NNTP-Posting-Host: emerald.cse.tek.com

[e-mail] (Claton Cadmus):

>A j-pole is simply an end feed verticle dipole.  A dipole has a gain of
>2.18 dbi.  However, a J-pole due to the matching sectio has a gain on
>1.89 dbi slightly less then the dipole.  A quarter wave verticle is
>about 0dbi so the j-poles do better by 2db.

A vertical dipole and J-pole have very nearly the same gain. A quarter-wave
vertical does also, but it's difficult to compare directly since it's
restricted to being close to or at ground level. If you elevate the
quarter-wave vertical and its ground system, you have a "ground-plane"
antenna which also has essentially the same gain as the J-pole and vertical
dipole.

Roy Lewallen, W7EL
[e-mail]


From [e-mail] Fri 23 Jun 95 21:03:19
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news.starnet.net!wupost!news.inlink.com!vulcan.inlink.com!raiar
From: [e-mail] (Gary V. Deutschmann Sr.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What`s the gain of a 2M J-pole
Date: 20 Jun 1995 23:41:51 GMT
Organization: inlink
Lines: 8
Message-ID: <3s7mbv$[e-mail]>
References: <3rpe02$[e-mail]> <3rs2q2$[e-mail]>
NNTP-Posting-Host: vulcan.inlink.com
X-Newsreader: TIN [version 1.2 PL2]

The gain of any J-Pole is directionally proportional to the cost of your
materials vx a store bought unit.

Mine presented a gain of $50.00 over a Ground Plane, into the Hip National
Bank!

Gary


From [e-mail] Fri 23 Jun 95 21:03:20
Path: grape.epix.net!news.sprintlink.net!news.primenet.com!lager
From: [e-mail] (Woody Harper)
Newsgroups: rec.radio.amateur.antenna
Subject: Which Antenna For Me?
Date: 22 Jun 1995 19:36:45 GMT
Organization: Primenet [phone]
Lines: 13
Message-ID: <3scgod$[e-mail]>
NNTP-Posting-Host: usr3.primenet.com
X-Newsreader: TIN [version 1.2 PL2]

Here's my question for the day. I have a couple of IC-24ET HTs as my only
radios. I would like to leave one set up at home as a "base station"
while the other travels with me. These radios broadcast on 140-150MHz and
440-450Mhz but apparently seem capable of receiving everything from
.00MHz to 1310.00MHz. What sort of antenna(s) do I need to make the most
of these little radios? I am definately interested in shortwave listening
as well as making the most of my transmitting abilities (after I get my
license of course). I am a total rookie, so any help is appreciated.

--
-------------------------------------------------------------------------------
Home Page: http://www.primenet.com/~lager


From [e-mail] Fri 23 Jun 95 21:03:20
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!howland.reston.ans.net!usc!nic-nac.CSU.net!cello.gina.calstate.edu!swrl73.gina.slip.csu.net!timstep
From: Timothy Stephenson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: WTD plan for 800MHz ant
Date: 21 Jun 1995 14:24:59 GMT
Organization: Teacher/Disaster Planner
Lines: 3
Distribution: world
Message-ID: <3s9a3r$[e-mail]>
NNTP-Posting-Host: 130.150.1.73
X-UserAgent: 1.1
X-XXMessage-ID: <[e-mail]>
X-XXDate: Wed, 21 Jun 95 14:29:47 GMT

I am hoping for plans on building (cheap) 800 Mhz antennas for disaster
preparedness for my school district.  Any suggestions?  Thanks. -Tim
[e-mail]

From [e-mail] Fri 23 Jun 95 21:03:21
Path: grape.epix.net!news.sprintlink.net!cam.news.pipex.net!pipex!soap.news.pipex.net!pipex!edi.news.pipex.net!pipex!swrinde!elroy.jpl.nasa.gov!usc!nic-nac.CSU.net!cello.gina.calstate.edu!swrl21.gina.slip.csu.net!timstep
From: Timothy Stephenson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: WTD plan for 800MHz ant
Date: 21 Jun 1995 17:12:37 GMT
Organization: Teacher/Disaster Planner
Lines: 12
Distribution: world
Message-ID: <3s9ju5$[e-mail]>
References: <3s9a3r$[e-mail]>
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Continuing...  I have my own 15 watt Motorola Maxar 80 radio (800 MHz)
that I will be using on District frequencies (I am a disaster planner for
the District).  I will also be making emergency antennas for 25 watt
mobile radios (that we may wish to pull out of their installation for use
outside, for example).  I hope for plans for 1) an omnidirectional
antenna (e.g., the length and diameter of a wire I should use off the end
of a coax connector, and the size of the ground plane), and a directional
antenna (quad? yagi?) for use on the bus that goes to an outlying
community, for use from my home to the District, and for use by a couple
of outlying schools. Ne c'est pas?  Any suggestions would be appreciated.
 Also, is 50 ohm line standard with 800 MHz?  Respectfully,  -Tim  KC6WGD
 [e-mail]

From [e-mail] Fri 23 Jun 95 21:03:22
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From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: WTD plan for 800MHz ant
Date: Wed, 21 Jun 1995 15:00:01 GMT
Organization: Ericsson
Lines: 15
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References: <3s9a3r$[e-mail]>
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Timothy Stephenson <[e-mail]> wrote:

>I am hoping for plans on building (cheap) 800 Mhz antennas for disaster
>preparedness for my school district.  Any suggestions?  Thanks. -Tim
>[e-mail]

Maybe someone could offer assistance if we knew what KIND of antenna
you were looking to build.  Will it need to be directional or more
general coverage?  Will it be for transmitting and recieving, or just
recieving?  What kind of radio will it hook to?

With those questions answered, a cheap solution can usually be found.

Mike  KD6PKJ



From [e-mail] Tue Jun 27 15:26:59 1995
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!usenet.eel.ufl.edu!news.iag.net!pm1-orl15.iag.net!user
From: [e-mail] (Patrick Stickler)
Newsgroups: rec.radio.amateur.antenna
Subject: "Flutter" noise from 2m through glass 1/4L mobile antenna
Date: Sun, 25 Jun 1995 15:03:45 -0400
Organization: Orlando, Florida USA
Lines: 31
Message-ID: <[e-mail]>
NNTP-Posting-Host: pm1-orl15.iag.net


I just installed my first 2 meter mobile antenna ever, a 1/4 wavelength
through glass vertical. I followed the instructions completely and for
the most part it works very well -- until the car moves! The vibration
and other movements of the antenna induced by the car's movement causes
alot of static "flutter" noise, making communication very annoying. At
the exact same location, with the car still, I get full quieting reception,
but as soon as I start driving, the audio reception degrades to barely
usable.

Is this normal for a mobile antenna? I noticed that the glass mounted
2 meter mobile antenna in the ARRL handbook had the shield of the coax
grounded right at the antenna to the roof support metal structure. In
my installation, the rig chassis is grounded at the transmission hump
on the floor. Does this make a difference?

Any suggestions will be greatly appreciated.

Thanks,

Patrick Stickler
Orlando, Florida
[e-mail]
KC4YYY

=========================================================================
 Patrick Stickler * KC4YYY * Orlando, Florida U.S.A. * [e-mail]
-------------------------------------------------------------------------
 Don't put off until tomorrow what you can do today; for if you enjoy it
 today, you can do it again tomorrow...
=========================================================================


From [e-mail] Tue Jun 27 15:27:01 1995
Path: grape.epix.net!news.sprintlink.net!gatech!usenet.eel.ufl.edu!ukma!rsg1.er.usgs.gov!stc06.ctd.ornl.gov!usenet
From: "Walter L. Zorn" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: "Flutter" noise from 2m through glass 1/4L mobile antenna
Date: Sun, 25 Jun 95 17:01:37 EDT
Organization: Oak Ridge National Lab, Oak Ridge, TN
Lines: 73
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To: [e-mail]

On Sun, 25 Jun 1995 15:03:45 -0400,
Patrick Stickler  <[e-mail]> wrote:

>I just installed my first 2 meter mobile antenna ever, a 1/4 wavelength
>through glass vertical. I followed the instructions completely and for
>the most part it works very well -- until the car moves! The vibration
>and other movements of the antenna induced by the car's movement causes
>alot of static "flutter" noise, making communication very annoying. At
>the exact same location, with the car still, I get full quieting reception,
>but as soon as I start driving, the audio reception degrades to barely
>usable.
>
>Is this normal for a mobile antenna? I noticed that the glass mounted
>2 meter mobile antenna in the ARRL handbook had the shield of the coax
>grounded right at the antenna to the roof support metal structure. In
>my installation, the rig chassis is grounded at the transmission hump
>on the floor. Does this make a difference?
>
>Any suggestions will be greatly appreciated.

Patrick (KC4YYY),

The additional noise you get while moving seems, based on you post, to be
"mobile flutter" (multipath of signals) AKA "picket-fencing".  Hence, as
you move the multipath changes and moves you into and out of "poor" spots.
However, you seem to state that when still (implied - at all times when
still) everythings fine.  Sooooo, I'd rule this out as you should be able
to move into a poor spot and stay there - you could verify by being
relatively near (maybe within 5 or 10 miles of a good repeater) and with
good path to a known station and checking again.

I believe that you have a least two possible problems.  First, as stated in
the ARRL handbook, the shield of the coax should be grounded right at the
antenna to the roof support metal structure or good ground.  Generally, the
roof metal is good.  The gronding of the radio transceiver, as stated, is
fine.  Second, the antenna's vibrating?  Alot?  Seems the bonding on the
glass may need improvement.  Hummmm.  The capacitance thru the glass bond
may be changing with vibration.

What I'd do is ground the coax shield at the antenna - as stated.  (Some
installations have ground quarterwaves off the antenna at this point -
horiz.; but, you didn't mention them.  Might not be a bad idea to add
them.)  Then try again.

You should be able to 'see' a bad antenna system with an an SWR meter while
driving - be sure to not try checking the SWR without a friend doing the
driving.  If the SWR changes and "flutters" - bingo, you have evidence of a
poor antenna system.  If not, and SWR is fine, time to try something
else.

You my want to try a tempory "mag-mount" 2M antenna just to confirm you
antenna problem as being an antenna problem.  I'm sure you can find
someone to loan you one.  (You may want to by one for emergencies anyway.)
If you have the same conditions with a different antenna - mostlikely, the
problem is not the antenna.

If the grounded coax shield doesn't help.  Then it's down to the antenna
installation - as stated above - OR, Three, filtering the DC Power (or
connecting directly to the battery - if you haven't done that.)  Note that
if the 'static "flutter" noise' changes pitch with engine RPM - it's
alternator noise and, mostlikely, a DC Power connection or filtering
problem.  Is it present when the engine is running?  Even at idle, the
alternator noise can often be detected - especially on the transmitted
signal.  (My transmissions had a noticable increased alternator noise when
my turn signals were on - took me the longest to figure how all the hams
new I was going to make a turn!  :}  ) Again, are you sure you have a
*good* ground at the rig and have DC connected directly to the battery?

Good luck and I'm sure other will provide their analysis, critique mine or
both.

Walt / KF0OS



From [e-mail] Tue Jun 27 15:27:01 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!news.cyberstore.ca!nwfocus.wa.com!krel.iea.com!comtch!n0dh
From: [e-mail] (D.C. Henderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 160 Tunable Ant.???
Date: 26 Jun 1995 18:16:41 GMT
Organization: CompuTech, Spokane WA
Lines: 19
Message-ID: <3smti9$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: comtch.iea.com
X-Newsreader: TIN [version 1.2 PL1]

Jeffery A. Purtle ([e-mail]) wrote:
: Has anyone heard of a 160 meter vert. that can be tuned remotely?  I have
: an old electric screw driver that I thought I could use to turn a variable
: inductor.  This would be for the roof of my house.  What values and sizes
: should I use?
: Thanks,
: Jeff AC6IW

Jeff

Before I moved to more spacious digss I used to tune my Butternut HF6V
remotely except that rather than use a tuneable inductor, I replaced the
400pf fixed caps in the 160 meter resonator unit with a 500pf vaccumn
variable which in turn was tuned using an electric screwdriver motor.

Good luck
Dave
N0DH/7
[e-mail]


From [e-mail] Tue Jun 27 15:27:02 1995
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!library.ucla.edu!unixg.ubc.ca!rover.ucs.ualberta.ca!alberta!adec23!mark
From: [e-mail] (Mark G. Salyzyn)
Subject: Re: 3/8 wave 2M vert question
Organization: Mr Bill Show
Date: Mon, 26 Jun 95 19:47:24 GMT
Message-ID: <[e-mail]>
Followup-To: rec.radio.amateur.antenna
Lines: 18
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Xref: grape.epix.net rec.radio.amateur.homebrew:7955 rec.radio.amateur.antenna:11466

Followups directed to rec.radio.amateur.antenna.

Garry Foster <[e-mail]> writes:
>On Sat, 24 Jun 1995, J. Patrick Tyker wrote:
>> 1/4 wave I have now is made of about 36 guage berylium-copper wire
>> and 4 lb fishing line.  The ground plane is the steel box that the air
>> conditioner sits in (protrudes out from the building).  The fishing
>> line runs from the top of the 36 ga radiator to the gutter, holding
>> it vertical.
>Why don't you make a 1/2 wave JPOLE in a PVC pipe. Paint the pipe to
>match your house and if any one aske tll them its an ultra sonic burglar
>alarm. Use non metalic paint of course.

Why not make the J Pole out of copper pipe then, using the appropriate
unions. It will look exactly the same once painted, and would have the
additional advantage of a flatter SWR curve due to some broad-banding.

Ciao -- 73 de VE6MGS/Mark -sk-


From [e-mail] Tue Jun 27 15:27:03 1995
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!casaba.srv.cs.cmu.edu!bb3.andrew.cmu.edu!andrew.cmu.edu!mv0t+
From: Meg Alison Papa <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Antenna Rotor Help
Date: Sun, 25 Jun 1995 17:29:29 -0400
Organization: Electrical & Computer Engineering, Carnegie Mellon, Pittsburgh, PA
Lines: 7
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: po8.andrew.cmu.edu

Can anyone tell me how the controller for a 4 wire antenna rotator
works?  I've got a rotor on my roof, but unfortunately there is no
controller.

Any help would be greatly appreciated.

-Brian


From [e-mail] Tue Jun 27 15:27:04 1995
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Rotor Help
Date: 26 Jun 1995 02:47:59 GMT
Organization: News & Observer Public Access
Lines: 57
Message-ID: <3sl74v$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: grail1509.nando.net

Meg Alison Papa <[e-mail]> wrote:
>
> Can anyone tell me how the controller for a 4 wire antenna rotator
> works?  I've got a rotor on my roof, but unfortunately there is no
> controller.
>
> Any help would be greatly appreciated.
>
> -Brian
I don't know how much help I can be, for I can't give you a single
answer, there were just too many variations of indicator/control
box combinations for these rotators.

First, I assume you have one of the Alliance U-100 type rotators.
(Many sold by Radio Shack were similar)  They can be identified
visually by observing that on the U-100 type, the rotating mast
can go completely through the rotator.  That is why they are so
popular for sattelite work as AZ-EL rotators.

All I can say for certain is that 3 of the wires connect to the
motor.  One is common, and the other two determine the direction
of rotation.  The motor is of the split winding / capacitor-run
type.  The motor is operated on 24 VAC, and there is a capacitor
in the control box.  one leg of the 24 VAC transformer connects
to the common terminal on the motor, and the other leg of the
transformer connects directly to one of the other motor leads
AND also to the capacitor.  The non-transformer side of the
capacitor connects to the other motor lead.  To reverse the
motor, simply reverse the two motor leads - a DPDT switch will
accomplish this reversal - use one with a center off position
for a motor off position.

The indicator is another matter, some were nothing more than
an end of rotation indicator (switch in the rotator) which
turned on a lamp in the control box, while others had a cheap
wirewound pot that ran an AC meter at the control box, and still
others had a more complex system with a stepping dial indicator
that clicked until the motor matched the position set on the
control box.  There were too many to tell you what you have.
You might be able to decipher it by bringing the rotator down
and opening it too see what you have.

The U-100 was a good rotator, but having no breaking system it
would drift in a good wind.  If you are going to use it, I would
recommend creating a control box to run the motor, and use some
different than original system for the direction indicator.
Note that there is a positive mechanical stop in the rotator to
limit it to 360 degree rotation.  Those rotators that I have used
would not be harmed by power to the motor at rotation limits, but
the control box transformer would overheat.

Good luck with it,
73,
Don W3FPR





From [e-mail] Tue Jun 27 15:27:05 1995
Path: grape.epix.net!news.sprintlink.net!news.cloud9.net!news1.panix.com!zip.eecs.umich.edu!newsxfer.itd.umich.edu!sol.ctr.columbia.edu!news.oberlin.edu!ocvaxa.cc.oberlin.edu!PRUTH
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Antenna suitable for finicky autotuner
Date: 26 Jun 1995 14:13:17 GMT
Organization: Oberlin College, Oberlin, Ohio
Lines: 13
Message-ID: <3smf9t$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: ocvaxa.cc.oberlin.edu

I have a Yaesu FL7000 linear amp/autotuner which requires
an unbalanced input of no more than 150 ohms and no less
than 16 ohms 80-10m, less on 160m.  A Butternut HF6V at
ground level can be made to accept 500w on much of most
bands, but due to severe RFI I must consider another
antenna, on the roof, either a wire or a vertical.  The
FL7000's manual goes on to say its autotuner can accept
a 3:1 SWR to match the amp, provided it can bring the
SWR down to 1.2:1 or less.  I was considering a G5RV at
first, but now I'm not so sure it will work with the
FL7000's autotuner.  What would work well on all the WARC
bands with such a finicky autotuner?  73 de Bill KB8USZ
[e-mail]


From [e-mail] Tue Jun 27 15:27:06 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna suitable for finicky autotuner
Date: 27 Jun 1995 01:14:56 GMT
Organization: News & Observer Public Access
Lines: 53
Message-ID: <3snm2g$[e-mail]>
References: <3smf9t$[e-mail]>
NNTP-Posting-Host: grail415.nando.net

[e-mail] wrote:
>
> I have a Yaesu FL7000 linear amp/autotuner which requires
> an unbalanced input of no more than 150 ohms and no less
> than 16 ohms 80-10m, less on 160m.  A Butternut HF6V at
> ground level can be made to accept 500w on much of most
> bands, but due to severe RFI I must consider another
> antenna, on the roof, either a wire or a vertical.  The
> FL7000's manual goes on to say its autotuner can accept
> a 3:1 SWR to match the amp, provided it can bring the
> SWR down to 1.2:1 or less.  I was considering a G5RV at
> first, but now I'm not so sure it will work with the
> FL7000's autotuner.  What would work well on all the WARC
> bands with such a finicky autotuner?  73 de Bill KB8USZ
> [e-mail]

My solution for this problem is to use a 102 ft antenna fed
in the center with ladder line - htat is almost like a G5RV
antenna except that the balanced feedline is the right length
to reach from the antenna to the shack - and I take care that
this feedline is mounted at least three times the width of the
feedline away from mounting surfaces - i.e. it is mounted on
standoffs - and has only gentle curving bends along it's length.

Then I use a balanced antenna tuner at the shack entrance.
You can call me old fashioned, but I use plug-in coils for this
tuner - the plugs on the connector strip also select the right
combination of capacitors and the configuration (parallel or
series tuning) for each band.  It is mounted in the open, and
I have marked the capacitor settings for each mid-band point.
To change bands, I plug in the proper coil, set the capacitors
and let the "automatic" antenna tuner in my rig Yaesu FT-900AT
do the rest of the work for my excursions about the band.

Balanced antenna tuner designs are few and far between now-a-days,
but my favorite is in the ARRL Radio Amateurs Handbook for 1967.
This one is link coupled, and I have always had good success
with that type, although I have never been satisfied with my
attempts at a bandswitching design - so I still use plug-in
coils.

There is an L-network type Balanced Antenna Tuner design in
QST Feb 1990 pgs 28-32.  It looks like a good design, but the
mechanical part of tracking two rotary inductors could be
gruesome without a small machine shop.  This design might work
well with either plug-in coils or switched taps (switches could
be manual tap points on the coils.

I don't know if this helps you, but it works FB for me.

73,
Don W3FPR



From [e-mail] Tue Jun 27 15:27:07 1995
Path: grape.epix.net!news.sprintlink.net!qns3.qns.com!news.ecn.uoknor.edu!news.ysu.edu!malgudi.oar.net!news.erinet.com!uunet!news.delphi.com!usenet
From: [e-mail] (Joanne Dow)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 25 Jun 1995 05:46:32 GMT
Organization: Delphi Internet Services Corporation
Lines: 43
Message-ID: <3sit7o$[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Joanne Dow)
NNTP-Posting-Host: bix.com
X-Newsreader: NetBix 0.48
X-Newsreader-Author: [e-mail] (Loren Wilton)
    This message has been posted with development version software.
    If there are any problems with the message format, send me mail.

In article <[e-mail]>,
   Garry Foster <[e-mail]> wrote:
>
>
>On 21 Jun 1995, W8JI Tom wrote:
>
>> >Tom
>> I agree fully that many so called PI tuners work as "L's" so what do you
>> think of an L tunner?
>>
>>                                                              Garry
>> (WB0NNO)<
>>
>> Gary,
>>
>> They work great because they provide maximum BW, maximum efficiency,
>> smooth tuning, and harmonic supression. The only draw back is a little
>> tougher time matching reactive loads and very low impedance
>> transformations, but it can all be handled.
>>
>> 73 Tom
>>
>>
>While looking at the drawing for the Icom AH3 (I think) that was
>published in CQ a few years ago I noticed that it was an  "L" even though
>the Icom rep at Datton was insisting that it was a PI. What it  had was a
>serries inductor and a bank of capicators that could be either from the
>input side of the inductor to ground or the output side to ground. The
>thing that interested me was there  are 3 low value capicators to ground on
>the output side that wern't switched.  I'm guessing that yhese are to help
>with resonant lenghts of antenna. Any ideas on this.
>
>                                                               Garry(WB0NNO)
>

At the highest frequencies covered the desired network Qs lead to certain
minimum capaciticances in the PI network when you make assumptions that the
matching network's potential load is within a limited range. From your
description it sounds like the range of VSWRs the tuner could handle was more
limited than with most tuners.

{^_^}     Joanne Dow     The Wizardess



From [e-mail] Tue Jun 27 15:27:08 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: [e-mail] (Joanne Dow)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 25 Jun 1995 09:29:15 GMT
Organization: Delphi Internet Services Corporation
Lines: 43
Message-ID: <3sja9b$[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Joanne Dow)
NNTP-Posting-Host: bix.com
X-Newsreader: NetBix 0.48
X-Newsreader-Author: [e-mail] (Loren Wilton)
    This message has been posted with development version software.
    If there are any problems with the message format, send me mail.

In article <[e-mail]>,
   Garry Foster <[e-mail]> wrote:
>
>
>On 21 Jun 1995, W8JI Tom wrote:
>
>> >Tom
>> I agree fully that many so called PI tuners work as "L's" so what do you
>> think of an L tunner?
>>
>>                                                              Garry
>> (WB0NNO)<
>>
>> Gary,
>>
>> They work great because they provide maximum BW, maximum efficiency,
>> smooth tuning, and harmonic supression. The only draw back is a little
>> tougher time matching reactive loads and very low impedance
>> transformations, but it can all be handled.
>>
>> 73 Tom
>>
>>
>While looking at the drawing for the Icom AH3 (I think) that was
>published in CQ a few years ago I noticed that it was an  "L" even though
>the Icom rep at Datton was insisting that it was a PI. What it  had was a
>serries inductor and a bank of capicators that could be either from the
>input side of the inductor to ground or the output side to ground. The
>thing that interested me was there  are 3 low value capicators to ground on
>the output side that wern't switched.  I'm guessing that yhese are to help
>with resonant lenghts of antenna. Any ideas on this.
>
>                                                               Garry(WB0NNO)
>

At the highest frequencies covered the desired network Qs lead to certain
minimum capaciticances in the PI network when you make assumptions that the
matching network's potential load is within a limited range. From your
description it sounds like the range of VSWRs the tuner could handle was more
limited than with most tuners.

{^_^}     Joanne Dow     The Wizardess



From [e-mail] Tue Jun 27 15:27:09 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: [e-mail] (Joanne Dow)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 26 Jun 1995 07:13:15 GMT
Organization: Delphi Internet Services Corporation
Lines: 43
Message-ID: <3slmmb$[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Joanne Dow)
NNTP-Posting-Host: bix.com
X-Newsreader: NetBix 0.48
X-Newsreader-Author: [e-mail] (Loren Wilton)
    This message has been posted with development version software.
    If there are any problems with the message format, send me mail.

In article <[e-mail]>,
   Garry Foster <[e-mail]> wrote:
>
>
>On 21 Jun 1995, W8JI Tom wrote:
>
>> >Tom
>> I agree fully that many so called PI tuners work as "L's" so what do you
>> think of an L tunner?
>>
>>                                                              Garry
>> (WB0NNO)<
>>
>> Gary,
>>
>> They work great because they provide maximum BW, maximum efficiency,
>> smooth tuning, and harmonic supression. The only draw back is a little
>> tougher time matching reactive loads and very low impedance
>> transformations, but it can all be handled.
>>
>> 73 Tom
>>
>>
>While looking at the drawing for the Icom AH3 (I think) that was
>published in CQ a few years ago I noticed that it was an  "L" even though
>the Icom rep at Datton was insisting that it was a PI. What it  had was a
>serries inductor and a bank of capicators that could be either from the
>input side of the inductor to ground or the output side to ground. The
>thing that interested me was there  are 3 low value capicators to ground on
>the output side that wern't switched.  I'm guessing that yhese are to help
>with resonant lenghts of antenna. Any ideas on this.
>
>                                                               Garry(WB0NNO)
>

At the highest frequencies covered the desired network Qs lead to certain
minimum capaciticances in the PI network when you make assumptions that the
matching network's potential load is within a limited range. From your
description it sounds like the range of VSWRs the tuner could handle was more
limited than with most tuners.

{^_^}     Joanne Dow     The Wizardess



From [e-mail] Tue Jun 27 15:27:10 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: [e-mail] (Joanne Dow)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 26 Jun 1995 08:46:00 GMT
Organization: Delphi Internet Services Corporation
Lines: 33
Message-ID: <3sls48$[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]> <[e-mail]> <3si4vh$[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Joanne Dow)
NNTP-Posting-Host: bix.com
X-Newsreader: NetBix 0.48
X-Newsreader-Author: [e-mail] (Loren Wilton)
    This message has been posted with development version software.
    If there are any problems with the message format, send me mail.

In article <[e-mail]>,
   Garry Foster <[e-mail]> wrote:
>
>
>
>On 24 Jun 1995, Joanne Dow wrote:
>
>> >
>> >                                                            Garry(WB0NNO)
>> >
>>
>> At the highest frequencies covered the desired network Qs lead to certain
>> minimum capaciticances in the PI network when you make assumptions that the
>
>> matching network's potential load is within a limited range. From your
>> description it sounds like the range of VSWRs the tuner could handle was more
>> limited than with most tuners.
>>
>> {^_^}     Joanne Dow     The Wizardess
>Well its the AH2 not AH3 and it is supposed to be a very wide range
>tunner. Eight foot piece of wire for 40 or above. I know it to be much
>wider than many of the tunners on the market today. The total of the
>fixed capacitance was only 30 pf or so. I think itwas in there so that
>when it ran into a condition that had a an mismatch but the j factor was
>at or near zero it made it slightly capacitive ant not confuse the computer.
>
That makes sense.

>                                                       Garry(WB0NN0)
>
>
{^_^}     Joanne Dow     The Wizardess



From [e-mail] Tue Jun 27 15:27:12 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: [e-mail] (Joanne Dow)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 26 Jun 1995 08:46:08 GMT
Organization: Delphi Internet Services Corporation
Lines: 43
Message-ID: <3sls4g$[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Joanne Dow)
NNTP-Posting-Host: bix.com
X-Newsreader: NetBix 0.48
X-Newsreader-Author: [e-mail] (Loren Wilton)
    This message has been posted with development version software.
    If there are any problems with the message format, send me mail.

In article <[e-mail]>,
   Garry Foster <[e-mail]> wrote:
>
>
>On 21 Jun 1995, W8JI Tom wrote:
>
>> >Tom
>> I agree fully that many so called PI tuners work as "L's" so what do you
>> think of an L tunner?
>>
>>                                                              Garry
>> (WB0NNO)<
>>
>> Gary,
>>
>> They work great because they provide maximum BW, maximum efficiency,
>> smooth tuning, and harmonic supression. The only draw back is a little
>> tougher time matching reactive loads and very low impedance
>> transformations, but it can all be handled.
>>
>> 73 Tom
>>
>>
>While looking at the drawing for the Icom AH3 (I think) that was
>published in CQ a few years ago I noticed that it was an  "L" even though
>the Icom rep at Datton was insisting that it was a PI. What it  had was a
>serries inductor and a bank of capicators that could be either from the
>input side of the inductor to ground or the output side to ground. The
>thing that interested me was there  are 3 low value capicators to ground on
>the output side that wern't switched.  I'm guessing that yhese are to help
>with resonant lenghts of antenna. Any ideas on this.
>
>                                                               Garry(WB0NNO)
>

At the highest frequencies covered the desired network Qs lead to certain
minimum capaciticances in the PI network when you make assumptions that the
matching network's potential load is within a limited range. From your
description it sounds like the range of VSWRs the tuner could handle was more
limited than with most tuners.

{^_^}     Joanne Dow     The Wizardess



From [e-mail] Tue Jun 27 15:27:13 1995
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 26 Jun 1995 13:41:17 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 33
Sender: [e-mail]
Message-ID: <3smrft$[e-mail]>
References: <3sls4g$[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com


>At the highest frequencies covered the desired network Qs lead to certain
>minimum capaciticances in the PI network when you make assumptions that
>the matching network's potential load is within a limited range. From
your
>description it sounds like the range of VSWRs the tuner could handle was
more
>limited than with most tuners.

>{^_^}     Joanne Dow     The Wizardess

Hi Joanne, And so it is with most amateur tuners manufactured. The problem
is that the load impedances are random and usually center around 50 ohms
for coaxial lines (say from a few to a few hundred ohms) and from a few
ohms to several thousand ohms with single wire and balanced 300-450 ohm
lines.

The original values given by the other fellow using dual 750 pF capacitors
exclude the network from functioning as a "pi" below a certain impedance
and frequency. It happened that the frequency was around 7 MHz for typical
load values experienced in typical amateur installations.

Most tuners sold to amateurs commercially as "pi networks" can not act as
pi's with the load impedances specified by the manufacturers and typically
supplied by the end user. That is the basis for my observation, and while
it was a broad general statement....it certainly is true. For example one
commercial tuner uses around 200 pF as the low Z cap for the input of the
alleged pi...it is obviously operating as an L below 30 MHz at any 50 ohm
input Z with moderate load Z's.

My point was because it LOOKS like a pi, it does NOT mean it actually IS a
pi electrically! I prefer to call a spade a spade (as in cards) not a
shovel. 73 Tom


From [e-mail] Tue Jun 27 15:27:14 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: [e-mail] (Joanne Dow)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 27 Jun 1995 01:44:30 GMT
Organization: Delphi Internet Services Corporation
Lines: 33
Message-ID: <3snnpu$[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]> <[e-mail]> <3si4vh$[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Joanne Dow)
NNTP-Posting-Host: bix.com
X-Newsreader: NetBix 0.48
X-Newsreader-Author: [e-mail] (Loren Wilton)
    This message has been posted with development version software.
    If there are any problems with the message format, send me mail.

In article <[e-mail]>,
   Garry Foster <[e-mail]> wrote:
>
>
>
>On 24 Jun 1995, Joanne Dow wrote:
>
>> >
>> >                                                            Garry(WB0NNO)
>> >
>>
>> At the highest frequencies covered the desired network Qs lead to certain
>> minimum capaciticances in the PI network when you make assumptions that the
>
>> matching network's potential load is within a limited range. From your
>> description it sounds like the range of VSWRs the tuner could handle was more
>> limited than with most tuners.
>>
>> {^_^}     Joanne Dow     The Wizardess
>Well its the AH2 not AH3 and it is supposed to be a very wide range
>tunner. Eight foot piece of wire for 40 or above. I know it to be much
>wider than many of the tunners on the market today. The total of the
>fixed capacitance was only 30 pf or so. I think itwas in there so that
>when it ran into a condition that had a an mismatch but the j factor was
>at or near zero it made it slightly capacitive ant not confuse the computer.
>
That makes sense.

>                                                       Garry(WB0NN0)
>
>
{^_^}     Joanne Dow     The Wizardess



From [e-mail] Tue Jun 27 15:27:15 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: [e-mail] (Joanne Dow)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 27 Jun 1995 01:44:37 GMT
Organization: Delphi Internet Services Corporation
Lines: 43
Message-ID: <3snnq5$[e-mail]>
References: <[e-mail]> <3s8v2j$[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Joanne Dow)
NNTP-Posting-Host: bix.com
X-Newsreader: NetBix 0.48
X-Newsreader-Author: [e-mail] (Loren Wilton)
    This message has been posted with development version software.
    If there are any problems with the message format, send me mail.

In article <[e-mail]>,
   Garry Foster <[e-mail]> wrote:
>
>
>On 21 Jun 1995, W8JI Tom wrote:
>
>> >Tom
>> I agree fully that many so called PI tuners work as "L's" so what do you
>> think of an L tunner?
>>
>>                                                              Garry
>> (WB0NNO)<
>>
>> Gary,
>>
>> They work great because they provide maximum BW, maximum efficiency,
>> smooth tuning, and harmonic supression. The only draw back is a little
>> tougher time matching reactive loads and very low impedance
>> transformations, but it can all be handled.
>>
>> 73 Tom
>>
>>
>While looking at the drawing for the Icom AH3 (I think) that was
>published in CQ a few years ago I noticed that it was an  "L" even though
>the Icom rep at Datton was insisting that it was a PI. What it  had was a
>serries inductor and a bank of capicators that could be either from the
>input side of the inductor to ground or the output side to ground. The
>thing that interested me was there  are 3 low value capicators to ground on
>the output side that wern't switched.  I'm guessing that yhese are to help
>with resonant lenghts of antenna. Any ideas on this.
>
>                                                               Garry(WB0NNO)
>

At the highest frequencies covered the desired network Qs lead to certain
minimum capaciticances in the PI network when you make assumptions that the
matching network's potential load is within a limited range. From your
description it sounds like the range of VSWRs the tuner could handle was more
limited than with most tuners.

{^_^}     Joanne Dow     The Wizardess



From [e-mail] Tue Jun 27 15:27:16 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (Cobra295)
Newsgroups: rec.radio.amateur.antenna
Subject: Best Scanner Antenna?
Date: 26 Jun 1995 12:51:50 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 11
Sender: [e-mail]
Message-ID: <3smoj6$[e-mail]>
Reply-To: [e-mail] (Cobra295)
NNTP-Posting-Host: newsbf02.mail.aol.com

I'm about ready to buy a scanner and I'm starting to consider antennas...
I need something that will work from 25-1300Mhz... I really don't know
what to use... Some suggest using a discone, while others say I'm better
off just using something like a 220 monobander.... I was considering just
making a dipole... I already have an HF dipole.. but read in the ARRL book
that the formula is only good up to 30MHz...   I have many
possibilities... discone, 11 meter whip, dipole, dual band, etc. etc.. but
I'm not sure what to use... if anyone has any ideas of a good broadbanded
scanner antenna, I'd appreciate any help.. thanks...

Sean, N2ZJJ


From [e-mail] Tue Jun 27 15:27:16 1995
Path: grape.epix.net!news.sprintlink.net!hookup!news.kei.com!newshost.marcam.com!uunet!blkcat.blkcat.org!f41.n109.z1.fidonet.org!f42.n109.z1.fidonet.org!fforum.blkcat.com!not-for-mail
Date: Sun, 25 Jun 1995 15:42:00 -0400
From: [e-mail] (James Barnes)
Subject: Re: Comments on GAP Antennas, Anyone?
Message-ID: <NOMSGID_1=3A109=[e-mail]>
Newsgroups: rec.radio.amateur.antenna
X-Comment-To: (Rblank)
Organization: Net 109 Fidonet<->Internet gateway
Lines: 4
X-Gateway: FIDOGATE 3.9.0
X-FTN-Tearline: TriToss (tm) Professional 1.0 - #149
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X-FTN-Seen-By: 109/41 42 239 582
X-FTN-Path: 109/239 42

Hey I have that gap ant and lt works great for me even on 2 meters.
I have a daily sked with 3 friends in various parts of the country and
2 of them on 40 meters use it also with excellent results.Works very
well for me on dx as well.I highly reccomend it.Good luck de kc4vw 73.


From [e-mail] Tue Jun 27 15:27:17 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!spool.mu.edu!bloom-beacon.mit.edu!satisfied.apocalypse.org!news2.near.net!news.delphi.com!usenet
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Convert a 1/4 wave to 5/8 wave
Date: Wed, 21 Jun 95 00:22:34 -0500
Organization: Delphi ([e-mail] email, 800-695-4005 voice)
Lines: 10
Message-ID: <[e-mail]>
NNTP-Posting-Host: bos1g.delphi.com

I bought a 1/4 wave mag-mount to use with my HT recently and
thought I would experiment a little. I bought a 5/8 whip and
replaced the orginal 1/4 wave and it seems to work fine even
though I'm told you out to match the impedence when you make
such a change. The rig only puts out 5W so does it really
matter that much? Does anyone have any ideas as to how I could
match this attenna inexpensively?

Tim Meece
KC5MPP


From [e-mail] Tue Jun 27 15:27:18 1995
Path: grape.epix.net!news.sprintlink.net!gatech!purdue!mozo.cc.purdue.edu!constellation.ecn.purdue.edu!wb9omc
From: [e-mail] (Duane P Mantick)
Newsgroups: rec.radio.amateur.antenna
Subject: Cushcraft CS50M
Date: 27 Jun 1995 17:19:30 GMT
Organization: Purdue University
Lines: 14
Message-ID: <3spej2$[e-mail]>
NNTP-Posting-Host: constellation.ecn.purdue.edu
Summary: problems
Keywords: bandwidth?
X-Newsreader: NN version 6.5.0 (NOV)


Wonder if anyone else owns one of these and has had difficulty tuning
it?

I got one recently and had just NOT been able to get that sucker
under about 2:1.  Now several people have said that this should
be "OK", but those numbers bug me a bit.....

Was trying to tweak it in the 52 to 53 MHz range, BTW.

email:

[e-mail]



From [e-mail] Tue Jun 27 15:27:21 1995
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Dipole Antenna:  Why won't mine work?
Date: 25 Jun 1995 17:14:46 GMT
Organization: News & Observer Public Access
Lines: 96
Message-ID: <3sk5i6$[e-mail]>
References: <3sifrv$[e-mail]>
NNTP-Posting-Host: grail805.nando.net

[e-mail] (JohnStk) wrote:
 >
 > My nephew and I tried to make a simple dipole for use with his CB.  A
 > diagram of our setup follows:
 >
 > string                      wire         wire
 > ....................------------------------------------------------.......
 > ..................
 >                                          I
 >                                          I
 >                                          |
 >                                          |
 >                                          |
 >                                          |  <- 52 ohm coax from CB
 >
 > The attempt was to make a horizontally polarized dipole.  Two 9' 3" wires
 > were prepared.  One was attached to the center wire of the coax.  The
 > other was attached to the ground shield at the end.  A string over 10'
 > long was tied to each end of the wire.  The antenna was stretched
 > vertically about 12' off the ground.  No attempt was made to trim the
 > length.
 >
 > The coax hung down nearly perpendicular.  The best SWR we got was well
 > over 3.  From what I understand the impeadance of the dipole should have
 > been around 73 ohms theoreticlly.  I believe the wavelength of the CB band
 > is arount 11 meters.
 >
 > My nephew and I would appreciate any suggestions especially good
 > references for making a SIMPLE and INEXPENSIVE first anetenna for a CB
 > offering good performance.  Also, any suggestion for making a better
 > dipole would be appreciated.  I am an electrical engineer who is knew to
 > radio and does not remember much about EM theory.
 >
 > Some questions I have are as follows:
 >
 > 1.  What are the causes of the poor SWR.
 >     *  The impeadance mismatch?
 >     *  The height of the antenna?
 >     *  Falure to trim the length?
All the above are factors, but you should be able to trim it to length
that yields a 1:1 VSWR which will compensate for the other factors.
Just one point, you are feeding with 50 ohm and a flat-top dipole is
as you stated 73 ohms (theoretical value - in practice this will vary
due to the proximity of other objects including the earth).  You could
mount the antenna as an inverted vee (center high) which will tend
to lower the feedpoint impedance.
 >
 > 2.  I am heading down the right track?  I though I constructed the antenna
 > as a HAM coworker suggested.  However, I did not trim the length.  Would
 > that make much of a difference.  The wires (solid copper with insulation)
 > started at 9' 3" but probably ended up about 9' long because of a looped
 > the ends to attache a string.

Before trimming, I would try to find out whether it is too long or
too short, and by how much.  You can plot the SWR readings over the
range of CB channels and determine whether it is decreasing toward
the low frequency end or the high end.  This will give you an indication
of which way to go, and with a little math based on the formula for
a halfwave antenna  468/frequency(MHz) plus a bit of intuitive logic
- such as - if it tunes 10% too low, modify the formula by 10% higher
and calculate the new length, and then cut it to the result, then try
again.  We call it cut and try - and it works.

Note that with the insulation on the wire, the effective length of
your antenna is near the full length of the copper.  If it is bare
and you fold it back and twist it to the standing leg, you short out
a portion of the length, but if it is insulated, you will still have
near the same electrical length, with perhaps some small inductance
created by effectively coiling the ends to make a loop.
 >
 > 3.  What is the correct method of matching the impeadance?  Would a single
 > stub tuner made with 50 ohm cable work.  If so, how would I calculate the
 > length and distance of the stub connection from the antenna?

There are a number of ways of matching the impedance including stubs.
In most practical installations this is not a big concern for a
mis-match of 50 ohms to 73 ohms.  This represents only a 1.5 SWR on
a 50 ohm line, and as long as your 50 ohm coax has reasonably low
loss to start with your losses will not be very great.  For example,
RG-58A at 30 MHz has a loss of 2.5 dB per 100 ft. when matched.
100 ft of this line running at a 1.5 SWR has an additional loss of
about 0.12 dB for a total loss of 2.6 dB.  Not much point in matching
it for only 0.12 dB of gain.  However, at an SWR of 3, the additional
loss is about 1 dB, and at SWR of 10, the added loss is close to 3dB,
so in these cases it would be a big benefit to match it.
 >
 > 4.  Are there any good books that might be available at a good public
 > library.
 >
That all depends on your library.  I can recommend the Transmission
line and Antenna sections of the ARRL Handbook, or the ARRL Antenna
handbook as starters for you.

Good luck with it.
73,
Don W3FPR


From [e-mail] Tue Jun 27 15:27:22 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (JohnStk)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Dipole Antenna:  Why won't mine work?
Date: 25 Jun 1995 21:51:18 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 7
Sender: [e-mail]
Message-ID: <3sl3qm$[e-mail]>
References: <3sk5i6$[e-mail]>
Reply-To: [e-mail] (JohnStk)
NNTP-Posting-Host: newsbf02.mail.aol.com

Thanks for your reply.  We are going to go down to the library and get a
book I found in our electronic library catalog coverning the consturction
of CB, HAM, and SW antennas.  It sounds like we are on the right track.
If we can end up with an SWR of less than 2 I think we will be happy.  At
least the SWR was on the our meter.  Thanks again for your input.

John Sotack


From [e-mail] Tue Jun 27 15:27:22 1995
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!simtel!news.kei.com!newshost.marcam.com!uunet!jmx.net!news
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: DONT READ JUST A TEST
Date: Sun, 25 Jun 1995 13:22:43 GMT
Organization: JMX.NET
Lines: 2
Message-ID: <3smdu4$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: datares.jmx.net
X-Newsreader: Forte Free Agent v0.56





From [e-mail] Tue Jun 27 15:27:23 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (JohnStk)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: FAQ:  Where?
Date: 25 Jun 1995 23:30:08 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 5
Sender: [e-mail]
Message-ID: <3sl9k0$[e-mail]>
References: <3sifsd$[e-mail]>
Reply-To: [e-mail] (JohnStk)
NNTP-Posting-Host: newsbf02.mail.aol.com

I have answered my own question.  The FTP site rtfm.mit.edu.site has a
hierarchial structure of news group faqs.  Unfortunately I could only find
a general Amature Radio FAQ and did not find one specifically on antennas.

John Sotack


From [e-mail] Tue Jun 27 15:27:24 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!netcom.com!wa2ise
From: [e-mail] (Robert Casey)
Subject: G5RV 80 thru 10 meter all band antenna plans
Message-ID: <[e-mail]>
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
Date: Tue, 27 Jun 1995 02:02:38 GMT
Lines: 23
Sender: [e-mail]

plans for a G5RV antenna, for 80 to 10 meters

         <--51 feet------------>   <------51 feet------->     non-conductive
rope--ooo----------------------+ooo+---------------------ooo----rope
           ^ 14 gauge CU wire  |   |  ^                insulator
                               | O |  |
                               |   |  |
450 ohm ladder line, balanced> | O | 17 feet
300 ohm twinlead will work     |   |  |
  IF it is not wet with rain   | O |  |
                               |   |  v
                                \ /
                               choke  < coil coax 6 turns, diameter
                                | |      approx 1 foot to 1.5 foot
50 or 75 ohm coax, longer than  | |    coax shield to one side of ladder
 70 feet, not counting choke -> | |    line, center to other side, after
                                | |    coax goes thru choke coiling
                                | |
                                | |
                             antenna tuner  < needed to tune antenna, it is
                                | |          reactive
                                RIG



From [e-mail] Tue Jun 27 15:27:25 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!netcom.com!herbr
From: [e-mail] (Herb Rosenberg)
Subject: Help with Dentron MT3000A Antenna Tuner
Message-ID: <[e-mail]>
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Subject: Help with Dentron MT3000A Antenna Tuner
Newsgroups: rec.radio.amateur.equipment
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
Summary:
Keywords:

I just picked up a used Dentron MT3000A antenna tuner at a swap meet, and
I was looking to hear back from those of you that have used this tuner,
to hear your comments and experience with this tuner.  I haven't opened
it up on the inside yet, but the former owner said it works fine, and I
think I bought it at a fair price.  He didn't have the manual for it, but
he did have a manual for the Dentron MT2000 which he said was the same
tuner without the meters and dummy load.

Any comments regarding this tuner would be apprecaited.  I want to use it
to experiement with various dipoles, and loop antennas both 50 ohm and
300-450 ohm for 10 - 80 meters.  I am in a restricted antenna QTH so I
working with antennas in a second story bonus room, and / or maybe lying
on the roof of the house.

Thanks.



--
[e-mail]


From [e-mail] Tue Jun 27 15:27:26 1995
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help with Dentron MT3000A Antenna Tuner
Date: 26 Jun 1995 01:28:37 GMT
Organization: Ocean Surveys, Inc.
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In <[e-mail]>, [e-mail] (Herb Rosenberg) writes:
>
>I just picked up a used Dentron MT3000A antenna tuner at a swap meet, and
>I was looking to hear back from those of you that have used this tuner,
>to hear your comments and experience with this tuner.  I haven't opened
>it up on the inside yet, but the former owner said it works fine, and I
>think I bought it at a fair price.  He didn't have the manual for it, but
>he did have a manual for the Dentron MT2000 which he said was the same
>tuner without the meters and dummy load.
>
>Any comments regarding this tuner would be apprecaited.  I want to use it
>to experiement with various dipoles, and loop antennas both 50 ohm and
>300-450 ohm for 10 - 80 meters.  I am in a restricted antenna QTH so I
>working with antennas in a second story bonus room, and / or maybe lying
>on the roof of the house.
>

It's a good tuner (I also have one).  Like most tuners with switched
inductors rather than roller inductors, there may be certain times
when it is difficult or impossible to get a decent match on a certain
band/antenna combination.  Keep an alternate feedline around, or switch
in an extra length of coax/open wire feeder for those situations.

I always had problems tuning with the meter arrangement, so normally
use an Autek WM-1 (which indicates the correct SWR at all power levels,
even while tuning).

Enjoy!



P.J. "Josh" Rovero                            work:  [e-mail]
Ocean Surveys, Inc.                           play:   [e-mail]
Old Saybrook, CT 06475 USA               Amateur Radio:  KK1D



From [e-mail] Tue Jun 27 15:27:27 1995
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Herb Rosenberg)
Subject: Help with Distributed Capacity Twisted Loop Antenna?
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I would like to hear from anyone out there with any experience using the
Distributed Capacity Twisted Loop Antenna.  I saw an article for this
antenna in the July 1994 issue of CCQ magazine.  I have the following
questions:

1.  What experince and results have you goitten with this antenna.  On
what bands, and how was the antenna located?

2.  Are there any other articles describing this type of antenna, and if
so, where can they be found?

3.  Are there any improvements you made over the instructions given in
this article.


I am looking to use this antenna from inside the house in a second story
bonus room.  I am looking at 80, 40, and 20 meters.

Any help, comments, or suggestions would be greatly apprecicated.

73's and tnx.

Herb - KG6OK


--
[e-mail]


From [e-mail] Tue Jun 27 15:27:27 1995
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help with Distributed Capacity Twisted Loop Antenna?
Date: 26 Jun 1995 14:00:38 -0400
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>I would like to hear from anyone out there with any experience using the
>Distributed Capacity Twisted Loop Antenna.  I saw an article for this
>antenna in the July 1994 issue of CCQ magazine.  I have the following
>questions:

Herb, I don't know if that is a good way to tune a small loop antenna!
While I'm sure it will radiate, the efficiency must be pathetic compared
to a well designed conventional loop. Actual design criteria dictates as
compact and as lumped capacitor as possible so the current in the loop are
as high as possible, and the losses in the capacitor are as low as
possible. .73 Tom


From [e-mail] Tue Jun 27 15:27:28 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netnews
From: [e-mail] (Fred Zimring)
Newsgroups: rec.radio.amateur.antenna
Subject: info pse on self-supporting tower
Date: 26 Jun 1995 02:27:11 GMT
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I plan to purchase a self-supporting tower (about 45-50 ft) and know
very little about them. I will probably use a Cushcraft 3 ele tri-band
beam and a rotatable dipole. Any suggestion and comments will be
appreciated...Tnx, Fred, W5HTR


From [e-mail] Tue Jun 27 15:27:28 1995
Path: grape.epix.net!news.sprintlink.net!gatech!asuvax!news.asu.edu!aztec.asu.edu!hamop
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ladder Line Q
Date: 25 Jun 1995 19:49:20 GMT
Organization: Arizona State University
Lines: 10
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NNTP-Posting-Host: aztec.asu.edu


The mismatch at the antenna will cause standing waves on the line
so that the balun at the sending end will see an impeance very
different from the Zc of the line.  A line must be terminated in
its Zc in order to be "flat" and exhibit its Zc at the sending
end/.

Charlie,  W7XC
--



From [e-mail] Tue Jun 27 15:27:29 1995
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From: [e-mail] (ED GASS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ladder Line Q
Date: 26 Jun 1995 12:10:10 -0400
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Tony,

Your Internet address didn't get through and Lafayette claimed not to know
you.  Send me your Internet address at "[e-mail]" or to
"[e-mail]" when you get a chance.  (Or FAX to 713-782-4944.)

Ed Gass
K5INZ
HJ3INZ


From [e-mail] Tue Jun 27 15:27:30 1995
Path: grape.epix.net!news.sprintlink.net!news.onr.com!usenet
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: NEC Manuals: Anyone got one?
Date: 25 Jun 1995 17:18:15 GMT
Organization: Onramp Access, Inc.
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I've gotten the PD copies of PC-compatible NEC from
ftp.netcom.com/pub/ra/rander/NEC
and this site does have some info on where to get printed manuals.

Are any of these worth having? Isn't there a user-friendly manual out there
somewhere in the public domain? One of these days I'll get the original
text (1968 vintage) describing the method of moments (a Dr. Richardson
wrote it?). I skimmed a copy of it once and, since I'm not an
electromagneticist, didn't get much out of it other than some insight on
how the pulses work.

Eventally , I'll get a copy of ELNEC or EZNEC but right now I'm just trying
to evaluate generic NEC's usefulness to the occaisional field questions
that pop up. (It looks extremely handy but the tabular data is a bit hard
to interpret and writing a parsing/plotting program isn't my idea of fun).

Any help is appreciated. Thanks.

-Geoff   NQ7A-



From [e-mail] Tue Jun 27 15:27:31 1995
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: PL-259's and 9913
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3rsd8h$[e-mail]> <3rsm7e$[e-mail]> <3s4hps$[e-mail]>
Date: Sun, 25 Jun 1995 18:51:17 GMT
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Xref: grape.epix.net rec.radio.amateur.antenna:11440 rec.radio.amateur.equipment:13601

In article <3s4hps$[e-mail]> Jim McHale - NM1W <[e-mail]> writes:
>Solderable N connectors are available and avoid the hassles of cable twisting
>and coming out;
>I prefer the soldered connections.

Better still, if you have the proper tooling, are the crimp connectors.
The Kings line is excellent. Applied properly, they'll support your
weight, if the coax will. When done right, crimp connectors form a
gastight seal that will not fail electrically or mechanically. NASA
uses them. The crimp tooling, tool and the proper die set for your
cable and connector, is expensive, over $200, but its a lifetime
investment.

Beware, however, there are shoddy crimp connectors and shoddy tooling
out there. They won't produce good results. You must use the proper
connector for the cable, and the proper dies for that connector. There
are no shortcuts. Kings makes a connector for 9913, and it works
beautifully. It's a tad cheaper locally than the Amphenol solder
and wrench type which I hate.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Tue Jun 27 15:27:32 1995
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From: Bill Bressler <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Reducing station - station interference in close proximity
Date: 27 Jun 1995 12:44:55 GMT
Organization: Nortel/BNR RTP, NC
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I need help in solving a problem. Our Field Day group has grown from only
one station per band to two (CW & SSB). We had considerable interference
problems this past field day. Contributing factors:

 - all stations in 1000 foot diameter (FD rule)
 - all stations running <= 150 Watts  (FD rule)
 - some stations using non-resonnant antennas
 - some stations using Beam antennas

I know all FD sites have the same problem(s). I would like to know
how other FD groups have solved or bettered the situation.

Possible solutions are:

 - running 50 Watts power
 - using resonnant antennas
 - using bandpass filters (anbody know of good sources or designs?)
 - using a coaxial stub at the transceiver to act as either a bandpass
   of band-reject (any source of information on this would be helpfull)
 - a mix of vertical and horizontal antenna polarization
 - any other ideas ?


Bill Bressler

Nortel/BNR RTP, NC

[phone]  Voice
[phone]  FAX
[e-mail]



From [e-mail] Tue Jun 27 15:27:32 1995
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From: [e-mail]
Newsgroups: rec.radio.amateur.digital.misc,rec.radio.amateur.antenna
Subject: request for Info on Cushcraft 214B/214FB
Date: Mon, 26 Jun 95 13:54:28 PDT
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I'm looking for an assembly guide or manual on the Cushcraft Jr. Boomer Model#
214B/214FB. I bought the antennae in the box and have no assembly instructions.
I will be using this for two meter packet so any information, advice or opinion
on the usefulness for this is deeply appreciated...
73, de
N5ZGW
Jake


From [e-mail] Tue Jun 27 15:27:34 1995
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From: [e-mail] (Lee Jones)
Newsgroups: rec.ponds,rec.puzzles,rec.pyrotechnics,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.cb,rec.radio.scanner,rec.radio.shortwave,rec.radio.swap,rec.railroad,rec.roller-coaster,rec.running,rec.scouting,rec.scuba,rec.skate,rec.skiing.alpine,rec.skiing.snowboard,rec.skydiving,rec.sport.baseball,rec.sport.baseball.fantasy,rec.radio.amateur.antenna
Subject: Responding to Spams
Date: 27 Jun 1995 18:07:42 GMT
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In article <[e-mail]>,
Tse-Sung Wu  <[e-mail]> wrote:
>Spam somewhere else, dude.

Folks - re-posting to a spam does nothing but lengthen its life.  You
want to do something about the spammers (and I'm all for that), contact
[e-mail].   The big online services (aol, prodigy) seem to
produce the most spams (probably because they have the most users, and
many of those are fairly clueless :-).  The good side of that is that
those big online services also respond very quickly to spamming problems
originating inside their walls.

The current one we're dealing with did *not* originate there - it came
from a site called "ixc.net", which means nothing to me, but I'm going to
send an e-mail to the [e-mail], just in case.

Regards, Lee
--
Lee Jones     | "Jesus just left Chicago, and he's bound for New Orleans."
[e-mail]  |            -Z.Z. Top
415-390-3356  |


From [e-mail] Tue Jun 27 15:27:34 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!agate!dog.ee.lbl.gov!newshub.nosc.mil!news!avalon.chinalake.navy.mil!usenet
From: Bill Harwood <[e-mail]>
Subject: Re: SGC-230 auto tuner
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I will kick my two cents in.  I find that the 303 works a lot better
than a metal whip but not as well as center or top loaded whips when
used with the SGC-230.  I have found that the SPIDER antenna is an
expetional mobile when feeed from the SGC-230.  This configuration has
beat everything except the DK-3 types in side by side tests.  The Navy
(San Diego) did a lot of research in the 1960's to determine where to
load an HF whip.

The closer to the top the better was the unqualified answer.  Thus the
SPIDER.  Yes it is ungainly and requires guys and straps and things but
it does work.  On 40 and 80 the SGC-230 and SPIDER combination is within
6 to 9 db of my full length dipole.

TYhe SGC 303 is good on a 4wd in the out back.  Not the best performer
but it will still be there at the end of the day.

Bill Harwood
AB6DY

The good and bad about the SGC.




From [e-mail] Tue Jun 27 15:27:35 1995
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From: [e-mail] (WA6UBE)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SGC-230 auto tuner
Date: 27 Jun 1995 01:46:25 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 9
Sender: [e-mail]
Message-ID: <3so5vh$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (WA6UBE)
NNTP-Posting-Host: newsbf02.mail.aol.com

I am also a proud and happy owner of an SG230 autocoupler -
am curious tho - in stating that your antenna combination is within 6 to 9
dB of your dipole antenna, how far away was the station located that gave
you the signal reports on the mobile arrangement vs the dipole ??

and for comparison, was the mobile whip and the dipole using the same
polarization ?? i.e. both horizontal ??

-> de Trish/ <[e-mail]>


From [e-mail] Tue Jun 27 15:27:36 1995
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The PARALLEL 95 OHM COAX that wouldn't die!
Date: 26 Jun 1995 13:50:49 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Sender: [e-mail]
Message-ID: <3sms1p$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com


: The loss with two parallel 100-ohm cables driving a 50-ohm load will be
: the same as with one 100-ohm cable driving a 100-ohm load.

Right on, Ian. And the other issue is the dominate R loss causing losses
to drop if the impedance is raised. That only holds true for:

Very short lines that are so short they can hardly have any loss anyway.

A restricted range of impedances, looking at a typical RG-8 style cable
the dielectric losses are ten times the conductor losses at 30 MHz. So if
the load is increased to 3.16 times the surge Zo, dielectric losses will
predominate and the efficiency will drop again. That is for a near zero
length line. If the line is made longer, the advantage in mis-terminating
the line (lower loss at higher R load and source) will disappear...with
the peak efficiency quickly being obtained at lower R operation until at a
small fraction (I calculated around 1/3 ) of a wl the optimum load becomes
50 ohms exactly.

73 Tom


From [e-mail] Tue Jun 27 15:27:37 1995
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The PARALLEL 95 OHM COAX that wouldn't die!
Date: 27 Jun 1995 11:07:19 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 7
Sender: [e-mail]
Message-ID: <3sp6r7$[e-mail]>
References: <3sms1p$[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com

>A restricted range of impedances, looking at a typical RG-8 style cable
>the dielectric losses are ten times the conductor losses at 30 MHz. So if
>the load is increased to 3.16 times the surge Zo, dielectric losse


Operator fadeout!!!! Should be ....The dielectric losses are ten times
*less than* conductor losses.....not ten times (more).


From [e-mail] Tue Jun 27 15:27:37 1995
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From: NEWS@PSYC (NEWS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Tonna 2m/70cm beam
Date: 27 Jun 1995 03:18:03 GMT
Organization: PSYCHOLOGY CANTERBURY UNIVERSITY
Lines: 18
Message-ID: <3snt9b$[e-mail]>
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In article <[e-mail]>, [e-mail]
says...
>
>In article: <3rpfe7$[e-mail]>  "Fraser Robertson (G4BJM)" >
From: "Fraser
>Robertson (G4BJM)" <[e-mail]>
>

>+-----------------------------------------------------------------------
--+Hello, from the antipodies. Yes, just reinforcing the issue of phasing
harness, here in Christchurch a person has the appropiate technology to
manufacture the harness. Myself I'm just trying to listen at present on a
dual 144Mhz / 432 Mhz J-Pole but also have another vertical antennna with
gain. J-Pole is at 12m height above HF antenna.
  / / /
{ ^_^ }     73, Winton ZL3AO
 (   )



From [e-mail] Tue Jun 27 15:27:38 1995
Path: grape.epix.net!news.sprintlink.net!news.bluesky.net!solaris.cc.vt.edu!swiss.ans.net!prodigy.com!usenet
From: [e-mail] (Jason Smith)
Newsgroups: rec.radio.amateur.antenna
Subject: Uniden Scanner Antenna??
Date: 26 Jun 1995 01:15:48 GMT
Organization: Prodigy Services Company  1-800-PRODIGY
Lines: 4
Distribution: world
Message-ID: <3sl1o4$[e-mail]>
NNTP-Posting-Host: inugap1.news.prodigy.com
X-Newsreader: Version 1.2

Does anyone know of a fairly inexpensive antenna for use on a Uniden
BC700A scanner? Looking for something with good amplification of the
higher 800-956mhz frequencys... Thanks alot.



From [e-mail] Tue Jun 27 15:27:39 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!news.telalink.net!uro!jackatak!root
From: [e-mail] (Jack GF Hill)
Subject: Re: What's a Bugcatcher?
Organization: Jack's Amazing CockRoach Capitalist Ventures
Date: Sun, 25 Jun 1995 17:55:56 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>
Sender: [e-mail] (Superuser)
Lines: 48

Al Bolton <[e-mail]> writes:

> Excuse my ignorance, but what is a "Bugcatcher" type of mobile aerial?
Good question!  ;^)

The BugCatcher(tm) is fast approaching becoming a generic term for a
large mobile antenna with Hi-Q air-wound coils.

> and it would seem to be a good efficient mobile aerial.
And, it is... My own installation -- I, too, operate exclusively
mobile -- is a bit extreme. I took my "Full Dress BugCatcher" to
Dayton this year again, and drew loads of comments...

The vehicle is a BMW 5-body sedan (1984 vintage) with a frame mounted
support for the antenna. I have used some different approaches to
keeping things efficient, and would be happy to share ideas, but back
to the antenna itself...

The bottom "matching" coil is air wound, #10 silver plated copper wire
on a 3" diameter form... shunted to ground via an alligator clip.
There is a one foot long 3/4" stainless mast "stub" to a machined
brass quick disconnect. Then a 5 foot long 3/4" stainless mast, a
LARGE 6" diameter 7" tall coil, air-wound, also silver plated copper
with Lexan(tm) support/spreaders and a rigid plastic core... above the
coil is an 18" 3/4" mast section with a 20" diameter steel capacity
hat, and topped off with a 48" whip.

With no taps on the coil, the self-resonant frequency seems to be
about 3.2 MHz... I have played with several configurations of capacity
hat and location of components. The "best" to date is the
configuration described, but I have to run a substantially shorter
antenna in teh summer when the leaves weigh down the tree limbs and
tear up my antenna!  ;^)

The term bugcatcher comes from the great number of (large) insects
"caught" on the antenna and in the coil... mine is more like a "Bird
Catcher" but then humane society might get on my case if I call it
that!  ;^)
--
73,
Jack, W4PPT/M (75M SSB 2-letter WAS #1657/#1789 -- both from the mobile! ;^)

+--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--+
| Jack GF Hill        |Voice: [phone] -             Ham Call: W4PPT |
| P. O. Box 1685      |Modem: [phone] -  Bicycling and SCUBA Diving |
| Brentwood, TN  37024|Fax:   [phone] -          Life Member - ARRL |
| [e-mail]  - "Plus ca change, plus c'est la meme chose" |
+--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--+


From [e-mail] Tue Jun 27 15:27:40 1995
From: [e-mail] (Claton Cadmus)
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!news.cyberstore.ca!skypoint.com!news3.mr.net!mr.net!medtronic.com!rosevax!hamlink!fredmail
Newsgroups: rec.radio.amateur.antenna
Subject: What's The gain of a 2m j
Message-ID: <[e-mail]>
Date: Fri, 23 Jun 1995 08:27:26 -0100
X-FTN-To: Uucp
Lines: 36

Hi Roy, you replied to my reply: (Huh??)

RO>[e-mail] (Claton Cadmus):


This is what I wrote:
RO>>A j-pole is simply an end feed verticle dipole.  A dipole has a gain of
RO>>2.18 dbi.  However, a J-pole due to the matching sectio has a gain on
RO>>1.89 dbi slightly less then the dipole.  A quarter wave verticle is
RO>>about 0dbi so the j-poles do better by 2db.


This is what you wrote:
RO>A vertical dipole and J-pole have very nearly the same gain. A quarter-wave
RO>vertical does also, but it's difficult to compare directly since it's
RO>restricted to being close to or at ground level. If you elevate the
RO>quarter-wave vertical and its ground system, you have a "ground-plane"
RO>antenna which also has essentially the same gain as the J-pole and vertical
RO>dipole.

I agree that the J-pole and dipole has about the same gain as that is
what I show.  However, a 1/4 wave ground plane antenna has 0.3 dbi
according to an antenna gain chart I have.  I believe the source was the
NASA antenna test range.  If you have info to the contrary I stand
corrected.

73 de  Claton Cadmus,  KA0GKC
   ______________________________________________________________
  |     FIDOnet= Claton Cadmus 1:282./100                        |
  |    INTERnet= [e-mail]                    |
  |   PACKETnet= KA0GKC@WB0GDB.#STP.MN.USA.NA                    |
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   If anything I have written makes any cents, I claim copyright!
 * SLMR 2.1a * Megahertz 1.) When something is *REALLY*REALLY* painful!




From [e-mail] Tue Jun 27 15:27:41 1995
Path: grape.epix.net!news.sprintlink.net!gatech!newsxfer.itd.umich.edu!agate!bark1mac28.berkeley.edu!user
From: [e-mail] (Kwai Lau)
Newsgroups: rec.radio.amateur.antenna
Subject: where to purchase?
Date: 26 Jun 1995 16:43:06 GMT
Organization: UC Berkeley
Lines: 17
Message-ID: <[e-mail]>
NNTP-Posting-Host: bark1mac28.berkeley.edu

Hello all,

I'm new to this group and I'm interested in getting a HAM radio.  Can
anyone send me some information on where I could purchase one at a fairly
reasonable price?  So far, the only place I've visited is Radio Shack.  If
there are mail order companies out there, could you forward me their phone
numbers?

Thanks a lot.

Kwai

--
Kwai Lau
Molecular & Cell Biology
University of California
[e-mail]


From [e-mail] Tue Jun 27 15:27:41 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!swrinde!elroy.jpl.nasa.gov!usc!news.cerf.net!newsserver.sdsc.edu!nic-nac.CSU.net!charnel.ecst.csuchico.edu!waldorf.csc.calpoly.edu!zimmer!news
From: [e-mail] (Rafael Solis)
Subject: Re: where to purchase?
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: zimmer.csufresno.edu
Organization: CSU Fresno
References: <[e-mail]>
Date: Mon, 26 Jun 1995 18:16:03 GMT
Lines: 38

In article <[e-mail]> [e-mail] (Kwai Lau) writes:
>Hello all,
>
>I'm new to this group and I'm interested in getting a HAM radio.  Can
>anyone send me some information on where I could purchase one at a fairly
>reasonable price?  So far, the only place I've visited is Radio Shack.  If
>there are mail order companies out there, could you forward me their phone
>numbers?
>
>Thanks a lot.
>
>Kwai
>
>--
>Kwai Lau
>Molecular & Cell Biology
>University of California
>[e-mail]

I have had good luck with AES (Amateur Electronic Supply). Don't have
the toll free number with me right now but you can get it from the
[phone] toll-free information #.  Also in Oakland there is a HRO
(Ham Radio Outlet) store (534-5757, 2210 Livingston St. East of
Embarcadero)  They also have good prices and selection but you'll have
to pay CA sales tax! Check with them first and play with the radios
before you decide to buy.

Hope this helps.

Rafael (KE6JSR)

PS: Are you licensed?  It is illegal to operate an amateur xceiver
without the proper FCC licence.







From [e-mail] Tue Jun 27 15:27:42 1995
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From: Listserv@ucsd (Mailing List Processor)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: your LISTSERV request "help with dentron mt3000a antenna tuner (2 msgs)"
Date: 26 Jun 95 16:46:22 GMT
Organization: ucsd usenet gateway
Lines: 3
Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]

The mailing list "with" could not be found.
You may use the INDEX command to get a listing
of available mailing lists.


From [e-mail] Tue Jun 27 15:27:42 1995
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From: Listserv@ucsd (Mailing List Processor)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: your LISTSERV request "info pse on self-supporting tower"
Date: 27 Jun 95 14:37:27 GMT
Organization: ucsd usenet gateway
Lines: 1
Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]

File on does not exist.


From [e-mail] Tue Jun 27 15:27:43 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!swrinde!ihnp4.ucsd.edu!network.ucsd.edu!news-mail-gateway
From: Listserv@ucsd (Mailing List Processor)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: your LISTSERV request "info pse on self-supporting tower"
Date: 27 Jun 95 14:37:26 GMT
Organization: ucsd usenet gateway
Lines: 1
Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]

File pse does not exist.


From [e-mail] Tue Jun 27 15:27:43 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!swrinde!ihnp4.ucsd.edu!network.ucsd.edu!news-mail-gateway
From: Listserv@ucsd (Mailing List Processor)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: your LISTSERV request "info pse on self-supporting tower"
Date: 27 Jun 95 14:37:29 GMT
Organization: ucsd usenet gateway
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Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]

File self-supporting does not exist.


From [e-mail] Tue Jun 27 15:27:44 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!usc!elroy.jpl.nasa.gov!swrinde!ihnp4.ucsd.edu!network.ucsd.edu!news-mail-gateway
From: Listserv@ucsd (Mailing List Processor)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: your LISTSERV request "info pse on self-supporting tower"
Date: 27 Jun 95 14:37:31 GMT
Organization: ucsd usenet gateway
Lines: 1
Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]

File tower does not exist.


From [e-mail] Fri Jun 30 17:05:20 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!news.larc.nasa.gov!xanth.cs.odu.edu!maui.cc.odu.edu!hearst.acc.Virginia.EDU!solitaire.cv.nrao.edu!sadira.gb.nrao.edu!dgordon
From: [e-mail] (David Gordon)
Newsgroups: rec.radio.amateur.antenna
Subject: 1/4 wave coax stubs question
Date: 29 Jun 1995 16:31:25 GMT
Organization: National Radio Astronomy Observatory
Lines: 11
Distribution: world
Message-ID: <3sukgt$[e-mail]>
NNTP-Posting-Host: osiris.gb.nrao.edu

I know that if you use a coax stub, shorted at the end
and cut for the frequency of operation plus the velocity
factor, you get a bandpass filter, so to say.

Now, the question is, could you do the same, but making it
a notch filter by leaving it open at the end instead of
shorting it out??? Thanks...please respond to here and or
my email address.

David - KB4LCI
[e-mail]


From [e-mail] Fri Jun 30 17:05:21 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!vixen.cso.uiuc.edu!news.uoregon.edu!europa.chnt.gtegsc.com!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 1/4 wave coax stubs question
Date: 30 Jun 1995 01:38:31 GMT
Organization: News & Observer Public Access
Lines: 24
Message-ID: <3svkin$[e-mail]>
References: <3sukgt$[e-mail]>
NNTP-Posting-Host: grail618.nando.net

[e-mail] (David Gordon) wrote:
>
> I know that if you use a coax stub, shorted at the end
> and cut for the frequency of operation plus the velocity
> factor, you get a bandpass filter, so to say.
>
> Now, the question is, could you do the same, but making it
> a notch filter by leaving it open at the end instead of
> shorting it out??? Thanks...please respond to here and or
> my email address.

A 1/4 wavelength (electrical length) of transmission line will
have the characteristics of a parallel tuned circuit when shorted
at the far end, and will have the characteristics of a series
tuned circuit with the far end open-circuited.

Based on the above information, the answer to your question is
yes, but the depth and width of the notch will be dependent on
the characteristics of the line as well as the losses.  With good
quality coax, the circuit Q should be quite high.

73,
Don W3FPR



From [e-mail] Fri Jun 30 17:05:22 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!netcom.com!wa2ise
From: [e-mail] (Robert Casey)
Subject: Re: 1/4 wave coax stubs question
Message-ID: <[e-mail]>
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
References: <3sukgt$[e-mail]>
Date: Fri, 30 Jun 1995 03:16:27 GMT
Lines: 15
Sender: [e-mail]

In article <3sukgt$[e-mail]> [e-mail] (David Gordon) writes:
>I know that if you use a coax stub, shorted at the end
>and cut for the frequency of operation plus the velocity
>factor, you get a bandpass filter, so to say.
>
>Now, the question is, could you do the same, but making it
>a notch filter by leaving it open at the end instead of
>shorting it out??? Thanks...please respond to here and or

This is correct.  short a 1/4 wave stub and you see an open at
the other end on its frequency.  Leave the far end open and it
looks like a short at its frequency.  You could make use of this
to trim a 1/4 stub, keep nibbling at the length untill a station
at the desired station gets wiped out, then short the end, and
you should have a bandpass and hear that station loudly.


From [e-mail] Fri Jun 30 17:05:23 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!cam.news.pipex.net!pipex!edi.news.pipex.net!pipex!sunic!sunic.sunet.se!erinews.ericsson.se!usenet
From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 1/4 wave coax stubs question
Date: Fri, 30 Jun 1995 02:12:04 GMT
Organization: Ericsson
Lines: 16
Message-ID: <3svmhj$[e-mail]>
References: <3sukgt$[e-mail]>
NNTP-Posting-Host: pc125011.exu.ericsson.se
X-Newsreader: Forte Free Agent v0.55

[e-mail] (David Gordon) wrote:

>I know that if you use a coax stub, shorted at the end
>and cut for the frequency of operation plus the velocity
>factor, you get a bandpass filter, so to say.

>Now, the question is, could you do the same, but making it
>a notch filter by leaving it open at the end instead of
>shorting it out???

Sure.  What ever you do at the end of a 1/4 wave line has an opposite
effect on the other end of the line.  BUT, only over a somewhat narrow
frequency range.

Mike Groves  KD6PKJ



From [e-mail] Fri Jun 30 17:05:24 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: 12: 1 balun
Message-ID: <[e-mail]>
Keywords: wanted 12: baluns
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3squei$[e-mail]>
Date: Fri, 30 Jun 1995 13:23:58 GMT
Lines: 23

In article <3squei$[e-mail]> [e-mail] (randson) writes:
>
>   Who know where can get find a 12:1 of balun, what factory or comapny
>   sale this one, or who want to sale, active is ok,
>   I want to using on inverted V diploe!

Er, uh, found a bargain on 4.16 ohm coax did you? :-)

An inverted Vee antenna should present an impedance close to 50 ohms.
If you use a balun at all, you want a 1:1 ratio. The simplest one is
just six or seven turns of the coax feedline coiled into a 6 inch diameter
coil and taped in place at the feedpoint.

Perhaps you're trying to do something unusual that isn't apparent from
your post. Explain in a bit more detail what you're trying to do and
maybe we can be more helpful.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:05:24 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!europa.chnt.gtegsc.com!news.uoregon.edu!serv.hinet.net!nctuccca.edu.tw!aladdin.iii.org.tw!usenet
From: [e-mail] (randson)
Newsgroups: rec.radio.amateur.antenna
Subject: 12:1 balun
Date: 28 Jun 1995 06:56:18 GMT
Organization: Seednet, Institute for Information Industry, Taiwan
Lines: 14
Message-ID: <3squei$[e-mail]>
NNTP-Posting-Host: 139.175.169.15
Keywords: wanted 12: baluns
X-Newsreader: Winspan < ñññσ version 3.02 >




Hello, anybody home?

   Who know where can get find a 12:1 of balun, what factory or comapny
   sale this one, or who want to sale, active is ok,
   I want to using on inverted V diploe!


                                            de Radnson Huang/ BV2DQ
                                               in Taipei, Taiwan
                                         [e-mail]



From [e-mail] Fri Jun 30 17:05:25 1995
Path: grape.epix.net!news.sprintlink.net!cam.news.pipex.net!pipex!soap.news.pipex.net!pipex!edi.news.pipex.net!pipex!swrinde!elroy.jpl.nasa.gov!lll-winken.llnl.gov!decwrl!pagesat.net!warp10.smartlink.net!NewsWatcher!user
From: [e-mail] (Jeffery A. Purtle)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 160 Tunable Ant.???
Date: Wed, 28 Jun 1995 12:29:16 -0800
Organization: Smart DOCS Internet Service [phone]
Lines: 24
Message-ID: <jpurtle-2806951229540001@0.0.0.0>
References: <[e-mail]> <3smti9$[e-mail]>
NNTP-Posting-Host: pm178-52.smartlink.net

> > Jeff
>
> Before I moved to more spacious digss I used to tune my Butternut HF6V
> remotely except that rather than use a tuneable inductor, I replaced the
> 400pf fixed caps in the 160 meter resonator unit with a 500pf vaccumn
> variable which in turn was tuned using an electric screwdriver motor.
>
> Good luck
> Dave
> N0DH/7
> [e-mail]

Dave,

Thanks!  Where would I find something like a 500pf vacume variable?  How
much $?  Do you think I could use something like a piece of copper tubing
in place of the HF6V?  Any guess as to the length and if the vacume
variable value would change too?

What do most people use for 160 Meters?  What works great for DX and for
local stuff?

Thanks,
Jeff AC6IW


From [e-mail] Fri Jun 30 17:05:26 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!uunet!in1.uu.net!iglou!iglou.iglou.com!n4lq
From: [e-mail] (Steve Ellington)
Subject: Re: 160m FULL SIZE HORI LOOP QUESTIONS
X-Nntp-Posting-Host: iglou.iglou.com
Message-ID: <[e-mail]>
Sender: [e-mail] (News Administrator)
Organization: IgLou Internet Services
X-Newsreader: TIN [version 1.2 PL2]
References: <[e-mail]>
Date: Wed, 28 Jun 1995 14:00:33 GMT
Lines: 34

Tracy Hooker ([e-mail]) wrote:
: Hi everyone,
: Over the winter I fabricated a full size 160 m loop antenna.  The specs are
: listed below:

: loop length about 550 feet
: wire size:  18 awg copper weld
: DC resistance around the loop is 12 ohms
: loop height is 30 feet above very rocky soil (poor ground).
: feed point is in the corner of the diamond, above my house
: Please let me know what you all think.

: Tracy
:
I have a 160 horiz loop. Supported in 5 places and up 50 to 65 ft.
I used 17ga aluminum electric fence wire. Checking the charts, I felt the
extra resistance was not a concern.
I understood the z would average 100 to 200 ohms on most bands.
I cut the length to resonate at about 1750khz so the harmonics would come
out right on 80-10
I'm feeding it with a pair of rg62 95 ohm coax cables which makes for a
190 ohm feeder. The feeder is about 55ft long straigh down into the shack.
On the rig end, I use a W2AU 4:1 balun. No other brand worked as well.
SWR on 160 is obviously high due to below band resonance. However at
1750khz it is quite low. On 80, 40, 20, 15 and 10 the swr is below 1.5
and no tuner is used. The warc bands require the tuner but even so, the
swr is within range of the ts940s's internal auto tuner.
73 Steve

--
  Steve
[e-mail]




From [e-mail] Fri Jun 30 17:05:27 1995
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!news.ti.com!magic
From: [e-mail] (BV/N0IAT)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2m Marine antenna
Date: Thu, 29 Jun 1995 16:55:01 GMT
Organization: Texas Instruments
Lines: 19
Message-ID: <3stpm6$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (BV/N0IAT)
NNTP-Posting-Host: 137.167.36.115

Sounds more like a colinear coaxial dipole than a j-pole.  Have you
confirmed that it's a j-pole?   I've had good luck with simple 1/2 wave
antennas on boats...they dont require a groundplane, have almost as much
gain as a 5/8 wave, and can easily "fit" inside the fiberglass sheath of
many common marine antennas--which means you can use the heavy duty
marine antenna mounts w/o worry of corrosion.

Just my 2 cents worth

73  from Joe in   Taipei, TAIWAN R.O.C.
 BV/N0IAT LOOKING FOR THE ELUSIVE DX QSO
               \\\|///
               ( 0 0 )
-------------oOO-(_)-OOo-------------


Ex. 7J1AOF  ex. KA0ZDH  ex. YU3/N0IAT
 Licensed Radio Amateur since 1986



From [e-mail] Fri Jun 30 17:05:28 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!asuvax!news.asu.edu!ericwood
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2m Marine antenna
Date: 28 Jun 1995 17:22:10 GMT
Organization: Arizona State University
Lines: 73
Message-ID: <3ss342$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: general2.asu.edu
X-Newsreader: TIN [version 1.2 PL2]

Glenn Mead ([e-mail]) wrote:
: I am trying to install a 2m (144-148) antenna on my boat.
: The Shakespear VHF/FM antenna was only $29, but is tuned
: for the marine bands (158-164 ?). The swr is unacceptable
: on the ham bands. The antenna is an 8' long tapered fiberglass
: tube with a ferrul on the base to mount to a std marine mount.
: I took the antenna apart, and found what appears to be a
: j-pole coax antenna inside. I would like to replace the
: existing j-pole with a coax j-pole tuned for the ham bands.
: Any help on building such an animal would be greatly
: appreciated.

: The existing antenna (measurements are at home)

:        |
:        |
:        |
:        |
:        | <---- Single , straight wire
:        |
:        |
:       |||  <---- coax (sheild and center not connected)
:       |||
:       |||
:       |||///  <---- short coax, end crimped and connected to center
:        *      <---- everything seems to be soldered to here
:        |
:        |      <---- coax feed line from radio

: Thanks.

Glenn,

I tried mailing this to you but it got kicked back to me so here it goes.

A few months ago I started the same project that you have going.  I finally
ended up pulling the classic 2m J-pole made out of 300 ohm television feed
line into the Shakespear tube.

According to a friends AEA antenna analyzer the SWR is around 2.1:1 at
146 MHz.  Although this isn't what I was hoping for it is alot better than
the 5 or 6 to 1 that the marine version gave.

I used a commercial version of the 300-ohm J-pole that MFJ manufactures.  I
got mine from a friend that wasn't using it any longer but he told me they
run $15 from MFJ.  Before putting the antenna into the tube it's SWR was
1.1:1 at 146MHz.  Being in close proximity to the fiberglass must be having
some effect.  One person suggested that the higher SWR was probably due
to the 300 ohm cable being pressed together in the tube.  I don't believe
that is the case since I observed the same increase in SWR when the J-pole
was hanging on the outside of the tube.

In any case good luck on your project.  If you find someone that recognizes
the antenna that came inside the Shakespear please forward the info to me.
I am still wanting to bring the SWR down to a more acceptable level.

One final note, in my search for a good antenna I found a company in
Seattle that manufactures commercial marine VHF antennas that has a model
for 2m.  It is rather large and made of stainless.  It also would cost in
excess of $100 by the time you purchased all the hardware.  If you would like
that info let me know and I'll try to find it.


___________      .__         ___________     __      __                 .___
\_   _____/______|__| ____   \__    ___/    /  \    /  \____   ____   __| _/
 |    __)_\_  __ \  |/ ___\    |    |       \   \/\/   /  _ \ /  _ \ / __ |
 |        \|  | \/  \  \___    |    |        \        (  <_> |  <_> ) /_/ |
/_______  /|__|  |__|\___  >   |____|    /\   \__/\  / \____/ \____/\____ |
       \/               \/              \/        \/                    \/

[e-mail] (KI7FM)




From [e-mail] Fri Jun 30 17:05:29 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: 2m Marine antenna
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]>
Date: Thu, 29 Jun 1995 15:50:07 GMT
Lines: 45

In article <[e-mail]> [e-mail] (Glenn Mead) writes:
>I am trying to install a 2m (144-148) antenna on my boat.
>The Shakespear VHF/FM antenna was only $29, but is tuned
>for the marine bands (158-164 ?). The swr is unacceptable
>on the ham bands. The antenna is an 8' long tapered fiberglass
>tube with a ferrul on the base to mount to a std marine mount.
>I took the antenna apart, and found what appears to be a
>j-pole coax antenna inside. I would like to replace the
>existing j-pole with a coax j-pole tuned for the ham bands.
>Any help on building such an animal would be greatly
>appreciated.
>
>The existing antenna (measurements are at home)
>
>        |
>        |
>        |
>        |
>        | <---- Single , straight wire
>        |
>        |
>       |||  <---- coax (sheild and center not connected)
>       |||
>       |||
>       |||///  <---- short coax, end crimped and connected to center
>        *      <---- everything seems to be soldered to here
>        |
>        |      <---- coax feed line from radio
>
>Thanks.

Using the same brand of coax, just scale the dimensions by
160/146 and you'll have your 2 meter antenna. How you're
going to squash that longer coax into the fiberglass tube
is another problem. If you can't make it fit, perhaps you
can use a coax with a lower velocity factor. Again, scale
the dimensions by the relative velocity factors as well as
by the relative frequencies to get the new dimensions.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:05:30 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!koala.scott.net!vulcan!wirenet!wa4fat
From: wirenet![e-mail] (WA4FAT)
Newsgroups: rec.radio.amateur.antenna
Subject: AAE Bandmaster Quads
Message-ID: <[e-mail]>
Date: Thu, 29 Jun 95 12:54:00 -0600
Reply-To: wirenet![e-mail] (WA4FAT)
Distribution: world
Organization: Vulcan - live long and prosper
X-Newsreader: PCBoard Version 15.21
Lines: 18

AAE Bandmaster Quads, a manufacturer of all-fiberglass communications
antenna systems invites you to visit their site on the World Wide Web.

Point your browser to: http://wweb.net/comart/marcom/bmstr.html

Bill Levey * WA4FAT
AAE Bandmaster Quads
3164 Cahaba Heights Road
Birmingham, AL 35243

[phone] Voice
[phone] Fax

---> http://wweb.net/comart/marcom/bmstr.html

---
* CMPQwk #1.4* UNREGISTERED EVALUATION COPY



From [e-mail] Fri Jun 30 17:05:31 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!cs.utexas.edu!asuvax!news.asu.edu!aztec.asu.edu!hamop
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Advice wanted: Calculating SWR from fwd vs. reflected pwr readings
Date: 29 Jun 1995 03:14:42 GMT
Organization: Arizona State University
Lines: 7
Message-ID: <3st5r2$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


SWR = 1+ square root of (Reflected Power/ Foreward Power) divided
by    1- square root of (Reflected Power/Foreward Power)

Charlie,  W7XC
--



From [e-mail] Fri Jun 30 17:05:31 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!noc.netcom.net!ix.netcom.com!netcom.com!azoth
From: [e-mail] (Az0th)
Subject: Antenna Analyzers
Message-ID: <[e-mail]>
Organization: Radiros'R'Us
X-Newsreader: TIN [version 1.2 PL1]
Date: Thu, 29 Jun 1995 19:18:07 GMT
Lines: 30
Sender: [e-mail]

Hiyall,

Would anyone care to comment on any or all of the current crop of
antenna system analyzers? Besides dippers and noise bridges that've
been around a while, I've come across three different devices that
ought to make short shrift of antenna system tuning and pruning
problems. The price spread between the devices is considerable,
but the goals and features seem much the same.

The most expensive is the AEA device, at around $300. This one sports
a GUI display of VSWR, which probably accounts for the price. It's not
clear to me whether VSWR is the only usable output; it may be the only
output you really need, and a graph is worth a thousand samples.

The MFJ analyzer is the next expensive, at around $200, depending on
the options chosen. Freq. counter, sig. gen., Z and VSWR bridges.
Looks quite versatile, as the included tools can be used independently,
but has analog readout for all but frequency. Close enough for government,
probably, and I've heard a lot of happy users talking them up on the air.
Uses 8 AA's if you want to work outside.

The Autek is the smallest, lightest and least expensive, at around $129.
It seems to do a lot of what the MFJ does, runs on a 9V battery, and has
big LC digital readout for freq, Z, VSWR and such. This one looks and
reads like it ought to be a sensible choice. Has anybody here used one?

Anyway, all comments welcome.

Cheers es 73
RF Buchanan


From [e-mail] Fri Jun 30 17:05:32 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!news.voicenet.com!netnews.upenn.edu!dsinc!newsfeed.pitt.edu!gvls1!edd
From: [e-mail] (Ed Dougherty)
Subject: Re: Antenna Analyzers
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: gvlf4-x
Organization: Paramax - A Unisys Company, Great Valley Labs, Paoli, Pa
References: <[e-mail]>
Date: Thu, 29 Jun 1995 19:57:35 GMT
Lines: 21

In article <[e-mail]> [e-mail] (Az0th) writes:
>Hiyall,
>
>Would anyone care to comment on any or all of the current crop of
>antenna system analyzers? Besides dippers and noise bridges that've

> .... deleted ...

>The Autek is the smallest, lightest and least expensive, at around $129.
>....  Has anybody here used one?
>

======

Yes, I have one and I'm very happy with it.  It basically does all that
it says.


Ed Doc
K3LPE



From [e-mail] Fri Jun 30 17:05:33 1995
Path: grape.epix.net!news.sprintlink.net!msc.edu!bweinman
From: bweinman@@mutt.hamline.edu (Bruce Weinman)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Analyzers
Date: 29 Jun 1995 21:34:27 GMT
Organization:
Lines: 18
Message-ID: <3sv693$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: mutt.hamline.edu
X-Newsreader: TIN [version 1.2 PL0]

Az0th ([e-mail]) wrote:
: Hiyall,

: Would anyone care to comment on any or all of the current crop of
: antenna system analyzers?

I've owned one of the very simple MFJ SWR Analyzers since they were about
79 bucks.  It has none of the bells and whistles of the newer ones, but
it greatly simplifies antenna building and installation.  It runs on a 9v
battery, and you don't need a radio to build and tune antennas.  I use it
with a frequency counter connected - the new ones with the integrated
counter would be a real advantage.  If you build and/or install a lot of
antennas, I think these things are a must.--
_____________________________________________________________________________
There are four kinds of homicide:             [e-mail]
felonious, excusable, justifiable             [e-mail]
and praiseworthy.
                -Ambrose Bierce


From [e-mail] Fri Jun 30 17:05:34 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!news.cyberstore.ca!vanbc.wimsey.com!unixg.ubc.ca!atha!rwa
From: [e-mail] (Ross Alexander)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Analyzers
Date: 30 Jun 1995 17:26:30 GMT
Organization: Athabasca University
Lines: 18
Message-ID: <3t1c46$[e-mail]>
References: <[e-mail]> <3sv693$[e-mail]>
NNTP-Posting-Host: aupair.cs.athabascau.ca
X-Newsreader: NN version 6.5.0 #10 (NOV)

>Az0th ([e-mail]) wrote:
>: Hiyall,

>: Would anyone care to comment on any or all of the current crop of
>: antenna system analyzers?

From what I've seen, all they report is VSWR (some graphically).
IMHO, a good noise bridge is a better all-around tool.  It tells you
more about what's going on than a VSWR reading does.  The downside of
a noise bridge is that it requires a good receiver as part of the
measurement system, and that can be awkward at the top of a tower.
This problem can be worked around if you're Smith-chart literate, of
course.

regards,
Ross ve6pdq
--
Ross Alexander, ve6pdq  --  [phone]  --  [e-mail]


From [e-mail] Fri Jun 30 17:05:34 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!cam.news.pipex.net!pipex!edi.news.pipex.net!pipex!sunic!sunic.sunet.se!news.funet.fi!nntp.utu.fi!mea.utu.fi!oh1jhx
From: [e-mail] (Teemu Peltonen)
Subject: Antenna for 70 cm?
Message-ID: <[e-mail]>
Sender: [e-mail] (Usenet News admin)
Nntp-Posting-Host: mea.cc.utu.fi
Organization: Posted from Matti Aarnio's workstation at University of Turku
X-Newsreader: TIN [version 1.2 PL2]
Date: Wed, 28 Jun 1995 10:43:26 GMT
Lines: 7

I have some troubles with my current 1/4 dipole antenna that I have on my 70
cm radio. Is there some kind of reference on what kind of antenna would be
the best to build and how to do one?

--
[e-mail]  II  System administration and user support
Pascal, ASM, HTML  II  "I don't believe in shell after death"


From [e-mail] Fri Jun 30 17:05:35 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!xlink.net!rz.uni-karlsruhe.de!news.uni-stuttgart.de!moritz
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna for 70 cm?
Date: 29 Jun 1995 10:38:39 GMT
Organization: Comp.Center (RUS), U of Stuttgart, FRG
Lines: 13
Message-ID: <3stvrf$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: ipers1.e-technik.uni-stuttgart.de

>I have some troubles with my current 1/4 dipole antenna that I have on my 70
>cm radio. Is there some kind of reference on what kind of antenna would be
>the best to build and how to do one?

Dear OM,

It depends on what radio you have and what you want to do
with it. Be aware that with vertical omnidirectional antennas
for mobile or portable use, exagerated claims as to gain are
very common.

73, Moritz DL5UH



From [e-mail] Fri Jun 30 17:05:36 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!newsjunkie.ans.net!interaccess!d120.nnb.interaccess.com!marcusj
From: [e-mail] (John Marcus)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna suitable for finicky autotuner
Date: Thu, 29 Jun 1995 16:13:46 -0600
Organization: InterAccess,Chicagoland's Full Service Internet Provider
Lines: 45
Message-ID: <[e-mail]>
References: <3smf9t$[e-mail]>
NNTP-Posting-Host: d120.nnb.interaccess.com
X-Newsreader: Trumpet for Windows [Version 1.0 Rev B final beta #4]

In article <3smf9t$[e-mail]> [e-mail] writes:
>From: [e-mail]
>Subject: Antenna suitable for finicky autotuner
>Date: 26 Jun 1995 14:13:17 GMT

>I have a Yaesu FL7000 linear amp/autotuner which requires
>an unbalanced input of no more than 150 ohms and no less
>than 16 ohms 80-10m, less on 160m.  A Butternut HF6V at
>ground level can be made to accept 500w on much of most
>bands, but due to severe RFI I must consider another
>antenna, on the roof, either a wire or a vertical.  The
>FL7000's manual goes on to say its autotuner can accept
>a 3:1 SWR to match the amp, provided it can bring the
>SWR down to 1.2:1 or less.  I was considering a G5RV at
>first, but now I'm not so sure it will work with the
>FL7000's autotuner.  What would work well on all the WARC
>bands with such a finicky autotuner?  73 de Bill KB8USZ
>[e-mail]


I have a G5RV, a Kenwood TS850S/AT and a Dentron 1kw amp.  The Kenwood manual
says it won't tune to a mismatch of more than about 2:1.  I am able to tune
the 10-80m G5RV up on 80-10m and sometimes on 160m.  Usually 160m gives poor
results.  My antenna is feedpoint is at about 16 feet, not the 35 or so
recommended.  I cause no tvi, even with the amp at 500W output.  I first turn
on all the equipment.  When the amp warms up, I put it in the active mode, not
standby and autotune the rig, (about 10-20w out).  When I see a 1:1 swr on the
rig, I tune up the amp for maximum power output.  I typically get to the full
500w out and increase my signal by a couple of s-units.  I managed a +20-+30
report from somone in Europe on 80m.

The G5RV is fabulous.  I also believe that a coax tuner that is rated at 2:1
or 3:1 and better will work well with the G5RV.

Good Luck, John - WD9AIS

*********************************
|-------------------------------|
|John Marcus                    |
|Contact Info:                  |
|                               |
|[e-mail]        |
|[phone] x164 at work    |
|[phone] at work (direct)|
|_______________________________|


From [e-mail] Fri Jun 30 17:05:38 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news2.near.net!news.delphi.com!usenet
From: [e-mail] (Joanne Dow)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 28 Jun 1995 07:27:13 GMT
Organization: Delphi Internet Services Corporation
Lines: 54
Message-ID: <3sr08h$[e-mail]>
References: <3sls4g$[e-mail]> <3smrft$[e-mail]>
Reply-To: [e-mail] (Joanne Dow)
NNTP-Posting-Host: bix.com
X-Newsreader: NetBix 0.48
X-Newsreader-Author: [e-mail] (Loren Wilton)
    This message has been posted with development version software.
    If there are any problems with the message format, send me mail.

In article <3smrft$[e-mail]>, [e-mail] (W8JI  Tom) wrote:
>
>>At the highest frequencies covered the desired network Qs lead to certain
>>minimum capaciticances in the PI network when you make assumptions that
>>the matching network's potential load is within a limited range. From
>your
>>description it sounds like the range of VSWRs the tuner could handle was
>more
>>limited than with most tuners.
>
>>{^_^}     Joanne Dow     The Wizardess
>
>Hi Joanne, And so it is with most amateur tuners manufactured. The problem
>is that the load impedances are random and usually center around 50 ohms
>for coaxial lines (say from a few to a few hundred ohms) and from a few
>ohms to several thousand ohms with single wire and balanced 300-450 ohm
>lines.
>
>The original values given by the other fellow using dual 750 pF capacitors
>exclude the network from functioning as a "pi" below a certain impedance
>and frequency. It happened that the frequency was around 7 MHz for typical
>load values experienced in typical amateur installations.
>
>Most tuners sold to amateurs commercially as "pi networks" can not act as
>pi's with the load impedances specified by the manufacturers and typically
>supplied by the end user. That is the basis for my observation, and while
>it was a broad general statement....it certainly is true. For example one
>commercial tuner uses around 200 pF as the low Z cap for the input of the
>alleged pi...it is obviously operating as an L below 30 MHz at any 50 ohm
>input Z with moderate load Z's.
>
>My point was because it LOOKS like a pi, it does NOT mean it actually IS a
>pi electrically! I prefer to call a spade a spade (as in cards) not a
>shovel. 73 Tom

My point is that if you look at the circuit over a WIDE frequency range it will
demonstrate behavior you'd expect of three reactive elements as opposed to what
you might expect of only 2.

Of course most of the circuits I have seen for ham tuners give you something
worse than an "L" network. They place the capacitive elements in series with the
load and the inductive element in parallel with the load. This is handy from a
construction standpoint. But it is about as assinine a thing as you can do from
a harmonic suppression standpoint. The tuners I built for myseslf (two of 'em)
both effectively had shunt C and series L. (The VHF/UHF puppy was inductive
coupled pair of wide tuning range butterfly resonators. So it sorta met that
criterion.) The HF tuner had a pair of series roller inductors and a shunt
vacuum variable. It worked quite well from 1.7MHz through about 22MHz. At the
low end it was sufficient to load the coax of an 80 meter antenna as a top
loaded 160 meter psuedo-vertical. It was a bit "iffy" at the high end because of
the strays. It also cut off harmonics very well.

{^_^}     Joanne Dow     The Wizardess



From [e-mail] Fri Jun 30 17:05:40 1995
Path: grape.epix.net!news.sprintlink.net!simtel!news.kei.com!eff!news.duke.edu!godot.cc.duq.edu!newsfeed.pitt.edu!dbisna.com!psinntp!psinntp!psinntp!psinntp!mgate.arrl.org!mgate.arrl.org!not-for-mail
From: [e-mail] (Zack Lau)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna tuners: T vs. pi?
Date: 28 Jun 1995 09:30:51 -0400
Organization: American Radio Relay League
Lines: 37
Message-ID: <3srlib$[e-mail]>
References: <3sls4g$[e-mail]> <3smrft$[e-mail]> <3sr08h$[e-mail]>
NNTP-Posting-Host: mgate.arrl.org
X-Newsreader: TIN [version 1.2 PL2]

Joanne Dow ([e-mail]) wrote:
: Of course most of the circuits I have seen for ham tuners give you something
: worse than an "L" network. They place the capacitive elements in series with the
: load and the inductive element in parallel with the load. This is handy from a
: construction standpoint. But it is about as assinine a thing as you can do from
: a harmonic suppression standpoint. The tuners I built for myseslf (two of 'em)

I'll argue that in terms of enhancing performance of an HF amateur
station, a high pass network may actually be better than a low pass
network.

Why is additional harmonic supression needed?  These days, with clean
rigs and cable TV, actual interference due to harmonics is quite rare.
Thus, for many amateurs, extra low pass filtering of the transmitter
offers no real benefit.  Virtually all the interference these days is
due to overload from the fundamental, rather than from harmonics.

On the other hand, look at the design of a modern day receiver and how
it is used.  Many do quite well at low pass filtering the receiver
input signals, often using the transmit filters.  On the other hand,
how much filtering is there of signals below the receive freqency?

Most amateurs operate close to the MUF, which tends to result in
better signals.  It also results in most interfering signals being
distributed below the operating frequency, since the higher bands
are dead!

Finally, AM broadcast interference, probably the most common form
of strong out of band interference to amateur HF operations, is below
the USA amateur bands. (We don't have 160 to 190 kHz).



--
Zack Lau  KH6CP/1           2 way QRP WAS
                           8 States on 10 GHz
Internet: [e-mail]   10 grids on 2304 MHz


From [e-mail] Fri Jun 30 17:05:40 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!simtel!news.kei.com!bloom-beacon.mit.edu!world!news
From: [e-mail] (Jim Martin)
Subject: Re: Best NMO Mobile Mount???
Message-ID: <[e-mail]>
Sender: [e-mail] (Mr Usenet Himself)
Nntp-Posting-Host: world.std.com
Organization: WK1V
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References: <[e-mail]> <[e-mail] <3sause$[e-mail]> <[e-mail]> <CSLE87-280695090208@145.1.114.19>
Date: Thu, 29 Jun 1995 03:16:27 GMT
Lines: 8

[e-mail] (Karl Beckman) wrote:

>If you insist on using installation tools not recommended by the
>manufacturer, please do not complain when RF and rain both end up inside
>the vehicle.  RTFM!

Touche OM!  :->



From [e-mail] Fri Jun 30 17:05:41 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!newsfeed.acns.nwu.edu!ftpbox!mothost!lmpsbbs!NewsWatcher!user
From: [e-mail] (Karl Beckman)
Subject: Re: Best NMO Mobile Mount???
Organization: Mot LMPS Analog Data
Date: Wed, 28 Jun 1995 09:02:07 -0500
Message-ID: <CSLE87-280695090208@145.1.114.19>
Followup-To: rec.radio.amateur.antenna
References: <[e-mail]> <[e-mail] <3sause$[e-mail]> <[e-mail]>
Sender: [e-mail] (LMPSBBS News Account)
Nntp-Posting-Host: 145.1.114.19
Lines: 35

In article <[e-mail]>, [e-mail] (Jerry
Gardner) wrote:

> : The drill is much much better than a punch.  It includes a "grinder" to
> : strip paint to bare metal for the edge of the NMO to contact, and that
> : makes ALL the difference.  An NMO mount that doesn't make excellent ground
> : to the metal it is drilled through is a bad deal.  An NMO that goes to
> : metal all the way around the edge (look closely at the arrangement of
> : metal and O rings) is the best you can do for a given location for a local
> : ground plane.
>
> : A punch doesn't strip the paint - which you really want inside the O ring
> : on a good NMO mount.
>
> True, a punch doesn't strip the paint from the metal, but it's very easy
> to do so after punching the hole using a piece of sandpaper. It took me
> less than five minutes to sand the paint around the hole down to bare
> metal.
>
>
>
> --
> Jerry Gardner          | Maintainer of the Large Format Digest
> [e-mail]    | Send subscription requests to [e-mail]

If you insist on using installation tools not recommended by the
manufacturer, please do not complain when RF and rain both end up inside
the vehicle.  RTFM!

--
Karl Beckman, P.E.                  <     If our English language is so  >
Motorola LMPS.RNSG.Pvt Data         <  precise, why do you drive on the  >
Schaumburg, IL  /  Parma, OH        <  parkway and park on the driveway? >
   Opinions expressed here do not belong to or represent Motorola Inc.
Amateur radio WA8NVW                        NavyMARS NNN0VBH @ NOGBN.NOASI


From [e-mail] Fri Jun 30 17:05:42 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!ix.netcom.com!netcom.com!jgardner
From: [e-mail] (Jerry Gardner)
Subject: Re: Best NMO Mobile Mount???
Message-ID: <[e-mail]>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
X-Newsreader: TIN [version 1.2 PL1]
References: <[e-mail]> <[e-mail] <3sause$[e-mail]> <[e-mail]> <CSLE87-280695090208@145.1.114.19>
Date: Thu, 29 Jun 1995 19:34:53 GMT
Lines: 25
Sender: [e-mail]

Karl Beckman ([e-mail]) wrote:
: In article <[e-mail]>, [e-mail] (Jerry
: Gardner) wrote:

: > True, a punch doesn't strip the paint from the metal, but it's very easy
: > to do so after punching the hole using a piece of sandpaper. It took me
: > less than five minutes to sand the paint around the hole down to bare
: > metal.

: If you insist on using installation tools not recommended by the
: manufacturer, please do not complain when RF and rain both end up inside
: the vehicle.  RTFM!

OK, I'll admit that I sometimes make grammatical mistakes, and my post
reads like I use sandpaper to punch holes, but I think what I said was
obvious from the context.

I've always used a Greenlee chassis punch to punch the 3/4-inch hole
for NMO mounts and then I've used sandpaper to remove the paint from
the area around the hole where the NMO mount makes contact. I've
never had one of these installations (~20) leak water or RF. I don't
see any problems with this procedure.

--
Jerry Gardner          | Maintainer of the Large Format Digest
[e-mail]    | Send subscription requests to [e-mail]


From [e-mail] Fri Jun 30 17:05:43 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Best NMO Mobile Mount???
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <[e-mail]>
Date: Thu, 29 Jun 1995 14:12:50 GMT
Lines: 30

In article <[e-mail]> [e-mail] (Greg Dolkas) writes:
>Cliff Frescura ([e-mail]) wrote:
>: I've installed two Larsen NMO mounts with no problems during or after
>: installation.  I would recommend spending the extra bucks and getting
>: a Greenlee chassis punch.  May seem like an unnecessary expense, but
>: I think it's worth it.  You might try to talk your local club into
>: buying one for the membership to use ;-).
>
>Ok, but the one thing *really* worrying me is *where* to punch that hole.
>How do I know that an antenna in that position will work properly, and not
>have a warped pattern, or kill the car's electronics?  This isn't an exact
>science, yet you'd better be very happy with the very first attempt.

Punch it dead center of the top. That's as good as you can do. Anywhere
else will have a more skewed pattern due to the asymmetric groundplane.
The center of the top also offers maximum shielding for any interior
electronics of the vehicle.

>Would a mag-mount be worth trying first?

No. The magmount's cable will distort its pattern from what you'd
get with a through hole mounting anyway.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:05:44 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Best Scanner Antenna?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3smoj6$[e-mail]>
Date: Thu, 29 Jun 1995 16:13:23 GMT
Lines: 28

In article <3smoj6$[e-mail]> [e-mail] (Cobra295) writes:
>I'm about ready to buy a scanner and I'm starting to consider antennas...
>I need something that will work from 25-1300Mhz... I really don't know
>what to use... Some suggest using a discone, while others say I'm better
>off just using something like a 220 monobander.... I was considering just
>making a dipole... I already have an HF dipole.. but read in the ARRL book
>that the formula is only good up to 30MHz...   I have many
>possibilities... discone, 11 meter whip, dipole, dual band, etc. etc.. but
>I'm not sure what to use... if anyone has any ideas of a good broadbanded
>scanner antenna, I'd appreciate any help.. thanks...

A discone will have the flatest gain response over the range you
require, but that gain will be zero, IE it has no gain over isotropic.
That's probably Ok for a scanner because too much signal will drive
the radio's wideband front end crazy with intermod. If there are
specific frequencies where you need antenna gain, a directional yagi
cut for that frequency band will work best. But of course it will
have negative gain at other frequencies far from it's design frequency.
That's good in that it'll reduce intermod problems from signals on
those other frequencies, but it's bad in that it won't be a good
antenna for wideband reception of signals on those other frequencies.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:05:47 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Broadband Dipole
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3s2v8l$[e-mail]>
Date: Thu, 29 Jun 1995 13:35:34 GMT
Lines: 61

In article <3s2v8l$[e-mail]> [e-mail] (Christopher Trask) writes:
>W8JI  Tom ([e-mail]) wrote:
>: Tom, I have seen some design like the one I described, I think it was
>: >called T2FD, but I don┤t have any desription left of it.
>X-Newsreader: TIN [version 1.2 PL2]
>
>: >I have also seen a antenna from Barker and Williamsson that look like
>: the one I described that they say works from 3.5-30 Mhz.
>
>: >The antenna is to be used in the Ham bands, but also in between them
>: for MARS type traffic.
>
>: Yes, but the difference is that your application is for receiving. The
>: receiver establishes the line SWR, not the antenna. So while the resistor
>: may help satisfy a transmitter, it will not help satisfy the receiver. The
>: only effect it can possibly have is to *decrease* the signal.
>
>: IMHO  I think adding a lossy feedpoint termination resistance is a
>: worthless addition to a receiving installation, and that is all the
>: antennas you mentioned do.
>
>: 73 Tom
>
>Gentlemen:
>       I need to point out the <FACT> that the resistor in the antenna
>is <NOT> a lossy termination.  It functions in exactly the same manner as
>does the terminating resistor in a rhomboid antenna, which is to force the
>current in the antenna arms, resulting in the directivity of the radiation
>pattern.  But rather than argue the point, I strongly suggest that ELNEC
>or MININEC be brought into the picture.  These are very simple antennas to
>model.  Having used AMP (the great-grandfather of the present antenna mod-
>elling programmes) and NEC (the real thing), I have a great appreciation of
>the simplicity and ease of ELNEC, although I would like to see patches and
>transmission lines added to the geometry.

While the resistor is used as a balance element, it's still a resistor,
and I can say from first hand experience that it gets hot when transmitting
into a terminated rhombic, or a T2FD. Thus I'd side with Tom and call it
a lossy element.

>       Furthermore, it is <ESSENTIAL> that a receiving antenna be matched
>to the receiver for exactly the same purpose as matching an antenna to a
>transmitter, which is to enable the best transfer of energy from the anten-
>na to the receiver.  Mismatching the receiver/antenna has exactly the same
>effect on VSWR, and can be measured as an increase in the effective antenna
>noise temperature.

Of course most RF preamps have best noise figure when their inputs are
mismatched. They generally want to see a lower than matched source
conductance, and a capacitive source susceptance for lowest noise figure.
Since the additional power losses due to VSWR are generally minimal
compared to the benefits of a low noise figure for the RF preamp,
mismatching for best device performance is generally worthwhile.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:05:49 1995
Path: grape.epix.net!news.sprintlink.net!gatech!psinntp!psinntp!psinntp!psinntp!mgate.arrl.org!mgate.arrl.org!not-for-mail
From: [e-mail] (Zack Lau)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Broadband Dipole
Date: 30 Jun 1995 12:26:27 -0400
Organization: American Radio Relay League
Lines: 45
Message-ID: <3t18jj$[e-mail]>
References: <3s2v8l$[e-mail]> <[e-mail]>
NNTP-Posting-Host: mgate.arrl.org
X-Newsreader: TIN [version 1.2 PL2]

Gary Coffman ([e-mail]) wrote:
: In article <3s2v8l$[e-mail]> [e-mail] (Christopher Trask) writes:

: >     Furthermore, it is <ESSENTIAL> that a receiving antenna be matched
: >to the receiver for exactly the same purpose as matching an antenna to a
: >transmitter, which is to enable the best transfer of energy from the anten-
: >na to the receiver.  Mismatching the receiver/antenna has exactly the same
: >effect on VSWR, and can be measured as an increase in the effective antenna
: >noise temperature.

Actually, the two cases are quite different.

        Suppose you have a significantly mismatched preamp fed with
        a lossy 50 ohm coax and 50 ohm antenna.  A signal from the
        antenna travels down the coax and is mostly reflected by
        the preamp.  The reflected signal then travels back down
        the coax and is radiated by the antenna.  Or, if you want to
        conduct and interesting experiment, substitute an HP 346A
        noise source for the antenna.  In this case the noise source
        dissipates that reflected signal as heat.  Note that the loss
        of the coax is just the *matched or 1:1 SWR* loss.

        On the other hand, graphs showing excess coax loss due to
        high SWR *assume* a conjugate match.  The signal makes
        multiple trips down the coax, so the loss is higher than for
        the 1:1 SWR case.

        Back to the experiment--get a bunch of preamps with good and
        bad input matches and lossy coax. Do you measure excess loss/NF
        due to high SWR?  A poor man's way of measuring noise figure
        is to listen to the amount of quieting on an FM signal.  Works
        even better as you widen up the occupied/detector bandwidth.


: Of course most RF preamps have best noise figure when their inputs are
: mismatched. They generally want to see a lower than matched source
: conductance, and a capacitive source susceptance for lowest noise figure.
: Since the additional power losses due to VSWR are generally minimal
: compared to the benefits of a low noise figure for the RF preamp,
: mismatching for best device performance is generally worthwhile.

--
Zack Lau  KH6CP/1           2 way QRP WAS
                           8 States on 10 GHz
Internet: [e-mail]   10 grids on 2304 MHz


From [e-mail] Fri Jun 30 17:05:49 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (KE0YG)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Cushcraft CS50M
Date: 28 Jun 1995 02:14:51 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 6
Sender: [e-mail]
Message-ID: <3sqs0r$[e-mail]>
References: <3spej2$[e-mail]>
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X-Newsreader: AOL Offline Reader

I have one of those antennas and they can be real picky as to where you
place them on the vehicle. The only place It worked on my 1988 Toyota
Tercel was dead center on the roof. They are also narrow banded  and you
only get about 2MHZ bandwidth of less than 2:1 SWR

Randall   KE0YG /3


From [e-mail] Fri Jun 30 17:05:50 1995
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!library.ucla.edu!unixg.ubc.ca!atha!rwa
From: [e-mail] (Ross Alexander)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Dipole Antenna: Why won't mine work?
Date: 28 Jun 1995 17:25:02 GMT
Organization: Athabasca University
Lines: 20
Message-ID: <3ss39e$[e-mail]>
References: <3sifrv$[e-mail]> <3spq4s$[e-mail]>
NNTP-Posting-Host: aupair.cs.athabascau.ca
X-Newsreader: NN version 6.5.0 #10 (NOV)

[e-mail] (KBersch) writes:

>In article <3sifrv$[e-mail]>, [e-mail] (JohnStk)
>writes:

>>The attempt was to make a horizontally polarized dipole.

>A horizontally polarized dipole for CB doesn't make a lot of sense
>considering sthat EVERYONE else is using vertically polarized antennas.
>Horizontal and vertical don't communicate well with each other.

If they're communicating via skywave, it will become randomly
polarized anyhow (courtesy of Faraday rotation and such).  The cross
polarization loss is an issue if they're on the ground wave; but if
they're that close who cares?

regards,
Ross ve6pdq
--
Ross Alexander, ve6pdq  --  [phone]  --  [e-mail]


From [e-mail] Fri Jun 30 17:05:51 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!Germany.EU.net!EU.net!dkuug!Norway.EU.net!telepost.no!usenet
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Dipole Antenna: Why won't mine work?
Date: 29 Jun 1995 10:21:58 GMT
Organization: Telepost Communications A/S
Lines: 27
Message-ID: <3stus6$[e-mail]>
References: <3sifrv$[e-mail]> <3spq4s$[e-mail]> <3ss39e$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: drammensnett112.telepost.no
X-Newsreader: IBM NewsReader/2 v1.03

>>A horizontally polarized dipole for CB doesn't make a lot of sense
>>considering sthat EVERYONE else is using vertically polarized antennas.
>>Horizontal and vertical don't communicate well with each other.
>
>If they're communicating via skywave, it will become randomly
>polarized anyhow (courtesy of Faraday rotation and such).  The cross
>polarization loss is an issue if they're on the ground wave; but if
>they're that close who cares?
>
>regards,
>Ross ve6pdq

Hello Ross.

I beleive that when I have contact on 14MHz and using a dipole with a station
using a vertical I will lose 3dB regardless of skywave. This because when switching
between vertical and horisontal polarisation there is signal loss even if it is
via skywave. I also think that this is not right, but it seem like it to me anyway.

Does someone have more info and experience about this?

la2daa Thor.

Tagline 95.
v.3049405
Under construction.



From [e-mail] Fri Jun 30 17:05:52 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Dipole Antenna: Why won't mine work?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3sifrv$[e-mail]> <3spq4s$[e-mail]> <3ss39e$[e-mail]>
Date: Fri, 30 Jun 1995 13:27:34 GMT
Lines: 26

In article <3ss39e$[e-mail]> [e-mail] (Ross Alexander) writes:
>[e-mail] (KBersch) writes:
>>In article <3sifrv$[e-mail]>, [e-mail] (JohnStk)
>>writes:
>>>The attempt was to make a horizontally polarized dipole.
>
>>A horizontally polarized dipole for CB doesn't make a lot of sense
>>considering sthat EVERYONE else is using vertically polarized antennas.
>>Horizontal and vertical don't communicate well with each other.
>
>If they're communicating via skywave, it will become randomly
>polarized anyhow (courtesy of Faraday rotation and such).  The cross
>polarization loss is an issue if they're on the ground wave; but if
>they're that close who cares?

CBers aren't allowed to "shoot skip". By regulation, all of their
communications is to be under 150 km. (Yeah, I know, they don't
pay attention to regulations, but why encourage them?)

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:05:53 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!swrinde!emory!cssun.mathcs.emory.edu!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Dipole Antenna: Why won't mine work?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3sifrv$[e-mail]> <3spq4s$[e-mail]> <3ss39e$[e-mail]> <3stus6$[e-mail]>
Date: Fri, 30 Jun 1995 14:31:04 GMT
Lines: 36

In article <3stus6$[e-mail]> [e-mail] writes:
>I beleive that when I have contact on 14MHz and using a dipole with a station
>using a vertical I will lose 3dB regardless of skywave. This because when switching
>between vertical and horisontal polarisation there is signal loss even if it is
>via skywave. I also think that this is not right, but it seem like it to me anyway.
>
>Does someone have more info and experience about this?

You take a 3 dB hit when receiving a *circularly* polarized signal
on a linearly polarized antenna (or vice versa). That's not the case
here. The Faraday rotation changes the polarization of the skywave,
but it doesn't make it circular. As the polarization changes (with
changes in the ionosphere), the vector rotates through 360 degrees,
being either horizontal or vertical at only two points. At those points,
the loss will either be 0 db or 30 dB depending on if the polarizations
match or cross. At all other points of rotation of the vector, some
intermediate value of signal loss will occur. This is why signals
fade in and out on paths with significantly varying Faraday rotation.
(They also fade in and out via selective fading, but that's a multipath
effect and doesn't enter into this discussion.)

If it's physically practical, it's better to use a circularly
polarized antenna and take the constant 3 dB hit rather than
the varying 0 to 30 dB hit of linear to linear antennas on a
Faraday rotated path. Even better is to setup dual diversity
reception with pairs of horizontal and vertical antenna/receivers
spaced several wavelengths apart and combined in a dual diversity
combiner at audio so that both Faraday rotation of polarization
and multipath selective fading can be avoided.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:05:54 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!ix.netcom.com!netnews
From: [e-mail] (Glenn Sparks)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Dipole Antenna: Why won't mine work?
Date: 30 Jun 1995 15:39:18 GMT
Organization: Netcom
Lines: 58
Distribution: world
Message-ID: <3t15r6$[e-mail]>
References: <3sifrv$[e-mail]> <3spq4s$[e-mail]> <3ss39e$[e-mail]> <[e-mail]>
NNTP-Posting-Host: ix-hou8-28.ix.netcom.com

In <[e-mail]> [e-mail] (Gary
Coffman) writes:
>
>In article <3ss39e$[e-mail]> [e-mail]
(Ross Alexander) writes:
>>[e-mail] (KBersch) writes:
>>>In article <3sifrv$[e-mail]>, [e-mail]
(JohnStk)
>>>writes:
>>>>The attempt was to make a horizontally polarized dipole.
>>
>>>A horizontally polarized dipole for CB doesn't make a lot of sense
>>>considering sthat EVERYONE else is using vertically polarized
antennas.
>>>Horizontal and vertical don't communicate well with each other.
>>
>>If they're communicating via skywave, it will become randomly
>>polarized anyhow (courtesy of Faraday rotation and such).  The cross
>>polarization loss is an issue if they're on the ground wave; but if
>>they're that close who cares?
>
>CBers aren't allowed to "shoot skip". By regulation, all of their
>communications is to be under 150 km. (Yeah, I know, they don't
>pay attention to regulations, but why encourage them?)
>
>Gary
>
>--
>Gary Coffman KE4ZV          |    You make it,     |
gatech!wa4mei!ke4zv!gary
>Destructive Testing Systems |    we break it.     |
emory!kd4nc!ke4zv!gary
>534 Shannon Way             |    Guaranteed!      |
[e-mail]
>Lawrenceville, GA 30244     |                     |


Just in case the original poster is still following this thread, the
antenna will work, but will probably need to be trimmed or added to.

Check the SWR on channel 1, then channel 20, then on 40.  Which is
better?  If channel 1 is better, trim, if Channel 20 is best, then you
have a problem with connection or feedline if it is not close to 1.5:1.
If channel 40 is better then you need to add a little lenght.

To add take an alligator clip and solder a short lenght to it and try
that on each end of the dipole the same.

When you trim be sure to trim the same on each end, no more than 1"
increments on 11m.

The Horizonal Vs Vertical argument.  IMHO:  the reduction in noise of a
Horizonal polarized antenna is greater than the loss of signal.
Remember almost all Man Made noise is vertically polarized.

Sparky  KI5GY
who_apologizes_for_the_original_question_not_to_have_been_answered,_but
a_debate_started_about_what_you_are_trying_to_do.


From [e-mail] Fri Jun 30 17:05:55 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Directional Antenna
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3semql$[e-mail]>
Date: Thu, 29 Jun 1995 15:52:09 GMT
Lines: 18

In article <3semql$[e-mail]> mpblaze <[e-mail]> writes:
>Can anyone recommend a GOOD directional antenna for use with a scanner
>at 46-49 mhz?  One that can pinpoint well would be nice, but of course,
>without the price of a satellite dish antenna.  Possible base, possible
>handheld ideas...

A yagi beam would be best for base use. Since a 6 meter beam is
rather large for handheld use, a small loop may be your only
choice for handheld use. It won't have the sensitivity of the
bigger beam of course.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:05:56 1995
Path: grape.epix.net!news.sprintlink.net!parsifal.nando.net!usenet
From: DB Wilhelm <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Formula help
Date: 29 Jun 1995 03:05:56 GMT
Organization: News & Observer Public Access
Lines: 63
Message-ID: <3st5ak$[e-mail]>
References: <3sro8p$[e-mail]>
NNTP-Posting-Host: vyger208.nando.net

[e-mail] (Ron Smith) wrote:
 >
 > Old age is the PITS!!  At one time I knew how to do ballpark
 > conversions from one antenna freq. to another (ie: a 2 Meter J-Pole to
 > a 440 J-pole) but now I can not remember which book I saw it it or
 > what formula I used to do the conversion.
 >
 > I recently saw a 5/8 wave 2 Meter antenna that I want to make for 440.
 > Two parts of the antenna are 5/8 Wave, one part is 1/4 Wave, and
 > another is 1/8 Wave.  I can come close with the 1/4 and 1/8 Wave
 > elements but the 5/8 Wave figures are off by about 1.5 inches.
 >
 > Seem like I was using the formula:
 >
 >     234
 >    -------       =   1/4 Wave stub in feet
 >    Freq.
 >
 > Multiplying the 1/4 wave in  feet x 12 will give the lenght in inches.
 >
 >
 > This formula seems to work with 440 J-poles with the rusultant 1/4
 > Wave stub being 6.3 inches and the 1/2 Wave element about 18.9 inches.
 >
 > Unfortunately this formula is not adaquate for x/8 measurements even
 > though 2/8 = 1/4 when working toward the 5/8 and up measurement it is
 > off by a figure greater than 1".
 >
 > Any hints, formulas, pointers would be greatly appreciated.
 >
 > Ron
 >
Yes, it will get you in the ballpark!
You have the normally accepted formula right, but it is really
only an approximation (besides being easy to remember).

The real formula for a full wavelength in free space is

 Length (meters) =  300,000,000/freq (Hertz)
or more commonly, a half-wave in free space in feet = 492 / f(MHz).

This formaula must then be modified for real antennas to compensate
for both velocity of propogation and end effects.
With thin wire antennas supported with end insulators,
the propogation velocity plus end effect factor is approximately
0.95, which yields the more common formula of 468/f(MHz) for a
half wave and simply dividing by two yields 234/f(MHz) for a
quarter wave.

Now these formulas are usually sufficient when dealing with
antennas for frequencies up to 30 MHz and not longer than 1/2
wave in length.  Over 1/2 wavelength, the end effect must only
be counted once for the entire antenna and not for each half
wavelength.  It is getting complicated now, and I recommend
that you refer to a good text on antennas, or resort to cut and
try techniques.  What I have hoped to accomplish is to explain
why the 234/f formula is useful sometimes and will give errors
in other situations.

73,
Don W3FPR




From [e-mail] Fri Jun 30 17:05:57 1995
Path: grape.epix.net!news.sprintlink.net!news.primenet.com!news
From: [e-mail] (Ron Smith)
Newsgroups: rec.radio.amateur.antenna
Subject: Formula help
Date: Wed, 28 Jun 1995 14:16:12 GMT
Organization: Primenet
Lines: 31
Message-ID: <3sro8p$[e-mail]>
NNTP-Posting-Host: ip185.boi.primenet.com
X-Newsreader: Forte Free Agent v0.55

Old age is the PITS!!  At one time I knew how to do ballpark
conversions from one antenna freq. to another (ie: a 2 Meter J-Pole to
a 440 J-pole) but now I can not remember which book I saw it it or
what formula I used to do the conversion.

I recently saw a 5/8 wave 2 Meter antenna that I want to make for 440.
Two parts of the antenna are 5/8 Wave, one part is 1/4 Wave, and
another is 1/8 Wave.  I can come close with the 1/4 and 1/8 Wave
elements but the 5/8 Wave figures are off by about 1.5 inches.

Seem like I was using the formula:

    234
   -------       =   1/4 Wave stub in feet
   Freq.

Multiplying the 1/4 wave in  feet x 12 will give the lenght in inches.


This formula seems to work with 440 J-poles with the rusultant 1/4
Wave stub being 6.3 inches and the 1/2 Wave element about 18.9 inches.

Unfortunately this formula is not adaquate for x/8 measurements even
though 2/8 = 1/4 when working toward the 5/8 and up measurement it is
off by a figure greater than 1".

Any hints, formulas, pointers would be greatly appreciated.

Ron




From [e-mail] Fri Jun 30 17:05:58 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!paladin.american.edu!news.ecn.uoknor.edu!bubba.ucc.okstate.edu!gcouger
From: [e-mail] (Gordon Couger)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Formula help
Date: 28 Jun 1995 22:01:02 GMT
Organization: Biosystems and Agricultural Engineering
Lines: 32
Message-ID: <3ssjeu$[e-mail]>
References: <3sro8p$[e-mail]>
Reply-To: Gordon Couger <[e-mail]>=
NNTP-Posting-Host: jsun.agen.okstate.edu

In article <3sro8p$[e-mail]>,
Ron Smith <[e-mail]> wrote:
>Old age is the PITS!!  At one time I knew how to do ballpark
All I can say is it beats the alternitive.

>conversions from one antenna freq. to another (ie: a 2 Meter J-Pole to
>a 440 J-pole) but now I can not remember which book I saw it it or
>what formula I used to do the conversion.
>
You can convert one antenna to another frequency using ratio and proprotion
thusly:

Current antenna frequency         desired antenna frequecy
________________________    =     ________________________
known measurment                  unknown measurment.

or a/b = c/x
x = b*c/a

Remember to scale all measurments including radiator diamater if it is
of meaningful size. You don't need to worry much abouta 1/8" scaling from
2 meters to 440 but you do need to worry about a 1 inch radiator. don't
forget the spacings either.

I trust this method to go from 10 meters to 2 meters but but I don't trust
it for all diminsions going from 160 meters to 440.

Good luck
Gordon AB5DG
Gordon Couger - 624 Cheyenne, Stillwater, OK 74075
[e-mail] 405-624-2855 evenings
    I do not speak for my employer


From [e-mail] Fri Jun 30 17:05:59 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!europa.chnt.gtegsc.com!news.uoregon.edu!serv.hinet.net!nctuccca.edu.tw!aladdin.iii.org.tw!usenet
From: [e-mail] (randson)
Newsgroups: rec.radio.amateur.antenna
Subject: FT-401
Date: 28 Jun 1995 06:51:16 GMT
Organization: Seednet, Institute for Information Industry, Taiwan
Lines: 1
Message-ID: <3squ54$[e-mail]>
NNTP-Posting-Host: 139.175.169.15
X-Newsreader: Winspan < ñññσ version 3.02 >




From [e-mail] Fri Jun 30 17:05:59 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news.sprintlink.net!europa.chnt.gtegsc.com!news.uoregon.edu!serv.hinet.net!nctuccca.edu.tw!aladdin.iii.org.tw!usenet
From: [e-mail] (randson)
Newsgroups: rec.radio.amateur.antenna
Subject: FT-401 OM
Date: 28 Jun 1995 06:53:04 GMT
Organization: Seednet, Institute for Information Industry, Taiwan
Lines: 9
Message-ID: <3squ8g$[e-mail]>
NNTP-Posting-Host: 139.175.169.15
Keywords: looking for circuit.
X-Newsreader: Winspan < ñññσ version 3.02 >


Hello, anybody home?

This is BV2DQ, I got a FT-401 on before, It's old more than my age!
No VFO parts, SO I need get circuit, please !!

                                 De Randson Huang/BV2DQ in Taipei,Taiwan
                                 [e-mail]



From [e-mail] Fri Jun 30 17:06:00 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!simtel!news.kei.com!newshost.marcam.com!uunet!in1.uu.net!iglou!iglou.iglou.com!n4lq
From: [e-mail] (Steve Ellington)
Subject: Re: GAP Titan experiences
X-Nntp-Posting-Host: iglou.iglou.com
Message-ID: <[e-mail]>
Sender: [e-mail] (News Administrator)
Organization: IgLou Internet Services
X-Newsreader: TIN [version 1.2 PL2]
References: <3r9jf1$[e-mail]> <3rfg7e$[e-mail]> <[e-mail]>
Date: Tue, 27 Jun 1995 13:38:33 GMT
Lines: 21

Larry ([e-mail]) wrote:
:
: I wanted to comment on the GAP line of antennas in general.  For the past
: year, I've owned the GAP Challenger.  If the Titan performs anything like
: the Challenger, you'll never ever need another antenna.  It's the best all
: around antenna I've owned and recommend it highly.  Anything I've heard, I've
: worked.
:
: 73,
:
: Larry Spinner
: N2ICZ
How would the Titan perform on top my 60ft tower? What about anyone who
has compared it with the MFJ 80-10 vertical? It is a bit cheaper but does
it work?

--
  Steve
[e-mail]




From [e-mail] Fri Jun 30 17:06:01 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!uunet!in1.uu.net!gonix!ivgate!hawgwild!bob.boetcher
From: [e-mail] (Bob Boetcher)
Newsgroups: rec.radio.amateur.antenna
Subject: Grounding
Date: Mon, 26 Jun 1995 18:31:59 GMT
Message-ID: <[e-mail]>
Organization: HAWG WILD! BBS [phone]
Distribution: world
Lines: 17

Hi
I'm setting up a new ham shack and want to know what is a good method of
grounding my radio, power supply and antenna tuner.  I've been reading
about "star" grounds and I'm not sure if I understand what this is.
Currently, I have one ground which grounds my radio, power supply and
antenna tuner.  The ground consists of one wire from a ground rod just
outside of the ham shack window and recently I have put an 8 foot radial
from this ground rod.  I'm I creating ground loops when I ground
everything to the same ground via the same wire?

Can I use the same ground for my antennas as I do for the equipment?  I
do plan to isolate the equipment from the antenna ground when electrical
storms are in the area.

Thanks for the help,

Bob


From [e-mail] Fri Jun 30 17:06:03 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!newsjunkie.ans.net!interaccess!d120.nnb.interaccess.com!marcusj
From: [e-mail] (John Marcus)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Grounding
Date: Thu, 29 Jun 1995 16:37:33 -0600
Organization: InterAccess,Chicagoland's Full Service Internet Provider
Lines: 70
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: d120.nnb.interaccess.com
X-Newsreader: Trumpet for Windows [Version 1.0 Rev B final beta #4]

A few notes on grounding.

RF grounding and Electrical grounding serve 2 seperate purposes.
Lightning protection is another world.

RF grounding serves as counterpoise for certain, (ie. vertical) antenna
systems.

Electrical grounding, to prevent ground loops, should be as follows.
        Ground rods near the electrical service input should be bonded
        to a heavy, (8 guage or better), ground wire and run as short a
        distance as possible to a ground bus, outside the shack.
        The ground buss, outside the shack is where
        lightning protection devices like Polyphaser can be bonded and
        connected inline with coax, rotor cables, etc.  The hamshack,
        (preferrably copper), ground buss should also be tied to this
        outdoor ground plate.  With the hamshack near the electrical
        service, all equipment cases would be at the ground and neutral
        potential.  The further from the service ground to the hamshack,
        the greater the possibility of a ground loop.

Other than lightning protection in proper station grounding and special
Isolators, some articles mention spline balls.  These are devices mounted
around ones tower, at certain intervals, bonded to one common ground at
the base of the tower.  A tower may develop a strong charge due to wind
friction.  Spline balls bleed off this extra charge over a large surface
area to help reduce the attraction of lightning to the tower.

When somone mentions a star ground, they are refering to a central
grounding point which has connections to other equipment in a star
configuration.  The other type of ground would be a series connection.
This would be from antenna ground to ligtning ground to shack ground
to service ground.  A series ground path is more likely to cause loops
and cause damage to equipment should the neutral line and service
ground change substantially in potential.


In article <[e-mail]> [e-mail] (Bob
Boetcher) writes:>From: [e-mail] (Bob Boetcher)
>Subject: Grounding
>Date: Mon, 26 Jun 1995 18:31:59 GMT

>Hi
>I'm setting up a new ham shack and want to know what is a good method of
>grounding my radio, power supply and antenna tuner.  I've been reading
>about "star" grounds and I'm not sure if I understand what this is.
>Currently, I have one ground which grounds my radio, power supply and
>antenna tuner.  The ground consists of one wire from a ground rod just
>outside of the ham shack window and recently I have put an 8 foot radial
>from this ground rod.  I'm I creating ground loops when I ground
>everything to the same ground via the same wire?

>Can I use the same ground for my antennas as I do for the equipment?  I
>do plan to isolate the equipment from the antenna ground when electrical
>storms are in the area.

>Thanks for the help,

>Bob


*********************************
|-------------------------------|
|John Marcus                    |
|Contact Info:                  |
|                               |
|[e-mail]        |
|[phone] x164 at work    |
|[phone] at work (direct)|
|_______________________________|


From [e-mail] Fri Jun 30 17:06:04 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!news.cyberstore.ca!skypoint.com!news3.mr.net!mr.net!news.mr.net!timbuk.cray.com!equalizer!network.ucsd.edu!news-mail-gateway
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ham-Ant Digest V95 #270
Date: 29 Jun 95 22:53:06 GMT
Organization: ucsd usenet gateway
Lines: 11
Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]

I have a R 7 antenna like to trade for a 3 element 3 band beam. My R 7 about a
year old. Storm killed my bean and need it more thanthe R 7 . 73 Louis/W4NRG

Louis J. Dupree
3015 Englewood Dr.
Kinston, NC 28501
[e-mail]
Ham Radio W4NRG





From [e-mail] Fri Jun 30 17:06:04 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!vixen.cso.uiuc.edu!glibm10.cen.uiuc.edu!njachimi
From: [e-mail] (Nathan Jachimiec)
Newsgroups: rec.radio.amateur.antenna
Subject: helix
Date: 29 Jun 1995 00:27:28 GMT
Organization: University of Illinois at Urbana
Lines: 7
Message-ID: <3sss1g$[e-mail]>
NNTP-Posting-Host: glibm10.cen.uiuc.edu

What is the recommened OD for a 440Mhz helical antenna?

That seems to be the missing description in all the articles on helix
design...

-N



From [e-mail] Fri Jun 30 17:06:05 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!swrinde!ihnp4.ucsd.edu!newshub.nosc.mil!rcp6.elan.af.mil!usenet
From: Chris Spacone <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help Needed on Spiral Ant from A-7 Aircraft
Date: 30 Jun 1995 18:48:31 GMT
Organization: Air Force Flight Test Center
Lines: 27
Message-ID: <3t1gtv$[e-mail]>
References: <3spl6s$[e-mail]>
NNTP-Posting-Host: 129.198.18.254
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.1N (Windows; I; 16bit)

[e-mail] (Henry  Laviers) wrote:
>On a lark I purchased a "A-7 Navy Aircraft Electronic Countermeasures Antenna" from
>a surplus place. ( well, it cost a grand total of $8, so I could not resist)
>

>The antenna is a small cone, 5cm in diameter at the base, 12.8 cm high vertically, with two
>spiral arms that start at the small end of the cone and spiral 5 times  figure this antenna has an included cone angle (theta) of about 11
>I am most unsure about the lowest useable frequency. According to one graph, the radius of the

>Spiral antenna pundits please come to the rescue.

Henry,

I'm no 'spiral antenna pundit' but I was an A7 Avionics Technician (A and
B models).  I also was responsible for 'sweeping' the active and passive
ECM/ESM systems on this particular airframe.  It sounds like you have an
antenna from an ALR-40/45 Threat System.  Because of my continuing
obligation to the Federal Govt (like I signed a bunch of really scary
paperwork) I can't discuss the frequency ranges the antenna covers.  But
I can say this, it was definitely meant for microwave work, not 10Mhz.

Chris

[e-mail]

My own opinions, etc, ad nauseum.



From [e-mail] Fri Jun 30 17:06:06 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!swrinde!ihnp4.ucsd.edu!newshub.nosc.mil!rcp6.elan.af.mil!usenet
From: Chris Spacone <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help Needed on Spiral Ant from A-7 Aircraft
Date: 30 Jun 1995 18:49:47 GMT
Organization: Air Force Flight Test Center
Lines: 7
Message-ID: <3t1h0b$[e-mail]>
References: <3spl6s$[e-mail]>
NNTP-Posting-Host: 129.198.18.254
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.1N (Windows; I; 16bit)

Henry,

Oops (I mis quoted you re:10 Mhz.), sorry I'll pay closer attention next
time.

Chris.



From [e-mail] Fri Jun 30 17:06:06 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!europa.chnt.gtegsc.com!library.ucla.edu!news.bc.net!rover.ucs.ualberta.ca!tribune.usask.ca!canopus.cc.umanitoba.ca!newsflash.concordia.ca!news.mcgill.ca!VM1.MCGILL.CA
From: "RAPP,ROBERT,MR" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: help with picking up stations
Date: 28 JUN 95 12:55:11 EST
Organization: McGill University
Lines: 7
Sender: [e-mail]
Message-ID: <[e-mail]>
NNTP-Posting-Host: vm1.mcgill.ca

Hello! I really don't know much about anything here, but I want to ask
a question. I really want to pick up 106.7 FM in Burlington Vt., and I
am in Montreal. I have a good tuner, with an antenna, and I want to know
how I can increase the reception, or hook up cable, or something. This
station has all sorts of things I like to listen to. Please help me if
you can....Jon. Thank you.



From [e-mail] Fri Jun 30 17:06:08 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: HF on Jeep Cherokee
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <3sajkb$[e-mail]>
Date: Thu, 29 Jun 1995 14:52:34 GMT
Lines: 63

In article <3sajkb$[e-mail]> [e-mail] (Dick Hughes) writes:
>[e-mail] (David Feldman) wrote:
>
>>I succumbed to the Jeep Grand Cherokee lease deal and ended up with one,
>>replacing my old 84 AMC. Anyway, I'd like to mount a HF antenna (hustler
>>type) and could use some words of wisdom.
>
>>Options I can think of:
>
>>  1. Mag mount on roof. I had this on the AMC. Worked great but hard to
>>  avoid damaging the finish, and this is a lease car and will go back in
>>  2 years.
>
>>  2. Trailer hitch mount. I got a class-3 trailer hitch, but it seems that
>>  putting so much of the mast down that low will hurt efficiency. WOuld it
>>  be worth extending the mast another foot or two? The hustler is only
>>  7 feet long or so but I could accomodate much higher overall length.
>
>>  3. One of those SGC type antennas. 13' whip would be nice, but I don't
>>  want to drop the $$. Also the rig is FT900/AT and has it's own tuner.
>
>>  4. Lip mount, but not sure where to mount it. Car doesn't have a rear
>>  trunk per se.

>Go for the trailer hitch mount.  Have Grand Cherokee and don't see any
>other practical way to do it without butchering the car.

Have a hitch house (or other metal fabricator) weld an extension to
the frame mount so that it extends out the *left* corner of the vehicle
to take the antenna. You don't want the antenna sticking up from
the hitch where you can't use the rear hatch or lower the tailgate
without removing it. Run it out the left side so brush and low hanging
limbs on the side of the road won't always be catching the antenna.

>Go for the DK3 type antenna (screwdriver type.)  Can't beat it.  Use
>cross-needle SWR meter that does not require adjustment.  DK3's can be
>purchased for under $200.  You can increase the length of the lower
>mast on the DK3 to get the coil above the roof, but will affect your
>ability to tune 10 meters when using decent length top section.  Need
>to compromise here (Unless no interest in 10 meters.)

A good whip and tuner, or a bugcatcher type antenna is generally
best. Hustler's aren't very efficient, and neither are the screwdriver
antennas.

>Forget the internal tuner.  Doesn't do any good.  Have to tune the
>antenna at the antenna, and match the base impedance at the antenna.
>DK3 does both.  73 and good luck with your project

The internal rig tuner *is* probably worthless for matching the
antenna because it doesn't have sufficient range, but a real tuner
doesn't have to be at the antenna end of the coax. It'll tune the
antenna from the transmitter end too. The only problem is excess
loss in the coax from the high VSWR. (The cable acts as a transmission
line transformer, effectively becoming *part* of the tuner.) Using good
cable, this is a negligible issue at HF.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:09 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!jussieu.fr!univ-compiegne.fr!kaa.hds.univ-compiegne.fr!capi
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: ic260e no ssb power when tos >1
Date: 29 Jun 1995 08:36:07 GMT
Organization: Universite de Technologie de Compiegne - France
Lines: 13
Message-ID: <3stoln$[e-mail]>
NNTP-Posting-Host: kaa.hds.univ-compiegne.fr
X-Newsreader: TIN [version 1.2 PL2]


73 to everybody from f1tyn
i've got a strange problem with my icom260e
this tx has an ouput power of 10 w in ssb and fm, and provide this power
only when the tos in 1. when this tos is greater (1.4) the ouput power in ssb
is only about 1w and only in ssb mode.
gp6 antenna     tos =1  10w in ssb and fm
1/4 wave        tos= =1.3 10w in fm and only 1w in ssb
2x11 elements   tos= =1.5 10w in fm and only 1w in sbb
who could help me ?
please reply to [e-mail]




From [e-mail] Fri Jun 30 17:06:09 1995
Path: grape.epix.net!news.sprintlink.net!ratty.wolfe.net!big.aa.net!news
From: Randy Seacat <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J Pole program for MSDOS computers
Date: 29 Jun 1995 19:45:17 GMT
Organization: Alternate Access Inc.
Lines: 47
Message-ID: <3suvsd$[e-mail]>
References: (none) <[e-mail]> <[e-mail]>
NNTP-Posting-Host: d206.aa.net

[e-mail] (Barbara Fehner) wrote:
>
> [e-mail] (Muenzler, Kevin) wrote:
>
>
>
> >>This program JPOLE.EXE calculates the lengths of the elements of a twinlead
> >>Jpole antenna.  Uses regular (not foam) TV 300 ohm twinlead, also be
> >>sure to use a choke coil or ferrite bead on the coax at the feedpoint
> >>(creates a 1:1 balun).
> >>
> >>Program runs on MSDOS PC's.
> >>====================== NETRUN V2.3D DOS PROGRAM >========================
> ><SNIP SNIP SNIP SNIP SNIP SNIP SNIP CRASH!>
> >Robert,
>
> >Please don't post binary files to this list!!
> >My intent is not to lecture you or tell you what to do.  I simply request
> >that if you intend to upload binary data please do so to a binary newgroup.
> >
> >
>
> >Kevin Muenzler, WB5RUE
> >[e-mail]
>
> I , for one, appreciated getting this program with a minimum of fuss
> and bother. Perhaps the fault lies not in the posting of the program
> but in your list server.
>
> Barbara Fehner  KK6IB
> E-Mail:  [e-mail]
>
>

I second the motion. And I sure dont see a rec.radio.amateur.binaries
group anywhere. I dont fell there is anything worng with posting a 12k
program to this group considering the uses of it.

Think of it this way, as far as bandwidth, that one post of the jpole
calculator possibly kept 40 more jpole questions from being repeated
on the group this week. Just a thought.

73 to all..

K-indly I-nsert 7 Z-einer D-iodes




From [e-mail] Fri Jun 30 17:06:11 1995
Newsgroups: rec.radio.amateur.antenna
Subject: J-Pole for Dual Band  2m
From: [e-mail] (Clint Bradford)
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!news.sprintlink.net!holonet!colossus.holonet.net!wwswinc!clint.bradford
Distribution: world
Message-ID: <[e-mail]>
Date: Tue, 27 Jun 95 15:12:00 -0500
Organization: WoodyWare Software, Inc. - 516-736-6662
Lines: 58

Subject: J-Pole for Dual Band  2m es 75cm

>>...a dual band J-Pole?


     === 2m/70cm Dual Band J-Pole made from 300 ohm twin lead ===

              _____      _______       ___
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                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
             54-1/4"    |       |    38-1/2"
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |      _|       |
                |       |   N |_       _|__
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |       |
                |       |       |    15-3/4"
                |       |       |       |
                |       |_______| ___   |
                |       |       | 1/4"  |
               _|_      |       | ___  _|__
                        ^       ^
                        |       |
                    Coax Inner  Coax Outer
                    Conductor   Conductor


         SWR is 2:1 across the 2m band and from 435mhz to
                     450mhz on the 70cm band.


1.  Use good quality TV twin lead.
2.  Strip insulation at the solder point for coax feedline.
3.  Cut out and remove the 1/2" long notch N.
4.  Feed with a length of 50 ohm coax and terminate with the
    appropriate connector.  Tape coax at feedpoint to the twin lead,
    or use heat shrink, and make sure the joints are insulated from
    each other.
5.  Antenna may be sleeved inside 1/2" PVC for outside mounting or
    hung on a loop of string run thru hole O.
---
 ■ wcECHO 4.1 ≈ AR-Net: ATTENTION to Details ■ Mira Loma, CA ■ 909-681-6221


From [e-mail] Fri Jun 30 17:06:12 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: more gain: 1/2 wave whip or j-pole for 2m?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]>
Date: Thu, 29 Jun 1995 15:43:03 GMT
Lines: 18

In article <[e-mail]> tyler harpster <[e-mail]> writes:
>I'm curious,  Which gives more gain on 2 meters?  I have an ht and I want to
> know if I would get more umph from a 1/2 wave hot rod whip, or a j-pole?
>anybody know the facts?  I'd appreciate any answers... Tyler.  N3SPD

They're both 1/2-wave verticals, with different matching arrangements.
There shouldn't be any difference if both are properly installed and tuned.
The more important question would be, which will be higher? The height
of a VHF omni vertical antenna above average terrain has more to do with
its performance than any gain figure. A crummy antenna mounted high
will outperform a great antenna mounted low.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:12 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!europa.chnt.gtegsc.com!casaba.srv.cs.cmu.edu!rochester!galileo.cc.rochester.edu!uhura.cc.rochester.edu!rdewan
From: [e-mail] (Rajiv Dewan)
Subject: NEC2 Modeling: Volage at segment edge
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: uhura.cc.rochester.edu
Organization: University of Rochester, Rochester NY
Date: Thu, 29 Jun 95 14:08:05 GMT
Lines: 23

I am trying to model a Vee shaped dipole using NEC2.  The dipole is in
a horizontal plane and its legs are at right angles to each other.  I
want to feed this in the center with a voltage excitation.  What EX card
should I use?

To understand the EX 5, voltage feed at an edge of a segment, I
tried the following two models of a simple dipole.

GW 0  29  -1.0   0.0   20.0    1.0    0.0    20.0
EX 0 0 15 0 1.0 0.0

and

GW 0  30   -1.0   0.0   20.0   1.0   0.0    20.0
EX 5  0  15  0   1.0   0.0


To my dismay, they give different results.
Any help would be appreciated.


Rajiv Dewan
aa2ui


From [e-mail] Fri Jun 30 17:06:13 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!sundog.tiac.net!news.kei.com!travelers.mail.cornell.edu!cornellcs!rochester!galileo.cc.rochester.edu!uhura.cc.rochester.edu!rdewan
From: [e-mail] (Rajiv Dewan)
Subject: NEC2 Modeling: Voltage Source, NEC file
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: uhura.cc.rochester.edu
Organization: University of Rochester, Rochester NY
Date: Thu, 29 Jun 95 17:28:07 GMT
Lines: 36


Here is the correct NEC input file:

I am trying to model a Vee shaped dipole using NEC2.  The dipole is in
a horizontal plane and its legs are at right angles to each other.  I
want to feed this in the center with a voltage excitation.  What EX card
should I use?

To understand the EX 5, voltage feed at an edge of a segment, I
tried the following two models of a simple dipole.

CM Test Dipole
CM Voltage Feed Type 1 at center of segment
CE
GW  1   19     -0.25       0.0       0.0      0.25       0.0       0.0    0.001
GE
FR                        285.
EX  0    1   10            1.0
XQ
NX
CM Test Dipole
CM Voltage Feed Type 5 at edge of segment
CE
GW  1   18     -0.25       0.0       0.0      0.25       0.0       0.0    0.001
GE
FR                        285.
EX  5    1   10            1.0
XQ
EN

To my dismay, they give different results.
Any help would be appreciated.


Rajiv Dewan
aa2ui


From [e-mail] Fri Jun 30 17:06:14 1995
Path: grape.epix.net!news.sprintlink.net!europa.chnt.gtegsc.com!library.ucla.edu!unixg.ubc.ca!fhw.ee.ubc.ca!not-for-mail
From: [e-mail] (Dave Michelson)
Newsgroups: sci.physics.electromag,sci.electronics,rec.radio.amateur.antenna
Subject: Numerical Electromagnetics Code - Mailing List
Date: 28 Jun 1995 14:28:18 -0700
Organization: University of BC, Dept. of Electrical Engineering
Lines: 25
Message-ID: <3sshhi$[e-mail]>
NNTP-Posting-Host: fhw.ee.ubc.ca
Xref: grape.epix.net sci.physics.electromag:4229 sci.electronics:132931 rec.radio.amateur.antenna:11519

During the past decade, the Numerical Electromagnetics Code (NEC) has
become the industry standard package for modelling and designing wire
antennas and related structures.

Users of NEC should consider joining NEC-List, the internet mailing list
for developers and users of NEC and related codes.  A variety of topics
are discussed ranging from questions and answers about NEC to
anouncements of NEC-related software.

Requests for additions and deletions to NEC-List should go to:

               [e-mail]

If you want to post a message, just send it to:

               [e-mail]

At the present time, the list has almost 300 subscribers.

--
Dave Michelson                             University of British Columbia
[e-mail]                                  Antenna Laboratory





From [e-mail] Fri Jun 30 17:06:15 1995
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!asuvax!news.asu.edu!aztec.asu.edu!hamop
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PARALLEL 95 OHM COAX LOSS?
Date: 27 Jun 1995 05:22:04 GMT
Organization: Arizona State University
Lines: 5
Message-ID: <3so4hs$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


Assumes matched in both cases of course!
Charlie,  W7XC
--



From [e-mail] Fri Jun 30 17:06:15 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news2.near.net!sunfish.hi.com!brainiac.hi.com!user
From: [e-mail] (Steve Byan)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: phased array receiving antennas
Date: Wed, 28 Jun 1995 12:49:30 -0400
Organization: Hitachi Computer Products, Inc.
Lines: 33
Message-ID: <[e-mail]>
NNTP-Posting-Host: brainiac.hi.com
Xref: grape.epix.net rec.radio.amateur.antenna:11508 rec.radio.amateur.homebrew:8001

A while back I posted a query to rec.radio.amateur.antenna and
rec.radio.amateur.homebrew about using R-C lattice networks to provide a
wideband Hilbert transformer (90 degree phase shift) for a receive antenna
phasing unit. These networks are commonly used to generate the audio phase
shift for SSB generation or detection.

I asked for a reference on how to design these networks. Yesterday, I
received the June 1995 issue of QEX, which has a great article  on these
networks: "Polyphase Network Calculation usaing a Vector Analysis Method"
by Tetsuo Yoshida, JA1KO.

Thanks to Tetsuo Yoshida for the excellent article, and QEX and ARRL for
publishing this kind of material.

My next problem is designing a high-input-impedance, high-dynamic-range
differential RF amp for the output of the phase shift network.

I've noticed the new JPS antenna noise canceling unit (which is a
phased-array receiving antenna, intended to null locally-generated RFI
noise) must use some kind of wideband phase-shift network, since it covers
at least 3 to 30 MHz with only a two-position bandswitch: low band and
high band. Has anyone opened one of these up? What does the phasing
network look like? Is it a polyphase network? What does JPS use for an
amplifier?

Thanks,
-Steve

--
Steve Byan                                  internet: [e-mail]
Hitachi Computer Products (America), Inc.
1601 Trapelo Road                           phone: [phone]
Waltham, MA 02154                           FAX: [phone]


From [e-mail] Fri Jun 30 17:06:17 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: phased array receiving antennas
Date: 29 Jun 1995 09:32:38 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 43
Sender: [e-mail]
Message-ID: <3sua1m$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (W8JI  Tom)
NNTP-Posting-Host: newsbf02.mail.aol.com
Xref: grape.epix.net rec.radio.amateur.antenna:11534 rec.radio.amateur.homebrew:8033


>>A while back I posted a query to rec.radio.amateur.antenna and
rec.radio.amateur.homebrew about using R-C lattice networks to provide a
wideband Hilbert transformer (90 degree phase shift) for a receive antenna
phasing unit. These networks are commonly used to generate the audio phase
shift for SSB generation or detection.

I asked for a reference on how to design these networks. Yesterday, I
received the June 1995 issue of QEX, which has a great article  on these
networks: "Polyphase Network Calculation usaing a Vector Analysis Method"
by Tetsuo Yoshida, JA1KO.

Thanks to Tetsuo Yoshida for the excellent article, and QEX and ARRL for
publishing this kind of material.

My next problem is designing a high-input-impedance, high-dynamic-range
differential RF amp for the output of the phase shift network.

I've noticed the new JPS antenna noise canceling unit (which is a
phased-array receiving antenna, intended to null locally-generated RFI
noise) must use some kind of wideband phase-shift network, since it covers
at least 3 to 30 MHz with only a two-position bandswitch: low band and
high band. Has anyone opened one of these up? What does the phasing
network look like? Is it a polyphase network? What does JPS use for an
amplifier?

Thanks,
-Steve<<

Steve,

I've been using phased arrays on HF since the early 80's. I use coaxial
delay lines and cross fire phasing with broad band untuned loop elements.
Some of the arrays have used as many as eight elements.

I am not sure why you would want to use a RC network for phasing. It does
not seem like an efficient way to obtain phase shift (in this application)
when coaxial delay lines provide lower attenuation and octave band widths
(with proper array design).

Can you expound on the merits of RC networks in this application??

73 Tom


From [e-mail] Fri Jun 30 17:06:17 1995
Path: grape.epix.net!news.sprintlink.net!EU.net!Belgium.EU.net!chaos.kulnet.kuleuven.ac.be!news.sri.ucl.ac.be!berg
From: [e-mail] (Guy Berger)
Newsgroups: rec.radio.amateur.antenna
Subject: Q: about R5 elevation
Date: 30 Jun 1995 11:37:44 GMT
Organization: University of Louvain (LLN) - Nuclear Physics Dept.
Lines: 16
Distribution: world
Message-ID: <3t0nm8$[e-mail]>
NNTP-Posting-Host: ifdh.sc.ucl.ac.be

Hello,

Just a simple question about the R5:
has anyone experience this vertical at ground level and compare its
performances with other antennas?

many thanks for info es best 73,     Guy

****************************************************************************
*  Guy Berger                       * Amateur radio : ON7ZV                *
*  Cyclotron Research Center        * tel.: ++/32-10-47 32 23              *
*  Universite Catholique de Louvain * Fax : ++/32-10-45 21 83              *
*  2 Chemin du cyclotron            * Packet radio : ON7ZV@ON7RC.#BT.BE.EU *
*  B-1348 Louvain-la-Neuve          * Internet : [e-mail]      *
*  Belgium                          *                                      *
****************************************************************************


From [e-mail] Fri Jun 30 17:06:18 1995
Path: grape.epix.net!news.sprintlink.net!cam.news.pipex.net!pipex!edi.news.pipex.net!pipex!sunic!sunic.sunet.se!mn5.swip.net!usenet
From: [e-mail] (Bo Sall)
Newsgroups: rec.radio.amateur.antenna
Subject: Rec Loop 160m
Date: 29 Jun 1995 21:59:22 GMT
Organization: SWIPnet AB
Lines: 13
Message-ID: <3sv7nr$[e-mail]>
NNTP-Posting-Host: dialup97-141.swipnet.se
X-Newsreader: WinVN 0.92.2


I've been trying some small loops for 160m last winter but
the results were not very promising.
Living in a very crowded area I can't use beverages.
I need suggestions/tips on what to try next. Also some tips
where to find some good articles on rec.loops, rec.loop.amps.
(I subsribe to QST)
If you have built a good one please let me know.

CU on TOPBAND in the winter season. Bob / SM7CKZ





From [e-mail] Fri Jun 30 17:06:19 1995
Path: grape.epix.net!news.sprintlink.net!gatech!bloom-beacon.mit.edu!satisfied.apocalypse.org!news2.near.net!llnews.ll.mit.edu!usenet
From: [e-mail] (John Kaufmann)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rec Loop 160m
Date: Fri, 30 Jun 95 13:59:51 GMT
Organization: M.I.T. Lincoln Laboratory
Lines: 37
Distribution: world
Message-ID: <3t0vgq$[e-mail]>
References: <3sv7nr$[e-mail]>
Summary: Comments on receiving loop antennas
Keywords: Beverage, loop, antenna
X-Newsreader: News Xpress Version 1.0 Beta #2.1

[e-mail] (Bo Sall) wrote:
>
>I've been trying some small loops for 160m last winter but
>the results were not very promising.
>Living in a very crowded area I can't use beverages.
>I need suggestions/tips on what to try next. Also some tips
>where to find some good articles on rec.loops, rec.loop.amps.
>(I subsribe to QST)
>If you have built a good one please let me know.


Here are some recent QST articles that may be of interest:
June 1993: Single 160 m receiving loop construction by W1LYQ;
August 1993: An array of small receiving loops with very good
directivity, occupying about 30 m linear space, by WA2WVL;
February 1995: An "inverted U' receiving antenna for 80 and 160m,
relatively compact, although not exactly a loop, by WA2WVL.

I have experimented with small receiving loops for the low bands
and based on my experience, I'm afraid I must report that a single
loop does not even come close to the performance of a good
Beverage.  There are 2 problems with the loop: (1) The
beam pattern of the loop is much broader than the Beverage
so that rejection of noise and QRM is not very good off to the
sides and is nonexistent off the back (since the loop is bi-
directional).  Sharp nulls are produced off the sides but only
over a small azimuthal range.  (2) Radiation resistance of the
loop is very low, making it difficult to impedance-match
efficiently.   On the Beverage with no preamp, received signals
are typically 15-20 dB down from the transmit antenna (a vertical)
on 160 but this is not a problem.  However, signals from the small
loop, even after matching, are down 40 dB or more, making a high
quality preamp is a must.  Still, if a Beverage is not possible, a
loop is better than nothing.  CU on 160.

John Kaufmann W1FV
<[e-mail]>


From [e-mail] Fri Jun 30 17:06:22 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!swrinde!emory!cssun.mathcs.emory.edu!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Reducing station - station interference in close proximity
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3soug7$[e-mail]>
Date: Fri, 30 Jun 1995 14:09:32 GMT
Lines: 74

In article <3soug7$[e-mail]> Bill Bressler <[e-mail]> writes:
>I need help in solving a problem. Our Field Day group has grown from only
>one station per band to two (CW & SSB). We had considerable interference
>problems this past field day. Contributing factors:
>
> - all stations in 1000 foot diameter (FD rule)
> - all stations running <= 150 Watts  (FD rule)
> - some stations using non-resonnant antennas
> - some stations using Beam antennas
>
>I know all FD sites have the same problem(s). I would like to know
>how other FD groups have solved or bettered the situation.
>
>Possible solutions are:
>
> - running 50 Watts power

Lower power obviously helps.

> - using resonnant antennas

This won't help because the antenna will be close enough to resonance
across the entire band to prevent it acting as much of a filter. It
can help for stations operating on *different* bands, but often not
that much.

> - a mix of vertical and horizontal antenna polarization

Using cross-polarization can theoretically give you 30 dB of isolation,
but on lower HF inside a 1,000 foot circle, near field effects will
reduce this isolation a lot, so this won't help very much. You can
arrange horizontal antennas so that they are end on to each other.
This puts the other antenna in the null of the first, and vice versa.
For verticals, arrange them one over the other. Either of these methods
will give some isolation. To avoid near field coupling, the spacing
should be as many wavelengths as feasible from end to end.

> - using bandpass filters (anbody know of good sources or designs?)
> - using a coaxial stub at the transceiver to act as either a bandpass
>   of band-reject (any source of information on this would be helpfull)

Now you're on to something. You want bandpass/bandreject filters so
that the CW and phone portions of the bands are separated at the
radios. This is similar in principle to the duplexers used on repeaters.
Unfortunately, the percentage bandwidth of the HF bands, except 80
meters, just isn't very much, so realizable bandpass/bandreject filters
are difficult. You may do better with just tunable notch filters.

You need tunable notches because everyone is going to want to be
frequency agile, so coax 1/4-wave notch filters aren't very good.
Just use a lumped series LC from a coax Tee to ground in the antenna
to rig line. Tune it to reject the other transmitter. Try for high
Q by using air core inductors and air variable capacitors. These
notches, especially if used with antenna orientation as mentioned
above, will virtually eliminate fundamental overload problems.

You are likely to still get broadband noise from one rig into the
other, especially with today's "no-tune" rigs. Using good high Q
antenna tuners on each rig in addition to the series notch circuit
will help a lot here.

We put up a huge low band horizontal loop at our Field Day site,
and it got into every other antenna there by near field effect,
but none of the other radios bothered its radio because the high
Q balanced tuner we used rejected their signals. Put the tune
back into those no-tune radios and a lot of your interference
problems will go away.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:23 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Repeater antennas?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3sc0gq$[e-mail]>
Date: Thu, 29 Jun 1995 15:15:17 GMT
Lines: 20

In article <3sc0gq$[e-mail]> bweinman@@mutt.hamline.edu (Bruce Weinman) writes:
>Can someone point me to some reading on what's necessary to run a 2m
>repeater through a single antenna?  The term "duplexer" has been
>mentioned, but my redearch has stalled there.
>Bruce N0NUN

The Handbook covers this topic. Basically, repeater duplexers are
just combinations of pass and notch cavities arranged to block
the transmitter's signal from the receiver while allowing signals
from the transmitter to reach the antenna and signals from the
antenna to reach the receiver. (That's possible because the
transmitter and receiver are on different frequencies, of course.)

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:23 1995
Path: grape.epix.net!news.sprintlink.net!hermes.is.co.za!usenet
From: [e-mail] (Graeme Mitchell)
Newsgroups: rec.radio.amateur.antenna
Subject: RG 142 coaxial cable
Date: 29 Jun 1995 17:21:14 GMT
Organization: Internet Solution
Lines: 7
Message-ID: <3sunea$[e-mail]>
NNTP-Posting-Host: t037.is.co.za
X-Newsreader: WinVN 0.92.6+


I am posting this request on behalf of a friend of mine who is looking
for RG 142 cable. Can anybody tell me if this cable spec is available
and if so where. We are based in South Africa. I will be visiting the
U.S.A in July if that helps at all. Any help greatly appreciated.

                Thanks Graeme


From [e-mail] Fri Jun 30 17:06:24 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!europa.chnt.gtegsc.com!news.sprintlink.net!cam.news.pipex.net!pipex!edi.news.pipex.net!pipex!sunic!sunic.sunet.se!erinews.ericsson.se!usenet
From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: RG 142 coaxial cable
Date: Fri, 30 Jun 1995 02:22:12 GMT
Organization: Ericsson
Lines: 22
Message-ID: <3svn4j$[e-mail]>
References: <3sunea$[e-mail]>
NNTP-Posting-Host: pc125011.exu.ericsson.se
X-Newsreader: Forte Free Agent v0.55

[e-mail] (Graeme Mitchell) wrote:

>I am posting this request on behalf of a friend of mine who is looking
>for RG 142 cable. Can anybody tell me if this cable spec is available
>and if so where. We are based in South Africa. I will be visiting the
>U.S.A in July if that helps at all. Any help greatly appreciated.

No problem, contact:

Times Microwave Systems
PO Box 5039
Wallingford, Connecticut USA 06492
203-949-8400 (voice)
203-949-8423 (fax)

They have RG142, RG142A RG142B, and the preferred M17/60-RG142 which
is screened to a higher standard for the military, but available to
the public.

Mike Groves  KD6PKJ




From [e-mail] Fri Jun 30 17:06:26 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!gatech!newsjunkie.ans.net!interaccess!d120.nnb.interaccess.com!marcusj
From: [e-mail] (John Marcus)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
Date: Thu, 29 Jun 1995 17:13:55 -0600
Organization: InterAccess,Chicagoland's Full Service Internet Provider
Lines: 85
Distribution: world
Message-ID: <[e-mail]>
References: <3rf6tn$[e-mail]> <[e-mail]> <3rhsmj$[e-mail]> <3s1ajn$[e-mail]>
NNTP-Posting-Host: d120.nnb.interaccess.com
X-Newsreader: Trumpet for Windows [Version 1.0 Rev B final beta #4]

The person who is not an expert appears to be the only person with correct
information!  I bought a Rohn 25 tower.  I have 50' of tower.  My city states
I may erect a tower to a maximum of 65 feet without the use of guy wires, (for
safety), and withstand an 80mph wind!

I called Rohn, and they shipped me a very thick engineering manual.  Their
book specifies that at about 30 feet, with up to about 10sq feet of windload,
I can withstand approximately an 80mph wind and survive freestanding.  I don't
have that book handy, but I recommend calling Rohn.  They were extremely
helpful.  Most of Rohn's ratings were at a 50mph wind.  They claim that at 40
feet, with around 10-14sq feet of loading, the tower will have no problem free
standing in the 50mph wind.  I can't recall the locations for guying, but
there is a science to it so that there is a minimal twist to the tower in
strong wind.

House  brackets work very well.  I can't remember where the bracketing was to
take place, but I think it was every 20 feet.  In any case, I don't think you
want to go more than 20 feet above a house bracket without additional guying.

If you want to contact me, I'll get the manual from home and look up your
requirements.  Drop me an email at [e-mail] or call me at work
[phone] x164 from out of 708 or 312 or call [phone] directly in
my area.

Good luck, John - WD9AIS

In article <3s1ajn$[e-mail]>
[e-mail] (Ron Klein) writes:>From: [e-mail] (Ron
Klein)>Subject: Re: Rohn 25, How many feet over last house bracket (un-guyed)
>Date: 18 Jun 1995 13:44:23 GMT

>In <3rhsmj$[e-mail]> [e-mail] (Doug Snowden)
>writes:

>>
>>: >I would like to put up some Rohn-25 with a 6 element uagi without guys if
>
>>: >possible.  I have 2 house brackets.  Someone said 30' over the last one
>>: >is ok.  Is this right?
>>: >
>>
>>: Absolutely NOT! Rohn 25G is designed to be guyed. It is rated to carry 30
>>: lbs./sq foot Wind load, with 6 sq ft of allowable load, but only when
>>: guyed. Even the 40 foot tower has two sets of guys in the plans, at 20
>>: feet and at 40 feet. If the top set are left out, the load should be
>>: derated by 50 %, which won't include any 6 el HF antenna.
>>
>>: This info is taken from the Unarco Rohn catalog.
>>
>>I am not an authority on this subject, but I am sure I have seen somewhere
>>that a Rohn 25 will support some sort of load up to 40ft unguyed. Of
>>course with a good base.
>>
>>--
>>Doug  Snowden
>>work: [phone]
>>home: (407) 98409360
>>[e-mail]
>>
>>

>The Rohn 25 is NOT designed to be unguyed - if you meen as a freestanding
>tower with no house bracket to support it.

>I recently testified as an expert witness (I hold a PE license) in a case
>involving just that question.

>--
>Ron Klein - W0OSK
>-----------------
>[e-mail]





*********************************
|-------------------------------|
|John Marcus                    |
|Contact Info:                  |
|                               |
|[e-mail]        |
|[phone] x164 at work    |
|[phone] at work (direct)|
|_______________________________|


From [e-mail] Fri Jun 30 17:06:27 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: SGC-230 auto tuner
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]>
Date: Thu, 29 Jun 1995 13:43:35 GMT
Lines: 29

In article <[e-mail]> [e-mail] writes:
>In article <[e-mail]>
>           [e-mail] "Rajiv Dewan" writes:
>
> > While I agree that  it would be better to mount the tuner right at
> > the base of the whip,  3 to 6 db gain seems high.
> >
> > So when the tuner is in the trunk, the couple of feet of coax or wire
> > is dissipating 50 to 75 Watts and yet does not even get hot to touch
> > after extended operation?
>
>1) The lost power may be radiated into the car's body or wiring and raise
>the temperature of those to a minimal extent.

Not unless that coax is mighty leaky. The purpose of coax is to
*contain* the RF. Besides, it's inside the closed trunk, a Faraday
cage, so I believe this line is bogus reasoning. Now the coax *does*
act as a transmission line transformer, and for certain lengths and
at certain frequencies, it may present an impedance to the tuner
that is outside its efficient matching range. Unless the cable gets
hot, however, I don't think it is a significant loss element.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:27 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!news-e1a.megaweb.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (TWBOWERS)
Newsgroups: rec.radio.amateur.antenna
Subject: Stacked TV antennas
Date: 29 Jun 1995 20:34:43 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 5
Sender: [e-mail]
Message-ID: <3svgr3$[e-mail]>
Reply-To: [e-mail] (TWBOWERS)
NNTP-Posting-Host: newsbf02.mail.aol.com

I want to know if I can stack two TV antennas to increase range. Do I have
to phase them together and do they have to be so far apart. Any HELP will
be GREAT.

Thanks Tom


From [e-mail] Fri Jun 30 17:06:28 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!holonet!colossus.holonet.net!vectorbd!ejm
From: [e-mail]
Subject: Stealth Antennas
Organization: Vector Board BBS
Date: Wed, 28 Jun 1995 02:46:51 GMT
Message-ID: <[e-mail]>
X-Newsreader: TIN [version 1.2 PL2]
Lines: 43


I am unfortunately buying a house (building actually) in a tract that has
(sigh :<) antenna restrictions.

I would like to get a number of antennas into the house (attic) as the
house is built.

Plan one:  a loop antenna in the attic strung from the joists....the
house dimensions are approximately 30 x 40 feet.  There was a plan
someplace that showed a wire loop with a relay in the middle to make the
loop complete or (when open), make a dipole.  Does anyone have any
experience with this or suggestions?  I am fortunate in htat the builder
will run a PVC conduit fron the attic to the basement for me.

The second antenna will be a small two meter fixed beam pointing at my
favorate packet repeater...also attic mounted.

The third antenna is a multi-band scanner antenna...strictly for my scanner.

The fourth antenna will be (probably) a Ventenna for tewo meters.

The fifth antenna will be a disguised flagpole...I am fortunate in that I
can lay down ground radials prior to the sod going in.  The builder is
also going to build in a pass-through for the coax from the "flagpole"
into the basement for me.

So far, so good.

My last antenna will be a 90' wire.  Along the back property line
(approximately 100' from the house) are a number of trees uo,about 40'.
I think I can get a wire up into the trees, anchored at both ends via
pulley/weight system.  I can run the coax down a treetrunk and
underground to the house.  Question:  Am I better off with an end-fed 90'
wire (sort of a GRV5 type antenna) or should I put up a center fed,
trapped or otherwise multiband dipole?

I would also appreciate other antenna suggestions.  I am on HF very
little but I listen alot.  I would like to try 6 meters but don't have
the place for a verticle on that band.

THANKS!  73 N2RQO  Ed :)




From [e-mail] Fri Jun 30 17:06:29 1995
Path: grape.epix.net!news.sprintlink.net!ns1.win.net!logcabin!bobndeb
Newsgroups: rec.radio.amateur.antenna
Message-ID: <[e-mail]>
Reply-To: [e-mail] (ROBERT G. FRICK)
From: [e-mail] (ROBERT G. FRICK)
Date: Mon, 26 Jun 1995 18:01:34 GMT
Subject: subscribe
Lines: 0




From [e-mail] Fri Jun 30 17:06:30 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!cs.utexas.edu!uunet!in1.uu.net!iglou!iglou.iglou.com!n4lq
From: [e-mail] (Steve Ellington)
Subject: Re: Tower/Coax Routing Question?
X-Nntp-Posting-Host: iglou.iglou.com
Message-ID: <[e-mail]>
Sender: [e-mail] (News Administrator)
Organization: IgLou Internet Services
X-Newsreader: TIN [version 1.2 PL2]
References: <3seqas$[e-mail]> <3sgodk$[e-mail]>
Date: Mon, 26 Jun 1995 15:33:33 GMT
Lines: 17

Ronald H Steinberg ([e-mail]) wrote:

:  My problem is that I run my coax to
: >the
: >ground level and along the side of my house to the shack. I have replaced
: >the
: >coax and rotator cable three times due to my dogs biting or otherwise
: >compromising the cable.

: Why dont you just put all the cables in conduit ????
:                 Ron Steinberg K9IKZ
If my dog did this, I would modify the dog.
--
  Steve
[e-mail]




From [e-mail] Fri Jun 30 17:06:31 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Tower/Coax Routing Question?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3seqas$[e-mail]>
Date: Thu, 29 Jun 1995 15:58:47 GMT
Lines: 29

In article <3seqas$[e-mail]> [e-mail] (ABLACKBELT) writes:
>I have an ez way 50 ft tower which telescopes and tilts with the pivot of
>the tilt about ten feet above the ground. My problem is that I run my coax to
>the ground level and along the side of my house to the shack. I have replaced
>the coax and rotator cable three times due to my dogs biting or otherwise
>compromising the cable. I wonder if I ran the coax down the side of the
>tower to a point approximately ten feet from the ground (the pivot pt) and over
>to the eves of the house (approximately 18') if I would be inviting a direct
>lightning strike to the house. Somehow I have it in my mind that running
>along the ground will dissipate some bit of a strike (which I did have a
>year ago and blew off a corner of concrete at ground level) if not all.  I am a
>bit apprehensive about doing the overhead thing. Any comments would be
>greatly appreciated. Also the run under the eves in 35 feet before it gets
>to the shack.

Bringing the cable off high will cause a large potential to exist
on the cable shields. For Rohn 25, there is enough inductance to
develop over 100,000 volts across a 10 foot section with an 8,000
ampere strike current. It's much better to bring the cables right
down to ground level (ground the shields to the tower at that point)
and then use underground conduit to conduct the cables over to
the house entrance ground window.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:31 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: TV antenna using electrical wiring
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3s5eo3$[e-mail]>
Date: Thu, 29 Jun 1995 13:54:57 GMT
Lines: 15

In article <3s5eo3$[e-mail]> [e-mail] (Scott M Weaston) writes:
>
>     I know this really doesn't apply to this group but does anyone know
>anything about those antennas that claim to give better reception for
>televisions?  I am trying to find some info on it...let me know what you know

House wiring makes a really lousy TV antenna. The length and orientation
is random, so you'll get ghosts galore.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:32 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: VHF Ant Help
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <[e-mail]> <3s9nh7$[e-mail]>
Date: Thu, 29 Jun 1995 14:17:32 GMT
Lines: 25

In article <3s9nh7$[e-mail]> [e-mail] (Bill Newkirk) writes:
>In <[e-mail]>, [e-mail] writes:
>>Do I need to use special quality of cable to run to an outdoor ant that covers
>>6m, 2m and 440 ???  The ant is a Comet triband mobile whip that I have
>>mounted on a 15 ft fiberglass pole that is set on the back of the house on a
>>2nd story deck.  Do I need special connectors too? THANKS. The ant will be
>>used only for FM work.
>
>i would think regular old RG-213/RG-8 would do.  heck even RG-58 if the
>run is only like 30 feet or so would work.

I wouldn't even use RG-58 as a jumper cable at 70 cm. I consider
RG-213 to be the minimum cable for the job. Better would be Belden
9913, or the Wireman equivalent. Best would be Andrew hardline.
Every dB of loss in the cable hurts you twice, once on transmit,
and again on receive. You can partially make up for transmit loss
by running more power, but once signal is lost on receive, it's
gone.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:33 1995
Path: grape.epix.net!news.sprintlink.net!matlock.mindspring.com!n4da.mindspring.com!n4da
From: [e-mail] (Luther M. Lord)
Newsgroups: rec.radio.amateur.antenna
Subject: Videos for repair and alignment
Date: Thu, 29 Jun 1995 00:45:01 -0400
Organization: MindSpring Enterprises, Inc.
Lines: 9
Message-ID: <[e-mail]>
NNTP-Posting-Host: n4da.mindspring.com
X-Newsreader: Trumpet for Windows [Version 1.0 Rev B]

For a complete listing of all the videos available for the repair and
alignment of HF radios; visit the Radio Doctor's home page.
at:
-------------------------------------------------------------------------------
  http://www.mindspring.com/~n4da/top.html
-------------------------------------------------------------------------------
The Radio Doctor's home page describes each video in detail along with full




From [e-mail] Fri Jun 30 17:06:33 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!vixen.cso.uiuc.edu!prairienet.org!no9z
From: [e-mail] (Lynn D. Osterbur)
Newsgroups: rec.radio.amateur.antenna
Subject: Want to phase KT34XA and A4 - need info pse
Date: 28 Jun 1995 22:45:48 GMT
Organization: University of Illinois at Urbana
Lines: 8
Message-ID: <3ssm2s$[e-mail]>
NNTP-Posting-Host: firefly.prairienet.org


I would like to phase my KT34XA (rotatable) and a Cushcraft A4 (fixed) on
the same tower.  The KLM tribander is at 105 feet and the A4 has yet to
be permantly mounted. It will probably have to be around 70 - 75 or 30 to
35 feet below the KLM.  Any advice would be appreciated.  i.e. is it
worth it and can I expect much improvement in signal over the KLM
alone?  I am curious what others have tried and their results.  73 de Lynn
--


From [e-mail] Fri Jun 30 17:06:34 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!news.cac.psu.edu!news.pop.psu.edu!hudson.lm.com!newsfeed.pitt.edu!dsinc!wells!w2up!barry
From: [e-mail] (Barry Kutner)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Want to phase KT34XA and A4 - need info pse
Message-ID: <[e-mail]>
Date: Thu, 29 Jun 95 01:13:07 GMT
References: <3ssm2s$[e-mail]>
Organization: W2UP, Newtown, PA
Lines: 41

[e-mail] (Lynn D. Osterbur) writes:

>
> I would like to phase my KT34XA (rotatable) and a Cushcraft A4 (fixed) on
> the same tower.  The KLM tribander is at 105 feet and the A4 has yet to
> be permantly mounted. It will probably have to be around 70 - 75 or 30 to
> 35 feet below the KLM.  Any advice would be appreciated.  i.e. is it
> worth it and can I expect much improvement in signal over the KLM
> alone?  I am curious what others have tried and their results.  73 de Lynn
> --

I have 2 TH7DXSs phased (76 and 40 ft, both rotatable) and am very
pleased with performance. I use the DX Engineering Universal phase box
which allows switching of upper/lower/both.  The box is a bit pricey for
what it is (relays, control box and 2:1 braodbanded toroidal xfmr).

If I were you, I would mount the lower antenna even lower than 70 ft. I
found a BIG improvement on 10 and 15 meters with the low antenna alone at
times. On 20 mtrs I usually get a 6 db better report with the stack
compared with either antenna alone. On 10 and 15 the stack is usually
better 6-10 db, but as mentioned, at times, the lower alone is better.
It's also nice to be able to point in two directions. For example, the
just after sunrise opening on 20, I point upper antenna at JA and lower
at EU during contests. On 10 or 15, upper at EU, lower south, etc.

Also, you have to be careful phasing dissimilar antennas.  When cutting
the phasing lines, you have to adjust for any difference in driven
element offset. For example, if the driven element of the KT34XA is at
the mast, & the driven el of the A4 is 3 ft from the mast, you must make
the KT34's phasing line 3 ft longer to compensate. This assumes coax with
a velocity factor of 100% which, of course, it isn't so you have to
adjust for that too.
GL/Barry

--
=======================================================================
Barry N. Kutner, W2UP       Internet: [e-mail]
Newtown, PA                 Packet Radio: W2UP @ WB3JOE.#EPA.PA.USA.NA
                            Packet Cluster: W2UP >WB2R (FRC)
.......................................................................



From [e-mail] Fri Jun 30 17:06:35 1995
Path: grape.epix.net!news.sprintlink.net!globe.indirect.com!bud.indirect.com!jbromley
From: [e-mail] (Jim Bromley, W5GYJ)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What's a Bugcatcher?
Date: 30 Jun 1995 06:31:00 GMT
Organization: Internet Direct
Lines: 33
Message-ID: <3t05n6$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: bud.indirect.com
Originator: [e-mail]

In article <[e-mail]>,
Al Bolton  <[e-mail]> wrote:

>Hello,

>Excuse my ignorance, but what is a "Bugcatcher" type of mobile
>aerial? I have noticed many references to it in this newsgroup and it
>would seem to be a good efficient mobile aerial. I operate almost
>exclusively mobile so any info would be much appreciated!

As the proud owner on a genuine Texas Bugcatcher, allow me to
extoll it virtues.

It is basically a center-loaded whip, but the loading coil is
six inches in diameter and about nine inches high.  The coil
is of open frame construction and: a) tends to accumulate a
lot of dead bug splatter in rural areas, b) resembles those
UV lamp/ high-voltage-grid gadgets that lure wayward bugs to
a shockingly fiery end. By using open air as the insulation
between the coil turns, the inductor achieves high Q.  And
a high-Q system is the key to radiation efficiency.

I consistently snag *unsolicited* favorable comments about
my signal strength from the mobile.  The drawback to the
system is that I have to get out of the vehicle to change
taps on the coil when I want to QSY.


W5GYJ/7






From [e-mail] Fri Jun 30 17:06:36 1995
Path: grape.epix.net!news.sprintlink.net!ratty.wolfe.net!big.aa.net!usenet
From: Randy Seacat <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What's the gain of a 2m j
Date: 28 Jun 1995 23:38:07 GMT
Organization: Alternate Access Inc.
Lines: 28
Message-ID: <3ssp4v$[e-mail]>
References: <3sd37f$[e-mail]>
NNTP-Posting-Host: d109.aa.net

[e-mail] (Roy W Lewallen) wrote:
>
> [e-mail] (Claton Cadmus):
>
> >A j-pole is simply an end feed verticle dipole.  A dipole has a gain of
> >2.18 dbi.  However, a J-pole due to the matching sectio has a gain on
> >1.89 dbi slightly less then the dipole.  A quarter wave verticle is
> >about 0dbi so the j-poles do better by 2db.
>
> A vertical dipole and J-pole have very nearly the same gain. A quarter-wave
> vertical does also, but it's difficult to compare directly since it's
> restricted to being close to or at ground level. If you elevate the
> quarter-wave vertical and its ground system, you have a "ground-plane"
> antenna which also has essentially the same gain as the J-pole and vertical
> dipole.
>
> Roy Lewallen, W7EL
> [e-mail]
>

Lets not forget that a co-linear j-pole (1/2 wave) will deliver somewhere
near 7db gain. And that if constructed using 5/8 wave radials the gain is
even more impressive!



ki7zd



From [e-mail] Fri Jun 30 17:06:37 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!uwm.edu!hookup!news.kei.com!ub!newserve!rebecca!news.crd.ge.com!ctrlnews.erie.ge.com!news.ge.com!news.drexel.edu!netnews.upenn.edu!news
From: Adam O'Donnell <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Which Antenna For Me?
Date: 24 Jun 1995 01:53:56 GMT
Organization: University of Pennsylvania
Lines: 30
Message-ID: <3sfr7k$[e-mail]>
References: <3scgod$[e-mail]>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.1N (Windows; I; 16bit)
To: [e-mail]

I suggest two antennas:

1 - A VHF UHF Discone.  It can transmit 50-1300mhz and receive there just
as well.  They look like this:

--------
   /\
  /  \
 /    \
/      \

Well, like a disk on top of a cone.

2 - For HF... well... I would go for a really long wire stretched all
over.  Under the carpet, through the ceiling fan, and far away from the
electric socket.

That is good for only reception on HF.
73

-----
Adam O'Donnell, N3RCS
Internet:  [e-mail]

My parents tell me that I all I do is just take up time and space.
It's true - I'm into relativity theory.

------ PGP PUBLIC KEY AVAILABLE UPON FINGER ------




From [e-mail] Fri Jun 30 17:06:38 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!gatech!kd4nc!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Which Antenna For Me?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <3scgod$[e-mail]>
Date: Thu, 29 Jun 1995 15:38:43 GMT
Lines: 43

In article <3scgod$[e-mail]> [e-mail] (Woody Harper) writes:
>Here's my question for the day. I have a couple of IC-24ET HTs as my only
>radios. I would like to leave one set up at home as a "base station"
>while the other travels with me. These radios broadcast on 140-150MHz and
>440-450Mhz but apparently seem capable of receiving everything from
>.00MHz to 1310.00MHz. What sort of antenna(s) do I need to make the most
>of these little radios? I am definately interested in shortwave listening
>as well as making the most of my transmitting abilities (after I get my
>license of course). I am a total rookie, so any help is appreciated.

First of all, though the display may show tuning from DC to light,
the radio's RF section can't actually do it. The real receiving range
is more on the order of 120 MHz to 512 MHz. Because of the extremely
wide front end needed to cover that range, and because of the low
standing currents due to the necessity of operating off of a battery,
the tuning display isn't really important since the radio will be
receiving on several frequencies at once, a problem called intermod,
if used with a gain outside antenna. (This is a problem common to
almost all HTs used on outside antennas.)

Now a discone is the usual antenna for such a scanner. It operates nearly
equally poorly on all frequencies in that range. That's good because it
reduces the strength of the intermod, but it's bad because it also reduces
the strength of the desired signals. Such is life. If you want good
performance on a particular frequency, good selective filters can be placed
in-line between a gain external antenna cut for that frequency and the HT in
order to keep the out of band crud from entering the HT and mixing to
produce the horrible howling intermod. Or you could trade the HT for
a desktop radio with high enough standing currents and good enough
internal filtering to work properly in the presence of out of band
signals. Or you can operate the HTs on their rubber dummy loads to
avoid most of the intermod.

It's unfortunate, but the laws of physics won't be repealed. Wideband
low power radios of small physical size are incompatible with good
performance with gain outdoor antennas.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | emory!kd4nc!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Fri Jun 30 17:06:39 1995
Path: grape.epix.net!news.sprintlink.net!simtel!col.hp.com!sony!sonysjc!sonybc!sonyfwbc!newsjunkie.ans.net!interaccess!usenet
From: [e-mail] (Ronald H Steinberg)
Newsgroups: rec.radio.amateur.antenna
Subject: WTB  TRANSCO  ANT  RELAYS
Date: 29 Jun 1995 04:19:34 GMT
Organization: Rent Com, Inc.
Lines: 7
Message-ID: <3st9km$[e-mail]>
NNTP-Posting-Host: d66.net.interaccess.com
X-Newsreader: WinVN 0.92.6+

Looking for Transco 141000 4 position ,n connector ,28vdc ant
relays or any  thing close by another mfg
              Ron Steinberg K9IKZ
               708 773 3583 HM
                   773 0822 FX
                   996 9376 PGR
                  OR E MAIL


From [e-mail] Fri Jun 30 17:06:39 1995
Path: grape.epix.net!news.sprintlink.net!matlock.mindspring.com!n4da.mindspring.com!n4da
From: [e-mail] (Luther M. Lord)
Newsgroups: rec.radio.amateur.antenna
Subject: WWW site for radio repairs and info
Date: Wed, 28 Jun 1995 11:26:07 -0400
Organization: MindSpring Enterprises, Inc.
Lines: 17
Message-ID: <[e-mail]>
NNTP-Posting-Host: n4da.mindspring.com
X-Newsreader: Trumpet for Windows [Version 1.0 Rev B]

From: [e-mail] (Luther M. Lord)
Subject: WWW site for radio repairs and info
Date: Wed, 28 Jun 1995 10:52:51 -0400

If you need a good place to get your amateur radio repaired; we can help.
Visit the Radio Doctor's home page at:
-------------------------------------------------------------------------------
           http://www.minspring.com/~n4da/top.html
-------------------------------------------------------------------------------
We will answer all technical questions recieved via E-Mail. This sevice is
offered presently at no charge.
Our E-Mail address is:
-------------------------------------------------------------------------------
   [e-mail]

-------------------------------------------------------------------------------



From [e-mail] Fri Jun 30 17:06:40 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!news.larc.nasa.gov!lll-winken.llnl.gov!uwm.edu!vixen.cso.uiuc.edu!news.uoregon.edu!europa.chnt.gtegsc.com!news.sprintlink.net!matlock.mindspring.com!n4da.mindspring.com!n4da
From: [e-mail] (Luther M. Lord)
Newsgroups: rec.radio.amateur.antenna
Subject: WWW site for radio repairs and info (correction)
Date: Wed, 28 Jun 1995 19:46:45 -0400
Organization: MindSpring Enterprises, Inc.
Lines: 6
Message-ID: <[e-mail]>
NNTP-Posting-Host: n4da.mindspring.com
X-Newsreader: Trumpet for Windows [Version 1.0 Rev B]

The URL address for the Radio Doctor's home page was incorrect in my previous
listing. It is correct as follows:
-------------------------------------------------------------------------------
   http://www.mindspring.com/~n4da/top.html
-------------------------------------------------------------------------------
The letter d was left from the word mindspring


From [e-mail] Fri Jun 30 17:06:41 1995
Path: grape.epix.net!news.sprintlink.net!demon!seuk.com!esoftc!alan.walker
From: Alan Walker <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Yagi aerials in a Vertical operation
Date: 25 Jun 95 20:01:03
Organization: SEUK, Guildford, UK
Lines: 16
Message-ID: <[e-mail]>
X-NNTP-Posting-Host: seuk.demon.co.uk

Hello All!

I wonder if someone could offer a few ideas, I need to put a 2m yagi in the vaertical position, with a 2m co-lin on top.

The problem I see is the vaertical boom will effect the radials on the yagi
and reduce the signal strength and distort the pattern, if I use a plastic
rod i fear the strength will not be good enough and will snap, I dont have
a lot of space, so the aerial is clamped to the side of the house, so guy
ropes are out of the question.

Looking forward to your replys...

All the best from Alan
--
Standard disclaimer: My views are strictly my own.


From [e-mail] Fri Jun 30 17:06:42 1995
Path: grape.epix.net!sc2c526a.ra.osd.mil!nova.sti.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!Germany.EU.net!nntp.gmd.de!news.rwth-aachen.de!news.rhrz.uni-bonn.de!news.uni-stuttgart.de!moritz
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Yagi aerials in a Vertical operation
Date: 29 Jun 1995 07:35:05 GMT
Organization: Comp.Center (RUS), U of Stuttgart, FRG
Lines: 19
Message-ID: <3stl39$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: ipers1.e-technik.uni-stuttgart.de

>I wonder if someone could offer a few ideas, I need to put a 2m yagi in the
>vaertical position, with a 2m co-lin on top.
>The problem I see is the vaertical boom will effect the radials on the yagi
                                                         ^^^^^^^
                                                         typo?

>and reduce the signal strength and distort the pattern, if I use a plastic
>rod i fear the strength will not be good enough and will snap, I dont have
>a lot of space, so the aerial is clamped to the side of the house, so guy
>ropes are out of the question.

There are two options: use a short (1 wl = 2meters) yagi in fore mast
mounting or two long yagis (> 2 wl) stacked side by side.
However a fiberglass pole through the yagi would be OK, you will have to
bring out the cable behind the reflector or sideways than.

73, Moritz DL5UH




From [e-mail] Fri Jun 30 17:06:42 1995
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!ihnp4.ucsd.edu!network.ucsd.edu!news-mail-gateway
From: Listserv@ucsd (Mailing List Processor)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: your LISTSERV request "help needed on spiral ant from a-7 aircraft"
Date: 29 Jun 95 15:01:27 GMT
Organization: ucsd usenet gateway
Lines: 3
Message-ID: <[e-mail]>
NNTP-Posting-Host: ucsd.edu
Originator: [e-mail]

The mailing list "needed" could not be found.
You may use the INDEX command to get a listing
of available mailing lists.


From [e-mail] Fri Jun 30 17:06:43 1995
Newsgroups: rec.radio.amateur.antenna
Path: grape.epix.net!news.sprintlink.net!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!ames!news.hawaii.edu!news
From: [e-mail]
Subject: Re: your LISTSERV request "help needed on spiral ant from a-7 aircraft"
X-Nntp-Posting-Host: math.hawaii.edu
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: University of Hawaii
References: <[e-mail]>
Date: Thu, 29 Jun 1995 17:20:18 GMT
Lines: 10

In article <[e-mail]> Listserv@ucsd (Mailing List Processor) writes:
>The mailing list "needed" could not be found.
>You may use the INDEX command to get a listing
>of available mailing lists.

Hey Kantor, are you ever going to fix your mail list so that it
doesn't spew this stuff on all the rra groups?

73 from Hawaii,
Jeff NH6IL