World of Ham Radio 1997/WOHR97_AmSoft_(1997-02-01).iso/usenets/1996_07/_antenna.txt

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From [e-mail] Sat Jul 06 13:42:38 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: (none)
Date: 2 Jul 96 16:38:30 GMT
Message-ID: <[e-mail]>

subscribe


From [e-mail] Sat Jul 06 13:42:38 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 40 m band antenna.
Date: 1 Jul 1996 15:37:05 GMT
Message-ID: <4r8rb1$[e-mail]>
References: <4qsluo$[e-mail]>

ermira <[e-mail]> wrote:
>Hai there,
>Anyone know the any type of good homebrew 40m antenna use on a very
>limited space area.

What, exactly, are your space limitations in all three dimensions?

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Sat Jul 06 13:42:39 1996
From: [e-mail] (W T Shaw)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 40 m band antenna.
Date: 3 Jul 1996 03:29:01 GMT
Message-ID: <wtshaw-0207962229530001@207.17.188.144>
References: <4qsluo$[e-mail]> <4ra9nm$[e-mail]>

> ermira <[e-mail]> wrote:
>
> >Hai there,
> >Anyone know the any type of good homebrew 40m antenna use on a very
> >limited space area.

My favorite is a plain inverted vee.  Get the apex at 28 t0 30 feet and
bring the wires down at 45 degrees so you get about 90 degree angle at the
top.  Feed with RG59.  No balun is really required.  Start with a little
more than a quarter wave in each leg, and trim.  If you still don't have
enough room, try a loading coil in each leg.  The higher the inductance,
the shorter the overall size of the antenna, accompanied by some loss in
efficiency.

Bill, K5PCW
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
[e-mail]   Mac Crypto Programs
 You should at least know how to use ROT13.
"Fhpprff vf n Wbhearl, Abg n Qrfgvangvba."
          http://www.htcomp.net/wts/
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/


From [e-mail] Sat Jul 06 13:42:40 1996
From: [e-mail] (Robert G. Strickland)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 40 m band antenna.
Date: Wed, 03 Jul 1996 08:34:02 -0400 (EDT)
Message-ID: <4rdpu4$[e-mail]>
References: <4qsluo$[e-mail]> <4ra9nm$[e-mail]>

>>
>You might try a double loop, sized as a 20 meter full wave loop, but
>run twice around.  I am a real fan of loops:  had an 80 meter 2 el
>quad and various other loops, with great success.  The horizontal
>"footprint" of the above should not be too large.

Tell me some more about this setup. I am using, and very happy with, a
fullsize 40m delta loop. If I could get something along these
dimensions to work on 80m, I'd be in heaven!. Looking forward to your
reply.

Robert



Robert G. Strickland KE2WY
[e-mail]
Syracuse, New York



From [e-mail] Sat Jul 06 13:42:41 1996
Newsgroups: rec.radio.amateur.antenna
From: "Al Koblinski  (W7XA)" <[e-mail]>
Subject: Re: 40 m band antenna.
Message-ID: <[e-mail]>
References: <4qsluo$[e-mail]>
Date: Wed, 3 Jul 1996 21:20:52 GMT

Limited space?  How limited.
The easiest is a base loaded vertical with some radials or a ground
screen.  Ground screen could be "chicken wire" extending out 5 meters or
more.
You could also use a mobile vertical.
Inverted Vee antenna is easy and does not have to be too high to work
and will fit on a small lot.
A full wave loop, or dipole laying on the (non-metallic) roof will work.
A local here in northern California uses an Aluminum awning as the
radiator with a match box tuner.
I think you get the idea.
Almost anything can work for local communicating.  The bigger and higher
will be much better for longer distances.
Experiment and have fun, you will be surprised what can work.  Do you
have access to any antenna handbooks or ARRL literature, or George
Moxon's book....all very useful.
Best Regards, Al




From [e-mail] Sat Jul 06 13:42:42 1996
From: [e-mail] ([e-mail])
Date: 02 Jul 96 00:51:00
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 40 m band antenna.
Message-ID: <[e-mail]>


From: [e-mail] (John DeCicco)
Subject: Re: 40 m band antenna.

ermira <[e-mail]> wrote:

>Hai there,
>Anyone know the any type of good homebrew 40m antenna use on a very
>limited space area.
>tx

>
You might try a double loop, sized as a 20 meter full wave loop, but
run twice around.  I am a real fan of loops:  had an 80 meter 2 el
quad and various other loops, with great success.  The horizontal
"footprint" of the above should not be too large.

GL and 73,
John, KC1IQ
Vermont

--
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From [e-mail] Sat Jul 06 13:42:43 1996
Newsgroups: rec.radio.amateur.antenna
From: Glenn Everett <[e-mail]>
Subject: 5/8 wave vertical question
Message-ID: <[e-mail]>
Date: Thu, 4 Jul 1996 20:00:56 GMT

Please comment on the design of a 5/8 wave vertical antenna.  I can not
find a great deal of information on these antennas as compared to other
antennas.  I am particularly interested in:

1. Impedance
2. Length of driven element formula
3. length of radials
4. angle of radiation description.

Thank you,
GJE



From [e-mail] Sat Jul 06 13:42:44 1996
From: "Earl Needham, KD5XB, in Clovis, NM" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna
Subject: 6/2 Mobile Antenna
Date: Tue, 2 Jul 1996 22:45:47 -0600
Message-ID: <01bb689a.806e86c0$[e-mail]>


        I want to thank everybody who replied to my query about building a mobile
antenna for 6 & 2.

        Unfortunately, my 5/8 wave Hustler has seen better days, so I ordered a
commercially-marketed antenna to do this.

        Tnx es 73
--
Earl Needham, KD5XB, in Clovis, NM
Phi Mu Alpha Sinfonia, Pi Chi '76
Have you really jumped ROUND PARACHUTES? (Overheard at the Clovis
Parachute Center)



From [e-mail] Sat Jul 06 13:42:45 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Alexander Vrenios)
Subject: [Q] Elevated Radials
Message-ID: <[e-mail]>
Date: Fri, 5 Jul 1996 19:47:03 GMT

   Re: Request for clarification, please:

   If I have a 30 meter vertical antenna (a 23' pole) with 4 or 6
radials - and this whole thing is up far enough to be free space -
the more radials I add, the better job they do of becoming a virtual
second half of the dipole; that if I had enough radials and it were
up high enough, I would get exactly the same performance (take off
angle, etc) as I would with a real, honest-to-goodness vertical di-
pole. True or False?

   (I just felt a little perspective was in order here, thanks.)


Regards,

Alex Vrenios                                      Distributed Algorithms
[e-mail]        _._  _.._  ____.  ..           Research Lab


From [e-mail] Sat Jul 06 13:42:46 1996
From: Merv Stump <[e-mail]@postoffice.worldnet.att.net>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Absorption vs. Ground
Date: 6 Jul 1996 13:42:04 GMT
Message-ID: <4rlqfc$[e-mail]>
References: <[e-mail]>


Joe, I have a 4square vertical array which is in the middle of woods so
dense that if I stand in the middle of the array I can't see 3 of the
verticals.  It appears to work slightly better after the leaves fall, and
the optimal frequency moves about 20Khz from summer to winter.  However, I
think it works great all the time and any absorbtion would appear to be
minimal.

However, I would point out that wet swampy ground, or even water, is very
little better than earth unless it is salt water.

Good luck, Merv



From [e-mail] Sat Jul 06 13:42:47 1996
Newsgroups: rec.radio.amateur.dx,rec.radio.amateur,rec.radio.amateur.antenna
From: [e-mail] (Alexander Vrenios)
Subject: Re: Antenna Driving me nuts
Message-ID: <[e-mail]>
Date: Mon, 1 Jul 1996 18:06:34 GMT
References: <4qsk9b$[e-mail]> <4r2ga2$[e-mail]> <[e-mail]>

>> Chris Valliant ([e-mail]) wrote:
>>
>> :       I have been trying for the last two weeks to build a half wave
>> : diapole antenna.  I have read the book twice, done my calculations down t
o
>> : the half inch, used several different gauges of wire, several makes of
>> : coax cable but I cannot get the SWR reading below 6:1.  Even with an
>> : antenna tuner I cannot get an acceptable SWR reading. It's driving me to
>> : the funny farm. I have about a mile of wire in my apartment and have run
>> : out of ideas.  Here is what I am trying to do:  to build a 1/2 wave
>> : diapole for the 28-29 mhz.  I splice the coax, solder one end to a length
>> : of wire 8.2 feet and the other braided end to a length of wire the same
>> : size. I suspend both ends using insulated clamps between two tree's,
>> : making sure that the whole antenna is parallel to the ground and it's 8
>> : feet above the ground. Now when I check the SWR, it's unbelieveable.  Lik
e
>> : I have said before, I have used different wire, different coax (the
>> : standard coax, just different brands). What am I doing wrong ?  Can anyon
e
>> :  spot my mistake ? I will gladly make it up to whomever spots my error.


             Left Half                 Right Half
     -----------------------\   /-----------------------
                             \  | <--- Center conductor
                             | ---
                             | | |
                             | | | <--- Center insulator (often white)
                  Braid ---> \\| |
                             -------
                             |     |
                             |     | <--- Outer shield (often black)
                             |     |
                             |     | <--- Coax (something
                             |     |      like RG8/U type)
                             |     |
                             |     |
                             |     |
                             |-----|
                            /       \
          Screw-on Ring --->|       | <--- PL-259 Connector
                            ---------      (Also called a
                 Center Pin --->|           UHF connector)

                            |---o---|
                            |       | <--- SO-239 on back of transmitter
                          -------------

   Left and right halves of dipole antenna are of equal lengths. These
two equal lengths should add up to the halfwave length of the frequency
at which you wish to operate. For example, if you wish to operate the
40 Meter band, at 7.150 MHz, divide that value into 468, resulting in
the total length of a dipole for 7.150 MHz, in feet:

                       468
                      -----   =   65.45 Feet
                      7.150

   This being approximately 65 1/2 feet, I would cut the two equal halves
to be 32 feet, 8 inches each. I would expect the SWR to measure well under
the 6:1 you reported earlier.

   I hope this helps you; these are, of course my opinions only: this is
what I would do in your place.

   One final note. I have had more trouble with SWR meters than I've had
with dipole antennas. That is, if you know you are correct, you might want
to ask someone to help you measure the SWR of your new antenna. (I can't
immagine anyone in this hobby refusing such a simple request, especially
since you've already got the antenna up and own a meter!) Best of luck,
and try not to let this negative experience influence you too much.


Regards,

Alex Vrenios                                      Distributed Algorithms
[e-mail]        _._  _.._  ____.  ..           Research Lab


From [e-mail] Sat Jul 06 13:42:48 1996
From: Don <[e-mail]>
Newsgroups: rec.radio.amateur.dx,rec.radio.amateur,rec.radio.amateur.antenna
Subject: Re: Antenna Driving me nuts
Date: Wed, 03 Jul 1996 21:39:29 -0400
Message-ID: <[e-mail]>
References: <4qsk9b$[e-mail]> <4r2ga2$[e-mail]> <[e-mail]> <[e-mail]>
Reply-To: [e-mail]

Sounds to me like you have a short. Check the center conductor to the
shield with an ohmmeter.  Should be infinity. W5BB


From [e-mail] Sat Jul 06 13:42:49 1996
From: [e-mail] (Mark and Beth Mowery)
Newsgroups: rec.radio.amateur.antenna
Subject: Backstay antenna
Date: 1 Jul 96 16:54:52 GMT
Message-ID: <[e-mail]>

Hello all,

Thanks to all who replied to my question about feeding the backstay as a
ham antenna. The results are in:

1)Top or bottom feed? Theory suggests that top feeding is better, but the
practical experience of those who replied say it doesn't make any
noticable difference. So, bottom feeding it is, as it's a whole heck of a
lot easier.

2)How to connect the feedline? No comments on that one.

3)Specific parts? West Marine has do-it-yourself insulators in their
catalog. I was suprised to see that because I thought I had that catalog
memorized ;-) .

Several suggested I contact Gordon West and/or 73 Magazine as he wrote
a series of articles on the subject several years ago. I plan to write to
both for their comments.

Thanks again.
Mark Mowery, AA8TC
S/V Gazelle
Lake Huron



From [e-mail] Sat Jul 06 13:42:53 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Baluns Revisited, was: Dbl Zepp
Date: 5 Jul 1996 16:44:51 -0400
Message-ID: <4rjus3$[e-mail]>
References: <4rjjnq$[e-mail]>

Hi Cecil,
In article <4rjjnq$[e-mail]>, Cecil Moore
<[e-mail]> writes:

>Hi Tom, that was a great experiment. Just wish there were more hams out
>there willing to do experimenting, testing, and reporting for free. :-)

>The 949E 4:1 voltage balun, designed for 300 watts into 200 ohms, was
>seeing about 500+j1500. There's not much information published on just
>how bad the mismatch can be before problems occur. If our flux density
>with 100w into 500+j1500 is less than 300w into 200+j0, are we safe in
>assuming the balun will do a low-loss 4:1 transformation that will yield
>close to 125+j375 at the input?

Well, I can measure it. There is a reactance modification Cecil, because
part of my test was to verify the 10 kW tuner was indeed the complex
conjugate of the 949E's impedance.

When I measured the large tuner, it produced lowest SWR at 6.65 MHz with
about 27 pF in series with 450 ohms. I've yet to measure the balun but it
appears that it must "look like" a shunt inductance as well as a balun.

>Does maximum power transfer occur through a balun at its design
impedance?

I think we can safely say that balun has no "design" impedance. But yes,
at a given frequency maximum efficiency has to occur at some fixed
impedance. Knowing the equivalent impedance of the balun should give us
that information.

>I know they get less efficient as the impedance is lowered. Do they get
>more efficient as the impedance is raised?

Sure, but is the curve symmetrical?

>Something else I've wondered about - Is it possible for the balun to go
>non-linear without overheating? We could still be radiating RF, just not
>as much as we think on the fundamental frequency.

Only with pulse transmitters. With CW, overheating occurs long before
saturation. In one mediacl device I designed, pulse width was 65 uS. With
a 30 pps signal, heat was of little concern. Core size was limited by
saturation.

>Finally, my signal strength increased noticeably on 75m when I achieved
>a conjugate match at the output of the balun vs a conjugate match at the
>input to the balun. Any idea why? I didn't detect any temperature change
>in the 10kw balun but my signal level was way down in N5AQM's receiver.

I always wonder about validity of groundwave or surface wave tests with
horizontally polarized antennas. Even the slightest change in feedline
common mode currents could produce large changes in FS because of the very
large path attenuation differences between H and V signals.

It should be easy enough to measure the balun under the expected loads.
What type was it? Maybe I have one.

BTW, I was going to do this test with a transmission line transformer
instead of the 10 kW tuner. Since I had the copper tubing coil, vacuum cap
tuner already available, it was easier. Why not re-test your balun with
some stubs and a 50 ohm terminating load?

73 Tom


From [e-mail] Sat Jul 06 13:42:53 1996
From: "William E. Sabin" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insulated or bare?
Date: Mon, 01 Jul 1996 14:46:47 -0700
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]> <4r67bu$[e-mail]> <4r924r$[e-mail]>

Richard Karlquist wrote:
>
>
> So, does anyone in the elevated radials camp claim that a system
> of ___ elevated radials is better than 120 buried ones?
>


How would you like to have all of those exposed and elevated radials
cluttering up your back yard?  Technical perfection isn't every thing (or
the only thing).  If they are just a couple of inches below the grass
that would be a good compromise.

Bill


From [e-mail] Sat Jul 06 13:42:54 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insulated or bare?
Date: 1 Jul 1996 20:25:34 GMT
Message-ID: <4r9c7u$[e-mail]>
References: <[e-mail]> <4r67bu$[e-mail]> <4r924r$[e-mail]> <[e-mail]>

"William E. Sabin" <[e-mail]> wrote:
>How would you like to have all of those exposed and elevated radials
>cluttering up your back yard?

How would a bunch of elevated chicken wire work? One could make a profit
raising chickens under the ground plane.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Sat Jul 06 13:42:56 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insulated or bare?
Date: 2 Jul 1996 11:13:22 -0400
Message-ID: <4rbeai$[e-mail]>
References: <4r924r$[e-mail]>

Hi Rick,
In article <4r924r$[e-mail]>, [e-mail] (Richard
Karlquist) writes:

>Is anyone in this debate claiming that the elevated radials
>would actually be *better* than buried ones?

One paper indicates elevated radials (in a computer model) provide more
field strength than full size conventional radial systems. The model
indicates 4 radials elevated 10 meters produce 3% more FS than 120 radials
(a system known to be nearly 100% efficient).

It's important to remember these estimates have never been verified by
direct comparison measurements (like the 1930's conventional system
measurements by Brown Lewis and Epstein). This is ONLY an unverified
computer estimated comparison.

Secondly, the computer model used 120 1/4 wl radials, which the B, L and E
study plainly indicates can be reduced to 60-80 radials with an almost
undetectable change in FS. To fully use 120 radials, the radials must be
near 1/2 wl long!

> If not, then the
>buried system is always at least as good as the elevated one.
>For my money, I'd rather bury the radials and get them out of
>harm's way than fool with elevated radials anyway, as long as
>I don't take a performance hit.  I don't mind having to have
>60 or 120 of them.

Another impoirtant factor to consider is, with four or six elevated
radials, the radial wires radiate.

Antenna base loop current divides proportionally between the radials. If
the base loop current is six amperes, and four radials are used, each
radial must have 1.25 amperes of common point current. The EM FS
surrounding the radial, in the near field, will be the same as exciting
any conductor with 1.25 amperes of RF current. Unwanted radiation from the
radial only cancels at two places, at the very center of the radial system
and a few wavelengths from the radials. Elevated radials emit strong
nearfield EM radiation along each radial, and each radial couples to it's
surrounding (including the lossy soil).

This effect is so strong that I received a nasty RF burn when I touched
thirty feet of wire lying on the ground below an operating elevated radial
system. How that much RF can exist below the radial on the surface of the
ground, and ground losses be minimized, is beyond me!

All radials do this, but with 60 radials the current in any individual
radial would be only 1/10 ampere in this example.

 >So, does anyone in the elevated radials camp claim that a system
>of ___ elevated radials is better than 120 buried ones?

Yes, even though a properly installed radial system with 110 radials has
been proven by actual measurement to be within two percent of the
theoretically perfect system, they make that claim.

The only documented measurements supplied by elevated radial proponents
are long and twisted indirect ***estimates*** using FCC field strength and
ground conductivity tables. These measurements come from a source in the
nucleus of the proponent group.

The only direct comparisons available appear to be my own A-B test, an A-B
test at a broadcast station, and my duplication of the BC station's test.
Those tests indicate the elevated system was several dB down in direct
comparison to a ~60 radial conventional system. While this data isn't
absolutely conclusive, it does show close agreement between independent
tests. These independent tests also closely agree with the 5 dB difference
between Hagn-Barker's low dipole study and NEC-2 models of the same
antenna. The Hagn-Barker low dipole measurements produced about 5 dB less
signal than Nec-2 models predict.

Until there are some conclusive monitored A-B tests, I think the jury is
still out.

73 Tom


From [e-mail] Sat Jul 06 13:42:57 1996
From: [e-mail] (Richard Karlquist)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insulated or bare?
Date: 1 Jul 1996 17:33:15 GMT
Message-ID: <4r924r$[e-mail]>
References: <[e-mail]> <4r67bu$[e-mail]>

In article <4r67bu$[e-mail]>,
W8JI  Tom <[e-mail]> wrote:
>>
>>I believe u were one of the attendees at the Antenna Forum at Dayton
>where
>>extensive results of field strength measurements were presented on a
>>quarter wave vertical with elevated radials and with buried radials.
>>
>>Obviously you feel that these results were inconclusive.  Could you share
>>your reasons for feeling that "the jury is still out" and describe the
>
>I have done my own A-B tests that strongly disagree with NEC models of
>elevated radials. I have seen results of tests done by independent
>consultants at other locations that appear to disagree with the claims.
>All of the data I have seen to date, and I even went so far as to collect
>proof of performance data from stations using elevated radials, either
>fails to support claims or is inconclusive.
>
>73 Tom

As a non-expert reader of this debate, it seems to me the
controversy revolves around the question:  can an elevated radial
system with < 120 half wave radials be *as good as* the "official"
broadcast system of 120 buried half wave radials?  The answers
I've seen seem to be either the elevated radials are *as good as*
the buried ones or *not as good*.

Is anyone in this debate claiming that the elevated radials
would actually be *better* than buried ones?  If not, then the
buried system is always at least as good as the elevated one.
For my money, I'd rather bury the radials and get them out of
harm's way than fool with elevated radials anyway, as long as
I don't take a performance hit.  I don't mind having to have
60 or 120 of them.

So, does anyone in the elevated radials camp claim that a system
of ___ elevated radials is better than 120 buried ones?

Hope to be reading more about this.  Thanks, guys, for all your
postings.

Rick Karlquist N6RK
[e-mail]


From [e-mail] Sat Jul 06 13:42:58 1996
From: Merv Stump <[e-mail]@postoffice.worldnet.att.net>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insulated or bare?
Date: 3 Jul 1996 14:00:18 GMT
Message-ID: <4rdudi$[e-mail]>
References: <4r924r$[e-mail]> <4rbeai$[e-mail]> <4rcfio$[e-mail]>

Once again there is no hard data, but based on having tried it both ways I
do believe that insulated radials laid on top of the ground give better
results than bare radials buried in the ground.  Not to mention all the
work saved in putting them down; the fact that they last longer; and
finally the grass will cover them up in one season.  Regards, Merv



From [e-mail] Sat Jul 06 13:42:59 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insulated or bare?
Date: 3 Jul 1996 16:30:18 -0400
Message-ID: <4rel8q$[e-mail]>
References: <4re29f$[e-mail]>

Hi Mike,
In article <4re29f$[e-mail]>, [e-mail] writes:

>    I was just trying to be of help if I could....

Atta boy Mike, we need more people to rollup their sleeves.

>if that is what is required.   I also have a portable single element full
>sized
>40 meter version of this deal we use for Field Day at the Bryan Amateur
>Radio Club site.  We use it every year mounted to a drive in stake to
hold
>the bottom.   It is guyed with three nylon 1/4 inch ropes to simply hold
>it up.  The "elevated" radials are four (4) 33 foot radials that are, for

>FD purposes, one foot off the ground.  It is gamma match fed, the
capacitor
>nulls it to about as close to a flat 1:1 as you could ever want, at
7038Khz.

Base impedance measurements would be useful, but only FS measurements are
required to prove or disprove the theory.

It is important to:

Verify applied power with the same reliable instrument. Knowing the
absolute amount of power isn't important, applying a fixed amount of power
during the tests is.

Make sure the antenna remains matched as the ground system is changed.

Isolate the feedline at at least two points during the test. (Doty failed
to do this.) One choke should be at the base of the antenna, the other
where the feedline leaves the radials outer perimeter. This prevents the
feedline from becoming part of the ground system.

Make field strength measurements at one or more fixed points after making
sure the measurement points and antenna are not sensitive to slight
movements of the FS meter or surrounding objects. Some locations will show
abnormal variations with slight distance changes. These locations should
be avoided. One clear stable measurement point should be sufficent since
we are only looking for an efficiency change, not a pattern plot.

Also have a few ground rods handy, while the elevated radials are
activated (all other radials must be removed) ground and unground the
radial common point. Let's see what happens if we add an earth path to the
isolated system. That could prove or debunk the "displacement theory" in
one quick test.

>In that the gamma match smashes everything to a perfect match, what will
>we learn if I go through this excercise?

Here's what I did Mike.
I installed a line between two trees a few hundred feet apart in a clear
area. I made a dipole and hung it a few feet above earth at the expected
height of the elevated radials.
I tuned the low dipole to resonance with a battery powered instrument (no
ground loops). I used one half the dipole length for all the radials in
the test.

I hung a vertical wire from the overhead rope, and using feedline chokes
and four elevated radials, tuned the wire to resonance. I matched the wire
with a high quality L network at the antenna base. I applied a fixed
amount of transmitter power to the antenna, and went to a clear empty
field about a mile away.

FS was measured with a calibrated meter. The measurement point was checked
to be sure the reading didn't randomly fluctate abnormally with small back
and forth antenna movements.

I raised and lowered groups of 4, 8, 16, and 60 radials. It measured this
way:
elevated radials
4 wires -4.3 dB 20.1 mV
8 wires  -2.4 dB 25 mV
16 wires -1.2 dB 28.7 mV
60 wires -.1 dB 32.5 mV

ground mounted radials
4 wires -5.5 dB 17.5 mV
8 wires -2.8 dB 24 mV
16 wires -1.3 dB 28.4 mV
60 wires (used as 0 dB reference) 33 mV.

The change I measured going from 4 to sixty wires is nearly identical to a
independently measured change at WVNJ some months later. WVNJ's system was
temporarily changed from 6 elevated radials to 120 ground mounted radials
on a single tower. WVNJ's FS increased an average of ~5 dB at a series of
measured points.

In my tests, with only a few radials the elevated system was about one dB
better. With 16 or more radials, there was almost no difference. I hope
you or someone else can do other real world comparisons.

73 Tom


From [e-mail] Sat Jul 06 13:43:00 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insulated or bare?
Date: 3 Jul 1996 08:36:31 -0400
Message-ID: <4rdpgf$[e-mail]>
References: <4rcfio$[e-mail]>

Hi Mike,

In article <4rcfio$[e-mail]>, [e-mail] writes:

>I don't have the accurate test equipment, but am wondering.  I have an
>elevated version on 7.0 Mhz and an identical ground mounted version of
>my 4 element 4 square on 3.5 Mhz, all on the same general soil area.

A comparison of two different arrays, or even an entire array would make
the data too cluttered to be useful. It needs to be a single element
preferably in the clear and the only change to that element must be the
ground system.

>There is an odd chance I could get a ball park answer for myself that
might
>add some verifiable test data to the arguement.

There are plenty of ballpark answers right now Mike. What is needed are
A-B tests that minimize unknown variables.

73 Tom


From [e-mail] Sat Jul 06 13:43:01 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Coax connectors at UHF
Date: 2 Jul 1996 09:34:11 -0400
Message-ID: <4rb8gj$[e-mail]>
References: <4r39i6$[e-mail]>

The bulk of the mismatch and loss in a properly installed UHF type
connector arrangement is always in the SO-239....not the male plug.

The only "troublesome" RF path in the male connector is through a very
sort portion of the center pin. RF current flows on the inside of the
coaxial cable right up to the very start of the male cener pin, and
immediately moves to the outside surface of the female connector's center
pin about one tenth inch later. The dielectric area of the male plug is
very short, also around one tenth inch.

Shield current also moves quickly from the inside of the coax to the front
of the 259, and within a tenth of an inch moves to the inside of the
SO-239's outer threaded conductor.

**The entire RF path length in a PL 259 is only a fraction of an inch.**
I've found no measureable difference between PL-259's except for voltage
breakdown. Silver or nickle, the RF path length in a properly installed
connector is so short losses are almost immeasurable.

The SO-239 completely dominates the connection. It controls connection
impedance and contains the major conductor path.

If all insulation is removed from the SO-239 (leaving only air) connection
impedance quickly rises close to 50 ohms (from the normal 25-35 ohms). RF
current flows for nearly a half inch on the outside of the center pin of
the 239, and a like distance on the inside of the SO-239's outer shell.
The SO-239 dielectric extends for a similar distance in the RF path,
nearly one half inch.

I'd not be overly concerned about the PL-259, but I'd make sure the SO-239
is reasonable quality and always use a hood on the rear of the 239 for VHF
critical loss and radiation applications.

73 Tom


From [e-mail] Sat Jul 06 13:43:02 1996
From: Philip Peake <[e-mail]>
Newsgroups: rec.radio.amateur.space,rec.radio.amateur.antenna
Subject: Crossed yagi - linear polarization ?
Date: Mon, 01 Jul 1996 13:14:21 -0700
Message-ID: <[e-mail]>

I have been playing with satellite communications on AO-20,
using a rather unsuitable antenna: a GP9.

I have been considering buying a much better setup, with crossed
yagis for 2m and 70cm. However, I don't want to spend *that* much
on something just for satellite work.

So, how much power loss would I get using circular polarization
where horizontal or vertical would normally be used ?
(I tend to think its 3db ..).

Also, is it possible to feed a crossed yagi to produce (switchable)
LHC, RHC, Hoizontal and Vertical polarizations ?

Philip, KC7FWB


From [e-mail] Sat Jul 06 13:43:03 1996
From: [e-mail] (Vinicio Coletti)
Newsgroups: rec.radio.amateur.antenna
Subject: Cubical quad
Date: Tue, 02 Jul 1996 23:43:29 GMT
Message-ID: <4rctm1$[e-mail]>

I want to build my own antenna and I am thinking of a cubical quad for
3 bands.
I have to resolve many problems, but the initial idea is the
following:
- a boom of 3 meters
- a 3 loops reflector on one side (20, 15 and 10 m)
- the 10 m (half size) radiator at about 2 meter from the reflectors
- the 20/15 m radiator at the end of the boom

This will give me a 0,2 spacing on 10 and 15 m and a 0,15 on 20 m
band.

What do you think about ?
Any advices ?
-
Vinicio Coletti
[e-mail]
http://www.webcom.com/vcoletti



From [e-mail] Sat Jul 06 13:43:04 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Peter Richeson)
Subject: Dayton dates
Message-ID: <[e-mail]>
Date: Tue, 2 Jul 1996 12:33:48 GMT

Saw a note saying May 17, 18 and 19.  According to my calander for 1997
those dates are Sat, Sun and Mon.  Did I see it correctly?

Would have responded to the note but my emailer crashed and I can't find
it.  I thought it was on this group.  If not Sorry. Could some one point
me to the correct one.

.      '''
.     (o o)
___ooO-(_)-Ooo________________________________________________________
Peter D. Richeson                    | "I don't believe in a no-win   |
Email: [e-mail] |  scenaro."                     |
Phone  [phone]                 |    - Admiral James T. Kirk     |
----------------------------------------------------------------------+
Web Stuff:                                                            |
Inside Boeing - http://matrix.hv.boeing.com/~richesop                 |
Outside Boeing - http://www.cici.com/~richesop                        |
----------------------------------------------------------------------+
I do not speak for any one but me, and some times not even for me.    |
----------------------------------------------------------------------+


From [e-mail] Sat Jul 06 13:43:05 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR comments
Date: 2 Jul 1996 06:35:29 -0400
Message-ID: <4rau1h$[e-mail]>
References: <[e-mail]>

Hi Tom,
In article <[e-mail]>, [e-mail]
writes:

>In deciding to use the
>loop, I remembered reading the article on the DDRR, and figured
>that the loop would be a fairly close approximation to the DDRR.

The loop is vastly different than a DDRR. The DDRR radiates from the
single short vertical section of the element, while the small loop carries
uniform currents throughout its length.

The small loop can be thought of as an infinite series of close spaced out
of phase radiators. That's why it has a null through the axis, and the
major lobe is throgh the plane of the loop.

The DDRR has a short uniform current vertical radiator and a bent over top
loading section. The horizontal section has a gradual current taper over
it's length, and reaches maximum voltage and minimum current at the
capacitor end. A good analogy for the DDRR is a conventional "inverted L"
antenna, with the horizontal section bent into a circle.

The horizontal section contributes very little useful radiation in the
DDRR, because it is close to a large ground screen carrying out of phase
currents. The close-to-ground-screen flat top primarily serves to top load
the short vertical antenna.

This is confirmed by measurements showing radiation resistance increases
by a factor of ~ four as the height of the vertical section is doubled.

>The article said that it was
>mounted about a foot off the counterpoise.  I used this figure for
>my initial mounting height.

The loop behaves much differently than the DDRR, since it carries uniform
in phase currents.

>checked back in.  Now they said I sounded like a big dog!  Just
>goes to show that a small antenna running qrp, mobile can be made
>to operate.  Don't know if you'd call this a DDRR, but if it looks
>like a duck, and you can make duck soup out of it, maybe it's the
>real McCoy.  Then again, maybe it just tastes like chicken.

Now the question is, what would signal reports have been like the same
time and the same day if the antenna was a conventional center loaded
vertical? With an 8 ft tall vertical mobile I've worked Europe and VK on
160 meters. My 160 mobile antenna easily beats some home stations, and I
cangenerally work anything I hear.

That all sounds good, until you consider my 1/4 wl tower on 160 beats my
mobile signal by many many dB. One morning on 160 a VK gave me an S5 from
the mobile, a few minutes later the same VK gave me a 20 over 9 when I
called him with my big 1/4 wl vertical.

Some very inefficient antennas (like the DDRR) receive glowing reports
(usually in magazines noted for having no technical editing at all) and
find favor among amateurs. I know my 160 mobile antenna works very well
for what it is. Before I ran off claiming a magical form of radiation and
spinning some wild yarn about the theory I did the math and some simple FS
comparisons. I know the efficiency is under one percent, nearly exactly as
pedicted in a paper analysis.

73 Tom


From [e-mail] Sat Jul 06 13:43:06 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR comments
Date: 2 Jul 1996 11:21:01 GMT
Message-ID: <4rb0mt$[e-mail]>
References: <[e-mail]> <4rau1h$[e-mail]>

>I know my 160 mobile antenna works very well
>for what it is. Before I ran off claiming a magical form of radiation and
>spinning some wild yarn about the theory I did the math and some simple FS
>comparisons. I know the efficiency is under one percent, nearly exactly as
>pedicted in a paper analysis.


Hello Tom,

I think you have hit it here. the two statements "works very vell"
and "efficiency is less than 1%" do not contradict each other.

Only that some folks are mislead to think that "works very well"
guarantees no more than 50% loss in signal strength. Well, actually
this is what Isotron and GAP try to tell us.

73, Moritz DL5UH


From [e-mail] Sat Jul 06 13:43:07 1996
From: Don Huff <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR comments
Date: Tue, 02 Jul 1996 12:52:30 -0700
Message-ID: <[e-mail]>
References: <[e-mail]> <4rau1h$[e-mail]>

W8JI Tom wrote:
>
> Hi Tom,
> In article <[e-mail]>, [e-mail]
> writes:
>
> >In deciding to use the
> >loop, I remembered reading the article on the DDRR, and figured
> >that the loop would be a fairly close approximation to the DDRR.
>
> The loop is vastly different than a DDRR. The DDRR radiates from the
> single short vertical section of the element, while the small loop carries
> uniform currents throughout its length.
>
> The small loop can be thought of as an infinite series of close spaced out
> of phase radiators. That's why it has a null through the axis, and the
> major lobe is throgh the plane of the loop.
>
> The DDRR has a short uniform current vertical radiator and a bent over top
> loading section. The horizontal section has a gradual current taper over
> it's length, and reaches maximum voltage and minimum current at the
> capacitor end. A good analogy for the DDRR is a conventional "inverted L"
> antenna, with the horizontal section bent into a circle.
>
> The horizontal section contributes very little useful radiation in the
> DDRR, because it is close to a large ground screen carrying out of phase
> currents. The close-to-ground-screen flat top primarily serves to top load
> the short vertical antenna.
>
> This is confirmed by measurements showing radiation resistance increases
> by a factor of ~ four as the height of the vertical section is doubled.
>
> >The article said that it was
> >mounted about a foot off the counterpoise.  I used this figure for
> >my initial mounting height.
>
> The loop behaves much differently than the DDRR, since it carries uniform
> in phase currents.
>
> >checked back in.  Now they said I sounded like a big dog!  Just
> >goes to show that a small antenna running qrp, mobile can be made
> >to operate.  Don't know if you'd call this a DDRR, but if it looks
> >like a duck, and you can make duck soup out of it, maybe it's the
> >real McCoy.  Then again, maybe it just tastes like chicken.
>
> Now the question is, what would signal reports have been like the same
> time and the same day if the antenna was a conventional center loaded
> vertical? With an 8 ft tall vertical mobile I've worked Europe and VK on
> 160 meters. My 160 mobile antenna easily beats some home stations, and I
> cangenerally work anything I hear.
>
> That all sounds good, until you consider my 1/4 wl tower on 160 beats my
> mobile signal by many many dB. One morning on 160 a VK gave me an S5 from
> the mobile, a few minutes later the same VK gave me a 20 over 9 when I
> called him with my big 1/4 wl vertical.
>
> Some very inefficient antennas (like the DDRR) receive glowing reports
> (usually in magazines noted for having no technical editing at all) and
> find favor among amateurs. I know my 160 mobile antenna works very well
> for what it is. Before I ran off claiming a magical form of radiation and
> spinning some wild yarn about the theory I did the math and some simple FS
> comparisons. I know the efficiency is under one percent, nearly exactly as
> pedicted in a paper analysis.
>
> 73 Tom


Hi Tom OM,

 Yours is one of the most lucid posts I have read regarding antenna
efficiency
vs the "I get S9 reports" kind of evalution.  I would go on to
say that virtually ALL of the ham magazines make unquantified claims and
observations about antennas (this specifically includes QST and CQ
mags), in
their "new products"  columns.  In good conditions, an antenna tuner's
open
coil in the shack can make contacts (and I can certainly HEAR many
stations
with such an arrangement).  Small loops are just a step up from being
such a leaky tank circuit, but look at the claims made for them by the
manufacturers' ads
as well as the glowing reports read in the so-called "new products
evaluation"
columns in the magazines.

   73!
            Don, W6JL


From [e-mail] Sat Jul 06 13:43:08 1996
From: [e-mail] (Moritz@ipers1.E-Technik.U)
Date: 02 Jul 96 07:21:00
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR comments
Message-ID: <[e-mail]>


From: [e-mail] ()
Subject: Re: DDRR comments

>I know my 160 mobile antenna works very well
>for what it is. Before I ran off claiming a magical form of radiation and
>spinning some wild yarn about the theory I did the math and some simple FS
>comparisons. I know the efficiency is under one percent, nearly exactly as
>pedicted in a paper analysis.


Hello Tom,

I think you have hit it here. the two statements "works very vell"
and "efficiency is less than 1%" do not contradict each other.

Only that some folks are mislead to think that "works very well"
guarantees no more than 50% loss in signal strength. Well, actually
this is what Isotron and GAP try to tell us.

73, Moritz DL5UH
--
|Fidonet:  Moritz@ipers1.E-Technik.U 1:377/51.1
|Internet: [e-mail]
|
| This message has passed thru The GIFfer Skylink



From [e-mail] Sat Jul 06 13:43:09 1996
Newsgroups: rec.radio.amateur.antenna
From: "Al Koblinski  (W7XA)" <[e-mail]>
Subject: Re: Directional Antenna- help please
Message-ID: <[e-mail]>
References: <4q8jk8$[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 3 Jul 1996 21:25:27 GMT

mfj, and some others have an "active antenna" consisting of a ferrite
loopstick antenna and preamp which is very bi-directional.  The addition
of a sense antenna (described in direction finding literature) can make
it a good unidirectional unit.
Sort of depends on how much bandwidth and which frequencies you want to
use.
Regards, Al




From [e-mail] Sat Jul 06 13:43:10 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Mon, 1 Jul 96 01:10:58 -0500
Message-ID: <[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]>

Cecil Moore <[e-mail]> writes:

>most of your signal in the coax because of high SWR in
>the coax.

Cecil: How high does the SWR have to be, before MOST of the signal is lost?


From [e-mail] Sat Jul 06 13:43:11 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Mon, 1 Jul 96 01:51:06 -0500
Message-ID: <[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]> <[e-mail]>

<[e-mail]> writes:

>Cecil: How high does the SWR have to be, before MOST of the signal is lost?

Hi Armond, dang, you made me haul out the Handbook. If we are
using RG-58 at 7MHz, the matched line loss in 200 ft is 2.4dB.
So if the SWR=2.7, 3dB (half) will be lost. If the SWR is 10,
the loss jumps to 5dB. I didn't take time to calculate the
loss when the SWR is 80:1 (sez EZNEC) but it is probably
higher than 12dB. With 250 ft of RG-58 at 7MHz, you lose
half your power even if your SWR is a perfect 1:1.

73, Cecil, W6RCA, OOTC


From [e-mail] Sat Jul 06 13:43:12 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Mon, 1 Jul 96 01:59:39 -0500
Message-ID: <[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]> <[e-mail]>

<[e-mail]> writes:

>Cecil: How high does the SWR have to be, before MOST of the signal is lost?

Hi again, went back and read and found the coax to be RG8
instead of RG-58. So 200 ft of RG8 at 7MHz has a matched
line loss of 1.1dB so any SWR over 3.3:1 will cause MOST
of the power to be lost. Again, at an 80:1 SWR, almost
all the power is lost even with 200 ft of RG8.

Please everyone, do not use more than a few feet of coax
when the SWR is high. Either use ladder-line or lower
the SWR.

73, Cecil, W6RCA, OOTC


From [e-mail] Sat Jul 06 13:43:13 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Mon, 1 Jul 96 01:39:39 -0500
Message-ID: <[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]>

Cecil Moore <[e-mail]> writes:

>ladder-line needs to be for best results. I will model
>it and report the results. But I'm sure you were losing
>most of your signal in the coax because of high SWR in
>the coax.

Hi again Terry, I modeled your antenna using EZNEC. The
feedpoint impedance at the end of the 44ft of 450 ohm
ladder-line was 532+j1372 resulting in an SWR of 82:1
at the coax/ladder-line junction. You were losing almost
all your power in the coax. EZNEC says that you should
have used 80 ft of 450 ohm ladder-line resulting in
an impedance of 46-j6 resulting in an SWR of 1.2:1 at
the coax.

Wouldn't it have been much easier and more rewarding to
model the antenna before you wasted your efforts on
field day? Divide the number of hours wasted into the
cost of EZNEC and you will find it will pay for itself
in saved time, time after time after time.

I use EZNEC as an example because that's what I have.

73, Cecil, W6RCA, OOTC


From [e-mail] Sat Jul 06 13:43:14 1996
From: [e-mail] (Terry Hubbard)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: 1 Jul 1996 13:08:10 -0500
Message-ID: <4r946a$[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]>

I'll check into the possibility of getting this software. As far as
mismatch in the coax, I thought that would not be a problem due to the
tuner being placed directly under the antenna, connecting the ladder line
to the tuner and matching the coax to the ladderline at this point. No
tuning was necessary at the radio end of the coax. The radio saw a swr on
the coax of 1.2 - 1. Ts440s-at ran 100 watts to antenna without using its
internal tuner.

Terry

--
-----
Terry Hubbard                  Internet:[e-mail]
Cudahy, WI                     Compuserve: 75347,2614



From [e-mail] Sat Jul 06 13:43:15 1996
From: [e-mail] (Rick Craig, N6ND)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Mon, 01 Jul 1996 17:05:37 GMT
Message-ID: <4r90jn$[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]> <4r7p0d$[e-mail]> <4r8mvl$[e-mail]>

Cecil Moore <[e-mail]> wrote:

>[e-mail] (Bill Nelson) wrote:
>>I suspect the problem was using the wrong length of ladder line.

>But Bill, the length of the ladder-line is what determines the SWR
>on the coax. 44 ft turned out to be close to worst case with an SWR
>of 82:1 per EZNEC. 80 ft gives a close to perfect SWR on the coax.
>If the coax was near lossless, the SWR wouldn't matter (within reason)
>so high SWR on the coax *was* what caused extreme losses.

No, No.  Read the original post, there is a tuner between the coax and
the ladder line.  The SWR on the ladder line was about 3:1 according
to your EZNEC numbers but the tuner should match that load to the
coax.  W8JITom probably had the right answer that the problem was due
to antenna pattern, certainly not loss in the coax.

73 Rick N6ND







From [e-mail] Sat Jul 06 13:43:16 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Tue, 2 Jul 96 01:24:10 -0500
Message-ID: <[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>

Cecil Moore <[e-mail]> writes:

>line loss of 1.1dB so any SWR over 3.3:1 will cause MOST

Back to the books,Cecil. I was proofreading some stuff the other night when
you were on the subject so it was coincidence or I wouldn't have had it at han
d.
Feedline of 100 ft.Has a matched loss of 0.5 dB. Additional power loss (note
loss,not reflected.) in dBs: 2:1 .12, 4:1 .47, 10:1 1.5, 20:1 3.


From [e-mail] Sat Jul 06 13:43:17 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Tue, 2 Jul 96 09:29:13 -0500
Message-ID: <[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>

<[e-mail]> writes:

>Anybody really uses RG-58? Surely you jest.

Hi Armond, I wish I was jesting. Just last week I went
over to a co-workers house to see what was wrong with
his 2m setup. He could get out better on an HT than
he could with his 40 ft high 1/4 wave. He had 100 ft
of RG-58, some of it coiled up because he didn't want
to break up the coax. Most hams don't know the loss
difference between RG-58 and any other coax.

73, Cecil, W6RCA, OOTC


From [e-mail] Sat Jul 06 13:43:17 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Tue, 2 Jul 96 09:36:23 -0500
Message-ID: <[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>

<[e-mail]> writes:

>Back to the books,Cecil. I was proofreading some stuff the other night when
>you were on the subject so it was coincidence or I wouldn't have had it at ha
nd.
>Feedline of 100 ft.Has a matched loss of 0.5 dB. Additional power loss (note

But Armond, the original posting said he was using about 200
ft, not 100 ft. You can't use the 100 ft loss numbers when
you are using 200 ft. 200 ft of RG8 has double the loss
of 100 ft. 0.55dB x 2 = 1.1dB. So my statement stands. 200ft
of RG8 with an SWR over 3.3:1 will lose MOST of your power
on 40m.  73, Cecil, W6RCA, OOTC


From [e-mail] Sat Jul 06 13:43:18 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: 1 Jul 1996 14:22:45 GMT
Message-ID: <4r8mvl$[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]> <4r7p0d$[e-mail]>

[e-mail] (Bill Nelson) wrote:
>I suspect the problem was using the wrong length of ladder line.

But Bill, the length of the ladder-line is what determines the SWR
on the coax. 44 ft turned out to be close to worst case with an SWR
of 82:1 per EZNEC. 80 ft gives a close to perfect SWR on the coax.
If the coax was near lossless, the SWR wouldn't matter (within reason)
so high SWR on the coax *was* what caused extreme losses.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Sat Jul 06 13:43:19 1996
From: [e-mail] (Charles Teclaw)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: 1 Jul 1996 16:48:20 GMT
Message-ID: <4r8vgk$[e-mail]>
References: <4qrlda$[e-mail]> <4r026f$[e-mail]>

W8JI  Tom ([e-mail]) wrote:
: In article <4qrlda$[e-mail]>, [e-mail] (Terry
: Hubbard) writes:
:
: >
: >Hi, for field day this year our group attempted to use a double zepp ant
: >for our 40 meter tent. The results were not as good as I had expected.
: >The overall length of the ant was 180 feet, 48 feet high, feed with 450
: >ohm ladder line from the feed point to the antenna tuner at the base of
: >the mast. The length of ladder line was approx 44 feet. From this point
: >rg8u of unknown length less than 200 feet to the tent. The length of the
: >ladder line was chosen for convenience. I am now wondering if more
: >attention should have been paid to this part of the feedline. I am trying
: >to figure out what detail might have been missed in the construction and
: >tuning of this antenna. Was the antennas radiation resistance low because
: >of the improper location of current and voltage nodes or ????.
:
: Hi Terry,
:
: Since there's very little that can be done wrong with the antenna, I'd
: consider the pattern your antenna produced the most likely problem
:
: An extended zepp antenna compresses the pattern, and the height used
: causes the antenna to be a high angle radiator. The antenna likely
: produced maximum gain straight up on a band normally requiring a pretty
: low wave angle.
:
: Without a screen or wire reflector on the lossy earth below the antenna,
: radiation efficiency would also be decreased. The antenna not only had a
: high wave angle, it was too close to earth to be efficient without a
: counterpoise system or screen.
:
: 73 Tom

Hi Terry, I was just wondering what your basis for evaluating the antenna
was? Fewer contacts or lower signal reports than a lesser antenna at the
same location? If the antenna was favoring a lower angle of radiation than
your comparison antenna (at the home QTH?), how would you have known? I
gather that you are not basing your disappointment on an A/B comparison,
but it is difficult to tell from your post whether the antenna even worked
at all! :))

Also, how did you tune the ATU at the base of the mast? Did you use an swr
bridge at the transmitter end of the coax or at the ATU itself?

73 de NT3G


From [e-mail] Sat Jul 06 13:43:20 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: 2 Jul 1996 09:50:16 -0400
Message-ID: <4rb9eo$[e-mail]>
References: <[e-mail]>

Hey come on now. All that attention to the feeedline and not the fact the
antenna was:

1.) Very close to lossy earth

2.) Radiated straight up with a focused pattern

It certainly may have had 2 or 3 dB of coax loss, but it almost certainly
produced a 20 dB null at useful wave angles (to say nothing of the
additional ground losses that greatly exceed feedline losses).

It could have been fed with lossless line and it still would have "stunk"
as a FD antenna, unless the thing was used as a NVIR antenna over a good
ground sscreen on 160 meters for 200 mile or less contacts.

73 Tom


From [e-mail] Sat Jul 06 13:43:21 1996
From: [e-mail] (Charles Teclaw)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: 2 Jul 1996 15:27:36 GMT
Message-ID: <4rbf58$[e-mail]>
References: <[e-mail]> <4rb9eo$[e-mail]>

W8JI  Tom ([e-mail]) wrote:
: Hey come on now. All that attention to the feeedline and not the fact the
: antenna was:
:
: 1.) Very close to lossy earth
:
: 2.) Radiated straight up with a focused pattern
:
: It certainly may have had 2 or 3 dB of coax loss, but it almost certainly
: produced a 20 dB null at useful wave angles (to say nothing of the
: additional ground losses that greatly exceed feedline losses).
:
: It could have been fed with lossless line and it still would have "stunk"
: as a FD antenna, unless the thing was used as a NVIR antenna over a good
: ground sscreen on 160 meters for 200 mile or less contacts.
:
: 73 Tom

Hi Tom,
While you raise interesting points, they do not seem to explain why the
antenna performed more poorly than the reference, which was at a lower
average height. Couldn't one make a case that the zepp favored low angle
radiation more than the delta they used? Is your point that the delta
lacked sharp nulls in the horizontal plane and thus was a better FD
antenna?

73 Chuck (NT3G)


From [e-mail] Sat Jul 06 13:43:22 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: Wed, 3 Jul 96 00:35:49 -0500
Message-ID: <[e-mail]>
References: <4qrlda$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>

Cecil Moore <[e-mail]> writes:

>he could with his 40 ft high 1/4 wave. He had 100 ft
>of RG-58, some of it coiled up because he didn't want

Oh, thanks for a good laugh.


From [e-mail] Sat Jul 06 13:43:24 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: 3 Jul 1996 08:36:48 -0400
Message-ID: <4rdph0$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, Cecil Moore
<[e-mail]> writes:

>Hi Tom, I went back and looked at the radiation patterns
>for this antenna over real ground. EZNEC reports 9dBi gain
>at TOA=40deg with -3dB points at TOA=19deg. That's 6dBi
>at TOA=19deg which would have worked fine if the power
>had gotten to the antenna. As you say, the horizontal
>beamwidth was only 36deg so the thing had to be aimed
>properly.

Hi Cecil,

There are so many variables associated with a typical installation we'd be
lucky if the estimate was within 10 dB of the real antenna, hi.

I also suspect it should have worked better than it did.

My point is this. Why all the debate about feedline and tuner loss when
the basic antenna has as much or more potential shortfall and variability
in performance than the feedline and tuner?

That tuner uses a choke balun, balun efficiency should be very high. If
the tuner was tuned correctly (maximum possible C) efficiency should have
been very good.

We're left with the loss in the feedline, which should have been low. We
know so little about the system it's a caldron of guesses.

I do know for a fact on 160 and 80 meters my simple 1/4 wl verticals are
better than dipoles 1/4 wl in the air by a good amount, unless I'm trying
to work within a few hundred miles  The computer indicates otherwise, yet
virtually all 160 meter ops I know of find verticals much better.

73 Tom


From [e-mail] Sat Jul 06 13:43:25 1996
From: [e-mail] (Cecil A. Moore~)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Date: 3 Jul 1996 21:01:44 GMT
Distribution: world
Message-ID: <4ren3o$[e-mail]>
References: <[e-mail]> <4rdph0$[e-mail]>

In article <4rdph0$[e-mail]>,
W8JI  Tom <[e-mail]> wrote:

>That tuner uses a choke balun, balun efficiency should be very high. If
>the tuner was tuned correctly (maximum possible C) efficiency should have
>been very good.

Hi Tom, I've got one of those tuners and it's a single core balun about
as big around as a 50 cent piece. It's looking at a 500+j1400 ohm
impedance. IMO, what they needed was a balanced tuner of some kind.
I'll try to set up similar conditions and measure the efficiency.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)


From [e-mail] Sat Jul 06 13:43:26 1996
From: [e-mail] ([e-mail])
Date: 02 Jul 96 10:36:00
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Message-ID: <[e-mail]>


From: Cecil Moore <[e-mail]>
Subject: Re: Double Zepp Help!

<[e-mail]> writes:

>Back to the books,Cecil. I was proofreading some stuff the other night when
>you were on the subject so it was coincidence or I wouldn't have had it at
hand.
>Feedline of 100 ft.Has a matched loss of 0.5 dB. Additional power loss (note

But Armond, the original posting said he was using about 200
ft, not 100 ft. You can't use the 100 ft loss numbers when
you are using 200 ft. 200 ft of RG8 has double the loss
of 100 ft. 0.55dB x 2 = 1.1dB. So my statement stands. 200ft
of RG8 with an SWR over 3.3:1 will lose MOST of your power
on 40m.  73, Cecil, W6RCA, OOTC
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From [e-mail] Sat Jul 06 13:43:27 1996
From: [e-mail] ([e-mail])
Date: 02 Jul 96 09:50:00
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Double Zepp Help!
Message-ID: <[e-mail]>


From: [e-mail] (W8JI  Tom)
Subject: Re: Double Zepp Help!

Hey come on now. All that attention to the feeedline and not the fact the
antenna was:

1.) Very close to lossy earth

2.) Radiated straight up with a focused pattern

It certainly may have had 2 or 3 dB of coax loss, but it almost certainly
produced a 20 dB null at useful wave angles (to say nothing of the
additional ground losses that greatly exceed feedline losses).

It could have been fed with lossless line and it still would have "stunk"
as a FD antenna, unless the thing was used as a NVIR antenna over a good
ground sscreen on 160 meters for 200 mile or less contacts.

73 Tom
--
|Fidonet:  [e-mail] 1:377/51.1
|Internet: [e-mail]
|
| This message has passed thru The GIFfer Skylink



From [e-mail] Sat Jul 06 13:43:28 1996
From: "C. J. Hawley" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: EAM-EZNEC soft.
Date: Thu, 04 Jul 1996 06:12:23 -0500
Message-ID: <[e-mail]>
References: <[e-mail]>

.. wrote:
>
> hi friends:does anybody knows where I can get EAM or EZNEC soft???
> any suggestion will be appreciated.
>
>                                                       sicerely yours.
> anibal
> LU4DVJ
> --
> ---
> E-mail: [e-mail]
> Buenos Aires - Argentina

You can get EZNEC from:

Roy Lewallen, W7EL
P.O.Box 6658
Beverton, OR 97007 U.S.A.

email: [e-mail]


73, Chuck, KE9UW



From [e-mail] Sat Jul 06 13:43:29 1996
From: Merv Stump <[e-mail]@postoffice.worldnet.att.net>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Elevated Radials (was Buried radials: Insulated or bare?
Date: 5 Jul 1996 17:03:07 GMT
Message-ID: <4rjhsb$[e-mail]>
References: <[e-mail]> <[e-mail]>

The mental picture of a 160 meter vertical with 50 elevated radials blows
my mind.  Please give us a little description of the antenna.

By the way, in my opinion there is NO merit to use of the MFJ artificial
ground in terms of this discussion.  Regards, Merv



From [e-mail] Sat Jul 06 13:43:30 1996
From: Dave Hand <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Elevated Radials (was Buried radials: Insulated or bare?
Date: Fri, 05 Jul 1996 08:44:42 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>

Interesting thread ....

I had an elivated 50 radial system up for 160 a couple years ago,
it was a real conversation piece. I have no good A/B numbers to
make any claimes but it seemed to work as well as simular stations
with on or underground systems.

I have a question for this illustrous group...

What is the merit of tuning the ground system to resonance with
something like the mfj artificial ground ???


From [e-mail] Sat Jul 06 13:43:30 1996
From: [e-mail] (Robert G. Strickland)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: EZNEC and Windows 95
Date: Fri, 05 Jul 1996 08:47:46 -0400 (EDT)
Message-ID: <4rj3g0$[e-mail]>
References: <4rblv4$[e-mail]>

[e-mail] (Don Taylor) wrote:

>I just upgraded from windows 3.11 to Windows 95.  Eznec isn't impressed.
>Has anyone been successful using Eznec with Windows 95?

>Don Taylor W9NFM

Don,
That combination on my Toshiba ran out of the box. The only "problem"
is that I can't print out the plots. For that, I have to run reboot
the computer in DOS mode. Everything works the same, but now I can
print plots. I haven't gotten an upgrade from Roy, so don't know if he
has fixed this yet. Take care.
Robert


Robert G. Strickland KE2WY
[e-mail]
Syracuse, New York



From [e-mail] Sat Jul 06 13:43:31 1996
From: [e-mail] (Ron Cole)
Newsgroups: rec.radio.amateur.antenna
Subject: Folder Unipole's for 160, 80 and 40 Meters
Date: Tue, 02 Jul 1996 02:38:59 GMT
Message-ID: <4ra1f1$[e-mail]>

Does anyone have comments on a Folded Uinipole system for the Low
bands.  I have used them for several years on MW Broadcast and have an
interest in trying it at 80 and 40 Meter HF, Perhape even 160 merrs
too.

My plans call for a Noprmal Ground place to 1/4 wave radials under the
tower and a remote control antenna tunning unit to match the antenna
to the coax.

Ron Cole
N5HYH




From [e-mail] Sat Jul 06 13:43:32 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Folder Unipole's for 160, 80 and 40 Meters
Date: 2 Jul 1996 17:36:35 -0400
Message-ID: <4rbmbb$[e-mail]>
References: <4ra1f1$[e-mail]>

Hi Ron,

In article <4ra1f1$[e-mail]>, [e-mail]
(Ron Cole) writes:

>Does anyone have comments on a Folded Uinipole system for the Low
>bands.  I have used them for several years on MW Broadcast and have an
>interest in trying it at 80 and 40 Meter HF, Perhape even 160 merrs
>too.

Even though an insulated tower is more useful and give equal performace,
I've used unipoles to avoid the mechanical and electrical complexity of a
base insulator.

I prefer using a conventional shunt fed tower tapped at the correct point,
because matching system Q is lower and bandwidth is better.

Efficiency and performance is virtually the same for all three types, so
the answer is usually in mechanical convience.

73 Tom



From [e-mail] Sat Jul 06 13:43:33 1996
From: [e-mail] ([e-mail])
Date: 01 Jul 96 22:38:00
Newsgroups: rec.radio.amateur.antenna
Subject: Folder Unipole's for 160, 80 and 40 Meters
Message-ID: <[e-mail]>


From: [e-mail] (Ron Cole)
Subject: Folder Unipole's for 160, 80 and 40 Meters

Does anyone have comments on a Folded Uinipole system for the Low
bands.  I have used them for several years on MW Broadcast and have an
interest in trying it at 80 and 40 Meter HF, Perhape even 160 merrs
too.

My plans call for a Noprmal Ground place to 1/4 wave radials under the
tower and a remote control antenna tunning unit to match the antenna
to the coax.

Ron Cole
N5HYH


--
|Fidonet:  [e-mail] 1:377/51.1
|Internet: [e-mail]
|
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From [e-mail] Sat Jul 06 13:43:34 1996
From: Joe Fitter BV/N0IAT <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: How do I attach an HF antenna to a Honda?
Date: Thu, 04 Jul 1996 14:32:52 -0700
Message-ID: <[e-mail]>
References: <4qqtl9$[e-mail]> <[e-mail]>

On my 1981 Honda Civic, I ran a Hustler system using a small
piece of angle iron bolted to the frame of the car from under the
bumper.   Worked fine.

Did the same on my 1986 Honda Civic with a Bug Catcher and it worked
well. Used that till I sold the car when moving overseas.  In 140,000
miles, I never had a problem and everything stayed nicely in place.

73 Joe
----------------------------------------------------------
Amateur Radio:  BV/N0IAT   Taipei TAIWAN Republic of China
ex.  7J1AOF (Japan)  YU3/N0IAT (Slovenia)  KA0ZDH (Novice)
Licensed Radio Amateur since 1986.  Comments are mine only.
----------------------------------------------------------


From [e-mail] Sat Jul 06 13:43:35 1996
From: Stacy Hamby <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Hygain TH3 tribander-info, documentation
Date: 2 Jul 1996 03:12:34 GMT
Message-ID: <4ra432$[e-mail]>

I'm looking for information on the perf. Hygain TH3 as compared to say Cushcra
ft A3.
Also looking for manual/instructions for the TH3.  Id be happy to pay copy cos
t, post
-age etc.  Any help wpuld be most appreciated.

Thx
Stacy
KC5PRR



From [e-mail] Sat Jul 06 13:43:36 1996
From: [e-mail] ([e-mail])
Date: 01 Jul 96 23:12:00
Newsgroups: rec.radio.amateur.antenna
Subject: Hygain TH3 tribander-info, documentation
Message-ID: <[e-mail]>


From: Stacy Hamby <[e-mail]>
Subject: Hygain TH3 tribander-info, documentation

I'm looking for information on the perf. Hygain TH3 as compared to say
Cushcraft A3.
Also looking for manual/instructions for the TH3.  Id be happy to pay copy
cost, post
-age etc.  Any help wpuld be most appreciated.

Thx
Stacy
KC5PRR

--
|Fidonet:  [e-mail] 1:377/51.1
|Internet: [e-mail]
|
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From [e-mail] Sat Jul 06 13:43:37 1996
From: [e-mail] (Jason Miles)
Newsgroups: rec.radio.scanner,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,fidonet.ham,rec.ham-radio,rec.ham-radio.swap,slac.rec.ham_radio,su.org.ham-radio,rec.radio.swap,tnn.radio.amateur
Subject: ICOM Dualband Handheld FORSALE
Date: 3 Jul 1996 22:03:59 GMT
Message-ID: <4reqof$[e-mail]>

VE3TYG Has the following item for sale :

MUST GO ! HF RADIO ON THE WAY !
Icom W2A Handheld
        2 Meter / 70 Centimeter
        Both Modules Expanded RX
        BP84 Battery & Wall Charger
        External Speaker Mic Included
        Mint Condition NOT A SCRATCH ON RADIO

        Asking $400
Contact Jason VE3TYG if interested at [phone]
or [e-mail]



From [e-mail] Sat Jul 06 13:43:38 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Steve Ellington)
Subject: Re: Inverted Vees vs. Sloppers
Message-ID: <[e-mail]>
References: <4rc8cd$[e-mail]> <4rdpht$[e-mail]>
Date: Thu, 4 Jul 1996 11:20:44 GMT

These area sometimes called half slopers. Some folks say they work, others
don't . The reason for this is the unpredictability of the tower/beam as
the other half of your antenna. RF on your feedline would be a very likely
problem due to the inbalance. I think you should stick it up there and
give it a try. If the swr is too high, you can slide the shield of the
coax down the tower and tap in somewhere else until it works. Have fun.



: Slopper is a good name for a top fed quarter wave sloper.

: 1.) It's pure blind sloppy luck if the tower provides an acceptable
: impedance for the shield connection.

: 2.) It's pure bind sloppy luck if the current induced in the tower by the
: shield connection don't spoil the pattern.

: It's like building a dipole, and using a fixed size random wire for one
: half.

: 73 Tom

--
Steve Ellington [e-mail]  Louisville, Ky


From [e-mail] Sat Jul 06 13:43:39 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Inverted Vees vs. Sloppers
Date: 3 Jul 1996 08:37:17 -0400
Message-ID: <4rdpht$[e-mail]>
References: <4rc8cd$[e-mail]>

In article <4rc8cd$[e-mail]>, [e-mail] (Jim Martin)
writes:

>
>But, this brings up a question... If there was such an antenna as a
>slopper...what would it look like?  My desk drawer with feedline??
>
>

Slopper is a good name for a top fed quarter wave sloper.

1.) It's pure blind sloppy luck if the tower provides an acceptable
impedance for the shield connection.

2.) It's pure bind sloppy luck if the current induced in the tower by the
shield connection don't spoil the pattern.

It's like building a dipole, and using a fixed size random wire for one
half.

73 Tom


From [e-mail] Sat Jul 06 13:43:40 1996
From: [e-mail] (Jason Miles)
Newsgroups: rec.radio.scanner,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,fidonet.ham,rec.ham-radio,rec.ham-radio.swap,slac.rec.ham_radio,su.org.ham-radio,rec.radio.swap,tnn.radio.amateur
Subject: Kenwood TM-742 6m/2m/70cm FORSALE
Date: 3 Jul 1996 22:03:07 GMT
Message-ID: <4reqmr$[e-mail]>

VE3TYG Has the following item for sale :

MUST GO ! HF RADIO ON THE WAY !
Kenwood TM 742 Mobile FM
        6 Meter Module Installed
        2 Meter Module Installed
        70 Centimeter Module Installed
        All Modules Expanded RX
        Detatchable Faceplate
        Service Manual Available
        Original Box Included
        Near Mint Condition
        Antenna & Triplexer Included

        Asking $1200
Contact Jason VE3TYG if interested at [phone]
or [e-mail]



From [e-mail] Sat Jul 06 13:43:41 1996
From: [e-mail] (Collier Chun)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Larsen KG2/70
Date: Wed, 03 Jul 96 06:43:53 PST
Message-ID: <4rdthj$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] says...
>
>Has anyone found a way to stop the Larsen KG2/70 glass mount dual band from "
singing" at
>highway speeds?

The one method I've seen--albeit ugly--is to stuff a small piece of sponge rub
ber in the middle of the coil.
Of course one wonders what that does to the coil's performance when it gets we
t...












From [e-mail] Sat Jul 06 13:43:42 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Alexander Vrenios)
Subject: Re: Looking for plans on homebrew antenna
Message-ID: <[e-mail]>
Date: Wed, 3 Jul 1996 17:55:26 GMT
References: <[e-mail]>

In article <[e-mail]>,
Dwayne Dickey  <[e-mail]> wrote:
>Does anyone have any plans on construction of a multi-band VHF antenna.
>It's primary use will be scanning with the possibility of 2m transmit
>(SWR permitting).  Can anyone help.
>
   Take a look at the diskcone antenna - designs/plans can probably
be found in most antenna "handbooks." I remember a company making
one that allowed transmit (up to 50W) on 2m, 220 and 440, but it was
also designed as a scanner receive antenna. (Careful about connecting
the scanner and the transmitter, however, unless they're part of the
same physical unit.) Visually, this antenna is a point-up cone with a
disk put on top of it. (The disk is horizontal and the cone points up.)
Both parts are made from metal rods, as I recall, and the size is the
same as a standard 2m quarter-wave whip, if memory serves me. It might
be fun to build!


Regards,

Alex Vrenios                                      Distributed Algorithms
[e-mail]        _._  _.._  ____.  ..           Research Lab


From [e-mail] Sat Jul 06 13:43:42 1996
From: John Cooksley <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Low Profile/Patch Antennas
Date: Fri, 05 Jul 1996 09:18:16 +0000
Message-ID: <[e-mail]>

Hi,
I'm looking for a supplier of low profile/patch antennas for S Band
2.2-2.4GHz
Does anyone know of a supplier or someone who might know?
Many thanks
John.

--

John R Cooksley.
|Email:[e-mail]
SSTL                    |www.ee.surrey.ac.uk/research.cser/uosat
CSER Building                           |tel: [phone] (x2308)
University of Surrey            |fax: [phone]
Guildford                       |
SURREY                          |The best way to accelerate Windows
GU2 5XH                         |is to throw it through one.


From [e-mail] Sat Jul 06 13:43:43 1996
From: John Cooksley <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Low profile/Patch antennas for S-Band
Date: Wed, 03 Jul 1996 13:08:47 +0000
Message-ID: <[e-mail]>

Hi,
I'm looking for a supplier of low profile/patch antennas for S Band
2.2-2.4GHz
Does anyone know of a supplier or someone who might know?
Many thanks
John.
--


John R Cooksley.                |Email:[e-mail]
Surrey Satellite Technology
Ltd.|http://www.ee.surrey.ac.uk/research.cser/uosat
CSER                            |tel: [phone] (x2308)
University of Surrey            |fax: [phone]
Guildford                       |
SURREY                          |The best way to accelerate Windows
GU2 5XH                         |is to throw it through one.


From [e-mail] Sat Jul 06 13:43:45 1996
From: [e-mail] (Sir Barry Duxbury)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: multiband horizontals vs. multiband verticals
Date: Wed, 3 Jul 1996 07:10:01 +0100
Message-ID: <4rd4r5$[e-mail]>
References: <4r4c54$[e-mail]> <[e-mail]>



> Hi Dave, If you can live without omnidirectional coverage,
> IMO a horizontal all-HF-band can't be beat for performance/
> price ratio. My 102 ft dipole outperforms a vertical on
> 20m-10m by a long shot. EZNEC says 10dBi vs 0dBi. On 75m
> and 40m, verticals outperform low dipoles for DX.
>
> The most efficient radiator, IMO, is a dipole fed with 450
> ohm ladder-line or open-wire line with the conjugate
> matching occuring on the balanced transmission line side,
> i.e. on the antenna side of the balun. Such an antenna
> costs about $50 and will, in general, outperform a $500
> all-band vertical.
>
> 73, Cecil, W6RCA, OOTC

Cecil & Dave,
 I strongly endorse Cecil's comments. I use a random length doublet
with open wire feed and balanced ATU (not a balun although a balun if
properly rated might do the job  depending on VSWR on the line) The
antenna will load and perform on ALL frequencies from 160 to 10
according to my analyser. No problems with ground systems and no
interference. No stray RF in the shack. The old timers new what they
were doing! One disadvantage is the need for a balanced ATU, but they
can be found or made.

73 Barry    (G4GAH)
--
 Barry Duxbury
[e-mail]
100031.2223@compuserve
G4GAH Oxford UK



From [e-mail] Sat Jul 06 13:43:46 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: multiband horizontals vs. multiband verticals
Date: Tue, 2 Jul 96 10:07:53 -0500
Message-ID: <[e-mail]>
References: <4r4c54$[e-mail]>

Dave Doyon <[e-mail]> writes:

>I would like to hear opinions from anyone who may have compared
>verticals with horizontals and which they would recommend.  A beam is

Hi Dave, If you can live without omnidirectional coverage,
IMO a horizontal all-HF-band can't be beat for performance/
price ratio. My 102 ft dipole outperforms a vertical on
20m-10m by a long shot. EZNEC says 10dBi vs 0dBi. On 75m
and 40m, verticals outperform low dipoles for DX.

The most efficient radiator, IMO, is a dipole fed with 450
ohm ladder-line or open-wire line with the conjugate
matching occuring on the balanced transmission line side,
i.e. on the antenna side of the balun. Such an antenna
costs about $50 and will, in general, outperform a $500
all-band vertical.

73, Cecil, W6RCA, OOTC


From [e-mail] Sat Jul 06 13:43:47 1996
From: [e-mail] ([e-mail])
Date: 02 Jul 96 11:07:00
Newsgroups: rec.radio.amateur.antenna
Subject: Re: multiband horizontals vs. multiband verticals
Message-ID: <[e-mail]>


From: Cecil Moore <[e-mail]>
Subject: Re: multiband horizontals vs. multiband verticals

Dave Doyon <[e-mail]> writes:

>I would like to hear opinions from anyone who may have compared
>verticals with horizontals and which they would recommend.  A beam is

Hi Dave, If you can live without omnidirectional coverage,
IMO a horizontal all-HF-band can't be beat for performance/
price ratio. My 102 ft dipole outperforms a vertical on
20m-10m by a long shot. EZNEC says 10dBi vs 0dBi. On 75m
and 40m, verticals outperform low dipoles for DX.

The most efficient radiator, IMO, is a dipole fed with 450
ohm ladder-line or open-wire line with the conjugate
matching occuring on the balanced transmission line side,
i.e. on the antenna side of the balun. Such an antenna
costs about $50 and will, in general, outperform a $500
all-band vertical.

73, Cecil, W6RCA, OOTC
--
|Fidonet:  [e-mail] 1:377/51.1
|Internet: [e-mail]
|
| This message has passed thru The GIFfer Skylink



From [e-mail] Sat Jul 06 13:43:48 1996
From: "Jeff Bertrand" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Need VLF Antenna for Omega Radio Navigation Reception
Date: Tue, 2 Jul 1996 09:18:57 -0600
Message-ID: <01bb6829.ca0391c0$[e-mail]>

Does anyone have any ideas on constructing a portable antenna for VLF
10khz - 16khz. I have acquired a couple of the Omega receivers and would
like to use them as a portable precision time source.

Thanks already;
[e-mail]


From [e-mail] Sat Jul 06 13:43:49 1996
From: [e-mail] ([e-mail])
Date: 02 Jul 96 11:18:00
Newsgroups: rec.radio.amateur.antenna
Subject: Need VLF Antenna for Omega Radio Navigation Reception
Message-ID: <[e-mail]>


From: "Jeff Bertrand" <[e-mail]>
Subject: Need VLF Antenna for Omega Radio Navigation Reception

Does anyone have any ideas on constructing a portable antenna for VLF
10khz - 16khz. I have acquired a couple of the Omega receivers and would
like to use them as a portable precision time source.

Thanks already;
[e-mail]
--
|Fidonet:  [e-mail] 1:377/51.1
|Internet: [e-mail]
|
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From [e-mail] Sat Jul 06 13:43:49 1996
From: [e-mail] (Russ Renaud)
Newsgroups: rec.radio.amateur.antenna
Subject: Non-coaxial coax??
Date: 4 Jul 1996 19:03:49 GMT
Message-ID: <4rh4il$[e-mail]>
Reply-To: [e-mail] (Russ Renaud)


I was thinking of running either a ground-mounted or elevated vertical
on multiple bands using an antenna tuner back in the shack.

If I feed it with normal coax, I'll encounter some substantial VSWRs
with the increased losses associated with same.

If I feed it with open line, I'll be feeding an unbalanced antenna
with balanced line, which could result in unbalanced current in my
feeder and subsequent feeder radiation.

What if I were to make my own hardline using 1/2 copper waterpipe,
#12 or #14 wire with teflon spacers every foot or so apart?  Certainly
the losses would be lower (comparable to open line feeders??).

However, when making bends with elbows, chances are the centre conducter
won't always be exactly centred in copper pipe, ie non-coaxial coax.

What effect would this have, given the high SWRs that could be on
this line?  What sort of losses could I expect?

Any thoughts on this?


From [e-mail] Sat Jul 06 13:43:50 1996
From: [e-mail] (Andy)
Newsgroups: rec.radio.amateur.antenna
Subject: Old-Newbie Design/theory question
Date: Thu, 04 Jul 1996 16:26:48 GMT
Message-ID: <4rgrfj$[e-mail]>

Before I spend a lot of time (that I really don't have) experimenting,
please look at the following. Will this antenna work for transmitting?
(This design is used for reception...) Five dipoles, each tied
together at the feedpoint, all wires spaced 3"-4" apart. I'm afraid I
never was really any good at antenna theory. Would this cause too much
coupling between the desired radiating element, and other non-tuned
elements for a given band - driving the SWR up? Or, being cut for a
specific band, would the unwanted radiators simply be "ignored"? I'm
sure this has been covered somewhere before, but I can't seem to put
my hands on it, and old antenna books are not to be found around here.
Many thanks to all who reply.

Andy
WD4RCC

--------------]------]  [------[----------80m dipole
    ----------]      ]  [      [----------40m dipole
         -----]      ]  [      [-----     20m dipole
           ---]      ]  [      [---       15m dipole
            --]      ]  [      [--        10m dipole
                     ]  [
                     ]  [
                     ]  [
                     ]  [
     Feed side ]  [ Shield side






From [e-mail] Sat Jul 06 13:43:52 1996
From: [e-mail] (CHRISTOPHER CARTWRIGHT)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Old-Newbie Design/theory question
Date: 5 Jul 1996 17:58:27 GMT
Message-ID: <4rjl43$[e-mail]>
References: <4rgrfj$[e-mail]>

Andy ([e-mail]) wrote:
: Before I spend a lot of time (that I really don't have) experimenting,
: please look at the following. Will this antenna work for transmitting?
: (This design is used for reception...) Five dipoles, each tied
: together at the feedpoint, all wires spaced 3"-4" apart. I'm afraid I

I have something quite similar in my attic and it seems to tune up very
well.  I "tuned" all the element seperately with an MFJ-259 before I
put the whole thing up in the attic.  It looks somewhat like a butterfly
with a 6M dipole on top, then 10, 15 and 20 below.  The 6M is horizontal
and the others slope downward more as they get longer.  All of them tie
to a common point (the end of the coax) and are stapled to the rafters.
So far up to 100 watts with no ill effects.  I did use #14 PVC jacketed
zip cord, so the elements came out about 10% shorter than calculated.  Then
again I didn't have any clue what the velocity factor was on this stuff.

After I got the whole mess installed in the attic, the only change I had
to make was to the 6M element (had to stretch it about 6" :)  I think
this was beacuse I tuned it up about 8' off the ground and at 30' things
were a lot different.  I've seen what you propose used with good results
in several places.  Spacing between the wires is usually about 2", and the
last foot or so angles up to the feed point.  The usual advice, make it a
little TOO long and cut it back to tune it.  Always easier to cut than
solder :>

-good luck,

-- Christopher Cartwright, Tech. Engineer    |  ...our chief weapons are fear,
-- Voice 301.295.0809      N3XRV             |  fear and surprise, and nice
-- Mail  [e-mail]         |  red uniforms, oh damn!!
--       [e-mail]                     |        -- Monty Python



From [e-mail] Sat Jul 06 13:43:53 1996
From: [e-mail] (ED WELCH)
Newsgroups: rec.radio.amateur.antenna
Subject: Quad help...
Message-ID: <[e-mail]>
Date: Thu, 04 Jul 96 23:49:00 -0600
Distribution: world
Reply-To: [e-mail] (ED WELCH)

I'm awaiting delivery of my Tech+ license from the FCC.  In the meantime
I'm working on putting together 4 element quad antenna for 10 meters.
Needless to say I have a lot of questions.  If someone could give me
some pointers on this I'd really appreciate it.

(1) I've about decided on building the antenna to be resonant at
28.35mhz.  I figure this will encompass the novice phone subband of the
10 meter band and still give me some good bandwidth for CW.  Any
thoughts on this?

(2) As for the physical wire lengths the following is what I've
determined:

Reflector - 36.33'
Driven    - 35.45'
Dir #1    - 34.39'
Dir #2    - 34.39'
Element Spacing -  5.32'
Boom Length     - 16.25'

Are these correct for 28.35mhz?  I used the 1005/freq to come up with
these figures.

(3) I'm not sure about the physical connection of the driven element to
the feedline.  I figuring on using a simple insulator with a PL259 plug
on it.  I hope that I can find an insulator that has wires rather than
eyebolts to hook to the element.  In my mind, these wire will actually
add to the driven element's overall length.  Should I adjust the
beginning length of the element to compensate for this, or just figure
on keeping as little as possible insulator wire from hanging loose by
wrapping it well around the antenna element?  Comments?

(4)  Wire.  I'm considering using some solid-strand 12awg insulated wire
that I have an abundance of.  I've heard in the past that insulated wire
will need to be cut at a different length than non-insultated wire.  Is
this correct, and if it is, would I be better off to strip the wire of
insulation?

Will the solid copper wire work as well as a stranded wire?  What about
when it comes to solder joints?  I know that I won't really be able to
twist this wire as well as I could a lighter gauge stranded wire, but
what about wrapping the joints with something like telephone wire before
I solder?  Will wrapping the wire like  this create any inductance or
anything that I should be aware of?  Would the wrapping be worth the
trouble?

(5)  I'm using a lot of information out of Orr's Cubical Quad book and
he states that a good impedance match can be made by coiling about 3
turns of coax cable through a 2.25" ferrite ring at about a 1/4
wavelength down the cable.  This is what I'm figuring on doing, but, if
a commercial balun would do a better job and make the antenna more
efficient then I'd really rather go this route.  This antenna will
eventually be my main antenna so I want to build it right.
Any feedback on this matter will be *most* appreaciated.

(6)  Coax line.  Would RG8x or RG213 be the best coax for the quad?  The
run will be less than 70'.

(7)  Are the SWR/Antenna analysers worth having for a Tech+ who's
interested in tinkering with antennaes?

That's all the questions for now, hope I didn't boar ya'll too much.
I really appreciate your time and trouble.  Take care,

73
[e-mail]
(waiting on my Tech+ ticket!!!) :)


From [e-mail] Sat Jul 06 13:43:54 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Question: Coaxial Dipole Antenna - How to build?
Date: 2 Jul 1996 09:41:33 -0400
Message-ID: <4rb8ud$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] (Leonard
Paris) writes:

>Can anyone tell me how to build a coaxial dipole antenna?  Or,
>perhaps, refer me to a book that covers the subject?  It's
>supposed to be a very broad bandwidth, single band antenna that
>gives results far superior to other dipoles.
>
>Thanks, and 73 from KD9S, Len, in Belleville, IL.

Hi Len,

The coaxial dipole has more loss, and gives poorer performance than a
regular dipole.

There are two main reasons for this. The woven shield has higher
resistance per unit length than a smooth conductor and the dielectric
increases losses.

These effects pretty small, and I doubt they would be noticed outside a
lab environment.

Claims of improved gain and performance for the "coaxial dipole" are
completely false. You'd get the same or better bandwidth, and better
performance, with a fan type ("bowtie") dipole.

73 Tom


From [e-mail] Sat Jul 06 13:43:55 1996
From: [e-mail] ([e-mail])
Date: 02 Jul 96 09:41:00
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Question: Coaxial Dipole Antenna - How to build?
Message-ID: <[e-mail]>


From: [e-mail] (W8JI  Tom)
Subject: Re: Question: Coaxial Dipole Antenna - How to build?

In article <[e-mail]>, [e-mail] (Leonard
Paris) writes:

>Can anyone tell me how to build a coaxial dipole antenna?  Or,
>perhaps, refer me to a book that covers the subject?  It's
>supposed to be a very broad bandwidth, single band antenna that
>gives results far superior to other dipoles.
>
>Thanks, and 73 from KD9S, Len, in Belleville, IL.

Hi Len,

The coaxial dipole has more loss, and gives poorer performance than a
regular dipole.

There are two main reasons for this. The woven shield has higher
resistance per unit length than a smooth conductor and the dielectric
increases losses.

These effects pretty small, and I doubt they would be noticed outside a
lab environment.

Claims of improved gain and performance for the "coaxial dipole" are
completely false. You'd get the same or better bandwidth, and better
performance, with a fan type ("bowtie") dipole.

73 Tom
--
|Fidonet:  [e-mail] 1:377/51.1
|Internet: [e-mail]
|
| This message has passed thru The GIFfer Skylink



From [e-mail] Sat Jul 06 13:43:56 1996
From: [e-mail] (Barry Kutner)
Newsgroups: rec.radio.amateur.antenna
Subject: Radio Shack rotor help needed
Message-ID: <[e-mail]>
Date: Thu, 04 Jul 96 12:05:21 GMT

Hi Have a Radio Shack 15-1225B (3 wire) rotor that died yesterday. Does
anyone have pinout info so I can hopefully troubleshoot from the ground?
Tnx/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] Sat Jul 06 13:43:57 1996
From: "Kathryn J. Goerg" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: RF/Microwave CAE Site
Date: Mon, 01 Jul 1996 13:29:07 -0500
Message-ID: <[e-mail]>

The Webb Laboratories RF/Microwave CAE Site is at:

        http://www.webblabs.com

Please inspect our receiver engineering, structure synthesis
and active filter design capabilities.

Kathy Goerg
Webb Laboratories
[e-mail]


From [e-mail] Sat Jul 06 13:43:58 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: rotatable dipoles
Date: 5 Jul 1996 16:35:35 GMT
Message-ID: <4rjg8n$[e-mail]>
References: <4qkq6r$[e-mail]> <4qkssu$[e-mail]> <4qn4d7$[e-mail]> <4qnbcm$[e-mail]> <4rfe7h$[e-mail]>

[e-mail] (Dale L. Martin) wrote:
>XYL? Proximity to in-laws?

I once had similiar problems. Solved them by moving from San Jose, CA
to Queen Creek, AZ. - alone. :-)

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Sat Jul 06 13:43:59 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: SAT DISH for EME? how?
Date: 1 Jul 1996 10:36:34 -0400
Message-ID: <4r8npi$[e-mail]>

Hello
i have a Clark Belt rotor system on a 9ft Dish
how can i put a ele/az rotor on so i can get any angle?
something easy please :)

thanks

DAvid
|-----------------------------------------------------------------------|
|         David Roseman       |          [e-mail]       OUTTA ORDER!
|      SysOp of NODE 3 BBS    |          The Flying HAm - BBS    |      |
|     Running OBV/2 Software  |          Technomage - BBS        |      |
|         610.838.2989        |          N3SQE/1     - HAm       V      |
|       (Parttime system)     |  [e-mail] - Packet  |
|-----My AWESOME home page :) http://www.lehigh.edu/~c002/c002.html-----|


From [e-mail] Sat Jul 06 13:43:59 1996
From: [e-mail] (Robert Patrick MacKinnon)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SAT DISH for EME? how?
Date: 4 Jul 1996 10:54:02 GMT
Message-ID: <4rg7sa$[e-mail]>
References: <4r8npi$[e-mail]> <4rf79j$[e-mail]>


okay on the tracking of the moon, but what freq are you using the dish for?
How are you feeding the dish ? ( yagi pointed from the focus inward, etc ? )
(maybe a helix?)
sounds interesting, how about some more details.
tnx de VE3PMK
Pat MacKinnon,
London Ontario



From [e-mail] Sat Jul 06 13:44:00 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Source for 300 ohm ladder line needed
Date: 1 Jul 1996 20:21:41 GMT
Message-ID: <4r9c0l$[e-mail]>
References: <[e-mail]>

[e-mail] (Pete Soper) wrote:
>It seems to be the end of an era. I've been trying to buy 300
>ohm ladder ("window") balanced line and have come up empty.

Hi Pete, try Antennas West, POBox 50062, Provo, UT 84605
tel [phone]  FAX [phone]

They call it "Airline".

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Sat Jul 06 13:44:01 1996
From: John Figliozzi <[e-mail]>
Newsgroups: rec.radio.shortwave,rec.radio.amateur.antenna
Subject: Re: SW Sloper antenna
Date: Mon, 01 Jul 1996 23:09:55 -0400
Message-ID: <[e-mail]>
References: <4r3764$[e-mail]>
Reply-To: [e-mail]
To: Scott Ryan <[e-mail]>

Hello, Scott.

Re: Your question.  I have an Alpha-Delta Sloper hooked to my Lowe
HF-150.  In short, I like the antenna.  Getting it outside and away
from much of the noise generated by my suburban home helps
significantly with weaker signals.  I live near a major interstate and
the antenna does not appear to pick up any hash from passing traffic
even though it is oriented in that direction.

My antenna is erected about 23 feet off the ground on the feed end and
8 feet on the far end, oriented west to east.  My experience is that
stations to the west are somewhat attenuated, but in my case this may
be because the house with aluminum siding, etc. sits in the way.  I
switch to a north-south suspended inverted L mounted in my attic for
those signals.

Larry Magne has an excellent white paper on the subject of active and
passive antennas which could be of considerable help to you.  You can
get these through Gilfer, Grove, Universal, EEB, etc.  The A/D Sloper
runs around $80 if memory serves from the same vendors.

Hope this helps!

----------------------------------------------------------------------
Check out the
THE WORLDWIDE SHORTWAVE LISTENING GUIDE
Comprehensive listings of shortwave programs from nearly 100 stations!
112 pages/$8.99
edited by John A. Figliozzi
available from your local Radio Shack dealer
----------------------------------------------------------------------




From [e-mail] Sat Jul 06 13:44:02 1996
From: [e-mail] (Russ Renaud)
Newsgroups: rec.radio.amateur.antenna
Subject: Tr-44 rotor info wanted
Date: 3 Jul 1996 15:43:39 GMT
Message-ID: <4re4fb$[e-mail]>
Reply-To: [e-mail] (Russ Renaud)


Does anyone have a recent number for Norm's Rotor service,
or where I can get info for a TR-44 rotor?

Any help would be appreciated.
tnx de [e-mail]


From [e-mail] Sat Jul 06 13:44:03 1996
From: [e-mail] (Christer Jogenborn)
Newsgroups: rec.radio.amateur.antenna
Subject: UHF 1.2G Yagi ?
Date: 4 Jul 1996 15:07:15 GMT
Message-ID: <4rgmn3$[e-mail]>
Reply-To: [e-mail]

Have: 4 separate 36 el 1296MHz Yagis
Want: To build a 4-stack
Need: the stacking data and more...

The Yagis are made by 'SHF DESIGN' Berlin, Germany
Mannfred Pl÷tz.
The driven element is a folded dipole with stub,
the large reflector is made out of eight elements.

Thank you! / Chris SM0NCL





From [e-mail] Sat Jul 06 13:44:04 1996
From: [e-mail] (David G.M. Smith)
Newsgroups: rec.radio.amateur.antenna
Subject: Wanted - Screwdriver HF Mobile Antenna
Date: Tue, 02 Jul 1996 04:52:43 GMT
Message-ID: <4ra9s3$[e-mail]>

Hi

I am looking for a screwdriver HF antenna for a motorhome mobile
setup.
Please send info and prices via email or via packet
VE7EC@VE7KIT

Thanks and 73 de Dave VE7EC, North Vancouver, B.C.
....David G.M. Smith                 VE7EC
Tel [phone]    Fax [phone]     Email: [e-mail]
--------------------------------------------------------------------
INTERFACE INTERNATIONAL  URL: http://www.interfaceweb.com
     Venture Capital and Management Consulting
---------------------------------------------------------------------



From [e-mail] Sat Jul 06 13:44:05 1996
From: "William M. Bickley KF2ON" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Wanted - Screwdriver HF Mobile Antenna
Date: Wed, 03 Jul 1996 11:14:47 -0400
Message-ID: <[e-mail]>
References: <4ra9s3$[e-mail]>

David G.M. Smith wrote:
>
> Hi
>
> I am looking for a screwdriver HF antenna for a motorhome mobile
> setup.
> Please send info and prices via email or via packet
> VE7EC@VE7KIT
>
> Thanks and 73 de Dave VE7EC, North Vancouver, B.C.
> ....David G.M. Smith                 VE7EC
> Tel [phone]    Fax [phone]     Email: [e-mail]
> --------------------------------------------------------------------
> INTERFACE INTERNATIONAL  URL: http://www.interfaceweb.com
>      Venture Capital and Management Consulting
> ---------------------------------------------------------------------

David:

Take a look at the High Sierra Antennas home page
(http://www.psyber.com/biz/high_sierra).  I have one of their antennas, and li
ke it very
much.

Bill KF2ON


From [e-mail] Sat Jul 06 13:44:06 1996
From: [e-mail] ([e-mail])
Date: 02 Jul 96 00:52:00
Newsgroups: rec.radio.amateur.antenna
Subject: Wanted - Screwdriver HF Mobile Antenna
Message-ID: <[e-mail]>


From: [e-mail] (David G.M. Smith)
Subject: Wanted - Screwdriver HF Mobile Antenna

Hi

I am looking for a screwdriver HF antenna for a motorhome mobile
setup.
Please send info and prices via email or via packet
VE7EC@VE7KIT

Thanks and 73 de Dave VE7EC, North Vancouver, B.C.
....David G.M. Smith                 VE7EC
Tel [phone]    Fax [phone]     Email: [e-mail]
--------------------------------------------------------------------
INTERFACE INTERNATIONAL  URL: http://www.interfaceweb.com
     Venture Capital and Management Consulting
---------------------------------------------------------------------

--
|Fidonet:  [e-mail] 1:377/51.1
|Internet: [e-mail]
|
| This message has passed thru The GIFfer Skylink



From [e-mail] Sat Jul 06 13:44:06 1996
From: Bill Levey <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Web Vendor Directory
Date: Mon, 01 Jul 1996 08:13:39 -0500
Message-ID: <[e-mail]>

A comprehensive directory of Amateur Radio-related vendors doing
business on the web may be found at:

http://www.scott.net/~wa4fat/vendor.html

73!


From [e-mail] Sat Jul 06 13:44:08 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What if I trim the dipole to fit
Date: 4 Jul 1996 17:21:54 GMT
Message-ID: <4rgujj$[e-mail]>
References: <[e-mail]> <4rguck$[e-mail]>

[e-mail] (Jim Henry) wrote:
>Randy aka ([e-mail]) wrote:
>: I'm setting up a 160-10 meter dipole but was a little too optimistic
>: about the length from one corner of my little city lot to the other.
>: The wire is now 134' long and about 14' too long to fit comfortably.

>While not ideal, these bends should affect your pattern more for the higher
>bands than at 160m (omni-skywarmer). Check it out with EZNEC if you're
>curious, and get on the air!  :-)

Hi guys, there's not a lot of difference between 134ft and 120ft dipoles
on 160. Both are lousey. :-) I modeled them at 50ft and EZNEC sez:

134ft dipole  4-j1000     120ft dipole  3.2-j1200    both SWRs > 100

With high ground losses, high take off angle, and the difficulty of
getting power to the load, Don't expect much DX on 160. :-) It might
work better to feed it Marconi style. That way you get at least some
low-angle radiation assuming a good ground.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Sat Jul 06 13:44:09 1996
From: [e-mail] (Jim Henry)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What if I trim the dipole to fit
Date: 4 Jul 1996 10:18:12 -0700
Message-ID: <4rguck$[e-mail]>
References: <[e-mail]>

Randy aka ([e-mail]) wrote:
: I'm setting up a 160-10 meter dipole but was a little too optimistic
: about the length from one corner of my little city lot to the other.
: The wire is now 134' long and about 14' too long to fit comfortably.
: My choices seem to be:
:
: 1) Erect a pole on the roof of my house to raise the center into an
: inverted V and take up the slack that way.  It would be a bend of some 30
: degrees, not 90!
:
: 2) snip those 14' right off (along with any hope for 160 meter contacts?).
:
: Can you comment on the pros and cons of either approach?  You can also
: tell me that 160 meters isn't worth trying to bother with 180 watts
: and a dipole, and I'll listen to you.  Thanks for any tips.   Randy
: --
:                                              [e-mail]

Option #1 is probably the best, but also consider bending the ends back
along your fenceline to form a 'Z', or drop them down vertically if height
permits.

While not ideal, these bends should affect your pattern more for the higher
bands than at 160m (omni-skywarmer). Check it out with EZNEC if you're
curious, and get on the air!  :-)

Trimming the dipole to fit is the "Lew McCoy" dipole. Use ladderline and
a tuner for all-band antennas. Lew and Cecil Moore discuss adjusting the
length of ladderline as required for a good match.

I'm evaluating a similar compromise at my QTH, and look forward to the
responses of others on this forum.

73 de Jim Henry KE6WGO
--



From [e-mail] Thu Jul 11 16:56:00 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.primenet.com!news.asu.edu!ennfs.eas.asu.edu!cs.utexas.edu!swrinde!ihnp4.ucsd.edu!news1.ucsd.edu!news-mail-gateway
From: [e-mail] (Wayne Barnhart)
Newsgroups: rec.radio.amateur.antenna
Subject: 18AVQ
Date: 6 Jul 96 03:48:41 GMT
Organization: ucsd usenet gateway
Lines: 9
Message-ID: <[e-mail]>
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]


I have a Hygain 18AVQ and sorely in need of the dementions - section
lengths for the CW part of the band. Also, have you ever got 80M to tune?
Thanks, and please respond direct, its faster.

Wayne  WB7WHI
Spokane, Wa.




From [e-mail] Thu Jul 11 16:56:01 1996
Path: news2.epix.net!uunet!in2.uu.net!news.sprintlink.net!new-news.sprintlink.net!news.monad.net!usenet
From: Chester Bowles <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 80m discone. well 40 to start and if it works :-)
Date: 8 Jul 1996 18:13:54 GMT
Organization: Crotched Mountain Foundation
Lines: 21
Message-ID: <4rrj52$[e-mail]>
References: <4rgsmn$[e-mail]>
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[e-mail] (Bob Duckworth) wrote:
>Anyone tried a discone for HF?
>I'm thinking of putting up one for 40m and up.
>


Seemed to work OK for Marconi! :>)  On the other hand, he had LOTS of
real estate at his disposal.

Chet, AA1EX
--
*---------------------------------------------------------------------*
| CHESTER S. BOWLES            | Education, rehabilitation, housing,  |
| Vice President               | and managed care for children,       |
| Crotched Mountain Foundation | adolescents and adults with physical |
| One Verney Drive             | and developmental challenges.        |
| Greenfield, NH 03047         | http://www.cmf.org                   |
| 603.547.3311 ext. 404        | [e-mail]                       |
*---------------------------------------------------------------------*




From [e-mail] Thu Jul 11 16:56:01 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!newsfeed.internetmci.com!news.kei.com!news.texas.net!news.sprintlink.net!news-fw-6.sprintlink.net!newsserver.pixel.kodak.com!newsserver.rdcs.Kodak.COM!consun52!rls
From: rls@consun52 (Bob Smith X31105)
Newsgroups: rec.radio.amateur.antenna
Subject: 80M with 14AVQ ?
Date: 9 Jul 1996 14:48:32 GMT
Organization: Eastman Kodak Company
Lines: 12
Message-ID: <4rtrg0$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: 129.126.37.43
X-Newsreader: TIN [version 1.2 PL0]

Hello All,

I have a 14AVQ 10-40 vertical that I'd like to put to use on 80...
I'm told that at one time an 80M option was available for this
antenna - a call to HyGain verified that - but they no longer have
the option in stock...  If anyone has any ideas on other possible
solutions, I'd like to hear 'em...

Thanks es 73,
Bob - N2YRJ




From [e-mail] Thu Jul 11 16:56:03 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!swrinde!cs.utexas.edu!news.tamu.edu!news
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Absorption vs. Ground
Date: 7 Jul 1996 05:24:23 GMT
Organization: Texas A&M University, College Station, TX
Lines: 52
Message-ID: <4rnhm7$[e-mail]>
References: <[e-mail]>
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NNTP-Posting-Host: 128.194.44.219
X-Newsreader: IBM NewsReader/2 v1.2

In <[e-mail]>, [e-mail]
m (Joe Wivoda) writes:
>I have a question regarding putting up a vertical. I have a 2 acre
>swamp in my backyard (very wet - i.e. good ground plane possibilities)
>but it is full of trees. Mostly oak, about 3-12 inches diameter. I
>would estimate about 1 tree per suare meter?  Needless to say I am
>concerned about the absorption of the RF by the trees here? Will it
>affect the antenna very much?
>
>If absorption is a big issue, I can put the antenna in my side yard.
>There are fewer trees (0.25 per suare meter) but the ground is not as
>moist. Which, in your opinions would be best?
>
>Thanks for any help.
>
>By the way, I do have a dipole up in the backyard that works great
>despite all the trees.
>
>---
>Joe Wivoda
>AB0AU
>[e-mail]
>

The attenuation problem is a lot dependent on the frequency in use!  I have
both a 4 square on 40 and a 4 square on 80.  They are in DENSE woods.
We are talking oak trees with 20 and more inch barrels, to say nothing of
the other stuff!  The 80 meter array doesn't even poke up above the tree
line much at all, and the 40 meter array is buried in it.

The 40 meter array changes noticeably between seasons, not so much for
the leaves, but for the sap content in the tree trunks, I think.

It makes no discernable difference in how the array performs in practice.

There is no discernable difference in the 80 meter array whatever.

If we were talking 20, 10 and up...   I am sure the porblem would be
more noticable.

Your wet ground is virtually no help, unless it is a salt marsh, I think.

In my case, the soil is undisturbed an mineral enriched creek bottoms for
many wavelengths around.  A substantial part of the mineral display is iron
derived.  My bet is that helps much more than the moisture.

:)

Mike @ W5WQN as a guest at leviathan.tamu.exu (no mail address there)






From [e-mail] Thu Jul 11 16:56:04 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-in.tiac.net!imci5!imci4!newsfeed.internetmci.com!in1.uu.net!bcstec!nntp
From: KG7HQ
Subject: Re: Almost direct hit - lightning
X-Nntp-Posting-Host: e397936.evt.boeing.com
Message-ID: <[e-mail]>
Sender: [e-mail] (NNTP News Access)
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Date: Wed, 10 Jul 1996 12:33:43 GMT
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Hello Bill,

>As a ham I'm supposed to know about this stuff!  Can anyone explain to me
>the physics behind the destruction of the TV's?   Any suggestions on what
>could be done to prevent this kind of damage?  (Someone told them to
>put knots in the AC power cords!!! I never heard that one before!) Do


Thats quite a wise tail!!<smiles> I never heard of the knot theroy before.
When comes to electrical storms, the best thing to do is isolate all
connections to your equipment (TV's, Radios etc). This includes power along
with antenna connections. Even though the primary strike was at a tree
near by, you could of had many secondary strikes at the same time that
could very easily damage the sensitive components in todays home
electronics equipment. I had placed a coax in a glass jar as isolation
during a storm and was amazed that there was carbon burns on the glass
afterwards. I never to a direct hit but it goes to show that the potental
was there. That discharge could of been through the front end of my radio.

73's for now......
KG7HQ [e-mail]


From [e-mail] Thu Jul 11 16:56:05 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!in2.uu.net!news2.amd.com!amd!canntp.amd.com!txnews.amd.com!news
From: Chris Broadbent <[e-mail]>
Subject: Re: Almost direct hit - lightning
Content-Type: text/plain; charset=us-ascii
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Bill Meara wrote:
>
> The tree in front of my sister's suburban home was hit by lightning last
> week.  As a result of the strike, all the TV's in her house are
> inoperable and a number of other electrical devices no longer function.
> As a ham I'm supposed to know about this stuff!  Can anyone explain to me
> the physics behind the destruction of the TV's?   Any suggestions on what
> could be done to prevent this kind of damage?  (Someone told them to
> put knots in the AC power cords!!! I never heard that one before!) Do
> insurance companies pay for this kind of thing?
>

There are two mechanisms involved in the destruction of electronic devices nea
r a
lightning strike.

The more obvious one: if the devices are plugged in or powered, a strike on th
e
power lines sends a surge into the device and kills it.  Even a strike near th
e
line may induce a surge great enough to wreak havoc (this blends into the less

obvious mechanism below).

The less obvious one: Electro-Magnetic Pulse (EMP for short).  The rapid rise/
fall
times and high current in a lightning bolt produces a powerful pulse of radiat
ing
electromagnetic energy.  This pulse can induce semiconductor destroying potent
ials
in nearby equipment.

Nuclear detonations also generate EMP (only even more powerful).  In the event
 of
nuclear war, both sides had plans to detonate a few devices in the ionosphere
above the oppononent's territory in order to wipe out as many electronic devic
es
as possible (read communication devices).

The ex-Soviets, with their less advanced semiconductor production used tubes i
n
more applications.  Tubes can survive EMP much more readily than semiconductor
s.
Semiconductor equipment requires special effort in order to make it EMP proof.

Can you protect against a direct equipment strike?  I believe the answer to th
at
is not reliably.  Can you protect against EMP pulses from nearby strikes?  Yes
,
use tube equipment where possible!

Why do I talk about this?  Our house was hit by lightning a month ago.  I lost

some semiconductor equipment, but not one piece of tube equipment (one of my
hobbies is the collection/renovation of old tube radios).  We had plasma in th
e
house.  That was not comforting.

Cheers,

Chris


From [e-mail] Thu Jul 11 16:56:06 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!in1.uu.net!iglou!news
From: Steve Ellington <[e-mail]>
Subject: Re: Almost direct hit - lightning
X-Nntp-Posting-Host: dp-2-37.iglou.net
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Should I be concerned about my transistors if an H-bomb is set off
over my house?



From [e-mail] Thu Jul 11 16:56:09 1996
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From: USCG TELECOMMS <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Almost direct hit - lightning
Date: Thu, 11 Jul 1996 15:01:41 -0400
Organization: Posted via CAIS Internet <[e-mail]>
Lines: 23
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References: <4s04kb$[e-mail]> <[e-mail]>
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Mime-Version: 1.0
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To: John Rice <[e-mail]>
In-Reply-To: <[e-mail]>



On 11 Jul 1996, John Rice wrote:

> The failures could be caused by a couple of different things. If the
> surge got into the AC power lines, the failures could be blown fuses,
> or power supply failures. On the other hand, when I took my tower 'hit'
> the surge got into the underground cable TV which ran about 3' from the
> tower base, and blew out the FET front end on the VHF tuner in the TV.
>
>
> Insurance should pay for this kind of damage.
>
Insurance will only pay if the damage was as a result of a lightning hit,
not a surge induced by lighting somewhere down the line.  Believe me, I've
had the experience.  All I showed the insurance company was a blown SO-239
which was attached to the 160 meter dipole center, and they paid for all
damages inside the house.  One half of the dipole, by the way, completely
disappeared (vaporized/melted).  By the way, the actual damage to my
eqipment was caused by the pulse traveling along the ground bus which also
blew the 200 amp breaker in the basement; this is why the insurance
company needed proof that lighting also hit the antenna......W4VR



From [e-mail] Thu Jul 11 16:56:10 1996
Path: news2.epix.net!uunet!inXS.uu.net!rcogate.rco.qc.ca!news.total.net!news
From: Vincent Charron <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: ANLI AT-2
Date: Fri, 05 Jul 1996 22:44:04 -0400
Organization: Total Net
Lines: 8
Message-ID: <[e-mail]>
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Does anybody know if this is a good twin-band mobile antenna? My local
ham dealer only has one left in stock and swears it's a good performer.
Although short in lenght apparantly has good db gain?

Please let me know.

Vince
VE2 IFR


From [e-mail] Thu Jul 11 16:56:13 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.earthlink.net!usenet
From: [e-mail] (Ross Archer)
Newsgroups: alt.ham-radio.vhf-uhf,alt.ham-radio.am,alt.ham-radio.fm,alt.ham-radio.ssb,rec.radio.amateur.dx,rec.radio.amateur,rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Re: Antenna Driving me nuts
Date: Sat, 06 Jul 1996 10:33:10 GMT
Organization: Woofmix Enterprises Int'l - Makers of Meowmix for dogs
Lines: 59
Message-ID: <4rlffs$[e-mail]>
References: <4qsk9b$[e-mail]>
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Xref: news2.epix.net rec.radio.amateur.dx:98 rec.radio.amateur.antenna:23140 rec.radio.amateur.equipment:30932

[e-mail] (Chris Valliant) wrote:


>       I have been trying for the last two weeks to build a half wave
>diapole antenna.  I have read the book twice, done my calculations down to
>the half inch, used several different gauges of wire, several makes of
>coax cable but I cannot get the SWR reading below 6:1.  Even with an
>antenna tuner I cannot get an acceptable SWR reading. It's driving me to
>the funny farm. I have about a mile of wire in my apartment and have run
>out of ideas.  Here is what I am trying to do:  to build a 1/2 wave
>diapole for the 28-29 mhz.  I splice the coax, solder one end to a length
>of wire 8.2 feet and the other braided end to a length of wire the same
>size. I suspend both ends using insulated clamps between two tree's,
>making sure that the whole antenna is parallel to the ground and it's 8
>feet above the ground. Now when I check the SWR, it's unbelieveable.  Like
>I have said before, I have used different wire, different coax (the
>standard coax, just different brands). What am I doing wrong ?  Can anyone
> spot my mistake ? I will gladly make it up to whomever spots my error.
>Anyway, thanks for listening.

>       73's
>       Chris Vallliant

You need to put your antenna higher or go to a vertical that works
against the ground if you can't raise it to at least 1/2 wavelength
high.

First, 8 feet off the ground is barely 1/4 wavelength off the ground
at 10 meters.  This is doing three bad things:
1.  It throws off (reduces) the impedance of the antenna
     feedpoint, because the ground is partially conductive
     and in the antenna's near-field.  This is bad, because
     a dipole is balanced and doesn't need a ground to work
     against.  And obviously, this raises the SWR.

2.  The ground actually will absorb power from your transmitter.
      It's the "heat the earthworm" factor.

3.   It messes up your radiation pattern.  It will look more like an
      isotropic antenna and put a lot of energy at high angles.
      At 10 meters, this you do not want.


That being said, I doubt your SWR is actually 6:1.
I read in the Radio Amateurs Handbook that you
need a balun at the antenna feedpoint, or otherwise
strong currents will flow on the outer conductor, pretty
much equal to the current flowing in the inner conductor.
For some reason I don't understand, this "confuses"
SWR meters and other equipment since the shield
is not supposed to carry current.

So, try the balun, and raise the antenna another 8 feet, and
I bet you'll get a much better SWR.
Just my $0.02 worth.

Ross




From [e-mail] Thu Jul 11 16:56:14 1996
Path: news2.epix.net!uunet!in1.uu.net!ott.istar!istar.net!van.istar!van-bc!nntp.portal.ca!news.bc.net!unixg.ubc.ca!aurora.cs.athabascau.ca!mag-net.com!ve7tcp.ampr.org!news1.ucsd.edu!news-mail-gateway
From: [e-mail] (Monty Newberry)
Newsgroups: rec.radio.amateur.antenna
Subject: Antenna on an Oldsmobile Sillouette Minivan
Date: 6 Jul 96 22:15:15 GMT
Organization: na
Lines: 4
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

Does anybody have any antennas attached to an oldsmobile Sillouette
minivan?? if so how other than on the glass type for vhf?
Monty Newberry
[e-mail]


From [e-mail] Thu Jul 11 16:56:15 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-fw-22.sprintlink.net!nntp.earthlink.net!usenet
From: Chris Boone <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna setup for Repeater I/O??? Duplexers??
Date: Wed, 10 Jul 1996 13:37:48 -0700
Organization: Help! I work for ENTERGY!
Lines: 11
Message-ID: <[e-mail]>
References: <[e-mail]>
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Drew Loker wrote:
>
> I am trying to configure my antenna setup for a crossband repeater
> operation, but am a bit confused. I am aware that on our club repeater,
> they have two antennas, one for the input freq., and another for the
> output. How exactly is this connected to a radio?
> All inband repeaters in the Beaumont area use duplexers and one antenna
per system.

Chris
WB5ITT


From [e-mail] Thu Jul 11 16:56:16 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!news.telalink.net!nash-pm3-s8.telalink.net!user
From: [e-mail] (Bruce W. Martin)
Newsgroups: rec.radio.amateur.antenna
Subject: Antenna's for a Saturn
Date: Sun, 07 Jul 1996 12:49:05 -0500
Organization: Dragoon Systems
Lines: 21
Message-ID: <[e-mail]>
NNTP-Posting-Host: nash-pm3-s8.telalink.net
Mime-Version: 1.0
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I am working with a prospective ham and he has a Saturn sedan. I am
looking for advice from Saturn owners for mounting antennas on the car. It
looks like an NMO on the trunk will work fine. Any information will be
appreciated.

73
Bruce, KQ4TV

--
--
*****************************************************************
* Bruce W. Martin           Internet: [e-mail]     *
* 4558 Brooke Valley Dr.    HAM Call: KQ4TV                     *
* Hermitage TN  37076-2650                                      *
* Voice:     [phone] Targeting:36 10 30 N/86 35 30 W     *
* FAX/MODEM: [phone]      APRS:3610.50N/08635.50W        *
* URL:  http://www.telalink.net/~martinbw/home.html             *
*        ftp://ftp.telalink.net/~martinbw                       *
*    I have a 486DX33 to play games and run some HAM programs,  *
*        when I want to do serious work I use a Macintosh.      *
*****************************************************************


From [e-mail] Thu Jul 11 16:56:17 1996
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From: [e-mail] (PATRICK STODDARD)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna's for a Saturn
Date: 10 Jul 1996 16:58:03 GMT
Organization: Arizona State University
Lines: 53
Message-ID: <4s0ner$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


Hello.

I have a '92 Saturn sedan, and I am currently using a glass-mounted
dual-band antenna (the RadioShack model - same as the one MFJ sells).
I only use 2m right now, sometimes with an amplifier for out-of-town
trips (40W to the antenna), and I have under 1.4:1 SWR across the
entire 2m band. I have not tried a 70cm rig on it, but I put the
short (6" approx.) metal whip that hooks around the coak connector
on the glass mount in anticipation of getting a dual-band mobile rig
or HT soon. The rear window should have a black strip around the edge
of the glass, and across the top of the rear window there are lots of
black dots with a clear square at the top-centre of the window. I
mounted the antenna there. No problems. Since it isn't on the centre
of the roof, the antenna can act like it favors certain directions,
but in general use it is OK.

On my trunk there is a support beam that runs from the glass edge to
the bumper edge, right down the middle. You might be able to get a
hole drilled, and - with some work - mount an NMO in the centre. If you
are installing 2 antennas (one on driver's side, one on passenger's
side, of the trunk) is no problem to do. Running the coax from the
rear to the front is not hard - the moldings along the door edge and
glass edge can be pulled back enough to tuck the coax into.


The RS/MFJ glass antenna looks like a cellular antenna on steroids -
26" length, with a coil about 1/3 of the way up from the bottom. Easy
to remove for car washes or very low garages - I can drive to the
Phoenix airport where the signs say 6'8" clearance and not hit a thing
with it straight up in the air off the glass.

(and the car, being almost 4 1/2 years old, has 128000 miles on the
odometer, and I could easily do a commercial for Saturn about how
reliable and cheap the car has been to drive and maintain).


The 40W doesn't seem to affect any of the computer circuitry in the
car, but - again - I haven't tried high power on 70cm (or any HF).
Once, with a mag-mounted 23cm antenna, Kenwood TH55AT 1200MHz HT,
and 10W amplifier I ran that in the car along with the 2m while in
Los Angeles and San Diego, and no problems with that. I have not
made any plans to permanently install the 23cm gear in the car, as
Phoenix's only 2 repeaters on 23cm are off-air at present, and there
isn't anyone using 23cm for much more than an input frequency for
an FMTV repeater (with output on 902MHz somewhere).

Good luck!
--
Patrick E. Stoddard           Internet:  [e-mail]
Glendale, Arizona, USA        AX.25:     [e-mail]
                              Facsimile: [phone]
                              ICBM:      33.3 N 112.0 W (close enough)


From [e-mail] Thu Jul 11 16:56:18 1996
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From: [e-mail] (Owen Evans)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Anyone ever used an Outbacker?
Date: 8 Jul 1996 13:12:14 GMT
Organization: Netway Technologies
Lines: 12
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References: <4rh8v8$[e-mail]>
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In article <4rh8v8$[e-mail]>, [e-mail] says...
>
>If so, are you happy you have?

I have used a terlin tuned to the 80, 40, 20, and ten meter bands with a
Kenwood 440s. I can use the inbuilt antenna tuner to tune the antenna set
to 80 meters on all the bands plus some rfds frequencies. It is probably
better to use the shorting plug but it has served me well. Many a
commercial operation uses Terlins and they cant all be wrong.

Owen, [e-mail]



From [e-mail] Thu Jul 11 16:56:18 1996
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From: [e-mail] (Alex Evonosky)
Newsgroups: rec.radio.amateur.antenna
Subject: apartment dweller
Date: Sun, 07 Jul 1996 23:09:37 GMT
Organization: Zippo
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Was wondering what would be a good OSCAR antenna for apatment
dwellers?  one for 145mhz and the other for 440mhz???

Any suggestions?

Best 73,
Alex - kb4lbx




From [e-mail] Thu Jul 11 16:56:21 1996
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (John Seboldt)
Subject: Balun on tuner input?
Message-ID: <rohrwerk-0607961258310001@10.0.2.15>
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I know there was a thread a while back that hotly debated whether putting a
balun on the *input* of a tuner (floating from ground) constituted a true
balanced tuner.  Example:  Zack Lau's "A Balanced QRP Transmatch" in QRP
CLASSICS, or Feb. 1990 QST, "A *Balanced* Balanced Antenna Tuner".

Well, a bit of empirical evidence came my way today, as I was refining my
small breadboard antenna tuner for QRP portable use.  It's an SPC circuit,
with a 1:1 balun on the input, 3 turns each winding on a BN-43-3313 core.
I added a switch to bypass the balun (just shorting each leg, I was too
lazy to do a full 4PDT switching arrangement :-) ).

I loaded up my 350 foot horizontal loop fed with ladder line, and tried
switching the balun in and out.  The matching adjustment changed only a
tiny bit, but there was a *dramatic* difference in the electrical noise
heard on receive!  I have always had a steady buzz/sputter on 20 meters at
this location during the day, which disappears occasionally for short
periods.  With the balun in, it was much reduced, while signals remained
pretty much the same (to my ear at least).

Which seems to confirm two things: 1) the immunity to man-made noise of
various loops (with proper balanced feed) and 2) that a tuner of this
configuration has at least some attributes of a true balanced tuner.

Confirmations? Confutations?

: John Seboldt \  Duke Ellington on CW:    It don't mean a thing
: [e-mail] | Ham: K0JD  \     If it ain't got that swing!
: Minneapolis, MN USA | Music Dir., \   Didah, didah, didah, didah,
:    Church of the Annunciation      \          ..........


From [e-mail] Thu Jul 11 16:56:22 1996
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From: "William E. Sabin" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Balun on tuner input?
Date: Sat, 06 Jul 1996 22:15:31 -0700
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John Seboldt wrote:
>
> An addendum:  using another tuner, same SPC configuration, but with a coax
> choke balun on the input (about 20 feet RG58 wound on 5 inch PVC pipe),
> the noise rejection was not as good.  Now apparently *this* is a far less
> satisfactory quasi-balanced tuner, whether because of the choke balun, the
> size and layout of the components (long leads, kind of sloppy layout), I
> don't know.
>


Is it possible that the balun is attenuating "common-mode" noise from
traveling *outward* from the shack to the antenna, where it is then
converted into a "conventional" noise signal that then gets back into
the receiver?  I believe I have encountered this problem due to noise
generated by a noisy TV set in my house.

Bill W0IYH


From [e-mail] Thu Jul 11 16:56:23 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Balun on tuner input?
Date: 7 Jul 1996 23:20:59 -0400
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Hi John,
In article <rohrwerk-0607961258310001@10.0.2.15>, [e-mail]
(John Seboldt) writes:

>I know there was a thread a while back that hotly debated whether putting
a
>balun on the *input* of a tuner (floating from ground) constituted a true
>balanced tuner.  Example:  Zack Lau's "A Balanced QRP Transmatch" in QRP
>CLASSICS, or Feb. 1990 QST, "A *Balanced* Balanced Antenna Tuner".

My comments were moving the balun to the input does nothing to improve the
choking ability of the balun. In other words, it doesn't improve the
ability of the balun to balance the system.

It has a useful effect on differential mode power limits.

>Well, a bit of empirical evidence came my way today, as I was refining my
>small breadboard antenna tuner for QRP portable use.  It's an SPC
circuit,
>with a 1:1 balun on the input, 3 turns each winding on a BN-43-3313 core.

>I added a switch to bypass the balun (just shorting each leg, I was too
>lazy to do a full 4PDT switching arrangement :-) ).
>
>I loaded up my 350 foot horizontal loop fed with ladder line, and tried
>switching the balun in and out.  The matching adjustment changed only a
>tiny bit, but there was a *dramatic* difference in the electrical noise
>heard on receive!  I have always had a steady buzz/sputter on 20 meters
at
>this location during the day, which disappears occasionally for short
>periods.  With the balun in, it was much reduced, while signals remained
>pretty much the same (to my ear at least).
>
>Which seems to confirm two things: 1) the immunity to man-made noise of
>various loops (with proper balanced feed) and 2) that a tuner of this
>configuration has at least some attributes of a true balanced tuner.

It should help that. If you move the choke balun to the output of the
tuner, it will help exactly the same amount.

73 Tom


From [e-mail] Thu Jul 11 16:56:24 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Balun on tuner input?
Date: 7 Jul 1996 23:53:17 -0400
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In article <[e-mail]>, "William E. Sabin"
<[e-mail]> writes:

>Is it possible that the balun is attenuating "common-mode" noise from
>traveling *outward* from the shack to the antenna, where it is then
>converted into a "conventional" noise signal that then gets back into
>the receiver?  I believe I have encountered this problem due to noise
>generated by a noisy TV set in my house.
>
>Bill W0IYH

Bill brings up a very good point in his comment.

Common mode currents cause multiple problems. Without a balun noise can be
conducted to the antenna, as well as the more obvious lack of a balun
unbalancing the antenna.

On ALL my low noise receiving arrays, I use multiple choke baluns spaced
every hundered feet or so along the feedline as the line gets near the
arrays. It makes a huge difference in conducted noise.

73 Tom


From [e-mail] Thu Jul 11 16:56:26 1996
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From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insu
Date: Tue, 9 Jul 1996 06:46:39 +0100
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CHARLES J. MICHAELS wrote:
>
>       Legend has it that Brown installed 32 MHz system for NY
>police.  He used an elevated resonant qurter wave vertical with two
>opposing horizontal radials at headquarters.
>       The police department consultants argued that this would
>produce a horizontal component (it wont, check it out with eznec or
>elnec) so to please them Brown added two more at 90 degrees.

Actually, the two-radial GP will produce four small horizontal sidelobes
in a clover-leaf pattern at +-45deg from the line of the radials.

A few years ago, sitting at a table in an English pub, I watched KC6W
calculate the complete current distribution and radiation pattern of the
two-radial GP from first principles. If those four minor sidelobes
hadn't dropped out from his math, I certainly wouldn't have known about
them   :-)

There was no chance of getting to sleep that night without cranking the
problem through NEC. If you run the program using pure horizontal and
vertical polarizations instead of the usual mixed-polarization sum,
there they are at about -10dB. The wisdom of hindsight says it's because
the opposing currents flowing in the radials are not quite coincident in
space.

The irony is that the four-radial GP has them too... as Brown probably
knew full well.


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


From [e-mail] Thu Jul 11 16:56:27 1996
Path: news2.epix.net!uunet!in2.uu.net!news1.erols.com!news
From: Jake Brodsky <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Buried radials: Insulated or bare?
Date: Mon, 08 Jul 1996 14:59:39 -0700
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Even if someone could show that a vertical antenna with an elevated
radial system is "better" than one at ground level, how does one
account for the simple fact that the antenna is higher?  I'm tempted
to build some models for VHF or UHF and study that.

And the real question is this:  If one could mount the elevated
version of the vertical at 1/2 wave above the earth ground --what
would it look like?  What would it look like if it were 1/4 wave
above the ground?  Aren't we playing around with the effectiveness
of the ground radial mirror here?  Isn't the quality of the earth
ground plane an issue here?

I think that what we're measuring here is the efficiency of earth
ground verses a radial ground.  Think about the elevated vertical plus
radials in free space.  Now think about it with a ground plane
somewhere below.  Does it really make any difference?  Only if the
radial system is less than perfect and/or the ground is less than
ideal.  --No wonder we're having trouble getting the models to
match reality.

73,

Jake Brodsky, AB3A
"Beware of the massive impossible!"


From [e-mail] Thu Jul 11 16:56:28 1996
Path: news2.epix.net!news
From: Scott Yerger <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Cushcraft R5 Antenna
Date: Thu, 11 Jul 1996 08:37:23 -0400
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Anyone,

   Looking for documentation for the Cushcraft R5 HF Vertical
 antenna.  Bought one used without docs.  Need docs for tuning
 antenna.  Any information appreciated!

Scott


From [e-mail] Thu Jul 11 16:56:29 1996
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Gary Wilcox)
Subject: Delta Loop
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ALL

        Where can I find plans for a Delta Loop. I would like to
put up a square loop but don't have 4 supports (trees). I do however
have 2 trees and a tower that form a triangle about 150' on each side.

tnx and 73's
---
                            \\|||//
                             |^ ^|
                             (0|0)
/------------------------oOO--(_)--OOo---------------------------\
|  Gary Wilcox (KE4VUN)          E-MAIL: [e-mail]|
|  Commonwealth Aluminum                                         |
|  Hwy 1957                      FAX:    [phone]          |
|  Lewisport Ky.                 VOICE:  [phone]          |
\---------------------------ooo-ooo------------------------------/


From [e-mail] Thu Jul 11 16:56:29 1996
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From: [e-mail] (Ludichrist)
Newsgroups: rec.radio.amateur.antenna
Subject: Directional 46-49mhz antenna
Date: 10 Jul 1996 05:23:11 GMT
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I purchased a book today on antennas, expecting to find some guidance to
building a DIRECTIONAL antenna specifically for the 46-49 Mhz range;
Unfortunately it was no help. Can Anyone recommend a good design for such
a set up? Right now I'm just using a dipole cut to specs. Thanks in
advance for any information on this...

-P.




From [e-mail] Thu Jul 11 16:56:30 1996
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From: warren <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Directional 46-49mhz antenna
Date: 11 Jul 1996 06:04:03 GMT
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What are you listen to cordless phones look out ppl goto jail for that!!!



From [e-mail] Thu Jul 11 16:56:31 1996
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From: Tim Robertson KC7QOM <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: DX Wire Antenna Suggestions?
Date: Thu, 11 Jul 1996 10:43:28 -0700
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Hello To All,
 I'm a fairly new TechPlus looking for advice and suggestions on antenna
selection. I'm interested in DXing and would appreciate input on what
makes and types of wire antennas would work best for Multiband DX. I
currently am using a shortened dipole from VanGorden but wondered about
if there was something better?
Thanks in advance.
73s
Tim,KC7QOM


From [e-mail] Thu Jul 11 16:56:33 1996
From: Jay123a <[e-mail]>
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Keith Nelson <[e-mail]> wrote:
>I am W6KLK.  I am using my Yaesu FT-890 in my 1992 Toyota PU V-6 for
>mobile operation.  The noise from the electronic engine control
>(located on the passenger side panel) is severe and making reception
>impossible.  I am an electrical engineer and I have done mobile
>noise supression in the past (1950ties) but I am stumped on this
>one.  It appears to be radiated interference, not conducted, but I
>may be mistaken.
>
>I would appreciate suggestions on how to solve the problem.
>
>Please respond by email.  Thanks!
>
>Keith W6KLK  <[e-mail]>

Hello Kieth:

Suggest you turn everything on and then remove the antenna connector to
the rig, if the noise disappeared then the noise is comming in through
the antenna. I had a problem with altenator noise getting into my cheap
CB Radio. I put together a high pass filter in the antenna coax line, it
suprisingly worked very well. The filter was a telephone surplus 88 mH
torid core inductor wired across a 1 or .1 none polarized capacitor, and
this was wired in series of the coax center conductor. I have no idea as
to what the insertion loss was but the radio seemed to work ok.

The tuned circuit worked in attenuating the radited noise from the
altanator, might give this a try for your problem. It shouldnt cost much
to put together.

Jay.



From [e-mail] Thu Jul 11 16:56:35 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Elevated Radials
Date: 7 Jul 1996 23:54:37 -0400
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Hi Lawrence,

In article <[e-mail]>, [e-mail] (Lawrence
Stoskopf) writes:
>
>This looks like the thread that won't die so here is a comment as an
>interested observer.  W8JI and N1MM (who I think was at Culpepper's talk
at
>Dayton) have forwarded some discussion and I see that Jim Breakall (the
>guhru of modeling just logged out of this group....what is the GIFfer
>Skylink anyway?) So same random background C.V.

I spoke with Jim at Dayton. We seemed to mutually agree that A-B
measurements were needed. I hope we eventually get them done. I really
would like someone near my area to come over some weekend, and I'll repeat
the tests. I have empty pastureland northeast of here that can be used for
a test.

>Sorry this got long and personal, but might be of interest to some.
Thanks
>to Christman, Culpepper, Brown, etc for the data and guys like Moritz and
>W8JI for keeping this forum active with candid and helpful comments.  A
few
>years ago we wouldn't have had this type forum.

Personally, I feel the proper point in time to scientifically test a new
innovative theory is before publication. To this date, that hasn't been
done in this area. To the best of my knowlege, there have only been two
A-B tests.

As for the other data using a long trail based on FCC estimated FS
intensity, it seems to me it takes longer to follow the winding trail of
estimates than it would take to make a proper test.

73 Tom


From [e-mail] Thu Jul 11 16:56:36 1996
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From: Jake Brodsky <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Elevated Radials (was Buried radials: Insulated or bare?
Date: Mon, 08 Jul 1996 15:15:01 -0700
Organization: Wheeeeee!
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Dave Hand wrote:

> What is the merit of tuning the ground system to resonance with
> something like the mfj artificial ground ???

Where would you put this thing?  How would you hook it up?  If you're
thinking of loading up the radials, I think that has already been
done.  Ever heard of an R7?  It works, but like any loading system
on the base or the radials, it doesn't work as well as a well matched,
vertical with lots of radials and/or a good ground.  There are no
shortcuts.  If you make those choices, the only question is how bad
is it likely to get?

73,

Jake Brodsky, AB3A
"Beware of the massive impossible!"


From [e-mail] Thu Jul 11 16:56:37 1996
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From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: EZNEC and Windows 95
Date: 6 Jul 1996 03:24:55 GMT
Organization: Arizona State University
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NNTP-Posting-Host: aztec.asu.edu


Don Taylor, W9NFM said -
        and dot matrix printers are obsolete.

Don,
        Quiet please, I don't want my dot matrix printer to know.
Charlie, W7XC
--


From [e-mail] Thu Jul 11 16:56:37 1996
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From: [e-mail] (FORREST GEHRKE)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: EZNEC and Windows 95
Message-ID: <[e-mail]>
Date: Sun, 07 Jul 96 13:45:00 -0300
Distribution: world
Organization: Central Core BBS, 201-575-8991
Reply-To: [e-mail] (FORREST GEHRKE)
References: <4rkma7$[e-mail]>
X-Newsreader: PCBoard Version 15.22
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Lines: 9

CM> and dot matrix printers are obsolete.

CM> Quiet please, I don't want my dot matrix printer to know.

Likewise.  I had to turn off my Okidata 390 dot matrix
so it wouldn't be able to read this post. ;-)
//
  k2bt
 * RM 1.3 02583 * ON THE EIGHTH DAY, GOD MADE THE BAGPIPES.


From [e-mail] Thu Jul 11 16:56:38 1996
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From: [e-mail] (Howard Sherer)
Newsgroups: rec.radio.amateur.antenna
Subject: FS Outbacker Perth mobile HF ant
Date: Mon, 08 Jul 1996 15:41:13 -0400
Organization: ProLog - PenTeleData, Inc.
Lines: 2
Message-ID: <[e-mail]>
NNTP-Posting-Host: cs4-2.con.ptd.net

Mint condition $220.
Howard AE3T


From [e-mail] Thu Jul 11 16:56:39 1996
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From: [e-mail] (Jim Garver)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Grounding Antennas
Date: 11 Jul 1996 16:29:16 GMT
Organization: Intel Corp., Hillsboro, Oregon
Lines: 16
Message-ID: <4s3a4s$[e-mail]>
NNTP-Posting-Host: pdx804.intel.com


While visiting the Toledo, Washington airport, I observed the NDB
(Non Directional Beacon) antenna and transmitter located on field.
The Toledo NDB is Morris identified as TDO at 219 Khz.
The antenna is a center loaded vertical about 30-40 feet high with a
capacitive hat of maybe 8 or 10 long radials.
A newer solid state transmitter had been installed and I followed the
ground wire down to where it connected to only one of many ground
wires sticking up out of the cement base.  Apparently there is a
large ground radial system there but for some reason the FAA technician
chose to use only one of the radials even though there was a common
bus bar connector nearby with most of the other radials connected to it.


--
[e-mail]          WA7LDV            I don't speak for Intel


From [e-mail] Thu Jul 11 16:56:40 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsfeed.internetmci.com!news.fibr.net!nntp.primenet.com!uunet!in1.uu.net!news.encore.com!psoper
From: [e-mail] (Pete Soper)
Subject: Re: Grounding Antennas and the NEC
Organization: Encore Computer Corporation
Date: Tue, 9 Jul 1996 23:40:42 GMT
Message-ID: <[e-mail]>
X-Nntp-Posting-Host: sysgem1.encore.com
References: <4ru16l$[e-mail]>
Sender: [e-mail] (Usenet News)
Lines: 45

Hello Jim,

[e-mail](Jim and Donna Sens ) writes:

>The NEC requires having a single point where the 115VAC neutral
>and the "earth" ground connect together.  In most cases, that point
>is inside a circuit breaker box.

>What do most of you do?

My reading of the NEC is that earth grounds must be bonded together.
I've given no thought to the neutral connections per se.

I've added 8' ground rods at four places around the back yard with
#6 copper wire bonding them together. The station ground is the center,
with grounds going out to the house service panel ground and the other
ground rods in a star arangement. The runs from the station ground are
approx. 30, 50, 100 and 130 feet. At the station ground is a copper plate
connected to a ground rod with a four inch, very stout connection. My
coax suppressors are bonded to the copper plate. At the base of the antennas
are ground rods with their own suppressors.  I feel it is very important to
arrange for a strike to go to a good ground and suppressor combination well
away from the station ground, and to run the feedlines as low as practical
to the station ground panel. It's beem pounded into me that a strike that can
follow a feedline into my station ground point will lead to severe grief,
no matter what is in the way. Disconnecting equipment during dangerous times
also seems to be a must.

The house has a very high capacity MOV based suppressor at the service panel
with legs between the two sides of the 220v and the ground/neutral point in
the panel. At the service panel of the station there is a similar suppressor.

Bye the bye, the 100 foot tulip poplar that held up one end of my prime
european antenna was destroyed by a thunderstorm last week. I think the
reason it came down is that it was hit by lightning last year and although
it seemed there was only a three inch wide black "tatoo" down its side, it
must have blasted the insides at the 50 foot point, as that's where it
snapped off last week. Sure put a crimp in my HF contesting plans as there
isn't another tree in the right position for a high gain wire antenna. It's
also redoubled my resolve to do everything I can afford to deal with the
"when, not if".

Regards,
Pete
KS4XG (on a ridge in North Carolina)


From [e-mail] Thu Jul 11 16:56:41 1996
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From: [e-mail] (Alex Evonosky)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Antennas..Evaluations
Date: Sun, 07 Jul 1996 23:14:16 GMT
Organization: Zippo
Lines: 23
Message-ID: <4rpgpg$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: 206.155.199.10
X-Newsreader: Forte Free Agent 1.0.82

[e-mail] (Glenn Taylor) wrote:

>Considering purchase of an Alinco DX-70T (HF + 6Mtr), Pwr Supply and
>either an MFJ Super Hi-Q Loop (Model MFJ-1786) or the AEA IsoLoop. I would
>have to install the antenna indoors due to condo restrictions. They are
>about $100 difference in price, but if one radiates better than the other,
>or matches easier than the other, price would not be a consideration.

>Does anyone have any experience with either antenna who might be able to
>provide comments that might influence a buying decision?

>Any insights would be appreciated,
>Glenn Taylor, K1ES

I have  the aea isoloop for my apartment.  Works very well and live on
the first floor.  I can't say abt the MFJ model, but as for me AEA
works good.  I would like to get the auto tuner, but other than that,
IT works fine.  A 50' tower with Force 12's would be better, hi hi..

best 73,
Alex - KB4LBX




From [e-mail] Thu Jul 11 16:56:42 1996
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From: [e-mail](Tom Wagner)
Newsgroups: rec.radio.amateur.antenna
Subject: How Do I Fix a Hy-Gain Balun?
Date: 7 Jul 1996 13:57:02 GMT
Organization: Pipeline
Lines: 21
Message-ID: <4rofne$[e-mail]>
NNTP-Posting-Host: 38.8.149.6
X-PipeUser: n1mm
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X-PipeGCOS: (Tom Wagner)
X-Newsreader: Pipeline v3.5.0

Last winter, my rotor came apart and my TH-7 started
"windmilling".  This pulled coax out of the balun that
comes with the antenna.  There is a SO-239 type
connecter in it and the threaded sleeve pulled away
from the bottom of the connector, leaving the center
insulator.

The balun enclosure is made of plastic, and seems to be
glued together.  I am at a loss as how to repair
the SO-239 without destroying the plastic enclosure.

Has anyone had this problem with their
station and found a good way to fix it?  If you had
to destroy the plastic enclosure, what did you to
replace it?

Thanks!

73,
Tom - N1MM



From [e-mail] Thu Jul 11 16:56:43 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Inverted Vees vs. Sloppers
Date: 8 Jul 1996 16:38:54 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 20
Sender: [e-mail]
Message-ID: <4rrrku$[e-mail]>
References: <4rrh57$[e-mail]>
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In article <4rrh57$[e-mail]>, Chester Bowles <[e-mail]>
writes:

>
>I know its not a sloper (or a slopper) in the true sense of the word, but

>what about a dipole with one end supported at the top of the tower and
>the other end supported 8-10 feet off the ground.  In which direction
>would the antenna radiate?  In the direction of the slope?  Or broadside
>the antenna (as with a typical dipole)?
>
>Chet, AA1EX

That is a true sloper Chet, and usually (but not always) they radiate in
the direction of the downward slope.

The self-resonant frequency of the tower can have large effects on the
direction pattern.

73 Tom


From [e-mail] Thu Jul 11 16:56:44 1996
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From: Chester Bowles <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Inverted Vees vs. Sloppers
Date: 10 Jul 1996 15:09:01 GMT
Organization: Crotched Mountain Foundation
Lines: 38
Message-ID: <4s0h2d$[e-mail]>
References: <4rrh57$[e-mail]> <4rrrku$[e-mail]>
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[e-mail] (W8JI  Tom) wrote:
>>what about a dipole with one end supported at the top of the tower and
>>the other end supported 8-10 feet off the ground.  In which direction
>>would the antenna radiate?  In the direction of the slope? Or broadside
>>to the antenna (as with a typical dipole)?
>>
>>Chet, AA1EX
>
>That is a true sloper Chet, and usually (but not always) they radiate in
>the direction of the downward slope.
>
>The self-resonant frequency of the tower can have large effects on the
>direction pattern.
>
>73 Tom


I hate to beat a dead horse, but what if the high end of the sloping
dipole is supported by a tree (or other non-metal structure) instead of a
tower?

I understand how a tower (or grain silo to use another example which
appeared in this string) would function as a "reflector" for the signal
from the dipole.  What happens if the supporting structure is NOT metal?

Chet, AA1EX

--
*---------------------------------------------------------------------*
| CHESTER S. BOWLES            | Education, rehabilitation, housing,  |
| Vice President               | and managed care for children,       |
| Crotched Mountain Foundation | adolescents and adults with physical |
| One Verney Drive             | and developmental challenges.        |
| Greenfield, NH 03047         | http://www.cmf.org                   |
| 603.547.3311 ext. 404        | [e-mail]                       |
*---------------------------------------------------------------------*




From [e-mail] Thu Jul 11 16:56:44 1996
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From: [e-mail] (Bob Bruhns)
Newsgroups: rec.radio.amateur.antenna
Subject: Long Wire Antenna
Date: 8 Jul 1996 18:07:12 GMT
Organization: LI Net (Long Island Network)
Lines: 17
Message-ID: <4rriog$[e-mail]>
NNTP-Posting-Host: linet01.li.net
X-Newsreader: TIN [version 1.2 PL2]

  A random longwire in the backyard - yes, that's what most of us did way
back when, and it does bring in shortwave much better than a short whip
will.

  The problem you can have with newer digital shortwave receivers is
out-of-band overload, because their front end selectivity is usually very
poor.  If you find that sometimes the big antenna picks up odd ghostly
interfering signals that you did not hear with the whip, the receiver is
probably being overloaded.  My DX-440 has this problem when I connect an
outside antenna, and it helps to turn down the RF gain.  The best thing
would be to use an antenna tuner, which would provide the front-end
selectivity that many of the digital shortwave receivers lack.  These can
be expensive to buy, but they are pretty easy to build if you have a well
stocked radio parts junkbox.

  Bob Bruhns, WA3WDR, [e-mail]



From [e-mail] Thu Jul 11 16:56:45 1996
Path: news2.epix.net!uunet!in2.uu.net!news.micron.net!news.sprintlink.net!news-stk-11.sprintlink.net!news1.inlink.com!news2.inlink.com!usenet
From: [e-mail] (Gary V. Deutschmann, Sr.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Looking for plans on homebrew antenna
Date: Sat, 06 Jul 1996 02:44:09 GMT
Organization: Inlink
Lines: 25
Message-ID: <4rkkcq$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: pm00113.inlink.com
X-Newsreader: Forte Free Agent 1.0.82

Dwayne Dickey <[e-mail]> wrote:

>Does anyone have any plans on construction of a multi-band VHF antenna.
>It's primary use will be scanning with the possibility of 2m transmit
>(SWR permitting).  Can anyone help.

>Thanks
>73's
>Dwayne
>N5TUI

Hi Dwayne

I have a multi-band J-Pole on my web page
http://www.inlink.com/~raiar   Amateur page to Copper Cactus page.

But I think a discone type antenna would probably be your best bet if
scanning is your principle interest.  Rat-Shack has one that works
quite well and transmits on 2-meter through 440 also.

TTUL
Gary





From [e-mail] Thu Jul 11 16:56:46 1996
Path: news2.epix.net!uunet!in2.uu.net!ott.istar!istar.net!news.nstn.ca!coranto.ucs.mun.ca!usenet
From: "Jim Johnston" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Need 80m antenna for small space
Date: Mon, 8 Jul 1996 16:22:55 -0230
Organization: Memorial University of Newfoundland
Lines: 12
Message-ID: <01bb6cfe.ac84d4e0$[e-mail]>
NNTP-Posting-Host: n098h018.remote.mun.ca
X-Newsreader: Microsoft Internet News 4.70.1080

I was wondering if anyone would be able to provide me with the plans for
an 80m antenna that does not require a lot of space.  My backyard is not
very large, and I do not have a tower to inable me to have a inverted V.
I was wondering if anyone has heard of any good atic antennas for 80m?

Please E-mail all responses to [e-mail]

73
V01ZM
Jim Johnston
St. John's, NF
Canada


From [e-mail] Thu Jul 11 16:56:47 1996
Path: news2.epix.net!uunet!in1.uu.net!newsxfer2.itd.umich.edu!netnews.worldnet.att.net!newsadm
From: [e-mail] (Douglas Cohron)
Newsgroups: rec.radio.amateur.antenna
Subject: Need antennae info gor 2m/440
Date: Sun, 07 Jul 1996 14:31:52 GMT
Organization: AT&T WorldNet Services
Lines: 6
Message-ID: <4ro75g$[e-mail]>
NNTP-Posting-Host: 174.bridgeton-2.mo.dial-access.att.net
X-Newsreader: Forte Free Agent 1.0.82

I need information on how to make a 2m/440 antenna for an apt. I live
on the first floor and have no crawl or attic space. Any and all help
appreciated. Also, need info on a window mount 2m/440 antenna for my
police car. Thanks Doug Cohron.... So new I don't have my call sign in
yet.



From [e-mail] Thu Jul 11 16:56:48 1996
From: [e-mail] (ED WELCH)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need INFO, EVERYONE PLEASE READ!!..theory?
Message-ID: <[e-mail]>
Date: Sun, 07 Jul 96 10:31:00 -0600
Distribution: world
Organization: The Crenshaw County BBS/Luverne, AL/334-335-3968/ CHEAHA!!!
Reply-To: [e-mail] (ED WELCH)
References: <[e-mail]>
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-> >">I have 12 guage wire i can use, but need a little info,  what
-> length >">should i cut it at, to use it at 145.470  (local Repeater)
-> I dont


-> >When we took the Ham test didn't we have to show that we could
-> figure >frequency to wave length?

-> No, you merely showed that you knew how to memorize all the questions
-> and answers provided to you in advance.

I used the "Now You're Talking" study course and I gotta admit, it's
good.  As you go through it and finish a section it refers you to
several questions in the question pool, thus you learn as you go. You're
right about memorizing the questions....you could pass the test this
way, but you don't learn very much.  I'm a green newcomer awaiting my
tech+ ticket, but the theory has become a personal interest of mine.
It's a shame for folks who don't want to delve into it deep enough to at
least get an idea of novice/tech theory....some useful stuff there!  For
instance....rather than putting out the $$$ for a 4 element yagi, I'm
going to be putting together a 4 element quad for 10 meters.  It'll be a
bit complicated for a newbie like me, but I'll get it built...and I'll
*learn* as I go.

As for the length of the antenna in question....1.6085' for 1/4wave?

73
[e-mail]


From [e-mail] Thu Jul 11 16:56:49 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.primenet.com!news.asu.edu!aztec.asu.edu!hamop
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Old-Newbie Design/theory question
Date: 6 Jul 1996 03:54:25 GMT
Organization: Arizona State University
Lines: 36
Message-ID: <4rko1h$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


Andy,WD4RCC asked -
Before I spend a lot of time (that I really don't have) experimenting,
please look at the following. Will this antenna work for transmitting?
(This design is used for reception...) Five dipoles, each tied
together at the feedpoint, all wires spaced 3"-4" apart. I'm afraid I
never was really any good at antenna theory. Would this cause too much
coupling between the desired radiating element, and other non-tuned
elements for a given band - driving the SWR up? Or, being cut for a
specific band, would the unwanted radiators simply be "ignored"? I'm
sure this has been covered somewhere before, but I can't seem to put
my hands on it, and old antenna books are not to be found around here.

Andy,
        Yes, works fine.  You can separate the longer ones from the
shorter ones (if you want to) and use them as guys.
        The tuning should start with the longer ones progressing to
the shorter ones as a small change in the longer oes can sometimes
influence the shorter ones such as the 40 relative to the 15 and
the 80 relative to tthe 20 for example.
        If you use the longer ones as guys or separate them from
the others, try to maintain symetry relative to the feed line drop
.  That is , either make the 40 and 80 each in its own vertical plane
and 90 degrees apart in azimuth.  Or, put the wtwo 40 halves at 90
degrees to eahch other and the 80 halves 90 degrees to eahc other
with 90 degrtees between the 40s and 80s.
        This will minimize unsymetrical coupling to the coax shiled///
shield.
        In fact I run a 10 through 80 but not having room for the
80 dipole, i used 120 uH at each end of the 40 and about 3 feet of
#12 beyond that to get a narrow bandwidth on 80 around the QCWA
loacal sunday morning net .  I use a vertical on 80 otherwise but
the horizonal is better for local coverage by high angle .

Charlie, W7XC
--


From [e-mail] Thu Jul 11 16:56:50 1996
Path: news2.epix.net!uunet!inXS.uu.net!netnews.worldnet.att.net!newsadm
From: Merv Stump <[e-mail]@postoffice.worldnet.att.net>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Optimal Height?
Date: 9 Jul 1996 15:49:54 GMT
Organization: AT&T WorldNet Services
Lines: 20
Message-ID: <4rtv32$[e-mail]>
References: <4rshau$[e-mail]>
NNTP-Posting-Host: 63.middletown-61.va.dial-access.att.net
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Gareth you may get a lot of mail on this one, but I'll start with a couple
of rules of thumb:

1.  If it stays up it wasn't high enough.
2.  Any height is ok in the north east so long as it was put up during the
third week of January.

On a more serious note, I have found that yaggi's can be expected to
perform well at 5/8 wave length or higher assuming there are no
obstructions in the directions you want to go.  Going higher serves
to vary the maximum angle somewhat and you may want to go higher or lower
depending on what you want to do. For example from the east coast to
Europe a 20 meter beam at 50 feet will many times out perform one which is
at 90 feet.  On the other hand the 90 footer will best the 50 footer every
time into Asia.  On 20, 15, and 10 I've never seen much improvement above
90 or 100 feet.

Regards, Merv




From [e-mail] Thu Jul 11 16:56:51 1996
Path: news2.epix.net!uunet!in2.uu.net!skypoint.com!usenet
From: [e-mail] (pdunn)
Newsgroups: rec.radio.amateur.antenna
Subject: Outbacker ant any good?
Date: 7 Jul 1996 15:36:35 GMT
Organization: org
Lines: 3
Message-ID: <4roli3$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: dial171.skypoint.net
X-Newsreader: WinVN 0.92.6+

Anyone with experience with outbacker antennae fixed or mobile?

Phil ki0dm


From [e-mail] Thu Jul 11 16:56:52 1996
Path: news2.epix.net!uunet!in1.uu.net!scnews.sc.intel.com!itnews.sc.intel.com!news
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: QST advice - good or bad?
Date: 10 Jul 1996 15:11:47 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 17
Message-ID: <4s0h7j$[e-mail]>
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It is well known that changing the length of ladder-line will change
the impedance seen at the transmitter end. Here's some advice from
"The Doctor is IN" from the June issue:

"... Try connecting an additional 1/8- or 1/4-wavelength piece
of transmission line (ladder-line) in series with your (present)
line. Loosely coil the new line and tack the coil up on the
wall..."

Won't this advice result in a linear-loading effect that messes
up the characteristic impedance and causes losses? Or maybe
"loosely" means keep the legs a few inches apart, in which case,
they should have said so?

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Thu Jul 11 16:56:53 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!malgudi.oar.net!news.infinet.com!crenshaw!ed.welch
From: [e-mail] (ED WELCH)
Newsgroups: rec.radio.amateur.antenna
Subject: Quad question...
Message-ID: <[e-mail]>
Date: Sun, 07 Jul 96 23:47:00 -0600
Distribution: world
Organization: The Crenshaw County BBS/Luverne, AL/334-335-3968/ CHEAHA!!!
Reply-To: [e-mail] (ED WELCH)
X-Newsreader: PCBoard Version 15.21
X-Mailer: PCBoard/UUOUT Version 1.10
Lines: 31

I'm working on putting a quad together for 10 meters.  I might go ahead
and add 15 meters to it while I'm at it.  The question that I have is
how far away from the antenna element should the metal spider arms be?

In other words, I'm planning on using electrical conduit for the spider
arms to fasten to the center plate and extend wood dowels outward from
the conduit to which I'll fasten the actual antenna wire.

From what I can find out conduit comes in 10' sections and the longest
dowels that I've found come in 4' pieces. If I cut a 10' section of
conduit in half that would leave a 5' section of conduit that would be
coming within a foot and a half to the 10m element.....is this too close
for comfort?

If I decide to go ahead with the addition of the 15m element then I'd
have to find something else other than the 4' dowels to use as outer arm
pieces....I'll need something longer.  Would a 6' piece of pvc pipe be
stout enough to handle the two elements?  Anybody got any thoughts on
using pvc pipe for the outer portion of the spider?

I've ran into a stump as for as what to use for the outer arms.  I could
use bamboo, but the from what I can find out (and what I've seen from
fishing poles laying around) the bamboo isn't know for it's longetivity.
As of yet I haven't found a source for fiberglass poles.

Any help would be *greatly* appreciated on this matter, as this is
what's holding up the project.

Thanks!!!
73
[e-mail]


From [e-mail] Thu Jul 11 16:56:54 1996
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.internetmci.com!uwm.edu!math.ohio-state.edu!cs.utexas.edu!news.tamu.edu!news
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quad question...
Date: 8 Jul 1996 15:10:42 GMT
Organization: Texas A&M University, College Station, TX
Lines: 46
Message-ID: <4rr8di$[e-mail]>
References: <[e-mail]>
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NNTP-Posting-Host: 128.194.44.221
X-Newsreader: IBM NewsReader/2 v1.2

In <[e-mail]>, [e-mail] (ED WELCH) write
s:
>I'm working on putting a quad together for 10 meters.  I might go ahead
>and add 15 meters to it while I'm at it.  The question that I have is
>how far away from the antenna element should the metal spider arms be?
>
>In other words, I'm planning on using electrical conduit for the spider
>arms to fasten to the center plate and extend wood dowels outward from
>the conduit to which I'll fasten the actual antenna wire.

One of the harder parts of building good quads is finding things that aren't
metal for use as the spider part.....

:)

>I've ran into a stump as for as what to use for the outer arms.  I could
>use bamboo, but the from what I can find out (and what I've seen from
>fishing poles laying around) the bamboo isn't know for it's longetivity.
>As of yet I haven't found a source for fiberglass poles.

as you have noticed.

However, they really are needed, as I understand all this.

I've not gone about the quest.  I replaced my two 3 element lower wire quads
for 40 meters with a 4 square vertical array and never looked back.  I realize

that your 10 meter solution and wish for a quad is NOT the same thing as my
40 meter problem and answers.  You can easily get enough height and tower
capacity to have fun on 10 meters for very few dollars compared to 40 meter
quad projects!

I was told that the best source for fiberglass poles was to contact any
company that makes fiberglass pole vaulting poles!  They have a number of
poles that come out of the process that are defective, not because they want
them to be, of course.  They just don't have the right spring and feel to be
a good pole, but are mechanically fine.

I was told they will sell the rejects at a reasonable price.

It was the only place, short of making them myself, where I thought I could
have gotten the 22 foot spreader arms for the 40 meter stuff.

I've not tried finding the companies, but you get the idea.

They might even be on the WWW, who knows?

Mike W5WQN as a guest at leviathan.tamu.edu (no mail addredd there)


From [e-mail] Thu Jul 11 16:56:55 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.charm.net!news.cais.net!nntp.primenet.com!news.texas.net!news.kei.com!newsfeed.internetmci.com!howland.reston.ans.net!news-e2a.gnn.com!usenet
From: Steve Arnold <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Radio Shack rotor help needed
Date: Thu, 04 Jul 1996 12:36:17 -0700
Organization: NetCon
Lines: 16
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: 71-101.client.gnn.com
Mime-Version: 1.0
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X-GNN-NewsServer-Posting-Date: 4 Jul 1996 19:37:42 GMT
X-Mailer: Mozilla 2.01E-GNN  (Win95; I; 16bit)

Barry Kutner wrote:
>
> Hi Have a Radio Shack 15-1225B (3 wire) rotor that died yesterday. Does
> anyone have pinout info so I can hopefully troubleshoot from the ground?
> Tnx/Barry
>
> --
> =======================================================================
> Barry N. Kutner, W2UP       Internet: [e-mail]
> Newtown, PA                 Packet Radio: W2UP @ WB3JOE.#EPA.PA.USA.NA
>                             Packet Cluster: W2UP >WB2R (FRC)
> .......................................................................I thi
nk that this is the same rotor that C-Crane sells, known as the
Chennel Master.  I'll try to locate their number.


Steve


From [e-mail] Thu Jul 11 16:56:56 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-fw-22.sprintlink.net!news.crocker.com!wizard.pn.com!news-in.tiac.net!news-old.tiac.net!usenet
From: PWOLF <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: RFI Problem ??
Date: Wed, 10 Jul 1996 12:18:27 -0700
Organization: The Internet Access Company
Lines: 46
Message-ID: <[e-mail]>
NNTP-Posting-Host: 206.119.197.61
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X-Mailer: Mozilla 2.01 (Win16; U)

Greetings,

I am a newly licensed Advanced operator, however I am not up to speed on
many aspects of the hobby.  I have started assembling my ôshackö and am
faced with some RFI problems that are (at this point getting the better
of me (and my wife... she hates the hobby)).  The RFI manifests itself in
the following ways:  Interference on the stereo, TV, telephones, and
computers (when on-line).  The computers are in the same room as my
radios.  The other items are in the opposite end of the house (40 ft
away).

My set up is as follows.  I have a G5RV strung up in the trees in an
inverted V.  I use a 50 ft RG8 coax as a feed line.  I have a used Yaesu
FT-890.  and FWIW a Yaesu 5200 dual band mobile that I use as a base.  it
is connected to a dual band vertical on the roof of my house and is fed
with RG-58.  The  dual bander works fine and causes no RFI anywhere.

My grounding (where I suspect my problem is) is as follows.  I have a 10
ft copper ground rod outside my house.  I have a copper buss bar (3 ft
long) on the back of my radio bench. The buss bar is connected to the
ground rod, by #10 solid copper wire.  It runs approx. 12 feet across my
room (with my feed line, telephone lines and AC extension cord (not used
for radios)  adjacent to it, through the wall, where it attaches via a
ground buss to another #10 solid copper wire that I use to ground my dual
band antenna on the roof which then continues down the side of the house
(approx. 15 ft) to the ground rod.   I have My Astron 20m plugged into a
known good (properly wired) 120v grounded AC outlet.  I have run a ground
braid from the Astron negative terminal to the buss bar.  Further, the
FT-890 also has a ground braid to the buss bar,

Getting my wife to cooperate with me and assist me in determining when
and on what frequency I am causing RFI is difficult.  For now I have only
ôconfirmedö that she hears me on 75/80 mtrs.  She also heard me on 20
meters over the telephone (corded, not cordless (though we have cordless
phones, they werenÆt in use at that time)

My plan is to get someone to assist me (from the living room)  and tell
me which bands I am causing the RFI on, and go from there once that
determination is made.  Hopefully it will only be on a couple and will be
relatively easy to isolate.

Any further suggestions would be appreciated.

Thanks...

Paul...KE1FA


From [e-mail] Thu Jul 11 16:56:57 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!tank.news.pipex.net!pipex!oleane!jussieu.fr!math.ohio-state.edu!uwm.edu!news-res.gsl.net!news.gsl.net!ix.netcom.com!news
From: AC6V <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Scanner newsgroup?
Date: Wed, 10 Jul 1996 07:03:43 -0700
Organization: Author
Lines: 26
Message-ID: <[e-mail]>
References: <4rvt5l$[e-mail]>
NNTP-Posting-Host: esc-ca1-19.ix.netcom.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-NETCOM-Date: Wed Jul 10  9:03:30 AM CDT 1996
X-Mailer: Mozilla 2.01 (Win95; U)
To: Ed Mou <[e-mail]>

Ed Mou wrote:
>
> Hi, sorry if this isn't quite the group, but is there a newsgroup
> dedicated to scanners?  They seem interesting, and I'd like to read more
> about em.  Thanks!

Howdy Ed.

Yep sure is -- try:

 alt.radio.scanner
 rec.radio.scanner

Also -- Go To De Ja News and type in scanner. URL is:

http://www.dejanews.com/

Good scanning

73 (Ham Speak for Best Regards)
Rod

--
Hark for I have hurled my words to the far reaches of the earth!
What King of old could do thus??
..... AC6V


From [e-mail] Thu Jul 11 16:56:58 1996
Path: news2.epix.net!uunet!in2.uu.net!scnews.sc.intel.com!itnews.sc.intel.com!news
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Small, easily portable HF antenna
Date: 6 Jul 1996 18:41:23 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 10
Message-ID: <4rmc0j$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: cmoore.ch.intel.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.1N (Windows; I; 16bit)

Matt Werner <[e-mail]> wrote:
>Hi all!  I'm looking to build a small, low impact HF antenna that is easy and
 quick to take up and down.

Hi Matt, I carry an 88ft dipole fed with 300 ohm ladder-line around with
me in my pickup complete with sling-shot launcher. Takes about 15min to
get it up and working assuming poles or trees (or cacti) are around.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Thu Jul 11 16:56:59 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!news-res.gsl.net!news.gsl.net!nntp.coast.net!news00.sunet.se!sunic!news99.sunet.se!cph-1.news.DK.net!dkuug!dknet!usenet
From: [e-mail] (Peter Frenning)
Newsgroups: rec.radio.amateur.antenna
Subject: Sommer Verticals (TCS-25), Opinions/Experience anyone?
Date: Mon, 08 Jul 1996 11:46:16 GMT
Organization: Siemens Nixdorf, Denmark
Lines: 17
Message-ID: <4rqsea$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: 149.212.14.30
X-Newsreader: Forte Free Agent 1.0.82

I'm contemplating buying a Sommer multiband Vertical TCS-25 (I don't have
the space for beams(small lot/building codes))  :-(

Has anyone any practical life experience with these, and/or theoretically
based opinions?

vy 73 de OZ1PIF


******************************   OZ1PIF   **************************
Peter Frenning, UNIX Product Mgr., Siemens-Nixdorf DK, Ph.: [phone]
Snailmail: Dybendalsvaenget 3, 2630 Taastrup, Denmark, Fax: [phone]
Email: [e-mail](...!dkuug!sni.dk!pef)(NERV: pfrenning.cph)
X400:C=DK; A=400NET; P=SCN; O=SNI; S=Frenning; G=Peter; OU1=CPH1; OU2=CC
       Private connection: [e-mail]
******  Come visit us on the web; URL http://www.sni.dk  ******



From [e-mail] Thu Jul 11 16:57:00 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-in.tiac.net!news.kei.com!newsfeed.internetmci.com!malgudi.oar.net!picker!news
From: Lloyd Korb <[e-mail]>
Subject: Stacked Yagi's
Content-Type: text/plain; charset=us-ascii
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: 144.54.67.12
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Organization: Picker International, Inc.
Mime-Version: 1.0
Date: Wed, 10 Jul 1996 15:08:07 GMT
X-Mailer: Mozilla 2.02 (Win16; I)
Lines: 5

I am trying to model 4 stacked yagi's using AO or NEC Wires.
Does anyone have a file that I could use as a guide?

Lloyd  K8DIO
[e-mail]


From [e-mail] Thu Jul 11 16:57:01 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!news-dc-9.sprintlink.net!news.sprintlink.net!news-dc-10.sprintlink.net!tezcat.com!netaxs.com!hunter.premier.net!news-res.gsl.net!news.gsl.net!swrinde!howland.reston.ans.net!newsfeed.internetmci.com!news.kei.com!news.texas.net!newsfeed.concentric.net!news-master!news
From: Russ Fitzpatrick <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Tahoe/Suburban Mobile Ant
Date: Wed, 10 Jul 1996 18:22:08 -0700
Organization: Concentric Internet Services
Lines: 9
Message-ID: <[e-mail]>
References: <4rp3nr$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: cnc131045.concentric.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 3.0b4 (Win95; I)

I have the S-10 Blazer, Gary, and put up a Diamond K550 roofrack mount
for my Diamond 770H. If you're looking for a 2/440 dualbander setup and
have a roof rack, that works fine and has a fold-down feature....works
GREAT as long as you don't forget to USE the fold down feature before
entering the GARAGE!

'73 & gud luk de Russ, KI8J




From [e-mail] Thu Jul 11 16:57:01 1996
Path: news2.epix.net!uunet!in2.uu.net!spool.mu.edu!munnari.OZ.AU!ihnp4.ucsd.edu!news1.ucsd.edu!news-mail-gateway
From: [e-mail] (Louise Carkenord)
Newsgroups: rec.radio.amateur.antenna
Subject: TET instruction/assembly booklet
Date: 9 Jul 96 18:13:13 GMT
Organization: ucsd usenet gateway
Lines: 10
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]



My friend W0GLG has just acquired a TET 4 element HF antenna.
It covers 10,15,20, and 40 meters. It is model # 442DX. He says
it was made in mid 1980's. He needs an instruction/assembly/parts
book. He is willing to pay for photocopy or fax or whatever....
Anybody help him out??????  Please contact me if yes.
Thank you....73....                                     Lee     KA0FPJ
                                        Louise  N0NNM



From [e-mail] Thu Jul 11 16:57:03 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!swrinde!ihnp4.ucsd.edu!news1.ucsd.edu!news-mail-gateway
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: TH3, etc.
Date: 5 Jul 96 13:25:29 GMT
Organization: ucsd usenet gateway
Lines: 36
Message-ID: <[e-mail]>
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

From: Stacy Hamby <[e-mail]>
Subject: Hygain TH3 tribander-info, documentation

>I'm looking for information on the perf. Hygain TH3 as compared to say
Cushcraft A3.  >Also looking for manual/instructions for the TH3.  Id be
happy to pay copy cost, post >-age etc.  Any help wpuld be most appreciated.

Hi, Stacy --

    IMO, there is no appreciable performance difference for similar antennas
such as the A3 or TH3 or any other shortboomed trapped tribander.  Antennas
with the same boom length will have about the same performance; the
differences are probably measureable but generally not enough to notice on
the air.

     The real difference in these two antennas is in the hardware.  The
Hy-Gain uses heavy duty hardware that will give years of reliabilty and wind
survival.  The Cushcraft uses the cheapest hardware they can get away with
(U-bolts, muffler clamps, etc.).

     I guess the real question is: what are you planning to do?  What are
your goals?  Restrictions?  The brand of antenna is just one piece of the
puzzle.  I have written an article called "Building A One-Tower Station" that
was presented at the Contest Forum at Dayton this year and addresses some of
the questions and possible solutions to your situation.  If you send me your
postal address, I'll send a copy out to you.

    Also, you may want to check out TOWERTALK - the antenna and tower
reflector.  It is populated with many knowlegeable and helpful folks (some
are seen here on a regular basis) and has many interesting discussions going
on.  Send a message to [e-mail] with the word subscribe in
the message and you'll get signed up.  See you there!

73,  Steve  K7LXC

    TOWER TECH -- professional tower supplies and services for amateurs


From [e-mail] Thu Jul 11 16:57:04 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!news-res.gsl.net!news.gsl.net!ix.netcom.com!news
From: Jim O'Connell <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Tower Standoff Hardware
Date: Sat, 06 Jul 1996 10:27:50 -0700
Organization: Netcom
Lines: 15
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: chi-il10-25.ix.netcom.com
Mime-Version: 1.0
Content-Type: text/plain; charset=big5
Content-Transfer-Encoding: 7bit
X-NETCOM-Date: Wed Jul 10  8:28:59 AM PDT 1996
X-Mailer: Mozilla 2.0 (Win16; I)
To: Barry Keating <[e-mail]>

Barry Keating wrote:
>
> I wish to mount a small (3 to 4 foot) vertical antenna on the side
> of an existing tower.
>
> Does anyone know of commercially available standoff hardware for
> such a mounting? Please reply by e-mail.
>
>         Barry Keating
>         Wd4MSM
>         [e-mail]

Barry: Doug, WD9IIX of IIX Equipment makes a line of tower mount
standoffs.  Check for his ad in QST, or write to his Callbook QTH
in Homewood, IL.  73, Jim, W9WU


From [e-mail] Thu Jul 11 16:57:04 1996
Path: news2.epix.net!uunet!in2.uu.net!scnews.sc.intel.com!itnews.sc.intel.com!news
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Tx/Rx Relay
Date: 9 Jul 1996 15:20:55 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 10
Message-ID: <4rttcn$[e-mail]>
References: <4rs6a9$[e-mail]>
NNTP-Posting-Host: cmoore.ch.intel.com
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] (Brian Watson) wrote:
>I saw a Tx/Rx relay a while back in one of the magazines <CQ/73's> but I
>can't remember which one or when it was.

The latest "Worldradio" carries a Henry Radio advertisment offering
TohTsu coaxial relays. [phone].

73, Cecil, W6RCA, OOTC




From [e-mail] Thu Jul 11 16:57:05 1996
From: [e-mail] (David Selby D.O.)
Subject: Under-water Beverage
Date: 8 Jul 96 05:39:32 -0700
Message-ID: <[e-mail]>
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-fw-12.sprintlink.net!news.sprintlink.net!news-fw-22.sprintlink.net!itnews.sc.intel.com!news.sprintlink.net!news-stk-200.sprintlink.net!news.msn.com!msn.com
Newsgroups: rec.radio.amateur.antenna
Organization: The Microsoft Network (msn.com)
Lines: 4

Does anyone have any experiance with using a Beverage antenna under
12 feet of water?
I would truely appreciate any information.
[e-mail]


From [e-mail] Thu Jul 11 16:57:06 1996
Path: news2.epix.net!uunet!in1.uu.net!jennifer.pernet.net!falcon.sat.net!usenet
From: Drew Loker <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Vertical Ringo Dual band vs. A148-10s 2m beam??? Need advice quick, please!!
Date: Mon, 08 Jul 1996 09:40:03 +0100
Organization: Texas Education Network
Lines: 42
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: wn-bpt10.sat.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.02 (Macintosh; I; PPC)
CC: [e-mail]

I currently have a Ringo (ARX-270) with a gain of 9/12. I wanted the
vertical for it's wide coverage, but I expected that I owuld be able to
bring in the repeaters from Houston, about 80-100 miles  from Beaumont,
Texas (depending on what side of Houston we are talking about). WIth
just the antenna at 25 ft (plus the additional 15ft fo the antenna), I
was only able to bring them in once in a while, and I couldn't reach
them back anyway. So then I added a a amp/preamp. Now I am occasionaly
able to bring them and reach them, but not predciatably, and only the
ones on this side of Houston.

As I have said in several other notes in different areas, I am about to
replace the 25ft mast with a 50ft tower. I went ahead and purchased the
rotor and plate at the time because it was a really good price (used). I
also was convinced by the guy selling it that a beam would get me to
Houston, no problem!

My plan currently is to put in an antenna switcher. When I am working
local simplex, or if I ever get it running, the phone patch for when I
am out mobile, will utilize the verticle dual band. THen when I am at
home working the dx simplex or repeater, then I cna switch to the beam,
which has a gain of 13.3. I realize that it is only 2m, but I will not
need the 70cm option.

But I don't know. Maybe the new height will be enough? Do I really even
need to get the beam. I am trying to place an order for the additional
coax that I will need, but I need to knwo if shoudl get enough to run
for another antenna.

Thanks for any feedback!!
Drew
--
 _______________________
| Communication Graphics|  Drew Loker - KC5QBP     [e-mail]
| & Yearbook Instructor |  955 Parson Drive           Provided by TENET:
|  Central Senior HS    |  Beaumont, Texas  77706       THE Network for
|     88 Jaguar Dr      |  [phone] (h)              Texas
Educators!!
| Beaumont, Texas 77702 |  [phone] (fax)
|  [phone], 566  |
|  [phone], fax  |  Visit our homepage at:
|_______________________|
http://198.213.26.193/beaumont/central/main.html


From [e-mail] Thu Jul 11 16:57:07 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!howland.reston.ans.net!tank.news.pipex.net!pipex!oleane!jussieu.fr!math.ohio-state.edu!usc!elroy.jpl.nasa.gov!decwrl!pagesat.net!abyss!usenet
From: Ron Lile <[e-mail]>
Subject: Re: VHF/UHF yagi spacing.
Sender: [e-mail] (news)
Organization: Your Company Here
Message-ID: <[e-mail]>
X-Nntp-Posting-Host: rel.bcl.net
Date: Sun, 7 Jul 1996 02:33:45 GMT
Lines: 27

[e-mail] (Gary Mitchelson) writes:
> I am putting up 4 yagi's (50, 144, 432 &1296 Mhz) that are all about
> 17 feet long. I have 11 feet of vertical mast at the top of my tower
> to play with.
>
> Since I can not space them at least 1/2 the boom length from each
> other what would be the best spacing?
>
> 50 at the bottom and 144 at the top with the 432 above the 50 and then
> the 1296?
>
> Any thoughts??
>
> N3JPU

My thoughts are - if I could be so lucky!!

With out doing alot of modeling, I would be inclined to place the 50 at the bo
ttom, the 144 at the top (my favorite band so height, even if 17 feet, is pref
erred), the 432 just above the 50 then 1296 just below the 144.
You could also go 50 and 144 together (same boom would be nice), in the middle
 of the mast,  with the 432 and 1296 seperated by the mast extremes.
I built a combo, 50 and 144 once, worked ok but was not as big as your antenna
s.

Anyone else.

By the way, how tall is the tower - or how high will the antennas be above the
 ground?

Ron K0RL



From [e-mail] Thu Jul 11 16:57:08 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.primenet.com!news.cais.net!news2.cais.com!news
From: [e-mail] (Gary Mitchelson)
Newsgroups: rec.radio.amateur.antenna
Subject: VHF/UHF yagi spacing.
Date: Sat, 06 Jul 1996 20:44:40 GMT
Organization: Posted via CAIS Internet <[e-mail]>
Lines: 13
Message-ID: <[e-mail]>
NNTP-Posting-Host: garym.cais.com
X-Newsreader: Forte Agent .99d/32.182

I am putting up 4 yagi's (50, 144, 432 &1296 Mhz) that are all about
17 feet long. I have 11 feet of vertical mast at the top of my tower
to play with.

Since I can not space them at least 1/2 the boom length from each
other what would be the best spacing?

50 at the bottom and 144 at the top with the 432 above the 50 and then
the 1296?

Any thoughts??

N3JPU


From [e-mail] Thu Jul 11 16:57:09 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!inXS.uu.net!in2.uu.net!hunter.premier.net!newsfeed.internetmci.com!news.sprintlink.net!news-stk-200.sprintlink.net!news2.noc.netcom.net!noc.netcom.net!netcom.com!pineapp
From: [e-mail] (Daniel Curry)
Subject: Re: Wanted - Screwdriver HF Mobile Antenna
Message-ID: <[e-mail]>
Organization: Netcom-Online Communication Services (408 241-9760 guest)
X-Newsreader: TIN [version 1.2 PL1]
References: <4ra9s3$[e-mail]>
Date: Tue, 9 Jul 1996 15:10:51 GMT
Lines: 33
Sender: [e-mail]

David G.M. Smith ([e-mail]) wrote:
: Hi

: I am looking for a screwdriver HF antenna for a motorhome mobile
: setup.
: Please send info and prices via email or via packet
: VE7EC@VE7KIT



  Contact Don Johnson, W6AAQ. He is located in Esparto, Cal.

If you are not aware who W6AAQ he is the one that invented the screwdriver (DK
-3)
antenna.

  Also stay tune and look for AEA new advertisement, QST, CQ, or others. W6AAQ
has license his antenna to them. THis was annouced here in Livermore Ca. swap
meet June 2, 1996 by Don Johnson himself.


: Thanks and 73 de Dave VE7EC, North Vancouver, B.C.
: ....David G.M. Smith                 VE7EC
: Tel [phone]    Fax [phone]     Email: [e-mail]
: --------------------------------------------------------------------
: INTERFACE INTERNATIONAL  URL: http://www.interfaceweb.com
:      Venture Capital and Management Consulting
: ---------------------------------------------------------------------

--
.----------------------------------------------+--------------------------.
| INTERNET: [e-mail]     (DC436)     | Daniel Curry             |
| AMPRNET : [e-mail]  [44.4.20.144] | WB6STW                   |
| AX.25   : wb6stw@n0ary.#NOCAL.CA.USA.NOAM    | DoD # 1450   SOHC4 # 136 |
'----------------------------------------------+--------------------------'


From [e-mail] Thu Jul 11 16:57:10 1996
Path: news2.epix.net!uunet!in1.uu.net!news.nts-online.net!news
From: James Lee Tabor <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: wanted:softwares helpful to build antennas
Date: Sat, 06 Jul 1996 02:37:26 -0500
Organization: Kangaroo Tabor Software
Lines: 34
Message-ID: <[e-mail]>
References: <4rhelb$[e-mail]>
NNTP-Posting-Host: ppp22.wtrt.net
Mime-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit
X-Mailer: Mozilla 2.02Gold (Win95; I)

Regis DP wrote:
>
> Hi !
>
> I search for softwares who could give me ray-diagramms, tos... of an
> antenna which would be described by me to the programm (3D
> description).
>
> In fact, i look for any software about antennas and radio
>
>         [e-mail]   alias    RΘgis

Greetings,

Here is a program that will assist you in analysis of antennas in actual use b
etween various transmit and
receive "circuits" anywhere on the earths surface. The name is CAPMan.

With CAPMan you can use "known" antenna gain patterns to analyze communication
s systems and circuits. You can
use antenna files generated by the well known ElNec and MiniNec programs.

CAPMan supports contour mapping with the CAPMap option. The MUF and numerous o
ther skywave parameters can be
displayed on user selected areas and world maps.

Visit the web site for details and sample maps and graphs.

http://ourworld.compuserve.com/homepages/KU5S

Lucas Radio/Kangaroo Tabor Software
Boulder, CO
Phone [phone], Fax [phone]

Hope this helps,
Jim



From [e-mail] Thu Jul 11 16:57:11 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-pen-4.sprintlink.net!news.sprintlink.net!news-pen-14.sprintlink.net!newsfeed.internetmci.com!news.campus.mci.net!calweb!usenet
From: [e-mail] (Stephen Douglas)
Newsgroups: rec.radio.amateur.antenna
Subject: Web Site Debut - DF Systems - Electronics
Date: Thu, 11 Jul 1996 10:35:27 GMT
Organization: DF Systems
Lines: 19
Message-ID: <4s2l1k$[e-mail]>
NNTP-Posting-Host: sac1-7.calweb.com
NNTP-Posting-User: account=topkick
X-Newsreader: Forte Free Agent 1.0.82

Announcing the debut of DF Systems Web Site.
We are located in Sacramento, California and we specialize in Amateur
Radio, Radio Direction Finding, Doppler DF, Surplus Electronics and
Communications Equipment.

We are located at:
http://www.dfsystems.com

Come on by and check us out!

Stephen Douglas K6HZT
DF Systems
Radio Direction Finding
Electronic Surplus
[e-mail]
http://www.dfsystems.com
P.O.Box 246925
Sacramento, CA 95824-6925



From [e-mail] Thu Jul 11 16:57:12 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.texas.net!nntp.primenet.com!uunet!in1.uu.net!iglou!news
From: Steve Ellington <[e-mail]>
Subject: Re: Windom Info Needed
X-Nntp-Posting-Host: dp-2-37.iglou.net
Content-Type: text/plain; charset=us-ascii
Message-ID: <[e-mail]>
To: [e-mail]
Sender: [e-mail] (News Administrator)
Content-Transfer-Encoding: 7bit
Organization: IgLou Internet Services
References: <[e-mail]>
Mime-Version: 1.0
Date: Wed, 10 Jul 1996 15:41:52 GMT
X-Mailer: Mozilla 1.1N (Windows; I; 16bit)
Lines: 18

How do you know they use a 1:1 balun?

A 50 ohm input on a Windom would not be a Windom. It would be a
dipole with the feed in the center and be a single band antenna.

I suspect they use a 6:1 balun as they should and possibly a
decoupling choke in series with the feeder.

Off-center fed antennas of all types are unbalanced antennas and
subject to RF problems on the feeder.

Also, keep in mind that an 80 meter dipole, Windom or whatever is going
to have distinct directional patterns on the higher bands and may prove
inferior to a short antenna in most directions. They don't make very good
"general coverage" antennas for the higher bands i.e. 20 thru 10 meters.





From [e-mail] Thu Jul 11 16:57:13 1996
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.internetmci.com!swrinde!elroy.jpl.nasa.gov!usc!news.cerf.net!ccnet.com!usenet
From: Andy Barrow <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Windom Info Needed
Date: Wed, 10 Jul 1996 07:02:09 -0700
Organization: CCnet Communications (510-988-7140 guest)
Lines: 10
Message-ID: <[e-mail]>
NNTP-Posting-Host: h108-4-61.ccnet.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 3.0b4Gold (Win95; I)

Antennas West makes a version of the Windom antenna that appears to use
a 1:1 balun.  I've read up, and I don't believe this can be done (but
obviously they do it).

Anyone know how they do it, and where this magic 50 ohm point is on a
Windom antenna?

Andy Barrow
[e-mail]
[e-mail]


From [e-mail] Mon Jul 15 17:00:41 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-fw-6.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-stk-3.sprintlink.net!nntp.coast.net!dispatch.news.demon.net!demon!ifwtech.demon.co.uk!G3SEK
From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 6/2M beam spacing?
Date: Sun, 14 Jul 1996 23:10:04 +0100
Organization: IFW Technical Services
Lines: 41
Distribution: world
Message-ID: <[e-mail]>
References: <4s8nb0$[e-mail]> <[e-mail]>
NNTP-Posting-Host: ifwtech.demon.co.uk
X-NNTP-Posting-Host: ifwtech.demon.co.uk
MIME-Version: 1.0
X-Newsreader: Turnpike Version 1.12 <9qI82xurdT5+z2vSgnCPFcKgQL>

Dave Cook wrote:
>Bob inquired about minimum vertical spacing of antennas for 6 and 2
>meters.
>
>The ARRL's "Antenna Book" states(herein paraphrased) (refering to a 2
>meter Yagi over a 6 meter Yagi) the bottom Yagi is going to look like
>ground to the top, if it has any effect at all.

The advice in the current ARRL Antenna Book comes word-for-word from
the ARRL VHF Handbook, vintage 1965, as if nothing had happened in the
intervening 30 years.

The "fraction of boom length" rule is very specifically based on typical
boom lengths of that era: there is no such magic fraction. The
recommended stacking distances based on the "looks like ground"
assumption are actually implying that the lower-frequency antenna looks
like a solid, continuous groundplane - which is obviously not true.

It was the best that anybody knew in 1965, but by now it's well past its
"sell by" date. Today we can model the exact situation and decide how
much interaction we are prepared to tolerate.

If you still want a non-mathematical rule of thumb, stack the higher-
frequency antenna at a distance where the larger, lower-frequency
antenna is just outside of its capture area. Look at the data sheet for
the higher-frequency yagi and find the manufacturer's recommended
stacking distance for an identical pair. This represents the distance at
which  their capture areas just barely touch edge-to-edge. So the
minimum distance for the higher-frequency antenna is one-half of the
manufacturer's recommended stacking distance for a pair.

The higher-frequency antenna is still within the capture area of the
lower-frequency one, so be prepared for be minor interactions both ways.
Even so, I think that's the best available rule-of-thumb.



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


From [e-mail] Mon Jul 15 17:00:42 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.primenet.com!news.cais.net!news2.cais.com!cais3.cais.com!gttm
From: USCG TELECOMMS <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Almost direct hit - lightning
Date: Wed, 10 Jul 1996 12:52:13 -0400
Organization: Posted via CAIS Internet <[e-mail]>
Lines: 17
Message-ID: <[e-mail]>
References: <4s04kb$[e-mail]>
NNTP-Posting-Host: cais3.cais.com
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
To: Bill Meara <[e-mail]>
In-Reply-To: <4s04kb$[e-mail]>



On 10 Jul 1996, Bill Meara wrote:

> The tree in front of my sister's suburban home was hit by lightning last
> week.  As a result of the strike, all the TV's in her house are
> inoperable and a number of other electrical devices no longer function.
> As a ham I'm supposed to know about this stuff!  Can anyone explain to me
> the physics behind the destruction of the TV's?

I experienced a similar problem.  The pulse came via the negative ground
bus.  I discovered that the diodes in the (-) leg of the bridge rectifiers
were shorted in all TV's.  In one set I also had to replace the Pass
transistor.  All sets had surge suppressors, but they did not do much.

W4VR



From [e-mail] Mon Jul 15 17:00:43 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!in2.uu.net!bcstec!nntp
From: KG7HQ
Subject: Re: Almost direct hit - lightning
X-Nntp-Posting-Host: e397936.evt.boeing.com
Message-ID: <[e-mail]>
Sender: [e-mail] (NNTP News Access)
Organization: Private Opinion
X-Newsreader: <TCP/Entry 1.03>
Date: Fri, 12 Jul 1996 11:36:44 GMT
Lines: 21

Hello Drew,


In article <[e-mail]> [e-mail] writes:

>Sorry for the igmo question, but could you explain that a bit more? DO
>you mean you just took a piece of coax, during any normal thunder storm
>and it had burns indicating that a lightening strike was immenent?

What I had found is that even though there were lightening hits in the
vicinity and none hit my antenna directly, there are still high electrical
potentials building up on my antennas. The carbon burn marks were produced
at where the PL259 connector met the bottom of the glass jar. This means
that there is a area of effect when it comes to lightening strikes. In
this area, electronic component damage can occure simuliar to what you
would experience with ESD devices when they are exposed to static
discharge.
So, in my opinion, the result would be a slow degradation of the electronic
components leading to premature failure of the effected device.

73's KG7HQ - Mike


From [e-mail] Mon Jul 15 17:00:44 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.inc.net!newspump.sol.net!newsfeeder.sdsu.edu!sgigate.sgi.com!news-res.gsl.net!news.gsl.net!hunter.premier.net!newsfeed.internetmci.com!news.radio.org!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Antenna Problems-Need Help!!
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <4s41uv$[e-mail]>
Date: Sun, 14 Jul 1996 02:18:23 GMT
Lines: 29

In article <4s41uv$[e-mail]> [e-mail]
.us (Brian Watson) writes:
>I have a Cushcraft 11 element beam for 2 meters (don't know model or
>anything) but I'm having problems on recieve with it.  I have it pointed
>toward a repeater about 40 miles from my QTH and am only getting about an
>S5 copy on it.  I live in S. Florida so terrain's not the problem.  The
>SWR is pretty flat (the highest is about 1.4:1)  I'm feeding the antenna
>with 50' of RG58/u coax.  Does anyone have any ideas on what I should do
>to figure out what is going wrong.  The problem has just started in the
>last few days.  I know it's not the radio since a repeater less than a
>mile away comes in full scale.  Any help will be greatly appreciated.

A flat SWR curve is a tipoff that losses are high, probably in the
feedline. You may have some water incursion into the feedline. And
speaking of water, Cushcraft beams tend to become detuned when they
are wet. Since you live in south Florida, salt buildup could be a
problem too.

I expect it is time to bring the antenna down, clean and inspect
it, paying particular attention to the gamma match capacitor, and
install some decent feedline, at least RG-8, but better would be
9913, or one of its competitors. Lengths of RG-58 make good dummy
loads at VHF/UHF.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Mon Jul 15 17:00:45 1996
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.internetmci.com!news.one.net!news
From: "David J. Hauck" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Base station antenna
Date: Thu, 11 Jul 1996 09:45:22 -0700
Organization: OneNet Communications HUB News Server
Lines: 2
Message-ID: <[e-mail]>
NNTP-Posting-Host: port-3-4.access.one.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.01 (Win16; I)

I am considering the SOLARCON ANTRON-99 antenna to operate my base
station? Is this a good choice, or is there a better copystick antenna??


From [e-mail] Mon Jul 15 17:00:46 1996
Path: news2.epix.net!uunet!inXS.uu.net!in2.uu.net!newsreader.sprintlink.net!news.sprintlink.net!news-pen-4.sprintlink.net!news.sprintlink.net!news-pen-14.sprintlink.net!itnews.sc.intel.com!news
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Coax Help
Date: 11 Jul 1996 19:08:46 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 9
Message-ID: <4s3jfu$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: cmoore.ch.intel.com
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] wrote:
>I thought that I read recently about a good quality type of coax that
>wasnt too expensive. About .12-.14/foot.

Hi Vince, RG8X is about .15 per foot (Ladder-line is .12).

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Mon Jul 15 17:00:47 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!arclight.uoregon.edu!chi-news.cic.net!news.compuserve.com!news.production.compuserve.com!news
From: Steve Beyers <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Conjugate matching
Date: 13 Jul 1996 02:08:10 GMT
Organization: CompuServe, Inc. (1-800-689-0736)
Lines: 18
Message-ID: <4s70ea$h6h$[e-mail]>

A common conjugate matching setup is a transceiver, a short length
of coax, a transmatch, a length of balanced transmission line, and
an antenna.

Question:  If I connect two or more balanced transmission lines,
baluns, and antennas to the transmatch in parallel, will all the
components be matched according to the conjugate theorem?

I'm trying this out with three quarter-wave elevated (seven feet)
ground plane verticals on 20 meters.  They are in-line and fed
in-phase for a broadside pattern.  Spacing is 210 degrees.  The
transmatch is a link coupler, and the transmission lines are open
wire.  All three lines run to the transmatch in the shack and are
connected in parallel there.  Baluns are 1:1 current type.  It
seems to work well - I'm getting good reports.

--
Steve Beyers W9HJW


From [e-mail] Mon Jul 15 17:00:47 1996
Path: news2.epix.net!uunet!in2.uu.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-pen-4.sprintlink.net!news.sprintlink.net!news-pen-14.sprintlink.net!itnews.sc.intel.com!news
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole question
Date: 11 Jul 1996 15:17:13 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 1
Message-ID: <4s35tp$[e-mail]>
References: <4s22c7$[e-mail]>
NNTP-Posting-Host: cmoore.ch.intel.com
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] (Dave Harrison) wrote:


From [e-mail] Mon Jul 15 17:00:50 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!news-res.gsl.net!news.gsl.net!nntp.coast.net!howland.reston.ans.net!newsfeed.internetmci.com!news.westnet.com!westnet.com!lgreco
From: [e-mail] (Luigi Greco)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Directional 46-49mhz antenna
Date: 11 Jul 1996 14:42:26 GMT
Organization: WestNet Internet Services
Lines: 3
Message-ID: <4s33si$[e-mail]>
References: <4rvenv$[e-mail]>
NNTP-Posting-Host: westnet.com
X-Newsreader: TIN [version 1.2 PL2]


Gee, what's it for???????



From [e-mail] Mon Jul 15 17:00:51 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-fw-6.sprintlink.net!news.telalink.net!news.wildstar.net!news.ecn.uoknor.edu!munnari.OZ.AU!harbinger.cc.monash.edu.au!nntp.coast.net!oleane!jussieu.fr!math.ohio-state.edu!usc!news.cerf.net!ent-img.com!wb6hqk!bart
From: [e-mail] (Bart Rowlett)
Subject: Re: forward/reflected power
Organization: wb6hqk
Message-ID: <[e-mail]>
References: <4s3kil$[e-mail]> <[e-mail]>
Date: Sat, 13 Jul 1996 20:28:50 GMT
Lines: 79

In article <[e-mail]>,
charles copeland <[e-mail]> wrote:
>In article <4s3kil$[e-mail]>,
>Cecil Moore  <[e-mail]> wrote:
>>Something has bothered me for years. With 100w into an antenna
>>tuner, a forward/reflected power meter on the tuner output can
>>read something like 110w forward and 10w reflected because of
>>the SWR. The transmitter is generating 100w which is being
>>delivered to the antenna. But take out the tuner and the forward
>>power reading is never above 100w with my ICOM745. The reflected
>>power goes up with SWR but the forward power is never above 100w.

Many solid state rigs limit the output power to protect the RF output
amplifier.  The strategy's vary but usually either limit the forward
power to some specified value, typically 100 W or limit the REFLECTED
power to some small value such as 10 watts.  In either case you are
seeing the effects of an outside control loop adjusting the RF drive
to the PA and not necessarily some consequence of basic network theory.

>I'm guessing, but think the 110w and 10w can't be added because
>they are results of complex compoents (inductance/capacitance).
>Using (x^2 + y^2)^.5 would be more correct, giving you 110.45w total.
>Still not 100w, but closer.

They can be added (subtracted).  Assuming the meter actually does
measure forward and reflected power along a specified impedance
transmission line (typically 50 ohms), you can subtract the reflected
from the forward and get the net power flowing through the meter towards the
load.  This even works if the meter is designed for a different
characteristic impedance than the transmission line actually used.
In practice you will lose accuracy but the theory is correct and can be
handy when dealing with 75 ohm cable TV coax.

>>Question is: Without the tuner when the forward power is 100w and
>>the reflected power is 10w and there is no conjugate match, is the
>>transmitter generating 100w and absorbing 10w or is it generating
>>90w because of foldback or something in between?

Without knowing more about what's happening inside the transmitter
you can't tell; so why care?  The rig is generating 90 watts in the
sense that a net power of 90 watts is leaving the box and getting absorbed
somewhere else, hopefully by the antenna system.  How much power is
absorbed by the amplifier is totally dependent on the design and
the intended application.  For example, signal generators are usually
designed with a well defined source impedance (50 ohms usually) but
the loss of half the 'generated' power is usually unacceptable for a
high power amplifier.

>
>At maximum power transfer, the radio burns 100w and the antenna
>burns 100w (AKA 1:1) ideally.

Most solid state RF power amplifiers have source impedances far less than
the 50 ohms implied above.  In practice if you try to load them with
an impedance equal to the internal source impedance you will exceed the
maximum current capability of the components and destroy something.  If
the amplifier manages to survive, it would no longer be operating anywhere
near the design point and would probably generate lots of distortion.

>The above would burn 110w in the radio and 100w in the antenna.

Not generally true.  Consider most high power linear amplifiers usually are
able to convert about 65% of the DC input to RF output power.  Class C
amplifiers used for FM applications are often more efficient.

>Some radios may actually generate slightly more
>than their ratings.

Most RF power amplifiers will generate considerably more than designed
but will become horribly distorted and maybe self destruct.  That is why
most modern amplifiers have some sort of automatic SWR shutdown circuitry.


Hope this helps.

bart   wb6hqk

[e-mail]



From [e-mail] Mon Jul 15 17:00:55 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 12 Jul 1996 19:52:49 -0400
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In article <[e-mail]>, [e-mail] (charles
copeland) writes:

>
>At maximum power transfer, the radio burns 100w and the antenna
>burns 100w (AKA 1:1) ideally. The above would burn 110w in the radio
>and 100w in the antenna. Some radios may actually generate slightly more
>than their ratings.

Great shades of Thevenin!

The models themselve have very plain rules that prohibit their use to tell
analyze the generators internal operation.

In any power amplifier with a conduction angle of 360 degrees, the
efficiency will be no better than 50% with a conjugate match (which has
NOTHING to do with a 1:1 SWR). But with a typical PA operating at less
than 360 degree conduction angle efficiency can be almost anything with a
conjugate match, it might be almost 100% efficient (with a very short
conduction angle) or less than 50% (with a crummy design and long
conduction angle).

The only thing we can say about a conjugate match is efficiency and power
transfer will be very close to, if not the, absolute maximum possible.

If the meter says 100 watts forward and 10 watts reflected, the net power
is 90 watts. The efficiency and power dissipated in the PA can be
anything. That information gives us no idea at all what the dissipation
is.

If the reflected power is ten watts, it does not mean "ten extra watts"
are being re-absorbed by the transmitter. A transmitter might actually be
dissipating LESS power and running cooler than with no reflected power,
since SWR does not tell us if the transmitter is conjugately matched.

73 Tom


From [e-mail] Mon Jul 15 17:00:57 1996
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From: [e-mail](Jeff Anderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 14 Jul 1996 13:39:03 GMT
Organization: Netcom
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In <4s8s5n$[e-mail]> Cecil Moore
<[e-mail]> writes:
>
>[e-mail](Jeff Anderson) wrote:
>>Cecil wrote:
>>>I've used a 50 ohm 6dB pad to verify that the transmitter looks
>>>like 50 ohms when looking back into the tank section...
>
>>    Cecil:  How did you use the 6 dB pad to measure the "source"
>>            impedance of your xcvr?
>
>Hi Jeff, note I didn't say I "measured" it. What I did was adjust
>the tuner SWR meter for a variety of SWRs with the 6dB pad in the
>circuit. Then I removed the pad and observed the indicated SWR.
>Since the SWR stayed the same whether the 6dB pad was in or out
>of the circuit, I *assumed* the impedance looking back into the
>transmitter coaxial connector was the same as looking back into
>the 6dB pad, i.e. 50 ohms. Hope that wasn't a rash assumption.

Hi Cecil, and thanks for the response.

    I'm not positive if this method works or not, but (following our
directional coupler discussion on rec.rado.amateur.homebrew), I'd say
that it doesn't, based on the following reason:

    In the example where the directional coupler consists of
current-sampling and voltage-sampling transformers, the ratio of the
"forward" and "reverse" voltages at the two measurement ports is
*independent* of any resistance value *before* the sampling
transformers (between the xmtr and the dir. coupler, for example).
Note the use of "ratio".  Although the voltage magnitudes change with
different "source" impedances, the ratio doesn't, and it is this ratio
that we use when measuring SWR.  So putting a 6 dB pad in front of the
SWR meter, although changing the magnitudes of the voltages, shouldn't
change the SWR reading.

    (Also, since SWR seems to be defined only in terms of the load
impedance and the transmission line characteristic impedance, not
source impedance, changes in source impedance should have no effect.
But it's been some time since I've looked at SWR from any point of view
other than tuning up my xmtr - I'm dusting off theory books not opened
in more than 20 years, so anyone, please correct me if I've got this
wrong.)

    (time out...)

    ...I just did a little experiment to check this out.  Connected a
qrp rig to a tuner and swr meter (an MFJ-941C modified with the dual
xfrmr sampler for the directional coupler).  At the tuner's output I
connected a 50 ohm load and adjusted SWR for 1:1.

    Then, placed a 25 ohm resistor in series between xmtr and
meter/tuner.  Measured SWR.  No change, although the "forward" voltage
is  lower.

    Removed resistor, de-tuned tuner for a 4:1 SWR.  Measured with &
without 25 ohm resistor in series.  No change in SWR reading.

    Repeated both measurements with 1000 pf cap in place of the 25 ohm
resistor.  Again, same SWR readings. (Interestingly, with the cap the
forward voltage is higher than no-cap.)

    Therefore, conclude that changing source impedance has no effect on
SWR (when using a dir. coupler consisting of v and i sampling xfrmrs.
I expect the same result occurs, though, when using another dir.
coupler topology).

73,

- Jeff





From [e-mail] Mon Jul 15 17:00:58 1996
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From: [e-mail](Jeff Anderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 15 Jul 1996 04:31:34 GMT
Organization: Netcom
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In <4sc4su$[e-mail]> [e-mail] (W8JI  Tom)
writes:
>
>In article <4sb69k$[e-mail]>, Cecil Moore
><[e-mail]> writes:
>
>>Question to all: Assume varying loads on a transmitter. If the
>>magnitude of the load voltage and the magnitude of the load
>>current change by 6dB when a 6dB 50 ohm pad is inserted,
>>does that indicate that the impedance at the transmitter coax
>>connector is 50 ohms?
>>
>
>Hi Cecil,
>
>A 6 dB pad has 6 dB attenuation regardless of input impedance.
>All that is required is the output impedance be correct.
>

(Tom's statement can also be proven by circuit analysis of a pad.)

There's another issue I'm trying to understand here, and that is that
Cecil also measured a 6 dB difference with *different* SWR's (as stated
in an earlier post).  Non-1:1 SWRs equate to non-50 ohm loads connected
to the pad's output. A 6dB pad designed for 50 ohms will only give 6dB
attenuation if its termination is 50 ohms.  If the load is different,
you'll get attenuation, but it won't be 6 dB.  I don't understand
Cecil's results for non-50 ohm loads, so I'm attempting to understand
exactly what he did so that I don't make any wrong assumptions.

Cecil also wrote:
>
>Will changing source impedance change the magnitudes of the two ratio
>SWR voltages? It won't change the ratio but will it change the
magnitudes?

I'll say, "Yes."  In my measurements this morning with the 25 ohm
resistor and the 1nF cap, in each instance there was a change in the
magnitude of the voltages.  This can also be shown via circuit analysis
of a directional coupler.  In the equations I posted for the dual
toroidal xfrmr coupler (5 July 96 on rec.radio.amateur.homebrew, and
please note that I forgot to label the source resistor, although it is
in the diagram), each of the measurement ports' voltages had an Rs
(source resistance) factor in the denominator of the equation.  In
other words, an increase in source resistance = a decrease in measured
voltage.  This factor cancels out when taking the ratio.


73,

- Jeff, WA6AHL


From [e-mail] Mon Jul 15 17:00:59 1996
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From: "William E. Sabin" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Sat, 13 Jul 1996 14:51:16 -0700
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Cecil Moore wrote:
>
> "William E. Sabin" <[e-mail]> wrote:
>
> >See QEX for September 1995
>
> Hi Bill, if that is the article entitled, "Where Does the Power
> Go?", I wouldn't recommend it. It is overly simplistic (no
> reactances) and has some errors.
>


Not the same article.  It is my article on dynamic resistance.

Bill


From [e-mail] Mon Jul 15 17:01:00 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 15 Jul 1996 06:12:34 GMT
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[e-mail] (W8JI  Tom) wrote:
>A 6 dB pad has 6 dB attenuation regardless of input impedance. All that is
>required is the output impedance be correct.

I may not be communicating this concept very well. A 6dB pad with the
output shorted or open would not show 6dB attenuation. I think a 6dB
pad designed for 50 ohms will not have exactly 6dB of attenuation unless
the load is 50 ohms. Is that correct or have I had too much scotch?

My reasoning is if the voltage and current into say, 100-j100, increase
by exactly 6dB and retain the same phase when the 50 ohm, 6dB voltage/current
pad is removed from the circuit, then the impedance at the coax connector
on the transmitter must be the same as the pad design impedance because the
reflections must be seeing 50 ohms and not being re-reflected. It's been
some time since I ran this experiment. I need to run it again paying
attention to phase as well as magnitude.

73, Cecil, W6RCA, OOTC




From [e-mail] Mon Jul 15 17:01:01 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 15 Jul 1996 06:30:04 GMT
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[e-mail](Jeff Anderson) wrote:
CM>>Will changing source impedance change the magnitudes of the two ratio
CM>>SWR voltages? It won't change the ratio but will it change the
CM>>magnitudes?
>
>I'll say, "Yes."  In my measurements this morning with the 25 ohm
>resistor and the 1nF cap, in each instance there was a change in the
>magnitude of the voltages.

Bear with me, Jeff. I still haven't phrased this question correctly.
If the load is 100-j100, there will be reflections. With a 6dB pad
in the circuit and a 50 ohm feedline, the reflections will be
attenuated, i.e. not re-reflected. We can calculate the exact
attenuation. Now if we remove the 6dB pad, the reflections will
reach the coax connector on the transmitter. We know there's not
a conjugate match. Now by looking at the forward power/voltage/
current/phase can we say the impedance at the coax connector on
the transmitter is the same as the 6dB pad *or* not the same as the
6dB pad *or* we can tell nothing from our indirect measurements?

73, Cecil, W6RCA, OOTC




From [e-mail] Mon Jul 15 17:01:02 1996
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From: "William E. Sabin" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Sat, 13 Jul 1996 17:19:27 -0700
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Bart Rowlett wrote:
>
> Most solid state RF power amplifiers have source impedances far less than
> the 50 ohms implied above.  In practice if you try to load them with
> an impedance equal to the internal source impedance you will exceed the
> maximum current capability of the components and destroy something.  If
> the amplifier manages to survive, it would no longer be operating anywhere
> near the design point and would probably generate lots of distortion.
>


Excellent!!!!!!

Bill W0IYH


From [e-mail] Mon Jul 15 17:01:04 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 14 Jul 1996 05:10:31 -0400
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Hi Jeff,

In article <4s829e$[e-mail]>, [e-mail](Jeff
Anderson) writes:

>    Tom:    1.  Are you using "complex conjugate" in the sense
>                that your load resistance equals your source
>                resistance, and the complex components are
>                equal and opposite?

Yes

>            2.  If (1) is true, does this mean that, for a class
>                C amp, if it has a "conjugate match" to the load,
>                that its source resistance, in the case of a 50 ohm
>                load, appears to be also 50 ohms, and not nonlinear
>                (nonlinear by virtue of < 360 degree conduction
>                angle)?  If it doesn't mean this, could you please
>                clarify?

Yes it absolutely does and it can easily be measured. All you need are the
DUT, a reverse generator, a tapped line, a bridging pad, a selective level
meter or spectrum analyzer, and a large terminating pad.

>            3.  If (2) is true, how does the nonlinear resistance
>                of the Class C amp's plate/drain/collector become
>                linear?

By the same mechanism that filters harmonics, the tank circuit. While the
impedance at the output device is time varying, it is synchronized with RF
in the tank. The tube (or transistor) gives the tank a little "tug" at the
right instant, it really isn't the source at all. For maximum energy
transfer that "tug" has to equal the impedance of the tank (load) like
matcing the speed of your hand to a flywheel. Pull too hard, fast, or slow
and energy is wasted. Pull too easy or at the wrong rate, and energy is
wasted.

If you excite the tank externally at somewhere around the right rate, the
tank averages the excitation and you measure the rate of current change
for a given voltage change. These across and through vectors are called
impedance.

>            4.  Is there any literature which also discusses this?

A Chaffe analysis of a PA surely proves it. The last step of the analysis
is calculating the optimum point of operation and determines the
fundamental RF voltage and current available. This is the operating
impedance of the anode, and the value used to design the network. A test
set up with a reverse generator and a tapped line section will confirm the
calculation. ALL of the reverse generator's energy is absorbed and
converted to other accountable energy, and as long as you are careful not
to overdrive the PA and change its characteristics the reverse generators
voltage is equal along the line section.

As a matter of fact, the PA can be tuned for maximum output power and
efficiency by watching the reverse generator's standing waves. I've done
it on dozens of PA's with feedback and without, class C through class A.

>
>    Thanks, guys!  I know we're going back over ground well-trod some
>time ago, but heck, maybe I'll learn something.

Hook one up and measure it! It takes less time that the debate does, hi!

Jack Belrose (VE2CV) wrote an excellent analysis of this, as did Bill
Sabin. Their analysis were almost identical, although they used different
jargon. I have copies of both if you like. As a matter of fact, I have a
stack of papers two feet high on this subject, most of it repetitive.

73 Tom


From [e-mail] Mon Jul 15 17:01:04 1996
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From: Pierre-Andre Rovelli <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: GAP ant modelization with EZNEC
Date: 15 Jul 1996 07:32:32 GMT
Organization: CompuServe, Inc. (1-800-689-0736)
Lines: 17
Message-ID: <4scs6g$6rb$[e-mail]>

They are many discussion around GAP antennas efficiency. Has
anybody tried to modelize these antennas with EZNEC? It should
give at least a theorical answer, but certainly very useful.I
would be very interested to have the exact mechanical dimensions
of the GAP Titan for putting into the EZNEC modelization
software.

Pierre-Andre Rovelli, Biel Switzerland
HB9FMN
[e-mail]
[e-mail]

--
Pierre-Andre Rovelli
HB9FMN
Aarbergstrasse 90
2502 Biel Switzerland


From [e-mail] Mon Jul 15 17:01:06 1996
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From: [e-mail] (Graham Seale)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: GE RTV 108 : Corrosive?
Date: Fri, 12 Jul 1996 23:10:03 GMT
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In message <31e58961.734323@137.149.3.1> David  C. Seeler wrote:

> THe local aquarium shop carries GE RTV 108 (industrial) but they have
> not used it and can not tell me if it "smells" like vinegar when it
> cures. So can anyone tell me if this compound is okay on copper
> wires/lug connections?

Hello David.

There are piles of tubes of bathroom/other RTV sealers in any DIY store.
Most "smell of vinegar" and are very corrosive, and you correctly deduce
that these are not what you need.

The one that is _not_ corrosive is Dow Corning 3145 RTV. I do not know
if the GE RTV 108 is a direct (ie. non-corrosive) competitor, but the use
of the term "RTV" suggests that it is. RTV - an acronym for (R)oom
(T)emperature (V)ulcanising is usually taken in the UK to mean the Dow
Corning version.

My antenna connections came out as if new after 5 years under black
self - amalgamating butyl tape. I use RTV to seal awkward shapes.
If put over connectors, it gets really awkward to recover them from
the welded-on silicone rubber.

Yeah - I know, its only 2cents worth, but I hope it helps..

73's + best wishes
G4WNT
--
Graham


From [e-mail] Mon Jul 15 17:01:07 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!inXS.uu.net!bcstec!matrix.hv.boeing.com!richesop
From: [e-mail] (Peter Richeson)
Subject: Re: GE RTV 108 : Corrosive?
X-Nntp-Posting-Host: matrix.hv.boeing.com
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Sender: [e-mail] (NNTP News Access)
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If you have a web browser go to http://www.ge.com/electromaterials/
For a start.  If not try calling 1 [phone].


In article <31e58961.734323@137.149.3.1>, [e-mail] (David  C. Seeler) wr
ites:
|> I have jsut finished placing another 30  1/4 w radials and would like
|> to "weather Proof" the connections at the antenna. In the past I have
|> used vaseline but thought I might try some non-corrosive RTV.
|>
|> THe local aquarium shop carries GE RTV 108 (industrial) but they have
|> not used it and can not tell me if it "smells" like vinegar when it
|> cures. So can anyone tell me if this compound is okay on copper
|> wires/lug connections?
|>
|>
|> Thanks for any information you might have. All other local shops
|> handle the standard materials.
|>
|>
|>
|> Regards,
|> David Seeler, VY2DCS
|> Charlottetown, PEI

.      '''
.     (o o)
___ooO-(_)-Ooo________________________________________________________
Peter D. Richeson                    | "I don't believe in a no-win   |
Email: [e-mail] |  scenaro."                     |
Phone  [phone]                 |    - Admiral James T. Kirk     |
----------------------------------------------------------------------+
Web Stuff:                                                            |
Inside Boeing - http://matrix.hv.boeing.com/~richesop                 |
Outside Boeing - http://www.traveller.com/~richesop                        |
----------------------------------------------------------------------+
I do not speak for any one but me, and some times not even for me.    |
----------------------------------------------------------------------+


From [e-mail] Mon Jul 15 17:01:07 1996
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From: Ted VanDenHeuvel <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Antenna Ideas for Apts?
Date: Fri, 12 Jul 1996 08:20:17 -0600
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QST has published numerous articles on mini-loop antennas. Also, the
ARRL Antenna Handbook devotes some space to them. I built a
"three-footer" that works great.


From [e-mail] Mon Jul 15 17:01:09 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Homebrew Mobile HF Antenna Query
Date: 10 Jul 1996 13:19:16 -0400
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Hi Paul,
In article <[e-mail]>, Paul Knight
<[e-mail]> writes:
>
>My idea is to create a vertical dipole, of sorts, which would allow the
>antenna to be used on "plastic" cars lacking a suitable metal ground
>plane.  To accomplish this, I was considering using a top section
>which is resonant on the band of interest (e.g., a hamstick, or hustler
>whip/resonator).  This top section would be fed with the center conductor
>of the coax feedline.  For the other leg/bottom section of the dipole,
>I'd like to try a helically-wound element, also resonant on the band
>of interest.

First, the feedpoint would have to have a high impedance choke balun.The
military has used similar antenna system for portable use.

Anytime charges accelerate, radiation occurs. The antenna you are using
for a "ground" will have an equal amount of current as the desired
antenna. If they are of equivalent electrical chariteristics, they will
both radiate equally. Half the energy will be wasted in the horizontal
leg. Both efficiency and bandwidth are improved by adding additional
counterpoise antennas.

The horizontal legs of the antenna will be tightly coupled to the car and
the lossy earth around the car. That causes RF to appear everywhere in the
car and increases the systems loss.

Both bandwidth and efficiency would be reduced over simply using a
conventional "metal car ground", but at least the antenna would work.

The system would be much more efficient and you would likely experience
fewer RFI problems if the antenna could be located where several ground
wires could be fanned out to various points on the car's chassis.

> I'd construct this element using 1/2 wavelength of wire,
>fairly closely wound on a length of PVC pipe which doubles as the
>mounting base.

A 1/2 wl of wire would not likely be resonant. The length of wire required
varies with the distributed capacitance and inductance in the winding. I
assume you'll still tune it to resonance after you build it.

If you don't use a large choke balun at the feedpoint, the coax, the rig,
the wiring, and eventually the car will become part of a directly
connected ground anyway.

73 Tom


From [e-mail] Mon Jul 15 17:01:11 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: I can make a balun, but how good is it?
Date: 14 Jul 1996 21:19:07 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 38
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In article <4sbfta$[e-mail]>,
[e-mail](Tom Wagner) writes:

>
>I have received different advice about this:
>
>1.  Fix the BN-86 and put it back up.
>2.  Replace it with 7 turns RG-213 6"
>    diameter (bunched).
>3.  Replace it with 6 turns 4"
>    diameter single-wound.
>4.  Use a ferrite choke balun.  I have
>    5 big #43 beads I could use.
>    Whether they are *really* #43, I'm
>    not sure.
>

2.) I wouldn't bunch the turns, it raises the stray capacitance and lowers
bandwidth of the balun.

4.) I wouldn't use the beads. They may overheat at high power. Air wound
coax works better and is cheaper if you have the room.

You are measuring it the correct way. 500-700 ohms sounds high, but if the
common mode impedance is also high you may run into trouble.

Remember the baluns job is to handle common mode impedance, not
differential mode. The common mode impedance can be very high or low
independent of feedline impedance, but in the case you are describing it
will almost certainly be low.

If the common mode impedance is 25 ohms, the balun will have to choke 194
volts at 1500 watts. If your unknown ferrite beads are primarily resistive
at the operating frequency, they will dissipate 63 watts. That isn't a lot
of power, but it is a lot of heat if the beads don't have a large amount
of surface area exposed to cooling airflow.

73 Tom


From [e-mail] Mon Jul 15 17:01:12 1996
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From: [e-mail] (Graham Seale)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: impedance question
Date: Sun, 14 Jul 1996 22:41:31 GMT
Lines: 58
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In message <4s1qfr$[e-mail]> Ed Griffin wrote:

> Could someone give me the formula for finding the characteristic
> impedance of an air-insulated parallel-conductor line...IF the two
> conductors are flat, like two flat aluminum bars or two square tubes.
> I know the formula from the ARRL Handbook but it is for round parallel
> conductors.

Hello Ed.

Hmm.. try this..

       __________b__________
      |_____________________| _
       _____________________  _ <---- Gap = a
      |_____________________|

     Zo =~= 377 * a/b   provided a << b

      Formula assumes air dielecric. For others, multiply Zo by 1/K
      where K is the dielectric constant of the stuff you put in the gap.

This formula neglects the "end fringe field effect", but if the width is
more than about ten times the gap, you would probably not care that the
answer is a tad high.

Hmm #2..
Now that I see a graph of Zo for balanced parallel strip transmission line,
it has a 3 decade vertical (Y-axis) for  a/b  going from 0.1 to 100.

So, (realising convex curved bits on a log graph work against the log law)
I would guess that that formula probably starts to get reliable for Zo
impedances below about 50 ohms.

Try these:     a/b        Zo ohms
               0.1        38   <------ nearly agrees with formula
               0.2        60  \
               0.3        80   | <--- looks sort of linear but does not
               0.4        100  |      agree particularly well with 377*a/b
               0.5        118 /
Then we get into a straight line on a log graph.
               0.6        130
               0.8        155
               1.0        180
               2.0        255
               3.0        300
              10.0        445
              20.0        525
              30.0        575

Source is Evan & Jessop VHF/UHF manual (RSGB). I would have just mailed
you direct, but I don't trust the formula yet, so we invite others with
maybe better data to have a go.

73's G4WNT

--
Graham


From [e-mail] Mon Jul 15 17:01:14 1996
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From: "<<J.F.S.>>" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Inside Antenna for an apt
Date: Thu, 11 Jul 1996 10:37:38 -0700
Organization: If you only knew !
Lines: 24
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References: <4s28hg$[e-mail]>
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Douglas Cohron wrote:
>
> Does anyone have any ideas for a 2m/440 antenna for the inside of an
> apt that is on the first floor? I have an HT dual band and have no
> crawl space nor much room for something big. Any and all help
> appreciated. Thanks in advance Doug "KF4KTJ" Cohron
> [e-mail] do not say if you do or do not have patio/porch
access. When I lived
in an ground floor apartment, I used a commercially made J-Pole antenna.
For a base, I used 40lb cement in a 5 gal paint bucket with a 2 foot
length of 2inch pvc pipe in the center of the pail. When not in use, the
J-pole came inside and rested diagonally in the corner of the room. This
also worked well when the weather was not the best (lightning storms,
cold, etc) to put the antenna on the porch/patio. I never had troubles
reaching most of the repeaters in the area.

73
John KE4KPV
Atlanta, Georgia, USA

We are born Nude ...

It is societal morals, not biblical morals
that prevent us from feeling free enough
to lie naturally in the sun.


From [e-mail] Mon Jul 15 17:01:14 1996
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From: [e-mail]  (Bill Newkirk)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Inside Antenna for an apt
Date: 12 Jul 1996 03:01:02 GMT
Organization: Space Coast Amateur Technical Group
Lines: 21
Message-ID: <4s4f5e$[e-mail]>
References: <4s28hg$[e-mail]>
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In <4s28hg$[e-mail]>, [e-mail]
(Douglas Cohron) writes:
>Does anyone have any ideas for a 2m/440 antenna for the inside of an
>apt that is on the first floor? I have an HT dual band and have no
>crawl space nor much room for something big. Any and all help
>appreciated. Thanks in advance Doug "KF4KTJ" Cohron
>[e-mail]
>
depending on the space available..there's things like using something along th
e
lines of the antenna specialists MON-48 discone...another approach is to build
 a
stand out of PVC and put a small beam on it -- this lets you direct your signa
l
towards other stations or repeaters so you can have things at least working
for you as much as possible.

could also tape a dipole to the window glass...anything to get the signal as c
lose
to the outside as possible...

Bill Newkirk WB9IVR                  The Space Coast Amateur Technical Group
Melbourne, FL                       duty now for the future of amateur radio
Lombardi's 1st Law of Business:
Companies succeed in spite of their best effort.  If they succeed at all.



From [e-mail] Mon Jul 15 17:01:15 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Inverted Vees vs. Sloppers
Date: 10 Jul 1996 13:18:59 -0400
Organization: America Online, Inc. (1-800-827-6364)
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In article <4rtjsj$[e-mail]>, Chester Bowles <[e-mail]>
writes:

>Thanks Tom, that's sorta what I thought.  I guess the tower acts as a
>reflector?
>
>Chet, AA1EX

Sorta kinda Chet, if its self-resonant frequency is correct!

With different self resonant points the tower can act like:

A director.
A reflector.
A big nothing.

I wonder how you know in advance which it will be?

73, Tom


It can act like a director also, but usually it is resonant well below the
operating frequency and acts like a "reflector".


From [e-mail] Mon Jul 15 17:01:16 1996
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From: Gary Zabriskie <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Is the MFJ 80-2 Vertical Antenna any good?
Date: Thu, 11 Jul 1996 14:25:28 -0700
Organization: NETConnect
Lines: 13
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We have just moved into a new home and I would like to put a new antenna
up.  Have seen the ads for the MFJ 80 through 2 meter vertical (the one
that doesn't (supposedly) need any ground plane wires.  Has anyone tried
this antenna? Does it work as advertised. How mechanically rigid is it?
Would you recomend it or some other antenna?

Please respond via this newsgroup _and_ via e-mail ([e-mail]) as
I don't always get a chance to get on here and might miss the response.

Thanks and 73,

Gary Zabriskie
N7ARE


From [e-mail] Mon Jul 15 17:01:19 1996
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From: Mel Dixon <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-Pole 2M Antenna - possible tunning?
Date: Thu, 11 Jul 1996 09:48:11 -0500
Organization: Advanced Power Supply Design
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Rich Griffiths wrote:
>
> Reginald M. Honyben wrote:
> >
> > Last night I built my own 2M J-Pole antenna.  To my pleasant surprise
> > it worked pretty well.
> > However I did receive this SWR readings:
> >    on 144.000 MHz I received 1 to 1.15 ratio,
> >    on 146.000 MHz I received 1 to 1.5 ratio,
> >    and on 148.000 MHz I received 1 to 2 ratio
> >
> > I like to transmit in the higher end of the band, around 147.000 to
> > 148.000 MHz.  Can anyone tell me how to tune the antenna so it is a
> > little more balanced, throughout the band?  Or are these readings OK,
> > and I am over worrying?  Thanks in advance!!!
> >
> > My E-mail address is {[e-mail]}
> > KC7MXV
> > 73's
>
> At first look, those readings just mean that the 1/2-wave portion of the
> antenna is too long, and trimming it about 2% would make it right.  You
> might also have to adjust the taps on the stub.
>
> But then again, it may depend on how you built the antenna -- twin lead??
> copper tubing??  other???
>
> Also, please be advised that you should avoid testing exactly at the band
> edges (144.000 or 148.000 MHz).  If you do, some part of your signal is
> almost certainly out of band.
>
> Rich Griffiths   W2RG

I agree with Rich, Your data indicates the antenna is a little long. If
you can, trim it down a bit, find the lowest SWR point and re-set the
tap. WB5BTG...


From [e-mail] Mon Jul 15 17:01:21 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-Pole gain
Date: 12 Jul 1996 18:27:22 -0400
Organization: America Online, Inc. (1-800-827-6364)
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In article <4s5v39$[e-mail]>, [e-mail] (Tim
Shearer) writes:

>
>I would say that the gain of a standard J-pole is 0 dBd or 2.15 dBi since

>it is just an end fed half wave dipole. The antenna does not require a
>ground plane like a 1/4 wave vertical does because both halves of the
>dip[ole are present and this is where the advantage lies. It also is a DC

>grounded antenna (if you metalically connect it to a grounded tower)
which
>is very advantageous in lightning storms.
>
>Tim KF8XW

Hi Tim,

Actually the J pole has a problem that can be verified in models or real
world measurements. Common mode current in the stub is out of phase with
current in the radiator, this causes a reduction in gain from a properly
fed half-wave.

Contrary to popular rumor, end-fed  half waves still require a ground
system, something the J pole lacks. The reason is simple......

The impedance of the end fed radiator is not infinite, and actually can be
pretty low if the element is thick. The J pole stub must act as the
"ground" or counterpoise, and that means it also radiates with destructive
out-of-phase radiation. This undesired radiation will be maximum when the
stub is grounded (or connected to a low RF impedance) at the very bottom.

A properly constructed 1/4 wl groundplane likely has more gain, and a true
center or asymetrically fed half wave certainly will.

73 Tom


From [e-mail] Mon Jul 15 17:01:22 1996
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From: Dan Richardson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Kansas Dipole Question
Date: Fri, 12 Jul 1996 10:31:16 -0700
Organization: LPS Systems
Lines: 6
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I understand that 73 magazine publish an article on the Kansas Dipole
some years back.
Does anyone know what issue it was in?

Dan K6MHE
e-mail [e-mail]


From [e-mail] Mon Jul 15 17:01:23 1996
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From: [e-mail] (PGSPersEng)
Newsgroups: rec.radio.amateur.antenna
Subject: Loading delta loop on multiple bands?
Date: 13 Jul 1996 00:19:36 -0400
Organization: America Online, Inc. (1-800-827-6364)
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NNTP-Posting-Host: newsbf02.mail.aol.com

On my sailboat I only have enough room to put up a delta loop for 20m.
Does anyone have any experience with one? How well will it load up on
80/40/30?

Thanks
Paul, AA1MI


From [e-mail] Mon Jul 15 17:01:24 1996
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From: [e-mail] (Robert Strickland)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quad question...
Date: Sat, 13 Jul 1996 00:10:59 -0400 (EDT)
Organization: ServiceTech, Inc.
Lines: 31
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Ed...
Just about all the current comercial quad manufacturers will sell you
their fiberglass spreaders for more-or-less reasonable fees. There are
also vendors who just sell fiberglass poles. A request for
"...fiberglass vendors..." here usually turns up the info. Avoid
bamboo. It was the original material for quads, performed poorly and
gave the antenna a poor reputation for reliability. Use the same
quality materials that one would use building a yage/etc. Back pages
of radio mag's regularly carry adds for quad components. IMHO, the two
element quad is the best "small" beam that one can put up. No need to
resort to separate feed bays for the higher bands. I've extensively
modeled quads on EZNEC [various opinions of usefulness], and it shows
no significant advantage for separate bays at the two-elemet level.
Use an 8ft boom and "bend" the spreaders outwards with the wires. This
gives sufficient spacing for 20 -15m and close enough for 12-10m.
IMHO, use separate feed lines and a switch box. Many opionions on this
point, so you have to do your "research" and make your own decision.
Don't tie the wires down to the elements. Let them "float" using a
bracket that uses tubing [Lightning Bolt Antenna has nifty brackets].
If you build smart with good materials, then the quad will stand up to
a surprising amount of weather. It's probably less sturdy than a
"heavy duty yagi", either comercial or re-worked, but it's good enough
given the performance. Email me if you have any detail questions. Good
luck.
...Robert


Robert G. Strickland
[e-mail]
Syracuse, New York



From [e-mail] Mon Jul 15 17:01:25 1996
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From: VE4KLM <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Questions on elevated radials. example, is wire gauge critical, etc.
Date: Thu, 11 Jul 1996 09:31:25 -0500
Organization: The University of Manitoba
Lines: 22
Message-ID: <[e-mail]>
NNTP-Posting-Host: access.mbnet.mb.ca
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII


I have a shortened vertical antenna sitting on top of my house. The base of
the antenna will be about 24 feet above ground. I have alot of thin copper
wire at my disposal and was thinking of using this wire for radials. The
gauge of the wire is that used in a typical yoke assembly in TV sets.

Is this wire appropriate to use. How much of the power going into the
antenna system winds up flowing in the radial system ? Is it negligible
enough to justify the use of this 'yoke' wire ?

Any comments would be appreciated.

Regards,

Maiko Langelaar
VE4KLM

 ---------------------
|  SLM Software Inc.  |
| [e-mail] |
 ---------------------



From [e-mail] Mon Jul 15 17:01:26 1996
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Gary Coffman)
Subject: Re: RG213 vs. 9913 cable
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <4s8ft2$[e-mail]>
Date: Sun, 14 Jul 1996 02:22:58 GMT
Lines: 17

In article <4s8ft2$[e-mail]> Tim Pekkonen <[e-mail]> writes:
>
>I am currently putting up a two meter vertical antenna and will have
>about 75-80 feet of feedline to it. I am contemplating feeding it with
>RG-213 cable. Can anyone tell me if there is any advantage in using
>RG-9913 cable instead ??

Sure, it has lower loss. But it is a bit harder to work with, and
it isn't very flexible.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sun Jul 21 18:40:51 1996
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From: [e-mail] (Alan)
Newsgroups: rec.radio.amateur.antenna
Subject: (none)
Date: 17 Jul 96 15:17:08 GMT
Organization: ucsd usenet gateway
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NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

subscribe Ham-Ant Alan And Charity



From [e-mail] Sun Jul 21 18:40:52 1996
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From: [e-mail] (Kirk Black)
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.amateur.antenna
Subject: ***Computer and HAM RADIO stuff for sale (In Canada)(VE3SLO)***
Date: Wed, 17 Jul 1996 14:16:54 GMT
Organization: Tech-Net Services
Lines: 86
Message-ID: <4sip7d$[e-mail]>
NNTP-Posting-Host: ppp5.execulink.com
X-Newsreader: Forte Free Agent 1.0.82
Xref: news2.epix.net rec.radio.amateur.equipment:31139 rec.radio.amateur.misc:105340 rec.radio.amateur.antenna:23295

STUFF FOR SALE

$50.00
Almost new!
Entertainment center for up to 26" TV or larger, VCR and Stereo
plus other storage places

Possibly you could even put your radio setup in this one! :)


HAM Stuff
----------
Battery Packs for HAM radio HT's
2 battery packs compatible with Icom and Realistic HT's
These are the battery shells that take standard AA cells that
Radio Shack sells
$10.00 One is empty and takes 6 AA cells
$30.00 The other has 6 new AA 650mAh rechargables included.
Only 3 days use at most.


$125.00
Must show or at least be able to prove you have a valid HAM licence to
purchase.
30 Watt 2 meter RF power amplifier
Custom built using Motorola RF power module.
300mW to 1.0 Watts in gets about 30Watts out.
Has 3 pole Voltage and capacitance tuneable helical filter built in
for receive to reduce intermod.
BNC input...SO-239 output.  Heavy duty thick heatsink, 100% duty cycle
at 12V, compact size.
CLEAN output
Power module spuroius emissoins rated at 70db below carier.
12V to 16V


$50.00
2 bay folded dipole
138-174MHz
Commercial design with HEAVYduty clamps
Much the same as Sinclair 210C-2 infact it might be that

Computer parts
---------------

$25.00
486SX-25 CPU
Runs reliably as a 33MHz CPU

4 of these...
$5.00 each or $15.00 for all
Unknown make of network cards.
Assumed to be ARC NET type.  8 bit, BNC, possibly have boot proms as
well.
AMD chipset on them.  These cards do work as they were pulled straight
from
service rescently.

$1.00
16bit MFM controller card.  not sure of the state it's in.

$1.00 for both
do not know if they work...
2 8 bit I/O cards for floppy.  Has DB36 female connector on rear of
card.

$4.00
I/O card for floppy.  Half card.  Has battery and BIOS with 2 serial,
1 game
and 1 LPT.  8 bit
I beleive this one does work.


$45.00
80 Meg Maxtor 2.5" 2585AT Hard drive.  (laptop drive)
formats to 85,018,624 bytes. (DOS)
No bad sectors.  Have the connection/power adaptor for standard equip.
Do not have the bay adaptor for this drive.


All private sale.  Open to only REASONABLE offers!

If interested reply by email to [e-mail]

Check this page too:  http://www.execulink.com/~kblack/tech-net.html



From [e-mail] Sun Jul 21 18:40:53 1996
From: [e-mail] (Claton Cadmus)
Path: news2.epix.net!uunet!in2.uu.net!mr.net!news.mr.net!medtronic.com!rosevax!hamlink!fredmail
Newsgroups: rec.radio.amateur.antenna
Subject: 10m 5/8w modeling needed.
Message-ID: <[e-mail]>
Date: Fri, 19 Jul 1996 17:08:35
X-FTN-To: All
Lines: 30

Hello all,

I have a CLR-2(?) 10 meter 5/8 wave antenna, it's a CB antenna I rescued
and put to a better use. It has 3 quarter wave radials.  Currently the
antenna is at about 30 ft at the base, I plan to take it down and raise
it to 40 feet.  I just thought as long as it's down I might improve it a
little.

So, I would be interested if one of you antenna modeling gurus might
advise if the radiation angle/characteristics would be improved with the
addition of more radials and/or if the radials were bent downward. Also,
I would be interested to know the angle of maximum radiation now and
after some possible suggested mods.

If you can send file attachments, print outs would be great! Send them
to [e-mail]

So here's a small challenge for someone.  A little weekender if you
will.

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 * Remember, you are unique, just like everyone else!




From [e-mail] Sun Jul 21 18:40:54 1996
Path: news2.epix.net!uunet!inXS.uu.net!newsreader.sprintlink.net!news.sprintlink.net!news-dc-10.sprintlink.net!news.smartlink.net!usenet
From: [e-mail] (BBWB)
Newsgroups: rec.radio.amateur.antenna
Subject: 2M mobile antenna?
Date: Sun, 14 Jul 1996 20:25:59 GMT
Organization: j%nki~wÇRJ3M-26XPLZ8L-BFGD44CT-1EA6BC82
Lines: 7
Message-ID: <[e-mail]>
NNTP-Posting-Host: pm43.smartlink.net
X-Newsreader: Forte Agent .99e/32.201

Any one have a suggestion on a good 2 meter mobile antenna?  The
vehicle it will go on is a 92 Explorer with a liggage rack.  The big
thing is that I don not want to punch holes through the body, mag
mounts are out as I have one I use for my 87 Firebird and I'm glad the
paint job is non exitent any way.  Thanks for any info.
Bud
omne ignotum pro magnifico


From [e-mail] Sun Jul 21 18:40:55 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!news-dc-9.sprintlink.net!news-res.gsl.net!news.gsl.net!nntp.coast.net!news.kei.com!newsfeed.internetmci.com!inXS.uu.net!excelsior.flash.net!usenet
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: 2mtr beam wanted
Date: Sun, 21 Jul 1996 16:01:47 GMT
Organization: Flash-Net Internet Service Provider, 888-FLASHNET
Lines: 5
Message-ID: <4stjtj$[e-mail]>
NNTP-Posting-Host: tpm1-18.flash.net
X-Newsreader: Forte Free Agent 1.0.82

hello I am looking for 2meter beam ant..something the neighbors wont
notice right away...Would considerer GROVE BEAM..jey I can tell them
its a TV ant..pls email me at [e-mail] or here at the
newsgroup    thanks jim



From [e-mail] Sun Jul 21 18:40:56 1996
Path: news2.epix.net!uunet!inXS.uu.net!jaring.my!usenet
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: 40 meter band
Date: 20 Jul 1996 00:11:53 GMT
Organization: Unconfigured
Lines: 4
Message-ID: <4sp889$[e-mail]>
NNTP-Posting-Host: j1.brf2.jaring.my
X-Newsreader: SPRY News 3.03 (SPRY, Inc.)

Can anyone give me some information on how to construct a 40 meter antenna on
a very limited space.
thank on advance
73
9m2me


From [e-mail] Sun Jul 21 18:40:57 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!newsfeed.internetmci.com!usenet.eel.ufl.edu!warwick!ral!usenet
From: Mike Willis <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 6/2M beam spacing?
Date: Thu, 18 Jul 1996 08:55:31 +0100
Organization: Rutherford Appleton Laboratory, Oxon, UK
Lines: 26
Message-ID: <[e-mail]>
References: <4s8nb0$[e-mail]> <[e-mail]> <[e-mail]>
NNTP-Posting-Host: bradman.te.rl.ac.uk
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 3.0b4Gold (Win95; I)

Ian White, G3SEK wrote:
>
> Dave Cook wrote:
> >Bob inquired about minimum vertical spacing of antennas for 6 and 2
> >meters.
> >
>
> If you still want a non-mathematical rule of thumb, stack the higher-
> frequency antenna at a distance where the larger, lower-frequency
> antenna is just outside of its capture area. Look at the data sheet for

This is the rule I apply. The HF antenna will not resonate at the lower
frequency and will have minimal effect, but the LF antenna will resonate
at the higher frequency. Putting the LF antena outside the capture area
of the HF antenna solves the problem, but might not be practical.

Why not find some local stable signal source with no QSB, at the higher
frequency, 2m in this case, and do some practical tests measuring
the signal strength against spacing. Minimum spacing is very probably a
lot less than the capture area.

On expeditions, we have stacked a pair of 70cm antennas between a pair
of 2m antennas, both at recommended stacking distance, without any
noticable problems. 2m went up first, later the 70cms kit arrived,
70cms went up. No change on 2m and good performance on 70cm, but nobody
about....


From [e-mail] Sun Jul 21 18:41:00 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!tank.news.pipex.net!pipex!news.be.innet.net!INbe.net!news.nl.innet.net!INnl.net!hunter.premier.net!news.uoregon.edu!pagesat.net!zappa.northnet.org!usenet
From: [e-mail] (Darron R. Birgenheier)
Newsgroups: rec.radio.amateur.antenna
Subject: 900MHz cordless phone antenna?
Date: Sat, 20 Jul 1996 13:55:44 GMT
Organization: DRB Gunsmithing
Lines: 27
Message-ID: <4sqoh9$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: ppp-1.lowville.northnet.org
X-Newsreader: Forte Free Agent 1.0.82

Howdy all,

        I recently bought a GE 900MHz cordless phone, hoping that it would live up to
the reputation I've heard of having great range. Well, no such luck. Although
it is very clear, it doesn't even have as much range as my brother's 46/49MHz
cordless.
        It has small rubber duck antennas on both the base and handset, about 4 inche
s
long (1/3 wave?) I took apart the base unit and found where the base antenna
attaches to the printed circuit board with a single screw. I attached a short
length of insulated braided wire to the screw, along with the original antenna
.
I extended the wire out of the base housing to act as a connector for trying
external antennas. I first tried connecting my SWL longwire antenna (75 feet)
to the base unit. It made little difference. Then I tried my outdoor TV
antenna, which worked quite a bit better. The TV antenna seemed to work best
with both conductors of the coax lead-in cable connected to the single wire on
the base unit.
        Does anyone have a frequency list for the UHF TV band? I'm wondering how clos
e
the upper channels are to the 900MHz range that the phone uses.
        Are there any outdoor antennas that are specifically designed for use with 90
0
MHz phones or other devices in the same frequency range? I would even
appreciate any thoughts on making or modifying an antenna for use with the
phone.

Thanks,
Darron R. Birgenheier
[e-mail]



From [e-mail] Sun Jul 21 18:41:01 1996
Path: news2.epix.net!uunet!in2.uu.net!spool.mu.edu!howland.reston.ans.net!newsfeed.internetmci.com!cdc2.cdc.net!newsfeed.concentric.net!news-master!news
From: [e-mail] (Mike Cook - AF9Y)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.space
Subject: A new Helix Antenna design for the Mars Observer Experiment
Date: 20 Jul 1996 06:22:49 GMT
Organization: Your Organization
Lines: 78
Message-ID: <4sptvp$[e-mail]>
NNTP-Posting-Host: cnc031051.concentric.net
Mime-Version: 1.0
Content-Type: Text/Plain; charset=US-ASCII
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Xref: news2.epix.net rec.radio.amateur.antenna:23332 rec.radio.amateur.space:7348

      A new Helix Antenna design for the Mars Observer Experiment

During the last few weeks, I've attempted to optimize a low cost Helix
antenna design suitable for detecting the Mars Observer.  Here are the
characteristics and modeling results:

     Reflector Screen: NONE - A single 10.66" loop reflector is used
                       which eliminates the cumbersome reflector screen

     Boom: 10 Foot length of 4" dia, thin wall PVC (normally used for
           tile). Weight is less than 5 Lbs and the cost is $3.50 (at
           Builder's Square)

     Helix: 23 Turns of 1/4" refrigerator copper tubing spaced 5.125"
            per turn. 55 Feet of tubing required at an approximate cost
            of $20.

            This design has a two step taper for the Helix Dia:

               Reflector Loop Dia: 10.66"

               First 4 Turns: 10.32"

               Next  7 Turns: 8.68"

               Last 12 Turns: 8.40"

             The reflector is positioned 0.375" ahead of the start
             point of the  first helix turn.


     Helix Support: 1/2" PVC tubing used as stubs which are glued in
     the 4" boom with a spacing of 2.5625"

     FeedPoint: 50 Ohm at <1.2 VSWR.  No matching network required.

     Gain: 15.9 dBci
           (approximately 1 to 1.5 dB better than the
             standard Helix antennas I have modeled)

     Pattern:  First Side lobes at 36 degrees down 14 dB
               Average of all remaining sidelobes <25 dB

     Bandwidth: <0.2 dB variability from 432 to 438 Mhz
                50 Ohm Match at <1.2 VSWR from 432 to 438 Mhz


     Construction accuracy:  The Helix diameter, especially the first
                             4 turns needs to be held to a  +/- 0.125"
                             tolerance to keep the gain within 0.5 dB.


     Estimated Total Cost:  <$30


Two of these antennas provide 18.9 dBci gain which could be enough
for detection of the Mars Observer.  Four would provide a nice margin
at 21.9 dBci.

The pattern/image plots and the AO-PRO input file are available from
my webpage. Additional pictures and sketches will be posted as
construction proceeds.  The webpage adr is: http://www.webcom.com/af9y

I would be happy to model any other helix designs if you email me the
dimensions.  I'll give any standard reflector screen designs the
benefit of a perfect reflector surface. (very time consuming to model
a real screen)


de Mike, AF9Y










From [e-mail] Sun Jul 21 18:41:02 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!newsfeed.internetmci.com!uwm.edu!math.ohio-state.edu!newsfeed.acns.nwu.edu!news.acns.nwu.edu!merle!necrolar
From: [e-mail] (Rene Carlos)
Newsgroups: rec.radio.amateur.antenna
Subject: Al and Cu tubing
Date: 15 Jul 96 13:45:29 GMT
Organization: Northwestern University, Evanston, IL, US
Lines: 22
Message-ID: <necrolar.837438329@merle>
NNTP-Posting-Host: merle.acns.nwu.edu
X-Newsreader: NN version 6.5.0 #2 (NOV)

Can anyone recommend a good source of aluminum
and copper tubing?  Besides the local hardware
store, of course, which doesn't have a huge
selection.  Any of the "big box," "category-
killer" stores, perhaps?  The Small Parts,
Inc. catalog is good, but may be more
expensive than shopping locally.  Any other
catalogs out there?

Related question: anyone use tubing cutters
instead of the tried-and-true hacksaw?  I'm
talking about those things that look like
C-clamps, except with a cutting wheel.  Some
friends want me to make antennae for them, so
I think a tubing cutter would be a lot faster.
Is there a maximum gauge they'll cut?

Rene Carlos
[e-mail]
[e-mail]




From [e-mail] Sun Jul 21 18:41:06 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!newsfeed.internetmci.com!news.kei.com!news.texas.net!nntp.primenet.com!uunet!inXS.uu.net!jennifer.pernet.net!falcon.sat.net!usenet
From: Drew Loker <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Almost direct hit - lightning, protection, arrestors, grounds?
Date: Thu, 18 Jul 1996 01:16:49 +0100
Organization: Texas Education Network
Lines: 30
Message-ID: <[e-mail]>
References: <4s04kb$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: wn-bpt6.sat.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.02 (Macintosh; I; PPC)

Is there any point in using a Lightening arrestor, like the LAC4? What
is the loss in dB for this pass through? I had a friend really dog that
I had gotten a LAC4, that it was worthless to put in line. I am really
confused.

The plan was to take two feed lines from a vertical and a beam, and run
them to an antenna switcher just out side my window, well outside of
direct water contact. THen put the LAC4 on the single side of the
switch. My friend had also said that the swticher will be high in loss
for 2m/70cm as well, defeating the purpose of putting up a higher and
better antenna. I also made a mistake and got the 9913, which I decided
almost imediately after it had shipped that I shoudl have gotten the
LMR400.

ANyway, any suggestions about grounding and lightening protection woudl
be most appreciated. I have two ground rods that I was going to ground
the tower with, and the then a seperate ground rod for the arrestor and
antenna swticher to hook up to.

Thanks!!
Drew
--
Communication Graphics & Yearbook Instructor
Central Senior HS
88 Jaguar Dr, Beaumont, TX 77702 [phone] x566, 835-0923 (fax)

Drew Loker - KC5QBP, [e-mail]
955 Parson Dr, Beaumont, TX 77706 [phone], 866-6565 (fax)

http://198.213.26.193/beaumont/central/main.html


From [e-mail] Sun Jul 21 18:41:07 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!nntp.coast.net!news.kei.com!newsfeed.internetmci.com!info.ucla.edu!news.bc.net!unixg.ubc.ca!van-bc!n1van.istar!van.istar!west.istar!ott.istar!istar.net!tor.istar!east.istar!newsjunkie.ans.net!newsfeeds.ans.net!prodigy.com!usenet
From: [e-mail] (Kn3a Plaques)
Newsgroups: rec.radio.amateur.antenna
Subject: Amateur Radio Plaques & Engraving
Date: 20 Jul 1996 02:53:09 GMT
Organization: Prodigy Services Company  1-800-PRODIGY
Lines: 2
Distribution: world
Message-ID: <4sphml$[e-mail]>
NNTP-Posting-Host: innugap6-int.news.prodigy.com
X-Newsreader: Version 1.2

http://members.gnn.com/kn3a/plaques.htm



From [e-mail] Sun Jul 21 18:41:08 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!in2.uu.net!news3.agis.net!agis!NEWS!not-for-mail
From: Bob Lewis <[e-mail]>
Subject: Re: Antenna Problems-Need Help!!
Message-ID: <[e-mail]>
Date: Mon, 15 Jul 1996 09:35:11 -0400
References: <4s41uv$[e-mail]>
Organization: AA4PB
X-Mailer: Mozilla 2.01 (Win95; U)
MIME-Version: 1.0
To: Brian Watson <[e-mail]>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 22

Brian Watson wrote:
>
> I have a Cushcraft 11 element beam for 2 meters (don't know model or
> anything) but I'm having problems on recieve with it.  I have it pointed
> toward a repeater about 40 miles from my QTH and am only getting about an
> S5 copy on it.  I live in S. Florida so terrain's not the problem.  The
> SWR is pretty flat (the highest is about 1.4:1)  I'm feeding the antenna
> with 50' of RG58/u coax.  Does anyone have any ideas on what I should do
> to figure out what is going wrong.  The problem has just started in the
> last few days.  I know it's not the radio since a repeater less than a
> mile away comes in full scale.  Any help will be greatly appreciated.
>
> --
> KE4QEY
> Brian Watson
> [e-mail]
> Fido:  1:3609/8
> Fax:   [phone]

I assume you have the antenna mounted vertically as it should be.  Are
there other metal items, such as the mast, that are nearby an my be
distorting the pattern?



From [e-mail] Sun Jul 21 18:41:09 1996
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.pitt.edu!kamst39
From: [e-mail] (Keith A Monahan)
Newsgroups: rec.radio.scanner,rec.radio.amateur.antenna
Subject: Antennas, preamps
Date: 19 Jul 1996 15:46:46 GMT
Organization: University of Pittsburgh
Lines: 52
Message-ID: <4soal6$[e-mail]>
NNTP-Posting-Host: unixs6.cis.pitt.edu
X-Newsreader: TIN [version 1.2 PL2]
Xref: news2.epix.net rec.radio.scanner:54261 rec.radio.amateur.antenna:23322

Let me start off by saying that I've *finally* read all the messages in
rec.radio.scanner!  Over 400 threads and probably around 1500 messages! I'm
glad to be caught up.  I wanted to thank everyone for their helpful responses
in my previous posts, I've learned a ton!

What I'm looking for is an antenna that best meets my purpose.  I use a
handheld multiband transceiver primarily in a handheld fashion, that is,
out and about, NOT in a car, and not as a base station.

I know I am looking for a 'one-size-fits-all' solution.  If this isn't possibl
e,
perhaps you could suggest antennas that are optimized to work in the airband
and the 800mhz band.

I am currently using
a Comet SH-55, which is a 16" whip.  I want to receive the airband(approx 108
to 135mhz), VHF-HIGH, UHF, and 800mhz public safety freqs.  The comet is
a dualband antenna, which means my VHF-HIGH and UHF bands are covered, and
I'm assuming it does a good job.  Are there other dual band antennas suitable
for handheld applications that have more gain than the Comet?  Please provide
brand names, model numbers, and listed db gain.  I've heard the Austin Condors
are good as well as the diamond series.  Can someone point me in the right
direction?  I'd consider purchasing one of those if there would be a noticeabl
e
difference.  Has anyone ever seen a review of 'portable' (ie not mobile or
base station) antennas?

Now, if my comet is one of the best(a local ham swears by his), my next
logical conclusion would be a scanner preamp.  From what I've heard,
these can increase the gain considerable.  I've never even *heard* intermod
on my transceiver, so I don't think there would be a problem there.  Any
idea on how effective these are for bringing in distant signals?  Can someone
suggest a quality brand name and model number, as well as approximate cost?
I believe Radio Shack sells one, but I'm very wary about purchasing items
from them.  Portability is an issue, but even if I was constrained to using
it at home, or in a car, would be fine.

My last concern is a mobile/car antenna.  I'm thinking a 1/4 wave would
probably be good.  A dual band 1/4 wave antenna designed for dual band use
should probably be effective in both 2m and 70cm, but also for airband, seeing
that it is so close to 2m.  Would this antenna be totally ineffective for
800mhz?  Can someone suggest the brand name/model of a quality dual band
1/4 wave antenna designed for mobile use?  I know this is a stupid question,
but I'm assuming that if this antenna is totally ineffective for 800mhz, would
a cellular antenna be the most effective for that range?

I appreciate your taking the time to read this, and any responses will be
helpful.

Thanks.
Keith Monahan
University of Pittsburgh
Future Ham



From [e-mail] Sun Jul 21 18:41:10 1996
Path: news2.epix.net!uunet!in2.uu.net!ftpbox!newsfeed.acns.nwu.edu!math.ohio-state.edu!jussieu.fr!oleane!tank.news.pipex.net!pipex!news.be.innet.net!INbe.net!news.nl.innet.net!INnl.net!hunter.premier.net!news2.cais.net!news.cais.net!nntp.primenet.com!news.texas.net!news.kei.com!newsfeed.internetmci.com!news.rio.com!news
From: "James S. Kaplan" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.dx,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space
Subject: ARRL lawyer to sue member
Date: Tue, 16 Jul 1996 22:19:41 -0700
Organization: KG7FU
Lines: 98
Message-ID: <01bb739f.8e9f00c0$[e-mail]>
NNTP-Posting-Host: p27.t0.rio.com
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
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Xref: news2.epix.net rec.radio.amateur.antenna:23293 rec.radio.amateur.digital.misc:16521 rec.radio.amateur.dx:129 rec.radio.amateur.equipment:31136 rec.radio.amateur.homebrew:16188 rec.radio.amateur.misc:105338 rec.radio.amateur.policy:35557 rec.radio.amateur.space:7335

ARRL lawyer to sue member

The following is a copy of a message I received today from
ARRL General Counsel Christopher D. Imlay N3AKD:


To:       James S. Kaplan, KG7FU
Copies:   Mary Lou Brown, NM7N
          Terry Baun
          John Poray
Date:     July 16, 1996
Re:       Your article, SBE Chapter 124 Newsletter, July, 1996
**************************************************************

     Jim, I have just finished reading your article in the July,
1996 Water Cooled Newsletter, page 6. In it, you argue that two of
my clients, the American Radio Relay League, Inc. and the Society
of Broadcast Engineers, Inc. should cooperate in certain government
relations projects, specifically spectrum protection. You note that
I serve as the General Counsel for both organizations. You then
jump from that argument to the following, which I quote:

     If Mr. Imlay can't resolve HIS OWN conflicts of interest,
     perhaps both ARRL and SBE should be seeking more
     effective counsel. No offense Chris, but we have work to
     do. We should not only be sending a message to the FCC
     and Congress, but to other radio industries.

                              (emphasis in original)

It is not useful for me to educate you on the subject of your
article to correct the errors in it, and I do not intend to do so.
What I do intend, however, is for you to print a retraction, in
unambiguous terms, in a form acceptable to me, and to furnish to
me, in writing, an assurance that such will be printed in the next
Chapter Newsletter for Chapter 124. Failing that, I am going to sue
you in the District of Columbia for libel.

     I have no intention of allowing you to falsely allege that I
have a conflict of interest in representing two of my best clients,
especially in an SBE publication. You are not entitled to damage my
reputation as a lawyer, which you have done in your article, or to
infer (without any basis at all) that I have violated the canons of
ethics governing attorneys, by which I govern my actions.

     I will await your response.

Chris Imlay, N3AKD


And here is my reply:



Dear Mr. Imlay:

Thank you for reading my column in the SBE Chapter 124 Newsletter
"Water Cooled".

I will not be giving you a retraction for any of my statements
published in the July 1996 issue as you have requested. My statements
are my personal opinions and views. I do apologize if you feel you
have been hurt or damaged by my statements. My intent is to spur
thought and action, not to personally attack. If your actions require
others to think or act, don't you think they have the right to be
informed? I believe my statements to be true and have been given
no reason to retract them. My statements, by the way, are my own
and don't necessarily reflect the views or opinions of Chapter 124,
it's officers or members.

I am a member in good standing of both groups and do many hours of
unpaid work for the benefit of both groups and their members. I take
personal offense at the threat of lawsuit by their counsel. It is
unprofessional and you are certainly coming close to conflict with
your fiduciary duty to both groups by proposing to sue a member. Perhaps
it is you who owe me, and the Society of Broadcast Engineers and the
American Radio Relay League an explanation for your actions and your
lack of action in certain critical spectrum protection matters.

After much discussion with SBE and ARRL BOD persons and members I have
decided that the best way to deal with this matter is to offer you the
chance to refute my statements or rebut, in your own words, in my column
for publication in the next issue. In other words, please give yourself
the chance to "educate me on the subject of my article to correct the
errors in it".

I know you'll also agree that, if you choose to pursue litigation, the
proper forum for legal action would be an Oregon court as the column was
written and published here.

Sincerely,

James S. Kaplan KG7FU
Member SBE
Member ARRL
[e-mail]
http://users.aol.com/kg7fu/home.htm
KG7FU@N7DXT.#EUGEN.OR.USA.NOAM


From [e-mail] Sun Jul 21 18:41:12 1996
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.dx,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space
Path: news2.epix.net!uunet!inXS.uu.net!cs.utexas.edu!howland.reston.ans.net!ixnews1.ix.netcom.com!netcom.com!jangus
From: [e-mail] (Jeffrey D. Angus)
Subject: Re: ARRL lawyer to sue member
Message-ID: <[e-mail]>
Organization: Grendel's Lair
References: <01bb739f.8e9f00c0$[e-mail]>
Date: Fri, 19 Jul 1996 13:03:38 GMT
Lines: 26
Sender: [e-mail]
Xref: news2.epix.net rec.radio.amateur.antenna:23316 rec.radio.amateur.digital.misc:16534 rec.radio.amateur.dx:133 rec.radio.amateur.equipment:31173 rec.radio.amateur.homebrew:16197 rec.radio.amateur.misc:105376 rec.radio.amateur.policy:35580 rec.radio.amateur.space:7341

"James S. Kaplan" <[e-mail]> writes:

>ARRL lawyer to sue member

>The following is a copy of a message I received today from
>ARRL General Counsel Christopher D. Imlay N3AKD:

It never fails to amaze me how the granting of an operating license
by the FCC is taken by some of our fellow hams.

Remember "Hatlo's, They'll Do It Every Time?"

Towit, the granting of a license absolves the grantee from any personal
responsibility for their actions.

Apparently a keyboard and access to usenet news works the same way these
days.

Jeff
Who shouldn't be amazed by anything these days....

--
 Amateur: WA6FWI@WA6FWI.#SOCA.CA.USA.NA  |  "It is difficult to imagine our
Internet: [e-mail]       |  universe run by a single omni-
 US Mail: PO Box 4425 Carson, CA 90749   |  potent god. I see it more as a
   Phone: [phone]               |  badly run corporation."



From [e-mail] Sun Jul 21 18:41:13 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-fw-12.sprintlink.net!news.sprintlink.net!news-fw-22.sprintlink.net!news.sprintlink.net!news-ana-7.sprintlink.net!news.sprintlink.net!news-ana-24.sprintlink.net!news.sprintlink.net!news-stk-3.sprintlink.net!news.sprintlink.net!news-stk-11.sprintlink.net!nntp.earthlink.net!usenet
From: [e-mail]      (Roger J. Buffington; W6VZV)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.dx,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space
Subject: Re: ARRL lawyer to sue member
Date: 21 Jul 1996 15:09:44 GMT
Organization: Earthlink Network, Inc.
Lines: 40
Message-ID: <4sth7o$[e-mail]>
References: <01bb739f.8e9f00c0$[e-mail]> <[e-mail]>
Reply-To: [e-mail] (Roger J. Buffington)
NNTP-Posting-Host: max1-gg-ca-38.earthlink.net
X-Newsreader: IBM NewsReader/2 v1.2.5
Xref: news2.epix.net rec.radio.amateur.antenna:23328 rec.radio.amateur.digital.misc:16550 rec.radio.amateur.dx:135 rec.radio.amateur.equipment:31202 rec.radio.amateur.homebrew:16208 rec.radio.amateur.misc:105402 rec.radio.amateur.policy:35590 rec.radio.amateur.space:7347

In <[e-mail]>, Jeff Cook <[e-mail]> writes:
>There also may be some liability in publicly posting a private legal communic
ation, I
>don't know. But I do know that spraying the net (8 newsgroups?) with your pri
vate gripe
>is kind of obnoxious and seems intended to intimidate your "opponent". If you
 wanted
>opinions from the group(s) about the original complaint, you should have disc
ussed it
>with us legitimately. You may be a bit casual with your use of mass communica
tion, and
>you may have also added to your difficulties by posting this way.
>
>--
>Jeff Cook

I am only a gonnabe lawyer, so I'm not going to express any legal opinions
regarding this dispute.  However, I am going to say that I don't care much
for a scenario where a lawyer threatens litigation against someone who airs
an opinion that the lawyer is acting improperly.  The First Amendment was
written precisely to permit ordinary citizens to criticize powerful members of
society without fearing legal retribution.  When an attorney seeks to exploit
his stronger position vis'a'vis his ability to litigate, in order to suppress
free speech, this is not good.

In fact, I suspect (this is not a legal opinion, just a guess) that a court wo
uld
make short work of any libel case connected with this matter.

As far as the use of the internet goes, I kind of think that the internet
strengthens free speech, by giving those without ordinary media access
a public forum in which to express opinions.  Nothing wrong with that, in
my opinion.


Roger J. Buffington
W6VZV
USC Law School Class of '97

[e-mail]

"I want to die peacefully, in my sleep, like my grandfather.
Not screaming, and in terror, like his passengers."





From [e-mail] Sun Jul 21 18:41:14 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.mindspring.com!usenet
From: [e-mail] (Ron & Suzanne Gill)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Best Mobile HF/MF Antenna???
Date: Thu, 18 Jul 1996 04:47:45 GMT
Organization: MindSpring Enterprises, Inc.
Lines: 39
Message-ID: <4shujj$[e-mail]>
References: <4shi44$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: user-168-121-41-103.dialup.mindspring.com
X-Newsreader: Forte Free Agent 1.0.82

Robert <[e-mail]> wrote:

>hello all,

>looking for some reports on the best mobile antenna setup to use with my
>ICOM IC 706.  I am running it in a Toyota Pickup, does anyone have any
>experiences with mobile antenna...would enjoy any comments, both good and
>bad.

>thanks in advance....73 Rob n4yhd

I've used a variety of verticals over the last two years on my Ford
Ranger Pickup. Ive found that they all worked about the same but some
were more convenient than others.
I had a Carolina Bug Catcher for a while. It was advertised as being
good for 10 - 80M however to work ten you had to change the stiger to
a shorter one, and I wasn't able to get higher in frequency than 15M
using the standard stinger. The fact that I could cahnge to the other
bands by just moving the coil tap was nice however. I wasn't used to
having a fiber glass mast of that size mounted high on my truck and I
broke the antenna before I broke myself of the habit of driving into
the garage without removing it. I currently use a hustler with
changeable coils. It works as well as the Carolina Bugcatcher did and
if I suspect that I'm going to be changing  bands I mount three coils
on a spider, but then I have to guy it or the mast WILL BEND. The
quick disconnect that Hustler makes is a more positive connection than
the one that came with the Carolina Bugcatcher, and I found that the
cheaper quick disconnects can generate noise on the received signals.
The Outbackers I hear on the air sound really good. The screwdriver
antennas like the High Sierra seem to be excellent (I'm looking foward
to building one). What ever antenna you chose mount it as high as you
can as close to the center of your vehicle as you can and make sure
that you have a good ground plane (counterpoise) as close to the base
of your antenna as possible. I have mine mounted on top of my tool box
in the bed of the truck. I work everything from 10M - 80M mobile.
Have Fun !
73
Ron Gill NV4U     [e-mail]



From [e-mail] Sun Jul 21 18:41:15 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.cdsnet.net!news.magicnet.net!nntp.newsfirst.com!nntp.crosslink.net!munnari.OZ.AU!harbinger.cc.monash.edu.au!nntp.coast.net!oleane!jussieu.fr!math.ohio-state.edu!usc!newshub.csu.net!csulb.edu!info.ucla.edu!unixg.ubc.ca!van-bc!n1van.istar!van.istar!west.istar!ott.istar!istar.net!tor.istar!east.istar!news
From: A Guy named Moe <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Building a Satalite Dish
Date: Sat, 20 Jul 1996 00:03:55 -0700
Organization: **************
Lines: 5
Message-ID: <[e-mail]>
NNTP-Posting-Host: burgessville-157.oxford.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 3.0b5a (Win16; I)

Does anyone know if you can build a Satalite dish or some antanna that
will pick up lots of TV stations from scratch?


thanks


From [e-mail] Sun Jul 21 18:41:16 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsfeed.internetmci.com!hunter.premier.net!news-res.gsl.net!news.gsl.net!portc01.blue.aol.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (MVenable)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: CellPhone Antenna
Date: 20 Jul 1996 13:05:31 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 8
Sender: [e-mail]
Message-ID: <4sr3kr$[e-mail]>
References: <4sepmr$[e-mail]>
Reply-To: [e-mail] (MVenable)
NNTP-Posting-Host: newsbf02.mail.aol.com

If I correctly recall the article I read the new technology is for the
cell sites not the mobiles.  In brief, it uses arrays of directional,
higher gain antennas which are switched by smart controllers to allow more
efficient management of cell channels without interfering between calls.
The goal is to get better coverage without building more cell sites.

regards
Mark Venable


From [e-mail] Sun Jul 21 18:41:17 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!news-dc-9.sprintlink.net!news-res.gsl.net!news.gsl.net!nntp.coast.net!news.kei.com!newsfeed.internetmci.com!usenet.logical.net!news.wizvax.net!news
From: Tom Homewood <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Delta Loop - Confused
Date: Sun, 21 Jul 1996 12:02:05 -0400
Organization: K8TH
Lines: 24
Message-ID: <[e-mail]>
References: <4st2oh$[e-mail]>
NNTP-Posting-Host: plp7.vgernet.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.02 (Win95; I)

nstn2527 wrote:
>
> I have used a Delta Loop cut for 40 mtrs. that has worked well for me
> for the past couple years.  The design came from Bill Orr's handbook
> "THE RADIO AMATUR ANTENNA HANDBOOK".  Each of the three sides are 45'10"
> and its fed with a 22'10" 75 ohm quarter wave coaxial transformer.  The
> original 1.5 bandwidth was about 7.075 to 7.560 but recently it measures
> about 6.746 to 7.036.  I have made no changes in the ant nor to other
> ants in the vicinity.
>
> Thinking that the wire may have strched over the years, I shortened the
> loop twice by a foot each time but it made no appreciable difference in
> the SWR bandwidth!  Should I be adjusting instead the length of the 75
> ohm quarter wave transformer?  If so, shorter or longer?
>
> How does the author arrive at 22'10" for the transformer?  According to
> my arithmetic, a qurter wave at 40 mtrs. is 10 mtrs., or about 32'9".
>
> Any comments would be appreciated.
>
> Les Hiltz  VE1WWH
> Email [e-mail] guess is that the coax used for the matching se
ction has weathered.

73, Tom K8TH


From [e-mail] Sun Jul 21 18:41:18 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!inXS.uu.net!iglou!news
From: Steve Ellington <[e-mail]>
Subject: Re: Dipole Idea. Need advice
X-Nntp-Posting-Host: dp-2-15.iglou.net
Content-Type: text/plain; charset=us-ascii
Message-ID: <[e-mail]>
To: [e-mail]
Sender: [e-mail] (News Administrator)
Content-Transfer-Encoding: 7bit
Organization: IgLou Internet Services
References: <[e-mail]> <[e-mail]>
Mime-Version: 1.0
Date: Fri, 19 Jul 1996 14:25:34 GMT
X-Mailer: Mozilla 1.1N (Windows; I; 16bit)
Lines: 22

NO. A trap dipole's trap would just be effective on one band. What
I'm talking about is a Low-pass filter that would show a high impedance
to all frequencies above, say 7mhz. Mike Valentine
<[e-mail]> wrote:
>Steve Ellington wrote:
>
>[snip]
>>
>> Is there such an animal as a low pass filter that would work on one leg
>> of this antenna?
>>
>> If such a thing exist, we should probably put two of them on each side.
>> One designed for about 7mhz and another for 14mhz. The 14mhz one should
>> be about 20ft down from the top.
>>
>> Think long and hard on this one. We may finally outdo the G5RV!
>
>Isn't this called a trap dipole?
>
>Mike - WA8MSF




From [e-mail] Sun Jul 21 18:41:19 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.texas.net!news.kei.com!newsfeed.internetmci.com!tetsuo.communique.net!communique!usenet
From: [e-mail]
Newsgroups: rec.radio.scanner,rec.radio.amateur.antenna
Subject: Do i need 50ohm coax?
Date: Wed, 17 Jul 1996 15:14:20 -0500
Organization: Communique Inc., New Orleans
Lines: 18
Message-ID: <[e-mail]>
NNTP-Posting-Host: 085.msy7.communique.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.0 (Macintosh; I; 68K)
Xref: news2.epix.net rec.radio.scanner:54161 rec.radio.amateur.antenna:23265

I was under the impression that a 50ohm coax (rg-8 or rg-58)is needed
for best reception on my scanner using a roof top antenna. But along
comes a handy little grove catalog, and inside it they say, quote:

"At vhf/uhf frequencies, common cb-type rg-58/U wiill actually absorb
signals. We recommend low loss rg-6..........

For lowest loss, use Belden 9913 or rg-11/U mini.

Dont be concerned with impedance, although your scanner is designed to
wrk with 50ohm cable, no antenna made maintains a constant impedance
over the wide frequency range of modern scanners. What you want is low
loss and 100%(or close to it) shielding." Unquote.

So which is right. Do I need 50ohm cable or not? Or should I just say
to hell with it and get the belden 9913.

Vince


From [e-mail] Sun Jul 21 18:41:20 1996
Newsgroups: rec.radio.scanner,rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.inc.net!newspump.sol.net!spool.mu.edu!howland.reston.ans.net!ixnews1.ix.netcom.com!netcom.com!dgf
From: [e-mail] (David Feldman)
Subject: Re: Do i need 50ohm coax?
Message-ID: <[e-mail]>
Organization: Organization? Me?
References: <[e-mail]> <4sjkq7$[e-mail]>
Date: Wed, 17 Jul 1996 21:52:47 GMT
Lines: 29
Sender: [e-mail]
Xref: news2.epix.net rec.radio.scanner:54165 rec.radio.amateur.antenna:23267

In article <4sjkq7$[e-mail]> [e-mail] (David Horak) write
s:
>In <[e-mail]> [e-mail] writes:
>
>>"At vhf/uhf frequencies, common cb-type rg-58/U wiill actually absorb
>>signals. We recommend low loss rg-6..........
>
>Good advice.
>
>>Dont be concerned with impedance, although your scanner is designed to
>>wrk with 50ohm cable, no antenna made maintains a constant impedance
>>over the wide frequency range of modern scanners. What you want is low
>>loss and 100%(or close to it) shielding." Unquote.
>
>More good advice.
>
>>So which is right. Do I need 50ohm cable or not? Or should I just say
>>to hell with it and get the belden 9913.
>
>It doesn't need to be 50 ohms.  Go with the RG6 or get some 9913 if you
>have the bucks.
>
>David

You should be able to get RG6 free or very cheap from your local cable
TV company. Call them and ask if they have any end-of-reel pieces. They use
tons of it wiring cable to people's houses, and lots of short runs end up
in the trash/recycle bin.

Dave


From [e-mail] Sun Jul 21 18:41:20 1996
Path: news2.epix.net!uunet!inXS.uu.net!fdn.fr!univ-lyon1.fr!jussieu.fr!math.ohio-state.edu!cs.utexas.edu!newshost.convex.com!not-for-mail
From: [e-mail] (David Horak)
Newsgroups: rec.radio.scanner,rec.radio.amateur.antenna
Subject: Re: Do i need 50ohm coax?
Date: 17 Jul 1996 16:09:27 -0500
Organization: Convex Technology Center of Hewlett Packard, Richardson, Tx USA
Lines: 21
Message-ID: <4sjkq7$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: eugene.convex.com
Xref: news2.epix.net rec.radio.scanner:54211 rec.radio.amateur.antenna:23292

In <[e-mail]> [e-mail] writes:

>"At vhf/uhf frequencies, common cb-type rg-58/U wiill actually absorb
>signals. We recommend low loss rg-6..........

Good advice.

>Dont be concerned with impedance, although your scanner is designed to
>wrk with 50ohm cable, no antenna made maintains a constant impedance
>over the wide frequency range of modern scanners. What you want is low
>loss and 100%(or close to it) shielding." Unquote.

More good advice.

>So which is right. Do I need 50ohm cable or not? Or should I just say
>to hell with it and get the belden 9913.

It doesn't need to be 50 ohms.  Go with the RG6 or get some 9913 if you
have the bucks.

David


From [e-mail] Sun Jul 21 18:41:22 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-stk-11.sprintlink.net!news.sprintlink.net!news-stk-3.sprintlink.net!news.sprintlink.net!news-ana-24.sprintlink.net!news.sprintlink.net!news-ana-7.sprintlink.net!nntp.primenet.com!news.cais.net!hunter.premier.net!newsfeed.internetmci.com!news.sprintlink.net!news-stk-200.sprintlink.net!news.clark.net!usenet
From: [e-mail] (Marcum N. Nance III)
Newsgroups: rec.radio.scanner,rec.radio.amateur.antenna
Subject: Re: Do i need 50ohm coax?
Date: Fri, 19 Jul 1996 12:47:05 GMT
Organization: Clark Internet Services, Inc.
Lines: 52
Message-ID: <4so04q$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: 199.186.15.137
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Newsreader: Forte Free Agent 1.0.82
Xref: news2.epix.net rec.radio.scanner:54219 rec.radio.amateur.antenna:23301

[e-mail] wrote:

>I was under the impression that a 50ohm coax (rg-8 or rg-58)is needed
>for best reception on my scanner using a roof top antenna. But along
>comes a handy little grove catalog, and inside it they say, quote:

>"At vhf/uhf frequencies, common cb-type rg-58/U wiill actually absorb
>signals. We recommend low loss rg-6..........

>For lowest loss, use Belden 9913 or rg-11/U mini.

>Dont be concerned with impedance, although your scanner is designed to
>wrk with 50ohm cable, no antenna made maintains a constant impedance
>over the wide frequency range of modern scanners. What you want is low
>loss and 100%(or close to it) shielding." Unquote.

>So which is right. Do I need 50ohm cable or not? Or should I just say
>to hell with it and get the belden 9913.

>Vince
There are two effects at work here.

1) impedance matching - The antenna / receiver both have 50 ohm
impedances, however they do vary with frequency. This is one of the
effects that cause  transmitters outside of its operating frequency
range to be 'unusable' (there are others which are beyond the scope of
this discussion). However within its band of operation the impedance
stays fairly close to 50 ohms. You should match the 50 ohms so that
as little power as possible is lost due to being reflected back at the
antenna due to cable missmatch.

2) LOSS AND NOISE PICKUP- once the signal is in the cable you want to
keep as much as possible there, keep external noise out and keep the
signal from being 'knocked down' due to passing through the cable.


SO YOU SHOULD
If you are going to operate over a wide range of frequencies, as in
the top frequency is 5 to 10 times (or more) the frequency on the low
end, operate the receiver with different antennas for different
ranges, (a shortwave antenna is not too good at 400MHz, and the 400MHz
antenna is useless at shortwave).  This ensures that the antenna is
well tuned to the frequencies in use and the impedance match is good.

Get cable that is low loss AT THE RANGE OF FREQUENCIES YOU WILL USE.
different cables are good at different frequency ranges, and no one
cable is perfect for all ranges.


marc
N3WEU



From [e-mail] Sun Jul 21 18:41:22 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.imagine.com!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-ana-7.sprintlink.net!news.sprintlink.net!news-ana-24.sprintlink.net!newsfeed.internetmci.com!swrinde!elroy.jpl.nasa.gov!ames!niven.ksc.nasa.gov!usenet
From: "Roger E. Koss" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Eggbeater Antenna(s)
Date: 17 Jul 1996 16:22:11 GMT
Organization: I-NET Space Services
Lines: 7
Message-ID: <4sj3vj$[e-mail]>
NNTP-Posting-Host: 163.205.78.66
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.1N (Windows; I; 16bit)

I know this question was asked and answered not too long ago, so I
apologize for the bandwidth in advance. Does anyone have or know of
information for designing or a plan for this type of antenna for 70 cm?
Thanks in advance.

                                    Roger, KD4ITU



From [e-mail] Sun Jul 21 18:41:23 1996
Path: news2.epix.net!uunet!inXS.uu.net!csnews!boulder!coopnews.coop.net!frii.com!usenet
From: Avatar <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ferrite Loaded Broadband HF Antenna
Date: Fri, 19 Jul 1996 22:59:20 -0700
Organization: Front Range Internet, Inc.
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David Shankman wrote:
>
> Hi there,
>
> Can anyone tell me about or give reference to information about the
> design of a ferrite (or any other for that matter) loaded broadband HF
> antenna. The antenna is supposed to be an inverted V monopole
> configuration.
>
> Thanks, and 73 from ZR6DAV, Dave.

I have been a Ham for 40+ years and I have no idea what you are using.
How can an inverted V (a dipole by definition) be a monopole? I have yet
to see an antenna that incorporated loading be classified as broadband?
Since I haven't seen any amateur radio magazines for awhile, maybe your
referring to an article where the author improperly described the
antenna. If I'm wrong, I sure would like to know how this antenna you
mention works.

Regards,
W0MAY



From [e-mail] Sun Jul 21 18:41:24 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 14 Jul 1996 16:12:36 GMT
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[e-mail] (Dan Richardson) wrote:
>I wonder if you could make the same test with a tube'd rig which has a
>pi network that will adjust to the load it sees.

Hi Danny, I'll have to borrow one but first I want to make sure
that I'm not beating my head against a brick wall.

Question to all: Assume varying loads on a transmitter. If the
magnitude of the load voltage and the magnitude of the load
current change by 6dB when a 6dB 50 ohm pad is inserted,
does that indicate that the impedance at the transmitter coax
connector is 50 ohms?

Seems to me if it weren't 50 ohms, there would be re-reflections
which would cause the ratio of the magnitudes to be something
other than 6dB.

thanks and 73, Cecil, W6RCA, OOTC




From [e-mail] Sun Jul 21 18:41:25 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 15 Jul 1996 13:48:55 GMT
Organization: AT&T WorldNet Services
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"William E. Sabin" <[e-mail]> wrote:
>SWR is measured as a steady-state thing after all reflections,
>re-reflections etc have settled down.
>If we just think in terms of impedance values rather
>than waves zipping back and forth, we get a better perspective on this
>thing called "SWR".

I didn't mean to concentrate on SWR. What I am trying to do is figure
out a way to find out something about the impedance at the coax
connector on the transmitter without making the same mistake that
Brune did. It seems logical to me that measurements on forward and
reflected waves could tell us something even if we had to watch what
was happening under trancient conditions at first key down.

>I do believe that the preoccupation with conjugate match at the output of
>a transmitter is most unfortunate and confusing, and also unnecessary.

I agree with you. Reflections cease to exist at a Z0 match and from that
point (usually at the input of the tuner) all the way back to the
transmitter a conjugate match is not necessary *because there are no
reflections*.

>If a transmitter is designed to deliver 100 W to a 50 Ohm load with 25 dB
>distortion products, all we need to do is supply the 50 Ohm load. What
>the impedance is looking back into the PA is not a consideration in
>getting this particular job done. And it has no effect on SWR.

But Bill, my *goal* is to measure the impedance looking back into the coax
terminal of the transmitter. For that goal, I am not concerned about
"getting this particular job done".

>Does this sound OK, Cecil?

It's all fine and good and true. Now how can I measure the impedance of
my transmitter looking back into the coax connector?

73, Cecil, W6RCA, OOTC




From [e-mail] Sun Jul 21 18:41:26 1996
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From: "William E. Sabin" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Tue, 16 Jul 1996 16:49:17 -0700
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CHARLES J. MICHAELS wrote:
>
>         As I remember, earlier in this thread the question of effect
> of source impedance on the reflection at the sending end came up.
>         Since the expression for the reflection factor involves only
> Zin and Zc (Rho = Zin - Zc / Zin + Zc) and the line could be fed by
> anything ranging from a current source (infinite impedance ) to a
> voltage source ( zero impedance) it seems to me that the line must
> be fed by something in order to get any wave, the source impedance
> has nothing to do with the reflection (or if you will, re-reflection)
> at the sending end.
> Charlie, W7XC
> --

By definition, rho and SWR involves Zin and Zc, not the generator
impedance. In the steady state there are just rwo waves, one forward wave
and one reflected wave. This re-reflected wave business does not show up
in the bi-directional wave equation at all. I wish this re-reflection
business would vanish from the scene. It causes more confusion than it is
worth.

Bill W0IYH


From [e-mail] Sun Jul 21 18:41:28 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 17 Jul 1996 05:09:38 GMT
Organization: AT&T WorldNet Services
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"William E. Sabin" <[e-mail]> wrote:
>The power that is actually delivered by the generator is equal to the
>power that is sent to the load minus the power that is returned from the
>load.

But that statement is by definition only. As far as I can see, there's
nothing to keep, for instance, half the reflected power from being re-
reflected and half dissipated as heat in the final. You would say the
half that got dissipated as heat never left the generator, but it sure
might have made a round trip to the antenna and back. Too bad we can't
color those energy packets to see exactly where they go. It is unbelievable
that the reflected energy packets separate themselves from the forward
energy packets and refuse to cross an invisible barrier until the power
is removed. That would be like a billion individual molecules of water
staying in the same river whirlpool forever and none ever being released
downstream and replaced by other molecules.

73, Cecil, W6RCA, OOTC




From [e-mail] Sun Jul 21 18:41:29 1996
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From: [e-mail](Jeff Anderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 16 Jul 1996 14:11:24 GMT
Organization: Netcom
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In <[e-mail]> Jon Bloom <[e-mail]> writes:
>

>> For example, consider a 3 element Butterworth filter, shunt C,
>>series L and shunt C, designed for 50 Ohms. If the generator is 1
>>Ohm, then the input C is practically short-circuited. Obviously,
>>something is wrong.
>
>I guess I'm dense; it's not obvious to me. Take an even simpler case:
>the source is a voltage source--zero impedance. Now the input
>capacitor *is* shorted out. Yet the response of the filter will still
>be a Butterworth response. I don't see the problem.
>
"Shorted out" is a bit confusing here.  If the generator is a current
source, lowering the source resistance would indeed short-out the cap,
but if it is a voltage source the cap isn't "shorted" if the source
resistance is 0 ohms.  Rather, it's effectively "open circuited" (that
is, it has no effect on the response).

>>The point is that if a lowpass filter presents a 50 Ohm input
>>impedance but is not terminated properly at the input it can have
>>problems near the the edge of the passband. You might like to
>>simulate some of these using the ARD program.
>
>I'll do so. But I suspect that the difference between the filters you
>are referring to and a "classic" 50-ohm filter for use with a 50-ohm
>source is not how it acts in the passband, but how it acts in the
>transition band and stopband. (Okay, include the region near the edges
>of the passband, too.) And even there, it's not the filter Vo/Vi
>response that's at issue, rather the impedance the filter presents to
>the source in those regions. Does that sound about right?

There is no essential difference between Bill's example and a "classic"
50-ohm filter (if I understand your definition of "classic").  For
example, a "classic" 3 element Tchebyshev filter, designed for 50 ohms
in/out, will exhibit changes in both the pass-band voltage transfer
function as well as the cut-off frequency as you vary source
resistance.

Does it still present 50 ohms to the source throughout the transition
band and stop-band?  Now I need to go back to the books! (but I believe
not.)

- Jeff, WA6AHL


From [e-mail] Sun Jul 21 18:41:29 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 17 Jul 1996 13:34:52 -0400
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In article <4sir5r$[e-mail]>, Cecil Moore
<[e-mail]> writes:

>
>Hi Tom, is 1% reflected power enough to cause the operating parameters
>to change?
>
>thanks and 73, Cecil, W6RCA, OOTC
>
>

Even .005% will, it just a question of how much before it means anything,
hi.
The shorter the conduction angle and less negative feedback the larger the
change, but I think we could consider that a very small change in any
practical situation.

73 Tom



From [e-mail] Sun Jul 21 18:41:30 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 17 Jul 1996 13:34:57 -0400
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In article <4siroh$[e-mail]>, Cecil Moore
<[e-mail]> writes:

>Seems to me, where there are no reflections, a conjugate match is
>not necessary.
>
>73, Cecil, W6RCA, OOTC
>
>

A conjugate match to the dynamic resistance is necessary if you desire
maximum power transfer and efficiency, even without "reflections", or did
you mean "Reflections"?

Whichever you meant, it remains true.  ;-)

73 Tom


From [e-mail] Sun Jul 21 18:41:31 1996
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From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 16 Jul 1996 19:50:38 GMT
Organization: Arizona State University
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        As I remember, earlier in this thread the question of effect
of source impedance on the reflection at the sending end came up.
        Since the expression for the reflection factor involves only
Zin and Zc (Rho = Zin - Zc / Zin + Zc) and the line could be fed by
anything ranging from a current source (infinite impedance ) to a
voltage source ( zero impedance) it seems to me that the line must
be fed by something in order to get any wave, the source impedance
has nothing to do with the reflection (or if you will, re-reflection)
at the sending end.
Charlie, W7XC
--


From [e-mail] Sun Jul 21 18:41:32 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Tue, 16 Jul 1996 16:19:09 -0700
Organization: Intel Corp., Chandler, AZ
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William E. Sabin wrote:
>I wish this re-reflection business would vanish from the scene.
>It causes more confusion than it is worth.

Hi Bill, I wish it would vanish also, but it keeps re-reflecting
in my head. :-) I'm like a snapping turtle when I don't understand
something. I chomp on to it and don't let go until it thunders.

We know a Z0 or Zg match results in 100% re-reflection. That's
why the forward power can be more than the generated power. It
would follow that if there is not a Z0 or Zg match, then 100%
re-reflection does not occur. If the reflected wave sees a
destination impedance equal to the Z0 of the transmission line,
theory says there will be no re-reflection.

Let's say we had a class-A amplifier with a 50 ohm output impedance
with no tank circuit and no protection circuitry. If we allowed
1% of the generated power to be reflected from the load and hit
the collector of the amplifier, would the output impedance of the
amplifier change?

73, Cecil, W6RCA, OOTC  (not speaking for my employer)


From [e-mail] Sun Jul 21 18:41:33 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 17 Jul 1996 13:48:34 GMT
Organization: AT&T WorldNet Services
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Message-ID: <4siqvi$[e-mail]>
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"William E. Sabin" <[e-mail]> wrote:
>Why is it necessary to get all fouled up with these complicated arguments
>that just hide the simple truth?

Funny, that's exactly what a lot of Einstein's peers said when he
introduced his special theory of relativity. Truth, being what men
believe, is usually simple. The objective facts, OTOH, may be rather
complicated. Knowing the facts won't make my rig work better. It will
give me peace of mind, something more important than my ham rig.

I believe that quantum energy packets can make a round trip to the
antenna and back and be dissipated as power in the final amplifier.
Consider a very long, lossless transmission line with reflections...

73, Cecil, W6RCA, OOTC






From [e-mail] Sun Jul 21 18:41:34 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 18 Jul 1996 07:18:01 -0400
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In article <[e-mail]>, Jon Bloom <[e-mail]>
writes:

>I agree with all of that except the part about measurement. I'm still
>looking for a analysis that shows that a valid measurement can be made,
>and how.
>
>--
>Jon Bloom, KE3Z

There are two measurement methods that confirm Mr. Sabin's and Belrose's
understandings. Neither is all that complicated or time consuming.

It's natural to argue or question measurements that disagree with our
mindsets, we all do that at times. When measurements repeat over and over
again it may be advisable to at least consider them meaningful, instead
postulating they aren't. Real world measurements clearly support Sabin and
Belrose, and repeat over and over again under all conditions I have tried.

The apparent "absorption" of reverse power indicated by measurement is
perfectly explainable, and can be verified by more complex and precise
measurement and analysis (that I have also done).

My money would be on the verifiable theory, rather than the speculative
one.

73 Tom


From [e-mail] Sun Jul 21 18:41:35 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 17 Jul 1996 13:51:55 GMT
Organization: AT&T WorldNet Services
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[e-mail] (W8JI  Tom) wrote:
>If the operating parameters change because of the load change, the output
>impedance also changes.

Hi Tom, is 1% reflected power enough to cause the operating parameters
to change?

thanks and 73, Cecil, W6RCA, OOTC




From [e-mail] Sun Jul 21 18:41:36 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 17 Jul 1996 14:01:53 GMT
Organization: AT&T WorldNet Services
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[e-mail] (W8JI  Tom) wrote:
>Don't put too much emphasis on the importance of conjugately matching a
>PA, unless you want to achieve maximum power transfer and efficiency.

Hi Tom, I think there is an argument over whether the antenna system
can be conjugately matched without the PA being conjugately matched.
I believe a conjugate match matters up to the point in an antenna
system where the reflections disappear, e.g. at an antenna tuner.
Seems to me, where there are no reflections, a conjugate match is
not necessary.

73, Cecil, W6RCA, OOTC




From [e-mail] Sun Jul 21 18:41:37 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 18 Jul 1996 08:57:27 -0400
Organization: America Online, Inc. (1-800-827-6364)
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In article <[e-mail]>, "William E. Sabin"
<[e-mail]> writes:

>
>I'm sure the Bruene method is OK, despite the remarks to the contrary,
>but I also think Tom Rauch has some good ideas on this subject. The "load

>pull" method that my article suggests also looks like a winner.
>
>Bill W0IYH

Bill,

Bruene's method is clearly workable, my only disgreement is with his
conclusions. He should be commended for making time and effort to measure
the tank, as should Cecil. Looking at Bruene's Alpha amplifier data, the
reverse SWR does cross 1:1 at a certain power above 1000 watts. I'd be
willing to wager money that is the point where the tank was optimized for
maximum efficiency and power output into 50 ohms.

I'd also like to point out the output impedance of an operating PA at a
harmonic can be measured by the tapped line method. I've found the output
source impedance at the harmonic esentially appears as the value measured
looking back into a non-operating PA with a network analyzer (when the
output network has more than ~10 dB of harmonic suppression). This can be
quickly confirmed by measuring the output port impedance at the harmonic
frequency with a varying termination at the network's input.

If I designed a tank using the "very low" transistor and "very high" grid
driven triode guess, or an unknown and immeasureable impedance, the
circuit would be an operational  mess. Using the old Chaffe Analysis
method, which is the basic method Bill Sabin expanded on, everything works
according to plan. Not only that, it works with tetrodes and pentodes,
with feedback or no feedback.

Since it works, is measurable by more than one measurement method, and has
always been repeatable in tests, I have no reason to doubt it.

73 Tom


From [e-mail] Sun Jul 21 18:41:38 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Thu, 18 Jul 1996 13:35:35 -0700
Organization: Intel Corp., Chandler, AZ
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Gary Coffman wrote:
> Of course the impedance at the transmitter's output connector will
> be nominally something near 50 ohms in either case.

Hi Gary, if we have configuration 1 with the XMTR putting out 100w:

XMTR---50 ohm coax----1:1 balun----1/2 WL 450ohm ladder-line----50ohm dipole

there will be 100w forward and 0w reflected at the balun primary.

If we change to configuration 2 with the XMTR settings the same:

XMTR---1:1 balun----1/2 WL 450ohm ladder-line----50ohm dipole

we have eliminated the coax. If the conditions are exactly the same
in both configurations, can we say the XMTR has a 50ohm impedance
since there is apparently still 100w forward and 0w reflected at
the balun primary? Seems the reflected energy is exposed to the same
impedance for both configurations or else conditions would change.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)


From [e-mail] Sun Jul 21 18:41:40 1996
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From: Andre'@GIRAFFE.ru.ac.za
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Fri, 19 Jul 1996 09:46:48
Organization: Rhodes University, Grahamstown
Lines: 67
Message-ID: <Andre'[e-mail]>
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NNTP-Posting-Host: psycho.slip.ru.ac.za

In article <[e-mail]> Cecil Moore <[e-mail].c
om> writes:
>From: Cecil Moore <[e-mail]>
>Subject: Re: forward/reflected power
>Date: Thu, 18 Jul 1996 08:57:23 -0700

>Andre'@GIRAFFE.ru.ac.za wrote:
>>       I was taught that if you tramsmitter has say 100 W out put and the
>> because load inpeadence must equal output impeadence the VSWR must be 1:1 t
o
>> get 100 W put at the antenna and if that match is not 1:1 there will be los
s
>> of radiated power. the reflected power that is generated will return back t
o
>> the rig and there will be disippitated as heat in the finals.

>Hi Andre', It's easy to disprove what you were taught. Consider the following
:

>XMTR---50ohm coax---1:1 balun----1/2 WL 450 ohm ladder-line---50ohm dipole

>There is a 9:1 SWR on the ladder-line. There is a Z0 match at the balun.
>There is a 1:1 SWR on the coax so there is no dissipation in the PA due
>to reflections. 450 ohm ladder-line is near lossless on HF. So what happens
>if we output 100w of HF RF from the transmitter?

>There will be 100w forward and 0w reflected "power" on the coax. There
>will be 278w forward and 178w reflected "power" on the ladder-line.
>Neglecting feedline losses, the amount of power generated by the
>transmitter will be radiated from the dipole. 278w of RF hit the
>antenna and 178w are rejected only to be re-rejected by the Z0 match
>at the balun. This is an example of a relatively high SWR with neglible
>losses and none of those losses occuring in the electronics.

>This is just one way of achieving a Z0 match. Another way is with an
>antenna tuner. If the reflected energy is re-reflected before it gets
>to the transmitter, then it cannot possibly be dissipated as power in
>the PA. Another not-so-obvious way of achieving a Zg match is with a
>pi network tank circuit in a tube PA. Reflected energy will be flowing
>in the pi network tank circuit inside the transmitter but no reflected
>energy will reach the PA tubes because of the Zg match.

>Now if the reflected energy is allowed to flow through the PA, there
>will be a real dissipative resistance existing that will dissipate some
>reflected power. But the overall dissipation of the PA could increase
>or decrease because that same reflected wave changes the load that the
>PA sees and therefore changes the operating point. Like W8JITom says,
>the overall PA dissipation can go up or down in the presence of reflections.

>73, Cecil, W6RCA, OOTC  (not speaking for my employer)

Hi Cecil

 Well it seems that that is the case but in the set up you layed out the
transmitter is protected by the balun and therefore does not receive any of
the reflected power and it is safe, but the ladderline offering nearly no
loss to the HF still (as you said as I understand it) only "passes" the 100W
to the load the antenna, the reflected power is dissipated by the ladderline
as something and this is usually heat, but because of its makeup it can
cope with that and we still have in fact 1:1 and a perfect match even though
the ladderline is 450 ohm and a 9:1 match with the dipole. We must remember
in true life a 50 ohm dipole does not actually exist an a dipole impeadence
can be from 50 to 500 ohm the normal being 75 ohm, all this is dependent on
hight above the ground, nearby objects, quality of the ground as an earth,
the nornal and best hight is 1/2 wavelength above the ground giving the 75
ohm. Yes an ATU does the same as the ladder line, does this mean that a
ladder line and an ATU can be called a "REFLECTED POWER SPONGE" absorbing
unwanted reflected RF in antenna mismatches. Just a thought.

73's and all

Andre'


From [e-mail] Sun Jul 21 18:41:41 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 18 Jul 1996 10:51:24 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Hi Andre
In article <Andre'[e-mail]>, Andre'@GIRAFFE.ru.ac.za
writes:
>
>      I was taught that if you tramsmitter has say 100 W out put and the
>because load inpeadence must equal output impeadence the VSWR must be 1:1
to
>get 100 W put at the antenna and if that match is not 1:1 there will be
loss
>of radiated power. the reflected power that is generated will return back
to
>the rig and there will be disippitated as heat in the finals.

It's unfortunate that is repeated so often. It is untrue.

Dissipation and stress on the final can become less, or it can become
more. It would be pure luck if it changed by ten watts! The fact is most
PA's we use, in the effort to overcome distortion, are overcoupled. That
means some SWR (in the right impedance direction) actually lowers heating
and raises efficiency and power output capability.

Absolutely every SSB PA I've seen is designed to be of higher source
impedance (when operated according to instructions) than the expected
load, and that includes solid state PA's. Moving the load lower in
impedance increases dissipation while moving it higher decreases
dissipation.

It's best to operate according to manufacturer's instructions, but the
extra heat from SWR is a myth.

73 Tom


From [e-mail] Sun Jul 21 18:41:42 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 19 Jul 1996 14:36:39 GMT
Organization: AT&T WorldNet Services
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Andre'@GIRAFFE.ru.ac.za wrote:

>transmitter is protected by the balun and therefore does not receive any of
>the reflected power and it is safe,...

Hi Andre', A 1:1 balun does not protect the transmitter except by absorbing
power itself (and unbalancing the currents). The only thing that protects
the transmitter in a normal ham installation is a Z0 or Zg match that
re-reflects all the reflected "power" (actually reflected energy).

>...the reflected power is dissipated by the ladderline
>as something and this is usually heat,...

It took me a long time to understand that reflected "power" is not power
unless it is dissipated somewhere. It is not dissipated anywhere in the
example, so it remains reflected energy, not power. It circulates but
doesn't change from energy to power until you stop transmitting. If a
transmitter is putting out 100w and 100w is getting to the antenna, there
is no power left to dissipate anywhere according to the law of conservation
of energy.

>We must remember
>in true life a 50 ohm dipole does not actually exist an a dipole impeadence
>can be from 50 to 500 ohm ...

In the original example, any real antenna impedance between 51 and 4049 ohms
will lower the SWR and therefore lower the losses.

>ladder line and an ATU can be called a "REFLECTED POWER SPONGE" absorbing
>unwanted reflected RF in antenna mismatches. Just a thought.

Not a sponge. Think of a properly matched antenna system with a high SWR
as a spring. The reflected energy compresses the spring but then the
spring uncompresses and releases the energy back into the system. The only
loss associated with this compression/uncompression is akin to friction
in a spring and is the additional loss due to SWR in the chart in the ARRL
Handbook at the end of the chapter on Transmission Lines. A match is achieved
on an antenna system by resonating the system. Anywhere along the transmission
line, you can change the impedance to purely resistive by attaching an
inductance at a capacitive point or attaching a capacitor at an inductive
point. When X(C)=X(L), that is resonance (except for X(C)=X(L)=0).

73, Cecil, W6RCA, OOTC




From [e-mail] Sun Jul 21 18:41:43 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Thu, 18 Jul 1996 08:57:23 -0700
Organization: Intel Corp., Chandler, AZ
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Andre'@GIRAFFE.ru.ac.za wrote:
>       I was taught that if you tramsmitter has say 100 W out put and the
> because load inpeadence must equal output impeadence the VSWR must be 1:1 to
> get 100 W put at the antenna and if that match is not 1:1 there will be loss
> of radiated power. the reflected power that is generated will return back to
> the rig and there will be disippitated as heat in the finals.

Hi Andre', It's easy to disprove what you were taught. Consider the following:

XMTR---50ohm coax---1:1 balun----1/2 WL 450 ohm ladder-line---50ohm dipole

There is a 9:1 SWR on the ladder-line. There is a Z0 match at the balun.
There is a 1:1 SWR on the coax so there is no dissipation in the PA due
to reflections. 450 ohm ladder-line is near lossless on HF. So what happens
if we output 100w of HF RF from the transmitter?

There will be 100w forward and 0w reflected "power" on the coax. There
will be 278w forward and 178w reflected "power" on the ladder-line.
Neglecting feedline losses, the amount of power generated by the
transmitter will be radiated from the dipole. 278w of RF hit the
antenna and 178w are rejected only to be re-rejected by the Z0 match
at the balun. This is an example of a relatively high SWR with neglible
losses and none of those losses occuring in the electronics.

This is just one way of achieving a Z0 match. Another way is with an
antenna tuner. If the reflected energy is re-reflected before it gets
to the transmitter, then it cannot possibly be dissipated as power in
the PA. Another not-so-obvious way of achieving a Zg match is with a
pi network tank circuit in a tube PA. Reflected energy will be flowing
in the pi network tank circuit inside the transmitter but no reflected
energy will reach the PA tubes because of the Zg match.

Now if the reflected energy is allowed to flow through the PA, there
will be a real dissipative resistance existing that will dissipate some
reflected power. But the overall dissipation of the PA could increase
or decrease because that same reflected wave changes the load that the
PA sees and therefore changes the operating point. Like W8JITom says,
the overall PA dissipation can go up or down in the presence of reflections.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)


From [e-mail] Sun Jul 21 18:41:44 1996
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From: "William E. Sabin" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Thu, 18 Jul 1996 15:24:39 -0700
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Gary Coffman wrote:
>
> This doesn't say anything about the source impedance of the device.
> The "matching" that is occurring is just the transformer action of
> the network transforming the presented load impedance to a value
> which satisfies the power output requirement of the device. That
> number is just a mathematical intermediate and doesn't represent
> any real dissipative resistance in the device or in the network.

I wish the term "impedance matching" would disappear in PA design. It
causes nothing but confusion and misunderstanding. As you say and as I
have been preaching, it is the "impedance transformation" that is
relevant.

Bill W0IYH


From [e-mail] Sun Jul 21 18:41:46 1996
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Gary Coffman)
Subject: Re: forward/reflected power
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <4sb69k$[e-mail]> <4sc4su$[e-mail]> <4scngi$[e-mail]>
Date: Sun, 21 Jul 1996 16:54:59 GMT
Lines: 86

In article <4scngi$[e-mail]> Cecil Moore <w6rca@w
orldnet.att.net> writes:
>[e-mail] (W8JI  Tom) wrote:
>>A 6 dB pad has 6 dB attenuation regardless of input impedance. All that is
>>required is the output impedance be correct.
>
>I may not be communicating this concept very well. A 6dB pad with the
>output shorted or open would not show 6dB attenuation. I think a 6dB
>pad designed for 50 ohms will not have exactly 6dB of attenuation unless
>the load is 50 ohms. Is that correct or have I had too much scotch?

That's right Cecil, and there's only one load in the system, down
at the antenna end of the coax.

>My reasoning is if the voltage and current into say, 100-j100, increase
>by exactly 6dB and retain the same phase when the 50 ohm, 6dB voltage/current

>pad is removed from the circuit, then the impedance at the coax connector
>on the transmitter must be the same as the pad design impedance because the
>reflections must be seeing 50 ohms and not being re-reflected. It's been
>some time since I ran this experiment. I need to run it again paying
>attention to phase as well as magnitude.

No, only the load impedance matters. You'll see a 6 db change only
if the presented load is the same as the design load impedance of the
pad and the line to which the pad is connected is "flat", IE unity VSWR.
(Obvious special case: if the line is a multiple of a halfwave, the
line does not have to be flat, IE a halfwave of 75 ohm coax will still
present a 50 ohm load to the pad if the terminating load at the far
end is 50 ohms, even though the line will have a VSWR other than unity.
Other transformer relations also apply. All that matters is what the
pad sees at its output terminal.)

Your main problem is that you're not using the wave model properly.
There aren't any "re-reflections" in the wave model. There is exactly
one forward wave and exactly one reverse wave. Each of those waves
is a plot of the resolved vector component sums of the voltage and
current vectors at each point on the line. The combined sum is the
standing wave. The the forward and reverse "waves" only exist on the
graph paper. They are not physical entities with a separate retained
identity, like ping-pong balls that bounce back and forth.

The wave model helps us visualize the relationships between voltage
and current along the line, but it is just a visualization tool, it
must not be taken as a literal physical wave that moves back and forth
on the line. A better model for visualizing what happens in your
scenario is to consider the transmission line as just a transformer.
With unity VSWR, it is a 1:1 transformer. At other VSWR values,
it exhibits some other transformer ratio. No ping-pong balls needed.

The waves we can plot are just a visualization of the internal operation
of the transformer, which is a function of the standing wave. The forward
and reverse components our VSWR meters purport to measure are just resolved
components of the vector sum which makes up the standing wave. Just as
we might resolve the motion of a ball as a horizontal and vertical vector,
the VSWR meter resolves the power flowing from source to load as a forward
and reverse vector (because the power is AC). But as with the flight of the
ball, there isn't  really a separate horizontal and vertical motion to the
ball, nor is there a separate reality to the forward and reverse components
of the standing wave. In both cases, the graph is just a visualization tool.

Let me try to go at this in another way. In the system you describe,
there is only one generator and one dissipative load. Net power can
only flow one way, from source to sink. The impedance the generator
sees looking into the source end of the coax is the impedance of the
load as transformed by the transformer action of the line, IE it is
an *image* like the one you see when looking through a telescope, and
the magnitude of the image is a function of the transformer ratio of
the line, just as the visual image is a result of the magnification
of the telescope. The impedance seen at the load end looking back
toward the generator doesn't matter because the load is *not a source*.
No voltages and currents originate at the load. To extend the metaphor
of the telescope, there's no "eye" at the load to see an image of any
source impedance.

This metaphor may seem like the Zen paradox of one hand clapping.
And that's the problem with any model, if you push it too far, you
fall into philosophical conundrums. To get two *separate* waves,
you need two sources (as getting applause requires two hands clapping).
If you try to treat the two components of the wave separately, you
get nothing.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sun Jul 21 18:41:47 1996
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From: [e-mail] (Alan)
Newsgroups: rec.ham-radio.swap,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.amateur.swap,rec.radio.swap
Subject: FS: Rohn HDBX-40 for 18sqft of antenna..  in SOCA
Date: Thu, 18 Jul 1996 19:19:13 -0700
Organization: Zippo
Lines: 9
Message-ID: <[e-mail]>
X-Newsreader: MicroPlanet Gravity v1.00 (30 Day Trial)
Xref: news2.epix.net rec.radio.amateur.antenna:23290 rec.radio.amateur.equipment:31127 rec.radio.amateur.misc:105325 rec.radio.swap:70382

For Sale, 40 foot tall self supporting tower. Heavy Duty will
support 18sqft of antenna wind load. There is 5 sections each
is 8' tall. This sells new for 475.00 + shipping and or Tax.
Will sell this one for 250.00. Its located 75-miles north of
San Diego, CA This is a pick-up only. It can be picked up in a
Toyota or Nissan type truck or larger. Would also consider
trades such as a 175-watt UHF amplifier or ???? 73, Alan

          [e-mail]


From [e-mail] Sun Jul 21 18:41:48 1996
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From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: GAP ant modelization with EZNEC
Date: 15 Jul 1996 12:04:43 GMT
Organization: Comp.Center (RUS), U of Stuttgart, FRG
Lines: 17
Message-ID: <4sdc4r$[e-mail]>
References: <4scs6g$6rb$[e-mail]>
NNTP-Posting-Host: ipers1.e-technik.uni-stuttgart.de

>They are many discussion around GAP antennas efficiency. Has
>anybody tried to modelize these antennas with EZNEC? It should
>give at least a theorical answer, but certainly very useful.

Hi Pierre-Andere,

You do not need EZNEC modelling to find that the GAP is *very*
inefficient. Short vertical radiators and their efficiency
have been extensively discussed in antenna engineering
literature, and it is found that changing the current distribution
(between a electrical 1/4 wave and a 1/2 wave) does not significantly
change ground losses.

Only GAP chooses to ignore these facts, but than again they are selling to
amateurs.

73, Moritz DL5UH


From [e-mail] Sun Jul 21 18:41:49 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Good Explanation of Q in an antenna ???
Date: Tue, 16 Jul 1996 17:29:13 -0700
Organization: Intel Corp., Chandler, AZ
Lines: 11
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charles copeland wrote:
> Since each S unit is a factor of 4, a Hi Q whip radiates
> 4-16 times better than a Lo Q Ham Stick.

Hi Charles, I don't think each S unit is a factor of 4. Most
of us here on this newsgroup seem to agree that an 'S' unit
in the average receiver is about 2-4dB. I know that my **40m**
ham stick on 3995 kHz was only 3-6dB down from the bugcatchers
in the CA HF mobile shootout and equal to some of the screwdrivers.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)


From [e-mail] Sun Jul 21 18:41:49 1996
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From: Jory McIntosh <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Good Explanation of Q in an antenna ???
Date: Tue, 16 Jul 1996 09:33:52 -0700
Organization: Tandy Information Services
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Can anyone give me a good explanation of Q in an antenna system ??? I
remember studying this for my advanced ticket, but now it is as clear
as mud.   Thanks for you help.


Jory McIntosh KB5UBS


From [e-mail] Sun Jul 21 18:41:51 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Good Explanation of Q in an antenna ???
Date: 18 Jul 1996 11:21:32 -0400
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Subject:        Re: Good Explanation of Q in an antenna ???
From:   [e-mail] (W8JI  Tom)
Date:   18 Jul 1996 08:15:58 -0400

In article <[e-mail]>, [e-mail] (charles
copeland) writes:

>>So, Charles,
>>      Do you really think that my 20 meter dipole at 23 feet
>>is less efficient than the Carolina Bug Catcher mobile Hi Q whip
>>since it (my 20 meter dipole) exhibits lower Q than the Bug Catcher.?
>
>I said no such thing. The comparison referred to mobile whips.
>
>>I explained Q as the fellow requested (not its repercussions etc...)
>
>It needed clarification.

Hi All,

Q can not be directly related to efficiency, in a mobile antenna or
otherwise.

Q is the ratio of resistance to reactance in the antenna, but the
resistance can be either radiation resistance (good) or loss resistance
(bad).

Let me give examples of a mobile antenna with high Q that is bad, and low
Q that is good.

Bad antenna.

An eight foot tall antenna very thick on the bottom and thin at the top.
It has a lot of capacitance across the coil (like the Hustler with it's
enameled wire and pretty metal end caps on the coil), the coil is low in
the structure, and there is no capacitance hat. Here's what happens.

1.) The stray C across the coil increases coil circulating currents and
losses while decreasing the bandwidth.

2.) The low coil position results in a lowering of radiation resistance
and efficiency.

3.) The lack of a hat means the coil has high reactance, and since Q is
X/R in the series circuit, Q is higher than it would be with a hat.

A good antenna with low Q. An antenna with a 2 foot tall and 4 foot wide
cage on the top and great effort to minimize stray C across the coil, and
a reasonable sized mast that has low distributed capacitance.

1.) Stray C across the coil is minimal compared to the antenna's end
capacitance. The coil handles necessary current only, losses are lower and
BW larger!

2.) Coil position isn't critical because the large end capacitance
terminates the current. Radiation resistance is over twice as high as in
the first antenna.

3.) The large end capacitance reduces the amount of inductance required,
so BW is greater.

Let me give fixed antenna examples:

A 1/4 wave vertical antenna with a good radial system (low Q, good
efficiency), and a 1/4 wave vertical with no radial system and an end
loading coil with no hat (high Q, poor efficiency).

As you can see, it can go either way with any antenna. Q has no
universally true relationship to efficiency.

73 Tom


From [e-mail] Sun Jul 21 18:41:51 1996
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From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Good Explanation of Q in an antenna ???
Date: 18 Jul 1996 19:05:09 GMT
Organization: Arizona State University
Lines: 16
Message-ID: <4sm1t5$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


Charles Copeland said in reply to my challange of his statement
on Q of antennas which was defined as a "simplification"

I said no such thing. The comparison referred to mobile whips.


Charles,
        Your comparison was probably intended to refer to only
mobile whips but the subject of the inquirey was "Good Explanation
of Q in an antenna" in the posting requesting it.  My answer was
in response to that.  Your "simplification" did not answer this
general question.

Charlie, W7XC
--


From [e-mail] Sun Jul 21 18:41:53 1996
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From: [e-mail] (Kevin  AstirCS "1U"   KO0B)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Good Explanation of Q in an antenna ???
Date: Wed, 17 Jul 1996 15:31:53 -0700 (PDT)
Organization: Aquila Technologies Group, Inc.
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[e-mail] (CHARLES J. MICHAELS) wrote:
>In response to my explanation of antenna system Q, WB0WOB wrote -
>More simply put, the lower the resistive component, relative
>to reactive component, the higher the Q. Hi Q is good, higher
>efficiency, more radiation. Unfortunately Hi Q also means
>narrow bandwidth.

TOO simply put.

Q is also influanced by the radiation resistance of the antenna, of
which more is better...so if the Q is low because of high radiation
resistance, not due to lossy loading coils, then effiency _and_
bandwidth can  both be  good.  The way to achieve this is to make the
antenna physically large, and use a low loss broad band feed
araingement (feed it at a current node)

This explains why a low  Q dipole will beat out most any  high Q
mobile whip in both gain and bandwidth.

It is close to true that for a given physical length, less than say
1/8 wave, lower bandwidth probably indicates higher effiency.
So if you are comparing equal length mobile whips, then the higher Q
design is likely to give a stronger signal.  So I agree with the
statement  I took exception to, in the context of mobile whips, but
this can't be generalized to other antenna types as has already been
done elsewhere in this thread.

-ko0b-



From [e-mail] Sun Jul 21 18:41:54 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Good Explanation of Q in an antenna ???
Date: 18 Jul 1996 11:00:49 -0400
Organization: America Online, Inc. (1-800-827-6364)
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In article <4skebp$[e-mail]>, [e-mail] () writes:

>
>Seems to me the Collins recievers were calibrated for an S9 meter
>reading at 100 uV input on 20 meters and that an S unit was
>approximately 6 dB.
>
>>Still, if you define an 'S' unit as 6dB, my 40m Hamstick on 3995 kHz was

>>less than one 'S' unit different from most of the bugcatchers in the
>>antenna shootout. That's usually not enough difference to detect without

>>looking at the 'S' meter.
>
>>73, Cecil, W6RCA, OOTC
>
>

I think you'll find it was Hallicrafter that used the 6 dB S unit. Collins
used a lower figure.

But regardless, 6 dB has never been an accepted standard, and still isn't
today.

Drake used 5 dB, my ICOM and Yesau use between 2 and 4 dB. The truth is
3-4 dB is much more correct for the S units we see on our rigs.

73 Tom


From [e-mail] Sun Jul 21 18:41:55 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Good Explanation of Q in an antenna ???
Date: 18 Jul 1996 11:15:32 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Subject:        Re: Good Explanation of Q in an antenna ???
From:   [e-mail] (W8JI  Tom)
Date:   18 Jul 1996 08:15:58 -0400

In article <[e-mail]>, [e-mail] (charles
copeland) writes:

>>So, Charles,
>>      Do you really think that my 20 meter dipole at 23 feet
>>is less efficient than the Carolina Bug Catcher mobile Hi Q whip
>>since it (my 20 meter dipole) exhibits lower Q than the Bug Catcher.?
>
>I said no such thing. The comparison referred to mobile whips.
>
>>I explained Q as the fellow requested (not its repercussions etc...)
>
>It needed clarification.

Hi All,

Q can not be directly related to efficiency, in a mobile antenna or
otherwise.

Q is the ratio of resistance to reactance in the antenna, but the
resistance can be either radiation resistance (good) or loss resistance
(bad).

Let me give examples of a mobile antenna with high Q that is bad, and low
Q that is good.

Bad antenna.

An eight foot tall antenna very thick on the bottom and thin at the top.
It has a lot of capacitance across the coil (like the Hustler with it's
enameled wire and pretty metal end caps on the coil), the coil is low in
the structure, and there is no capacitance hat. Here's what happens.

1.) The stray C across the coil increases coil circulating currents and
losses while decreasing the bandwidth.

2.) The low coil position results in a lowering of radiation resistance
and efficiency.

3.) The lack of a hat means the coil has high reactance, and since Q is
X/R in the series circuit, Q is higher than it would be with a hat.

A good antenna with low Q. An antenna with a 2 foot tall and 4 foot wide
cage on the top and great effort to minimize stray C across the coil, and
a reasonable sized mast that has low distributed capacitance.

1.) Stray C across the coil is minimal compared to the antenna's end
capacitance. The coil handles necessary current only, losses are lower and
BW larger!

2.) Coil position isn't critical because the large end capacitance
terminates the current. Radiation resistance is over twice as high as in
the first antenna.

3.) The large end capacitance reduces the amount of inductance required,
so BW is greater.

Let me give fixed antenna examples:

A 1/4 wave vertical antenna with a good radial system (low Q, good
efficiency), and a 1/4 wave vertical with no radial system and an end
loading coil with no hat (high Q, poor efficiency).

As you can see, it can go either way with any antenna. Q has no
universally true relationship to efficiency.

73 Tom


From [e-mail] Sun Jul 21 18:41:55 1996
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From: [e-mail] (Glasscock Family)
Newsgroups: rec.radio.amateur.antenna
Subject: RE: Grid squares locator on the internet
Date: 17 Jul 96 14:00:43 GMT
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NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

Buckmater has me on a map but it is around a 1,000 feet or so to the south is
were I am but on there map they have me else where.



From [e-mail] Sun Jul 21 18:41:56 1996
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: grounding question
Date: 19 Jul 1996 16:16:26 GMT
Organization: Texas A&M University, College Station, Texas
Lines: 57
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In <4so4je$[e-mail]>, [e-mail] (Harris) writes:
>ED WELCH ([e-mail]) wrote:
>: I've got my rig grounded via #4 copper wire.  When I'm not using the rig
>: I disconnect the antennaes and ground them to the same ground wire as
>: connected to my rig.  The rig is unplugged from AC, also.  Should a
>: lightening strike hit will the rig get fried being as the antennas are
>: hooked to the same ground?  Should I fix it where I can completely
>: removed the rig from both ground and AC?...I know this would be better,
>: but should I go the trouble of doing this?  Thanks for your help.
>
>I think you're setup is fine as is.
>
>BTW, contrary to popular belief, the most likely path of lightning surge
>into your shack is via the power lines -- not your antenna feedline. So
>your practice of disconnecting from AC is right on.
>
>73,
>
>--
>Art Harris N2AH
>Internet: [e-mail]
>      or  [e-mail]
>Packet Radio: [e-mail]
>TCP/IP: n2ah.ampr.org  [44.68.8.137]

From VERY bitter experience, it ain't necessarily so.

In that most installations do have ground paths that remain interconnected
even if you unplug your rig from both the power and antenna paths, what comes
in the building from the power lines goes right back through all the ground
paths BACKWARDS into your antenna site grounds!

That, usually hops around all over your desk and sstuff totally blitizing
everything even though it is totally disconnected.  All these MOV Varistor
surge protectors actually make thigs worse in many cases.

Take me.  I lost a complete Sony GVM-1310 professional monitor, two
computers, an ICOM 2 meter transeiver and a ton of other equipment that
was totally disconnected from everything!  It came in the power lines,
blew the empty Tripplite surge protector boxes to bits, played all over my
19 inch relay racks, then EXITED the place on the ground buss lines to the
outside ground network for my antennae!

Took all my HiFi equipment on Tripplite surge protectors as well as my
Microwave oven and some more stuff as well.

Everything tied TO the antennae network was fine (As long as it wasn't
fed from a switching power supply!)  Everything DISCONNECTED was wasted
along with everything in the place fed with switching power supplies that
remained connected!    Read Zero Surge's literature for the explanation as
well as study Polyphasor's stuff.

I'm glad I DIDN'T provide an neat arc path for that one of MANY hits I
have taken over the years....

Mike W5WQN as a guest at leviathan.tamu.edu (No mail address there)



From [e-mail] Sun Jul 21 18:41:57 1996
Path: news2.epix.net!uunet!inXS.uu.net!li.net!aharris
From: [e-mail] (Harris)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: grounding question
Date: 19 Jul 1996 14:03:26 GMT
Organization: LI Net (Long Island Network)
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ED WELCH ([e-mail]) wrote:
: I've got my rig grounded via #4 copper wire.  When I'm not using the rig
: I disconnect the antennaes and ground them to the same ground wire as
: connected to my rig.  The rig is unplugged from AC, also.  Should a
: lightening strike hit will the rig get fried being as the antennas are
: hooked to the same ground?  Should I fix it where I can completely
: removed the rig from both ground and AC?...I know this would be better,
: but should I go the trouble of doing this?  Thanks for your help.

I think you're setup is fine as is.

BTW, contrary to popular belief, the most likely path of lightning surge
into your shack is via the power lines -- not your antenna feedline. So
your practice of disconnecting from AC is right on.

73,

--
Art Harris N2AH
Internet: [e-mail]
      or  [e-mail]
Packet Radio: [e-mail]
TCP/IP: n2ah.ampr.org  [44.68.8.137]


From [e-mail] Sun Jul 21 18:41:58 1996
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From: "Tim" <[e-mail]>
Newsgroups: rec.radio.amateur,rec.radio.amateur.antenna,rec.radio.amateur.digital,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew
Subject: Hamfest
Date: Wed, 17 Jul 1996 18:04:36 -0700
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Xref: news2.epix.net rec.radio.amateur.antenna:23268 rec.radio.amateur.digital.misc:16512 rec.radio.amateur.equipment:31097 rec.radio.amateur.homebrew:16173

Hamfest, Fort Tuthill In Flagstaff, Arizona
July 19, 20, 21, 1996
Arizona's Largest Hamfest

For More Information: http://www.geocities.com/RainForest/2425/


From [e-mail] Sun Jul 21 18:41:59 1996
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help on swr changes
Date: Wed, 17 Jul 1996 15:24:40 -0700
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Avatar wrote:
>
> [e-mail] wrote:
> >
> > need help.  At low power 10 Watts my swr read real good say 1.1 ot 1.3.
> >  However when I go to high Power the swr goes to say 1.8 to 2.1 or so.
> > This happens on all bands.  I'v moved the antenna (a vertical), put in
> > new grounds, grounded everything I could think of, put chokes on the
> > anenna, coax, checked the coax with a dummy load(1:1).  Was getting big
> > time RFI on phone, TV house sterio wntill I put chokes on everything.  I
> > happen to put a fiewld strength meter in the room when I was Xmitting and
> > notice the neddle going ape when I transmitted. Anyone have any ideas on
> > whats causing the SWR to change with increased power I sure would
> > appreciate the help.  Thanks Lou KB6FFT
>
> You didn't quantify "hi power", so I assume you mean in the 100W area. I
> had a similar problem with a vertical just a few feet from my transmitter
> many years ago (before I really understood RF). One manifestation was my
> brother's bedroom light flashing while I was talking on 40M SSB (300W)
> even though the light switch was off. Evidentally, the wiring in his
> room (inductance) and the light switch (series capacitance) was self
> resonant on 40M! I had other problems like yours. I finally gave up and
> tore down the vertical.
>
> Verticals compared to horizontals produce intense ground waves. It sounds
> to me like you have a ground loop that is floating some RF in your house
> and possibly the Ham equipment. That ground loop probably is due to RF
> getting into the power wiring in your house. It also explains why your
> SWR readings change with power and the FS meter readings. Other than
> moving the antenna farther from your house, running low power, or going
> to an antenna that doesn't work against ground, I don't have a ready
> solution for you. Maybe this info will help anyway.
>
> Dave
> W0MAYThanks.  I'm glad(not really ) that your problem sounds just like mine.

At least I don't feel like beating my head against the wall anymore.  I
finally put a choke on the ferrite coax output from the xmitter that seem
to stop the  electron "ghost" from running through the house. Without the
room to use other than a vertical I guess I'll live with it. Thanks 73
Lou


From [e-mail] Sun Jul 21 18:42:00 1996
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From: [e-mail](James Bolit )
Newsgroups: rec.radio.amateur.antenna
Subject: Help...Looking for WX0B
Date: 21 Jul 1996 19:10:03 GMT
Organization: Netcom
Lines: 13
Message-ID: <4stvab$[e-mail]>
NNTP-Posting-Host: tem-ca1-15.ix.netcom.com
X-NETCOM-Date: Sun Jul 21 12:10:03 PM PDT 1996


I am looking for WX0B's e-mail address.

I know at one time he visited this group.

If anyone has his e-mail address I would appreciate it if you would
foward it to me via e-mail

Thanks in advanced

Jim
WA9ZBV



From [e-mail] Sun Jul 21 18:42:01 1996
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From: Dave Booth kc6wfs <[e-mail]>
Newsgroups: rec.radio.scanner,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.dx,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space,fidonet.ham,rec.ham-radio,rec.ham-radio.packet,rec.ham-radio.swap,slac.rec.ham_radio,su.org.ham-radio,swb.lists.linux.hams,rec.radio.swap,tnn.radio.amateur,uwarwick.societies.amateur-radio
Subject: homepage
Date: Tue, 16 Jul 1996 15:41:53 -0700
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If you get boared. Check out my Ham Page. Lots of good links!
http://www.geocities.com/Hollywood/5860
--
Dave Booth
kc6wfs


From [e-mail] Sun Jul 21 18:42:05 1996
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From: [e-mail](Tom Wagner)
Newsgroups: rec.radio.amateur.antenna
Subject: I can make a balun, but how good is it?
Date: 14 Jul 1996 18:56:42 GMT
Organization: Pipeline
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Hello!  I have a problem that I know
someone on this forum can help me with.

Here is my situation:  I am refurbishing
my tribander -- a TH-7 at 75'.  Last
winter the antenna "freewheeled" and broke
the BN-86 voltage balun on the antenna.
I have taken it down and repaired it.
That went fine.  There was no evidence
of arcing in the balun and I *could* put
it back up.

I have received different advice about this:

1.  Fix the BN-86 and put it back up.
2.  Replace it with 7 turns RG-213 6"
    diameter (bunched).
3.  Replace it with 6 turns 4"
    diameter single-wound.
4.  Use a ferrite choke balun.  I have
    5 big #43 beads I could use.
    Whether they are *really* #43, I'm
    not sure.

I'd like to try measuring some of these
options, but my only equipment is an
Autek RF-1 antenna analyzer.  It measures
L, C, Z and SWR vs. frequency.

Does anyone have any advice as to
procedures to use to measure the effective-
ness of the above options?

I've tried measuring the Z of the shield
(i.e. connect to shield at each end of cable)
for options 2 and 4 above and I think I'm
getting reasonable results.  I get between
500-700 ohms impedance for each at 14 and
28 mHz.  Is this the right thing to measure,
is 500 ohms good enough, what have I not
thought of?

Thanks in advance for you help.  Please post
to the newsgroup as I'm sure this will be of
interest to many others.

73,
Tom - N1MM


From [e-mail] Sun Jul 21 18:42:06 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-Pole gain
Date: 17 Jul 1996 09:39:41 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 22
Sender: [e-mail]
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In article <4se01v$[e-mail]>, [e-mail] (Tom Bruhns)
writes:

> Then the bottom quarter wave
>of the J-pole becomes coaxial, and the half-wave has a reasonable
>counterpoise to operate against and to decouple from the feedline.  This
>could be done with something like RG-8X for portability, or with copper
>plumbing  pieces for fixed installations.  Any interest in more details??
>
>
>

Hi Tom,

If that was done correctly, the antenna could be made to act as a 1/4 wave
in phase with a half wave, and have gain over a half wave instead of
loss.]

It seems like a shame to use all that space to lower gain, when it could
be used to improve it.

73 Tom


From [e-mail] Sun Jul 21 18:42:07 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-Pole gain
Date: 17 Jul 1996 10:52:37 -0400
Organization: America Online, Inc. (1-800-827-6364)
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In article <4sc71h$[e-mail]>, [e-mail] (Dan Richardson) writes:

>
>The same gain as a ╜ wave dipole..... the bottom section (╝ wave
>length long) does not radiate...
>
>Danny, K6MHE

Hi Danny,

I have one question. **What prevents the stub from radiating?**

It's my understanding that any transmission line, including both coaxial
or balanced lines, radiate when currents in both conductors are not equal
and 180 degrees out of phase.

At the top of the stub (which is a two wire transmission line), one
conductor hooks to the several hundred ohm element and the other hangs
free. Thus the currents in the stub can not be equal, or 180 degrees out
of phase, throughout the length of the stub.

Since stub currents can not be equal and opposite, the stub must radiate.

Tell me where my mistake is please.

73 Tom


From [e-mail] Sun Jul 21 18:42:08 1996
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From: Steve Jones <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Lightning Bolt Quads
Date: Sun, 14 Jul 1996 22:40:37 +0100
Organization: Isle of Anglesey
Lines: 18
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Message-ID: <[e-mail]>
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Hi All,
I am looking for reviews/opinions on the Lightening Bolt quads. I would
be grateful for any information, good/bad points, email adress, postal
address, telephone number for overseas orders, web page?,etc. I am just
in the process of putting up a second hand 60ft tower for 6 over 6 ele
yagi array on 6m, and am thinking of putting a three or five band quad
on my original 35ft wind up mast. Main interests are 6m and 10m (5 ele
mono yagi) but the quad looks like a good bet in terms of value for
money and signal per pound at a height of 35ft. Am new to the newsgroup
but have found the last week or so of reading the mail very interesting.
73 de Steve.
--
Steve Jones
GW0GEI in IO73TG, IOTA EU124
Ynys Mon / Island of Anglesey
Gogledd Cymru / North Wales
UK 6M Group Member 295
DX CLUSTER GB7ADX


From [e-mail] Sun Jul 21 18:42:09 1996
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From: [e-mail] (Robert G. Strickland)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Lightning Bolt Quads
Date: Mon, 15 Jul 1996 09:26:25 -0400 (EDT)
Organization: ServiceTech, Inc.
Lines: 17
Message-ID: <4sdhgv$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: regcon.syr.servtech.com
X-Newsreader: Forte Free Agent v0.38

Steve...
I have been using a LBA for about 3-4 years and have been satisfied.
Good mechanical design and materials. Many folk in USA are using them
and are happy. I have been doing computer modeling studies on quads
and am convinced that separate feeds for each band are the way to go.
Mike at LBA disagrees and has some good thoughts on the matter.
"That's what makes a horse race." Anyway, I think you'd be happy with
one. Mine has been through some very tough winters here in Central
Upstate New York, so I can vouch for its mechanical quality. I've been
able to up my DX total from a stagnant 130 using a vertical to 262
with the LBA and still climbing. LBA doesn't have a WEB site to the
best of my knowledge. Mike is very talkable, though, and will gladly
spend your money on longdistance! Have fun.
...Robert





From [e-mail] Sun Jul 21 18:42:10 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!news-res.gsl.net!news.gsl.net!nntp.coast.net!sdd.hp.com!col.hp.com!news.dtc.hp.com!hpscit.sc.hp.com!rkarlqu
From: [e-mail] (Richard Karlquist)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Lightning Bolt Quads
Date: 15 Jul 1996 17:54:02 GMT
Organization: Hewlett-Packard
Lines: 24
Message-ID: <4se0jq$[e-mail]>
References: <[e-mail]> <4sdhgv$[e-mail]>
NNTP-Posting-Host: mentor23.scd.hp.com

I just put up a Lightning Bolt Quad to replace my KLM KT-34A
(which is for sale for $150 BTW).  I was very happy with the
KT-34 except it didn't cover 18 and 24 MHz.  The LBQ was
considerably easier IMHO to assemble than the KT-34, has a
short 8 foot boom and is very lightweight.  The VSWR is
excellent across all bands, even being usable at the high
end of 10 meters where the KT34 wouldn't work.  The front
to back is not as good as the KT-34, although it is OK
for a 2 element beam (2 element beams, whether Yagi or
Quad aren't supposed to have as good F/B as 3 elements).
I used the published wire lengths and didn't try to tweak
it for optimum tuning.  I used the feed with the 50/100 ohm
transformer feeding all elements in parallel.  You can't
run a KW with this setup, which is OK with me.  Totally
subjective comment: I think there is less visual clutter,
you just see two X's and the boom, the wires being nearly
invisible.  The short boom makes it look "smaller".  Anyway,
neither the XYL or neighbors said anything against it;
one neighbor wanted to know how much range it had.  It is
somewhat flimsy as quads tend to be.  Back when I was WA9QXT
and we had ice storms, I would be skeptical of it surviving,
but I am near San Franscisco now, so that's not an issue.

Rick N6RK


From [e-mail] Sun Jul 21 18:42:11 1996
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From: Jim <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: LIGHTNING DAMAGE CONTROL
Date: Sun, 21 Jul 1996 13:11:29 +0000
Organization: AT&T WorldNet Services
Lines: 121
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Date: Sun, 21 Jul 1996 12:42:36 +0000

From: Jim <[e-mail]>

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MIME-Version: 1.0

To: [e-mail]

Subject: Re: grounding question - how much is enough???

References: <[e-mail]> <4so4je$[e-mail]>
<4soccq$[e-mail]> <4ss8c9$[e-mail]> <4sse8o$305@news.
tamu.edu>

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trimmed of previous text......

> Hams are not the only ones with empty pockebooks for protective costs!

>

> Mike W5WQN as a guest at leviathan.tamu.edu (No mail address there)



So, Mike now that you got my attention....WHAT CAN A HAM DO TO REASONABLY PROT
ECT HIS

STATION AS MUCH AS POSSIBLE?  CAN YOU TELL ME WHAT IS WRONG WITH THIS PICTURE?
:



I live in the lighting capital of the US.  Florida!  I have a PRO 67B3 on a 85
 ft tower.

 There are no other antenna's above the beam.  There are three vertically orie
nted 3

3-element VHF beams off the side.  The guys are 1/4 strand and are not broken
by

insulators.  Each guy at each guy point is grounded to a 16 ft ground rod at t
he guy

anchors.



I have the entire length of the tower clamped at each section to a continous #
4 solid

copper ground wire that connects to a 16ft ground rod at the base of the tower
.  From

the ground rod at the base of the tower the #4 copper continues to a network o
f 15 other

16ft ground rods spaced at 16ft intervals.  The #4 copper is finally terminate
d on a 1/4

inch thick 6X16 inch copper buss plate mounted on and outside brick wall.



Through the buss plate are all the coax feeds attached to N type bulkhead conn
ectors so

that the shield of the 213 coax is connected to the ground network.  The feeds
 are then

fed through the wall into the shack to another set of N type bulkhead connecto
rs on a

wall plate, to which the radio equipment is connected.  A common ground termin
al is also

fed through using 1/4-20 thread-all to which a strap is connected for the grou
nd buss

that all the equipment grounds are connected. Each piece of equipment has the
chasis

ground connected to the ground buss plate (1/4X6X16 solid copper) under the op
erating

console.



During the summer thunderstorms all equipment is disconnected from both AC pow
er as well

as all antenna feeds and common ground at the inside wall panel.  Shorting cap
s with

a center pin are placed on the bulkhead N type connectors on the inside wall p
anel so

that the shield and center conductors are shorted together to the common groun
d through

the ground buss plate on the outside wall.



What have I done wrong in this approach?  I realize that no one can prevent a
direct

hit.  However, we can be better prepared for DAMAGE CONTROL!  Give me some spe
cifics and

your thoughts on this.  I have many of the fact sheets that Polyphaser publish
es as well

as some of their books they recommend.  But as you imply, we not only have to
have

DAMAGE CONTROL but also COST CONTROL.  So, where is the mean point that is rea
sonable?



If their is one subject I find of most interest on the WWW, it is the subject
of

grounding and RFI protection.  Thanks for all your input you have already prov
ided as

comment.



Jim



[e-mail]




From [e-mail] Sun Jul 21 18:42:15 1996
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Lightning strikes!!!
Date: 19 Jul 1996 16:30:10 GMT
Organization: Texas A&M University, College Station, Texas
Lines: 28
Message-ID: <4sod6i$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: 128.194.44.219
X-Newsreader: IBM NewsReader/2 v1.2

In <[e-mail]>, Steve O'Donnell <[e-mail]>
writes:
>As an aircraft mechanic who maintains a single DC-9 for NASA, I must tell
>all that there are no absolute insulators for a direct strike! I have
>seen glass position light lenses melted and scarred from such encounters,
>and medium frequency antenna couplers (ADF) blown apart! And those
>strikes were above 20,000 feet in clouds. The only sure way to avoid
>damage is to DISCONNECT!73, N5LAP

As a medium high time pilot owner of Beech Barons, flown hard IFR for
a long time, I'll personally vouch for your aircraft notes.   It makes the
prettiest little burned spots where it hits you ever saw.  Makes lots of
tiny holes in the aluminum you get to patch when the strike gets way
up there in current flow...

You get disconnected by not flying IFR, I suppose.....

As to gear, and aside from the power line apprach to your QTH, disconnecting
just adds to the problems.  With near field EMP pulse and field induction
effects, even disconnect stuff gets fried.  I can show you boxes of it
including monitors, computers, even HIFI gear....

When you put up an antenna, you are increasing your chances to get hit.

The only best safest approach is to sink the stuff to ground BEFORE it can
get inside to your gear, then sink the gear as well on the ground side to
attempt to keep it from elevated during the inductive kick taken as well.

Mike W5WQN as a guest at leviathan.tamu.edu  (No mail address there)


From [e-mail] Sun Jul 21 18:42:16 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.internetmci.com!news.radio.org!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Lightning strikes!!!
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <4skd0n$[e-mail]>
Date: Thu, 18 Jul 1996 18:40:48 GMT
Lines: 63

In article <4skd0n$[e-mail]> [e-mail] (Bob Bruhns) wr
ites:
>  Does anyone have experience with those dandelion-like "puffs" a few
>inches in diameter, which are supposed to drain off overhead cloud
>charge by inducing corona discharge with its many sharp extruding points,
>driaining this off to ground as a continuous current of a few amps
>during thunderstorms?  I have read about this, and I have seen this
>type of "puff" on some radio towers in the New York City area.
>
>  Bob Bruhns, WA3WDR, [e-mail]

These brush dischargers can *attract* a lightning strike, but they
usually can't discharge enough charge to prevent one. Here's why.

A typical lightning discharge displaces 20 coulombs of charge. If
that displacement occurred over one second, the current flow would
be 20 amperes. But it occurs over about 2 microseconds, so the
current flow is more on the order of 10 million amperes. That's
what heats the air causing thunder, and what melts your antenna
and coax, and your radio and you, if they are in the path of the
discharge.

Now to prevent the strike, you have to neutralize that 20 coulombs
of charge *gently*. That's what the fuzzballs purport to do. However,
if the discharge from any given point exceeds about 20 microamperes,
a streamer develops. It is these ground to cloud streamers which
form the initial channel through which the main bolt, the return
stroke, neutralizes the cloud to ground charge with a massive
KABOOM.

So, we can't let any discharge point exceed 20 microamperes if
we want to avoid *attracting* lightning. Now a million points
would do that in one second, but these dischargers have far fewer
than a million points. Typically they have less than 1000 points,
so we'd need 1000 seconds, or about 16.66 *minutes* to discharge
the cloud charge responsible for a lightning bolt. I'm sure you've
noted that lightning bolts occur more frequently than that during
a thunderstorm. That's because the winds aloft move the clouds,
and the charge concentrations in the clouds, much more rapidly
than that. Therefore there is fresh charge over any given point
more frequently than once every 16.66 minutes.

These fuzzballs can serve the same purpose as a lightning rod,
IE serve as a preferred target for lightning, but they can't
prevent lightning strikes. Since these fuzzballs aren't very
robust, they usually can't handle a lightning strike as well
as a lightning rod, so they'll usually sustain damage in every
storm. A lightning rod is a better deal. It has a single discharge
point, and thus generates strong streamers which more reliably
attract lightning. And a lightning rod is robust enough to then
conduct the charge safely to Earth without sustaining major
damage in the process.

The FAA conducted tests in Florida a number of years ago which
confirmed this reasoning. None of the dischargers could prevent
lightning strikes, but all of them sustained more damage than
a properly installed lightning rod when strikes did occur.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sun Jul 21 18:42:17 1996
Path: news2.epix.net!uunet!in2.uu.net!news.u.washington.edu!netnews.worldnet.att.net!newsadm
From: Clifford Soderback <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Lightning strikes!!!
Date: Fri, 19 Jul 1996 21:52:20 -0700
Organization: AT&T WorldNet Services
Lines: 22
Message-ID: <[e-mail]>
References: <[e-mail]> <4skhvv$[e-mail]> <[e-mail]>
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Mime-Version: 1.0
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To: Cecil Moore <[e-mail]>

Cecil Moore wrote:
>
> [e-mail] wrote:
> > The ONLY way I've ever seen that is half way safe, is to do the job right,
> > starting with a through job of diversion to ground on your antennae,...
>
> Hi Mike, How about doing what I do. Disconnect the ladder-line from the
> banana plugs that lead into the house and toss the feedline 15 yards away
> from the house? Cheap, easy, effective and at least halfway safe. :-)
>
> 73, Cecil, W6RCA, OOTC  (not speaking for my employer)

 Cecil:
        Be sure to unplug your Rx & Tx from the AC line. The AC power
has a much higher chance of incurring a EMP pulse or a direct hit
than your antenna. I have had equipment destroyed several miles from
a hit by surges through the AC line. In one case it actually evaporated
the AC wire. I don't have much faith in the so called surge protectors,
but some offer a $25,000 insurance policy which might make the purchase
worthwhile in a high hit area.

                            Cliff, W7VVA


From [e-mail] Sun Jul 21 18:42:18 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!howland.reston.ans.net!vixen.cso.uiuc.edu!newsfeed.internetmci.com!hunter.premier.net!news-res.gsl.net!news.gsl.net!nntp.coast.net!zombie.ncsc.mil!newsgate.duke.edu!news-server.ncren.net!news.interpath.net!usenet
From: [e-mail] (Bob)
Newsgroups: rec.radio.amateur.antenna,rec.radio.shortwave
Subject: Re: Longwire grounding
Date: 17 Jul 1996 13:00:58 GMT
Organization: Interpath -- Providing Internet access to North Carolina
Lines: 21
Sender: -Not-Authenticated-[8753]
Message-ID: <4sio6a$[e-mail]>
References: <4sbckl$[e-mail]>
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Xref: news2.epix.net rec.radio.amateur.antenna:23259 rec.radio.shortwave:77254

Grounding made a *huge* difference in reducing noise on my longwire.
What I used was a standard 8' ground stake (available at local hardware
or home building supply stores) outside the window where the lead-in
wire comes into the house. I'm using a connector at the radio jack end
which has connectors for antenna and ground, so there are actually two
wires going through the window: one into the antenna, one out to the
ground.

I've read on the list that connecting a toroid to the ground stake and
feeding the antenna to it, then the grounded signal to the radio, may
give better performance, but haven't gotten to that yet.

I'm using a Sony 2010, so I disconnect when there is potential for
thunderstorms, etc, because of the potential for damage to the
front-end transistor.

Bob

You can't miss what you ain't got,
You can't lose what you ain't never had.
- Muddy Waters


From [e-mail] Sun Jul 21 18:42:19 1996
Newsgroups: rec.radio.amateur.antenna,rec.radio.shortwave
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-chi-13.sprintlink.net!nntp.coast.net!news.kei.com!newsfeed.internetmci.com!news.radio.org!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: Longwire grounding
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <4sbckl$[e-mail]>
Date: Wed, 17 Jul 1996 15:42:55 GMT
Lines: 34
Xref: news2.epix.net rec.radio.amateur.antenna:23260 rec.radio.shortwave:77258

In article <4sbckl$[e-mail]> Scott Ryan <[e-mail]> writ
es:
>I have a simple random longwire (approx. 80') & would like some ideas on
>correct grounding of this type of antenna.

In normal use, you don't want the antenna (RF) grounded at all. Of course
since it is unbalanced, you'll need to ground the radio (or the antenna
tuner if you're using one) in order to supply the counterpoise needed
to balance the system (though you can use a real counterpoise and avoid
an Earth connection completely).

>It's a Rat Shack kit & I'm using the insulated wire supplied as lead-in.
>I'm concerned about static discharge damaging my receiver.

Note that the insulation is just a convienence, it has nothing to do
with reducing static. Static buildup can be drained from the antenna
via a RF choke connected between the antenna and ground, or by a high
value resistor connected similarly. In either case, you want the
reactance (or resistance) to be at least 10x that of the radio input
at the RF frequency you're receiving so that the static drain won't
impact RF performance.

This is a separate issue from lightning protection. For lightning
protection, you need a *very* low impedance between the antenna
and Earth (at DC *and* at RF). Lightning is RF. Since that would
serve to short out normal signals, you need a device which won't
conduct at low voltages, but which conducts very well at higher
voltages. This is what a gas tube lightning suppressor does.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sun Jul 21 18:42:20 1996
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From: "Anthony R. Gold" <[e-mail]>
Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew
Subject: Re: Need INFO, EVERYONE PLEASE READ!!
Date: Fri, 19 Jul 96 13:25:45 GMT
Organization: Microvest Limited, New York
Lines: 20
Message-ID: <[e-mail]>
References: <4rgtmc$[e-mail]>
Reply-To: [e-mail]
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In <4rgtmc$[e-mail]> [e-mail] (RWC) wrote:

>       Well, I *was* looking into possibly starting a hobby out of HAM.
>But judging by these past 2 posts, one by Bill Newkirk WB9IVR, I see that
>the attitudes and childishness isn't lmited to the people on "CB" Radios.
>Perhaps HAM isn't for me after all, if Bill is any indication of the
>types of people that are out there.

If two whimsical comments by two individuals is sufficient to change
your mind about amateur radio as a hobby, I agree that you will
probably not be well suited to it.  Perhaps take up something like
stamp collecting, where you won't need to learn how to interact with
other human beings, even [horror!] those who don't agree with you.

Regards,
--
   Tony - G3SKR / AA2PM                  email: [e-mail]
                                                [e-mail]
                                        packet: g3skr@n0ary.#nocal.ca.usa.na


From [e-mail] Sun Jul 21 18:42:22 1996
Path: news2.epix.net!uunet!inXS.uu.net!info.htcomp.net!NewsWatcher!user
From: [e-mail] (W T Shaw)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need input on HF antenna idea
Date: 18 Jul 1996 05:40:18 GMT
Organization: Hometown Computing
Lines: 41
Message-ID: <wtshaw-1807960042470001@207.17.188.139>
References: <4se2s1$[e-mail]>
NNTP-Posting-Host: 207.17.188.139

In article <4se2s1$[e-mail]>, [e-mail] (David Genrich) wrote
:

> I am currently looking at a HF unit to add to my shack.  The problem is,
> I am in an apartment, making it diffuclt to put up a low band antenna.
>
> However, while out on my pouchh the other day I noticed the rain gutter
> comes down right at the edge of my pouch (I'm on the ground floor).
>
> Anyway, here is my idea:  Disconnected the raingutter from the ground,
> then load the gutter up through a matching transformer.  Would this
> work?  I'm also worried about how this RF energy would affect others.
> What if someone touchs it while transmitting (200 Watts)?  I figured
> that there was atleast 1000 feet of aluminum rain gutter going around
> the building (very conservitive figure).  Thus, with 200 Watts, there
> souldn't be that much RF at any one point that would harm anyone.  Maybe
> only transmit at night?  I'm also conserned on how it will affect other
> peoples TV and radio reception.
>
> So, will this idea work?  Any ideas, thoughts, or comments?
>
> David Genrich, KF6CZP
> [e-mail]

I take it that you do not own the apartment complex.  If that is the case,
consider the fact that connections between lengths of the gutter might be
poor, subject to arcing, little fires that can result in bigger fires, and
spark modulated signals are frowned upon, on the air and anyone with a
radio receiver near by.  Antennas can develop unusual patterns of voltage
and current, so you run the risk of that arcing with what you consider low
power.  Now, if you could fix the joints or you want to assume liability
for the results, that is another matter.

73's

Bill, k5pcw
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
[e-mail]   Mac Crypto Programs
 You should at least know how to use ROT13.
"Fhpprff vf n Wbhearl, Abg n Qrfgvangvba."
          http://www.htcomp.net/wts/
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/


From [e-mail] Sun Jul 21 18:42:23 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!netnews.nwnet.net!arclight.uoregon.edu!news.uoregon.edu!news.hawaii.edu!uhunix5!dholmes
From: Daniel J Holmes <[e-mail]>
Subject: Re: Need input on HF antenna idea
In-Reply-To: <4se2s1$[e-mail]>
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On Mon, 15 Jul 1996, David Genrich wrote:

> <snip>
> Anyway, here is my idea:  Disconnected the raingutter from the ground,
> then load the gutter up through a matching transformer.  Would this
> work?
Yes, it will work.
> I'm also worried about how this RF energy would affect others.
> <snip>
> Thus, with 200 Watts, there shouldn't be that much RF at any one point
> that would harm anyone.
Sorry David, Just because it is so long has nothing to do with it.  What
does matter is _where_ the voltage nodes occur.  This is where the current
is at a minimum, such as at the end of a conventional dipole or tip of a
1/4 wave vertical. As an example, I had a (foolish) broadcast engineer I
once worked with boast that he could grab the bottom of the nearly 400 ft.
AM broadcast tower and a grouned point with no harm. Technically he was
correct, but as the saying goes "thee are old engineers, bold engineers,
but no old bold engineers. I asked him to not do that when we worked
together. He wwanted to show that at the bottom (it was a 1/4 wave tower)
of the tower there should be high current, and nearly no voltage. The
reverse is true at the far end of this tower. There should be a maximum of
voltage and nearly no current.
This applies to you in that if you decide to load the gutter and down
spouts, thee will be points along it's length that will have high voltage
points: in other words you may endanger someone. remember that if some one
(fool) is reaching out the window with one foot in the john they may
conduct a fair amount of signal away from that rare DX you are trying so
desparately to call (are you screaming into the mike?) and through their
toes. Not a good idea. This is a hazard that many hams have taken over the
years and have found no problems. however you could be the first. . .
> only transmit at night?  I'm also conserned on how it will affect other
> peoples TV and radio reception.
Count on it: there _will_ be TVI.
> So, will this idea work?
BTW the voltages _probably_ would not be lethal, but do take care. Good
luck and good DXing
Aloha de NH6EU
Dan



From [e-mail] Sun Jul 21 18:42:23 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.primenet.com!news.cais.net!news.fc.net!news.infocom.net!usenet
From: GJ or DM Lundy <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: On glass mobile ant
Date: Sun, 14 Jul 1996 10:55:00 -0500
Organization: InfoCom Networks, Houston, Tx
Lines: 14
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References: <4s8eag$[e-mail]> <[e-mail]>
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Only problem with window or trunk mount is that you are placing
mechanical device, using compression screws to secure it, on either a
breakable window or on a nicely painted trunk deck edge.

I went the the other way, even at the cost of losing some gain, as I
don't like have anything clamping the body parts of my car (new camaro),
nor does it make a lot of sense to place an antenna on the edge of a
window where it can be used as a lever to make forced entry easier...
which has happend to a local acquaintence.

The db loss is not worth it, in my opinion.

Gordon
Houston,TX


From [e-mail] Sun Jul 21 18:42:24 1996
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.internetmci.com!news.sprintlink.net!news-stk-200.sprintlink.net!itnews.sc.intel.com!news
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: On glass mobile ant
Date: Thu, 18 Jul 1996 11:32:59 -0700
Organization: Intel Corp., Chandler, AZ
Lines: 7
Message-ID: <[e-mail]>
References: <4s8eag$[e-mail]> <4sbbb9$[e-mail]> <[e-mail]>
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Will Flor wrote:
> As with any glass mount, my personal max power limit is 15 watts,
> since I want to keep what's left of my hair as long as possible! :-)

Hi Will, If I go QRP, will my hair grow back?

73, Cecil, W6RCA, OOTC  (not speaking for my employer)


From [e-mail] Sun Jul 21 18:42:25 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.fibr.net!nntp.primenet.com!news.cais.net!hunter.premier.net!news.dra.com!news.starnet.net!thepit.trucom.com!usenet
From: [e-mail] (Marty Albert)
Newsgroups: rec.radio.amateur.antenna
Subject: Quad vs Ringo on Packet?
Date: Fri, 19 Jul 1996 18:11:17 GMT
Organization: TruCom Internet Services
Lines: 46
Message-ID: <4soj5n$[e-mail]>
NNTP-Posting-Host: dialup4.trucom.com
X-Newsreader: Forte Free Agent 1.0.82


Hello, Folks:

I have a question about a strange problem (?) I am having with a 2m
packet link that seems to be antenna related...

Set Up #1 is as follows:

   RIG     : Kenwood TM 2550A with 50 watts RF out
   ANT     : Ringo Ranger II at 40 feet
   FEEDER  : 60 feet 9913

Set Up #2 is as follows:

   RIG     : Kenwood TM 2550A with 50 watts RF out (same rig as above)
   ANT     : Home Brew 6 element quad at 50 feet
   FEEDER  : 60 feet 9913 (different run)

The other station's set up does not change.

Now, the wierd part...

When using the Ringo, there is no detectable change at the other
station in my signal when I switch between Voice and Packet modes as
measured on the receiver.

When I switch to the Quad, however, my received signal strength on
Packet is just a hair over one half of the signal when on voice. In
fact, the Quad's packet signal is LESS than the Ringo's packet signal
while the Quad's voice signal is much stronger than the Ringo's!

Any ideas?

Take Care & 73


Marty Albert - [e-mail]
Amateur Radio: KC6UFM@KC6UFM.#SEMO.MO.USA.NOAM

Heartland Internet Services

*****************************************************
Web Page Designers... Need extra cash?
http://www.adgrafix.com/info/calbertjr/sales.html
*****************************************************



From [e-mail] Sun Jul 21 18:42:26 1996
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: R7000 SWR problem
Date: Thu, 18 Jul 1996 10:25:21 UNDEFINED
Organization: Business & Financial Services
Lines: 31
Message-ID: <[e-mail]>
NNTP-Posting-Host: 129.89.26.195
X-Newsreader: Trumpet for Windows [Version 1.0 Rev B]

I have an r7000 mount about three foot off my roof. When first
installed it seemed to work fine. A few weeks ago I acquired a vintage
PA. A tempo 2000. What a great piece of equipment. Anyway, when I
fired up the amp it needed tuning . At first it was putting out around 3k
on peeks but a little tuning later got it down to 1.5k. After all was said
and done I noticed my SWR on 20 meters was really high. Oh, I must
add I never tuned the antenna as it seemed fine on CW(never
checked the swr on ssb). I decided I should tune the r7000. I went up
on the roof took down the antenna and laid it on the roof. I then tried to
tune it. Well no way! I could not get the swr down any way it was
adjusted. I took the antenna off the roof and tried tuning it in the back
yard. I had it lying horizontal again and again it would not tune. Next I
contacted cushcraft, who was very helpful. They thought I may have
ruined a trap when I ran all that power though it. To that end they sent
me new traps. I put the new traps on and tried to tune it again in the
backyard. Again no good. I called cushcraft back and was told I could
not tune it while it was lying on the ground. The ground was acting
like part of the antenna. Makes sense. But what about on my roof?
Why should I have the same problem on the roof. It's just an asphalt
roof. No metall anywhere. No ground close by. What I am asking is do
I have to raise my antenna more than three feet above my roof to get
the SWR down? I cannot see what difference it should make. Why did
it work fine an CW when I first put it up? This is very confusing. I want
to get this right. I am inclined to get a ten foot piece of mast and put it
up ten foot above the roof top. But will this be worth doing? Any
comments will be greatly appreciated.

P.S. I do not think I did any damage to those traps in the first place.
And I checked all my equipment with dummy loads and it works
perfect. Coax perfect! This is nuts! Thanks.



From [e-mail] Sun Jul 21 18:42:30 1996
Path: news2.epix.net!uunet!inXS.uu.net!spool.mu.edu!munnari.OZ.AU!harbinger.cc.monash.edu.au!nntp.coast.net!news.sprintlink.net!news-stk-200.sprintlink.net!newsfeed.internetmci.com!news.campus.mci.net!news.uky.edu!usenet
From: [e-mail] (Walter R Francis)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: R7000 SWR problem
Date: 19 Jul 96 02:42:48 -500
Organization: The hand that uses the Amiga is the hand that rules the world.
Lines: 30
Message-ID: <[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]
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X-Newsreader: THOR 2.31 (Amiga;TCP/IP) *UNREGISTERED*


On 18-Jul-96 05:25:21, pff articulated:

[Stuff deleted..]

>P.S. I do not think I did any damage to those traps in the first place.
>And I checked all my equipment with dummy loads and it works
>perfect. Coax perfect! This is nuts! Thanks.

Running 3k through an antenna designed for 1.5k max, and you don't think you
did any damage to the traps??  That's double the power!

Anything near an antenna is going to detune it.  Now the fact you were having
problems only on 20m seems to say to me that something is put together
backwards or something is wrong.  Check the direction of the 20m trap, I don't
know how the R7000 is set up, but I've heard of R7 traps being in backwards.

Can you stand the antenna up in the back yard (vertical) so it's easier to get
it tuned without bringing it up and down on the roof?

Good luck..  Might have been easier to go with a 20m dipole which would work
better anyway.. :)

--
 -.-. --.- -.-. --.- -.-. --.- -.-. --.- -.-. --.- -.-. --.- -.-. --.- -.. .
 .  Walter Francis                                               _. KT4LH  .
 -         HP48GX  Alinco DJ580  Icom 281  Kenwood 530S         o:o        -
 .  [e-mail]                                   Life begins on 80  .
 --... ...-- --... ...-- --... ...-- --... ...-- --... ...-- --... ...--  ..



From [e-mail] Sun Jul 21 18:42:31 1996
Path: news2.epix.net!uunet!inXS.uu.net!scnews.sc.intel.com!itnews.sc.intel.com!news
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Remote house auto-tuner?
Date: 15 Jul 1996 14:37:37 GMT
Organization: Intel Corporation, Chandler, AZ
Lines: 14
Message-ID: <4sdl3h$[e-mail]>
References: <4s93vn$[e-mail]> <4sd9cd$[e-mail]>
NNTP-Posting-Host: cmoore.ch.intel.com
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X-Mailer: Mozilla 1.1N (Windows; I; 16bit)

[e-mail] (MREISING) wrote:
>SGC makes an autotuner which will do what you want.  It will match random
>wires and mobile antennas over 8 feet long to frequencies from 1.8 to 30
>MHz.

Hi Mark, I have one that I use for mobile. It is an unbalanced unit
requiring a ground reference which is not trivial to obtain at the
top of a pole. If you connect the ground side of the SGC230 to a
vertical's ground plane, it will work beautifully. However, what do you
connect the ground to with an end-fed long wire 40 ft off the ground?

73, Cecil, W6RCA, OOTC  (not speaking for my employer)




From [e-mail] Sun Jul 21 18:42:32 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!in2.uu.net!news3.agis.net!agis!NEWS!not-for-mail
From: Bob Lewis <[e-mail]>
Subject: Re: Remote house auto-tuner?
Message-ID: <[e-mail]>
Date: Tue, 16 Jul 1996 07:54:56 -0400
References: <4s93vn$[e-mail]> <4sd9cd$[e-mail]>
Organization: AA4PB
X-Mailer: Mozilla 2.01 (Win95; U)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 23

MREISING wrote:
>
> SGC makes an autotuner which will do what you want.  It will match random
> wires and mobile antennas over 8 feet long to frequencies from 1.8 to 30
> MHz.  This tuner requires no input from the radio other than RF and it
> operates on 12 volts.  The standard version handles 150 watts and costs
> approximately $450 to $500.  A high power, 500 watt version is available
> for more money.  I have been using one for mobile and fixed operation for
> over 3 years with excellent results.
>
> 73 de Mark, WB9BVV

I also use an SG-230 at the house.  Tuner is mounted at the base of the
tower, grounded to the tower, and feeds an inverted-L 35 foot verticle
and about 85 foot horizontal.  Works great all bands including 160
meters.  Power and a "tune" indicator line come back to the shack along
with a coaxial cable.  The "tune" indicator is a simple LED that lights
when the tuner is properly tuned up.

I had one failure of an IC and SGC fixed that for free even though the
unit was 6 months out of warrenty.  Great service!

73, Bob



From [e-mail] Sun Jul 21 18:42:33 1996
Path: news2.epix.net!uunet!inXS.uu.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-pen-4.sprintlink.net!cs.utexas.edu!math.ohio-state.edu!pacific.mps.ohio-state.edu!freenet.columbus.oh.us!not-for-mail
From: [e-mail] (John Chapman)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Request info on lineing up C band dish
Date: 16 Jul 1996 10:27:25 -0400
Organization: The Greater Columbus FreeNet
Lines: 20
Message-ID: <4sg8sd$[e-mail]>
References: <01bb70dc.06ee09c0$[e-mail]>
NNTP-Posting-Host: login.freenet.columbus.oh.us
X-Newsreader: TIN [version 1.2 PL2]

[e-mail] ([e-mail]) wrote:
: I am trying to help a freind set up a 10 ft. C band TVRO dish witch is
: already "in the ground"
: vertical and attached. i'm not sure how to arrive at the angle of
: inclanation and am building
: an inclanometer useing a protractor and plum bob. I would appreciate
: learning any tricks
: about this process. Thanks VE3 XPO Peter Owens  [e-mail]

I know that there are several books out on the subject, you might check
your local library, they will give several good suggestions and
techniques. Also, the best group to ask this on is
rec.video.sattelite.tvro, they will probably give you a number of good
suggestions. Good luck!
73,
--
*-*-*-*-*-*-*-*-*-*-*-*-*-*-
John Chapman    WB8INY
Ohio Section ARES, District Emergency Coordinator, District 7
http://ourworld.compuserve.com/homepages/wb8iny     (try it, you'll like it)


From [e-mail] Sun Jul 21 18:42:34 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.internetmci.com!csn!nntp-xfer-1.csn.net!csn!nntp-xfer-2.csn.net!stortek!tatro
From: [e-mail] (Patrick Tatro)
Subject: Re: RFI/Touch Lamps
Message-ID: <4soh7n$[e-mail]>
Sender: [e-mail]
Organization: Storage Technology Corporation
X-Newsreader: News Xpress Version 1.0 Beta #3
References: <[e-mail]>
Date: Fri, 19 Jul 1996 17:39:03 GMT
Lines: 32

In article <[e-mail]>,
   Mike Reublin <[e-mail]> wrote:

>I've got a couple of touch controlled lamps. A 40
meter signal turns 'em
>off and on. The books say this can be cured by
putting an inductor and
>resistor (in series) in series with "the active
lead to the device". Any
>hints on how to identify this lead? My lamps
contain in the shell a
>potted module with one wire connected to the
shell, and two more going
>up into the socket.
>Thanks,
>Mike NF4L
Mike
  Isn't it funny when you as a question and get
a bunch of advice but no answers. I use to hammer
my touch lights with CW. The "Active" line I
believe is the one that attaches to the lamp
frame(ie. the touch part).

  I fixed my light show by putting a resistor in
series with the active line and wrapping the cord
in a ferrite doughnut. I hot glued the doughnut
inside the base of the lamp and fixed the RFI.
BTW I think it also fixed the RFI from the lamp as
well.

Good Luck
73's Pat N0WCG


From [e-mail] Sun Jul 21 18:42:35 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!newsxfer2.itd.umich.edu!netnews.worldnet.att.net!newsadm
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: RG213 vs. 9913 - VS 8C-3V - vs LMR
Date: 17 Jul 1996 14:06:55 GMT
Organization: AT&T WorldNet Services
Lines: 14
Message-ID: <4sis1v$[e-mail]>
References: <4s8ft2$[e-mail]> <[e-mail]> <[e-mail]> <4shtn9$[e-mail]> <[e-mail]>
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Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.22ATT (Windows; U; 16bit)

Mike Murphree <[e-mail]> wrote:
>It's definitely *NOT* ethernet cable. Construction is very
>similar to hardline except for the outer conductor and more
>flexible than hardline. The Aug issue of QST has an ad for
>it on page 173.

But Mike, Joe said he had a piece of unknown cable, described
it, and asked what it might be. How can you know it is LMR
cable based on Joe's description? He didn't even say it was
black.

73, Cecil, W6RCA, OOTC




From [e-mail] Sun Jul 21 18:42:36 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!csn!nntp-xfer-1.csn.net!csn!nntp-xfer-2.csn.net!symbios.com!kthompso.wichitaks.ncr.com!ken.thompson
From: [e-mail] (ken.thompson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: RG213 vs. 9913 cable
Date: Thu, 18 Jul 1996 08:49:38
Organization: Symbios Logic
Lines: 8
Message-ID: <[e-mail]>
References: <4s8ft2$[e-mail]> <[e-mail]>
NNTP-Posting-Host: kthompso.wichitaks.ncr.com
X-Newsreader: Trumpet for Windows [Version 1.0 Rev A]

 used
>to simulate a garden hose, but 9913 can. The air center of 9913
>can (and Murpy sez WILL) fill up with water.

I have used 9913 for eight years in Kansas and never had a problem with water
in it.  Must have properly installed it. :-)

What is the significance of "non-contaminating" cable?


From [e-mail] Sun Jul 21 18:42:37 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!nntp.primenet.com!news.cais.net!world1.bawave.com!newsfeed.internetmci.com!mr.net!newshub.tc.umn.edu!skypoint.com!usenet
From: [e-mail] (pdunn)
Newsgroups: rec.radio.amateur.antenna
Subject: SGC Smartuner Experience???
Date: 16 Jul 1996 01:28:57 GMT
Organization: org
Lines: 6
Message-ID: <4ser8p$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: dial092.skypoint.net
X-Newsreader: WinVN 0.92.6+

Anyone have experience with SGC Smartuners in a fixed situation? Vertical
 vs Horiz vs Inv V vs Endfed random?

TIA

Phil ki0dm


From [e-mail] Sun Jul 21 18:42:40 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Under-water Beverage
Date: 18 Jul 1996 07:34:18 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 31
Sender: [e-mail]
Message-ID: <4sl7fq$[e-mail]>
References: <[e-mail]>
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In article <[e-mail]>, "Ian White, G3SEK"
<[e-mail]> writes:

>
>Real-world antenna engineering work with NEC or MININEC is impossible
>without a 'shell' to help with the input and output: a simple language
>for describing the antenna, a graphics view to be sure you've 'drawn'
>the antenna correctly, option menus for choosing the type of analysis
>required, and graphics output of radiation patterns, antenna currents,
>frequency-swept VSWR etc.
>
>That's exactly what K6STI and W7EL are selling - not the original
>antenna analysis engines, but the enhancements that make NEC and MININEC
>usable.
>
>

While those programs are all very good, they do have practical
limitations.

Never take any model as an absolute answer without verification. This is
especially true when the model is something as complex as an underwater
antenna, or even an antenna close to real earth.

Even NEC-4 appears to need further verification when low horizontal wires
are modeled.

The current in my 500 foot Beverage eight feet above ground measures quite
different than NEC predicts, so the predicted pattern must also be wrong.

73 Tom


From [e-mail] Sun Jul 21 18:42:41 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-fw-6.sprintlink.net!tezcat.com!imci5!pull-feed.internetmci.com!news.internetMCI.com!newsfeed.internetmci.com!malgudi.oar.net!usenet
From: Paul Knight <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: VHF/UHF Beam Spacing Question
Date: Tue, 16 Jul 1996 11:17:35 -0700
Organization: Eaton Corp., Appliance Controls
Lines: 19
Message-ID: <[e-mail]>
NNTP-Posting-Host: firewall.etn.com
Mime-Version: 1.0
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I've just finished constructing a 3-ele 2M beam, and a 4-ele
440 MHz beam.  I plan to mount them in a vertically-polarized
fashion, stacked sideways (in a sense) so that they can share
a common rotor.  They will, of course, be fed with separate feedlines.
I cannot find any info on the appropriate spacing between the two
antennas to minimize interaction.  My gut tells me 1 lambda at 2M
should be enough (~6').

Any ideas?

--
Thanks!

Paul Knight WD8DKY
[e-mail]

-or-

[e-mail]


From [e-mail] Sun Jul 21 18:42:42 1996
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.internetmci.com!newshub.csu.net!newsserver.sdsc.edu!news.cerf.net!gde.GDEsystems.COM!gde.GDEsystems.COM!not-for-mail
From: [e-mail] (JT McBride)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What do you call this antenna design?
Date: 17 Jul 1996 17:35:58 -0700
Organization: GDESystems Inc.
Lines: 9
Message-ID: <4sk0te$[e-mail]>
References: <4sghaq$[e-mail]> <4sij4e$[e-mail]>
NNTP-Posting-Host: gde

I suspect it does act much like a J-pole, but does this arrangement have
a name? Is it made commercially, or custom?

Jim

--
 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
"The real voyage of discovery consists not in seeking new landscapes,
but in having new eyes."  -- Proust


From [e-mail] Sun Jul 21 18:42:43 1996
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From: Avatar <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: What's a Beverage Antenna
Date: Tue, 16 Jul 1996 20:30:01 -0700
Organization: Front Range Internet, Inc.
Lines: 53
Message-ID: <[e-mail]>
References: <4sdnas$[e-mail]> <[e-mail]>
NNTP-Posting-Host: ftc-60.ppp.frii.com
Mime-Version: 1.0
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[e-mail] wrote:
>
> In Article<4sdnas$[e-mail]>, <[e-mail]
.domain> write:
> > Path: news1.mnsinc.com!news.sprintlink.net!news-dc-2.sprintlink.net!news.i
nc.net!newspump.sol.net!spool.mu.edu!howland.reston.ans.net!newsserver.jvnc.ne
t!new
> > From: [e-mail] (Dale Chidester)
> > Newsgroups: rec.radio.amateur.antenna
> > Subject: What's a Beverage Antenna
> > Date: 15 Jul 1996 15:15:40 GMT
> > Organization: American Cyanamid Company
> > Lines: 18
> > Message-ID: <4sdnas$[e-mail]>
> > Reply-To: [e-mail]
> > NNTP-Posting-Host: 141.173.56.12
> >
> > I keep seeing references to Beverage Antennas, but have no idea what one i
s.  Could someone
> > explain?  I vaguely remember from the late 50's and early 60's a beverage
antenna that was made
> > from soldering beer cans together... they were then made of steel, not alu
minium... but I can't
> > imagine that's the meaning today.  That's the same time period that a bott
le of beer was known as
> > an 807.
> >       73 and tnx,
> >                       Dale
> >
> >
> > ------------------------------------------------------------------------>
> Dale H. Chidester, PhD           N3HAL      "Against stupidity, even the
> > Cyanamid Agricultural Research Center        Gods in vain doth contend."
> > Process Development Facility                                    Schiller
> > PO Box 400,  Clarksville Rd.           Phone: [phone]
> > Princeton, NJ  08543-0400              Email: [e-mail]
> > ------------------------------------------------------------------------>
>
> >
> There's a couple of articles on my home page that may help.
> http://www.moonstar.com/~wa4pgm/
> 73 Kyle

The Beverage antenna can be one wire, but most often two wires similar to
open wire feeders, one or more wavelengths long running close to the
ground (typically 6'). This antenna is used at low frequencies, typically
160M and lower. It is somewhat directional depending on the length. It
usually has a tuning network at each end (there may be more than two) and
one end is coupled to the radio. It's claim to fame is that it picks up a
lot less electrical noise than other antenna configurations. Beyond that
description you'll have to do some research and definitive information is
hard to find.

BTW: I recall both a beer can balun and a vertical made out of cans
soldered together in articles printed many years ago! I wonder if the
vertical was still up by the time the article was printed.


Dave
W0MAY




From [e-mail] Sat Jul 27 19:14:02 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!swrinde!ihnp4.ucsd.edu!news1.ucsd.edu!news-mail-gateway
From: [e-mail] (David Yanke)
Newsgroups: rec.radio.amateur.antenna
Subject: (no subject)
Date: 24 Jul 96 14:25:57 GMT
Organization: ucsd usenet gateway
Lines: 1
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

add ham-ant


From [e-mail] Sat Jul 27 19:14:03 1996
Path: news2.epix.net!uunet!in3.uu.net!newsfeed.internetmci.com!swrinde!ihnp4.ucsd.edu!news1.ucsd.edu!news-mail-gateway
From: /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/@safe.ia.GOV
Newsgroups: rec.radio.amateur.antenna
Subject: (none)
Date: 25 Jul 96 14:29:19 GMT
Organization: ucsd usenet gateway
Lines: 27
Message-ID: <[e-mail]>
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

>From /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/ Thu Jul 25 0
9:30:09 CDT 1996 remote from osiint.safe.ia.gov
Date: 25 Jul 1996 09:29:11 -0500
X400-Trace: US*ATTMAIL*IADPS
        arrival 25 Jul 1996 09:29:11 -0500
        action Relayed
From: /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/@osiint.safe.
ia.gov
To: "/RFC-822=Ham-Ant(a)ucsd.edu/OU=OSI-INTERNET/O=WALLACE/PRMD=IADPS/ADMD=ATT
MAIL/C=US/"@osiint.safe.ia.gov
In-Reply-To: <"\"/RFC-822=199607230047.RAA07875(a)mail.ucsd.edu/OU=OSI-INTERNE
T/O=WALLACE/PRMD=IADPS/ADMD=ATTMAIL/C=US/\""@osiint.safe.ia.gov>
Subject: Mor Gain coax
Importance: normal
Autoforwarded: FALSE
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tmail/C=us/@osiint.safe.ia.gov>
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Received: from osiint.safe.ia.gov by iadpshub.safe.ia.gov; Thu, 25 Jul 1996 09
:30 CDT
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Hello all.  I have a More Gain multiband dipole I'm going to put up.  I
notice it takes coax to feed it.  Can I use 75ohm RG-59 for that job?

Scott N0XZY
[e-mail]
[e-mail]



From [e-mail] Sat Jul 27 19:14:04 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-pen-4.sprintlink.net!news.sprintlink.net!news-pen-14.sprintlink.net!news.texas.net!news.kei.com!newsfeed.internetmci.com!uwm.edu!math.ohio-state.edu!magnus.acs.ohio-state.edu!lerc.nasa.gov!purdue!ames!waikato!newsource.ihug.co.nz!usenet
From: [e-mail] (Kevin Mitchell)
Newsgroups: rec.radio.amateur.antenna
Subject: 10 meters Repeater Antennas wanted
Date: Mon, 22 Jul 1996 05:34:09 GMT
Organization: The Internet Group
Lines: 27
Message-ID: <4sv6n4$[e-mail]>
NNTP-Posting-Host: port35.akl.ihug.co.nz
X-Newsreader: Forte Free Agent 1.0.82


Hi Everyone,

My repeater group is about to build a 10 meter repeater system for the
Auckland area in New Zealand.

What I would like to know is, does anyone have any information on
antennas suitable for a repeater. In my case, I need one for our RX
and one for out TX sites.

Is there comapnies that build good gain antennas for our use.

We will be operating on 29.640MHz -100Kcs.

Thanks in advance for any information.


Kevin Mitchell  ZL1UDD
South Auckland Repeater Group (S.A.R.G)


E-mail: [e-mail]
Packet: ZL1UDD@ZL1AB.#11.NZL.OC
:Amateur Radio helped Pioneer
 the way the World Communicates
 Today.:



From [e-mail] Sat Jul 27 19:14:04 1996
Path: news2.epix.net!uunet!in3.uu.net!newsfeed.internetmci.com!uwm.edu!math.ohio-state.edu!jussieu.fr!rain.fr!news.sprintlink.net!news-dc-9.sprintlink.net!news.sprintnw.com!usenet
From: Tim Robertson KC7QOM <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 10-meter Mobile Antenna?
Date: Wed, 24 Jul 1996 12:15:58 -0700
Organization: A.C.S.
Lines: 8
Message-ID: <[e-mail]>
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Hello to All,
 I am going to install an Icom 730 mobile in my pickup. Would like input
on which antenna to get. Will be primarily working 10-meter so that is
the priority but am considering multiband also. Will be running barefoot
in a Ford extended cab. Prefer not to cut any holes.
 Thanks in advance for your time and input.
73
Tim,KC7QOM


From [e-mail] Sat Jul 27 19:14:05 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!news.inc.net!imci5!pull-feed.internetmci.com!news.internetMCI.com!newsfeed.internetmci.com!news.kei.com!news-in.tiac.net!news-old.tiac.net!usenet
From: adamkern <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 160 meter "inverted L"
Date: 23 Jul 1996 17:53:52 GMT
Organization: The Internet Access Company
Lines: 8
Message-ID: <4t33jg$[e-mail]>
NNTP-Posting-Host: adamkern.tiac.net
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I'm also trying to put up a 160 meter "inverted L".  Can anyone help me
with the design, and with tips on installation.

73,
Adam Kern
N1TYF
[e-mail]



From [e-mail] Sat Jul 27 19:14:06 1996
Path: news2.epix.net!uunet!in3.uu.net!newsxfer2.itd.umich.edu!netnews.worldnet.att.net!newsadm
From: Merv Stump <[e-mail]@postoffice.worldnet.att.net>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 160 meter "inverted L"
Date: 23 Jul 1996 18:57:03 GMT
Organization: AT&T WorldNet Services
Lines: 37
Message-ID: <4t379v$[e-mail]>
References: <4t33jg$[e-mail]>
NNTP-Posting-Host: 51.middletown-61.va.dial-access.att.net
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To: [e-mail]

Adam, in the early 80's Coleman Rowland, W4TWW published an excellent
article in CQ on the Coaxial Inverted L For 160 meters.  I have built the
antenna and found it to be excellent.  In theory the antenna is 1/4 wave
long and is made of a 50 ohm coax section and a 300 ohm twin lead section.
 The coax section is an electrical quarter wave (246/FMHz times the
velocity factor) and the 300 ohm twin lead makes up the rest of the
quarter wave.

In reality through trial and error Coleman, found that the total length of
the antenna should be 230/FMHz; and the coax section should be 162.5/FMHz.
For 1.850 MHz this works out to 88 feet for the coax and 37 feet for the
twin lead for a total length of 125 feet.

Short the center conductor to the shield of the coax, and connect this to
the twin lead.  The twin lead is shorted at this connection point and also
shorted at the opposite end.

Feed it at the other end of the coax, using 50 ohm coax from your rig and
connect the center conductor of the coax from your rig to the shield of
the coax making the antenna; and the shield of the coax from the rig to
the center conductor of the coax making the antenna.  The center conductor
of the antenna coax goes to ground with as many radials as possible.

Mount it as vertical as possible and pull the rest out as horizontal as
possible.  If you can go up 88 feet it's good to get the entire coaxial
section vertical, but if you can't it will still work well.

The antenna is very broad and will be useable across the entire 160 meter
band without a tuner.  However, it is still fundamentally a vertical so
you need as many radials as you can possibly get.

I later made a change to W4TWW's design which I would recommend.  I simply
replaced the 300 ohm twin lead with another piece of 50 ohm coax.  It's
much stronger and I saw no difference electrically.

Good luck, Merv



From [e-mail] Sat Jul 27 19:14:07 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news1.inlink.com!news.starnet.net!spool.mu.edu!howland.reston.ans.net!ixnews1.ix.netcom.com!netcom.com!dgf
From: [e-mail] (David Feldman)
Subject: Re: 160/75M mobile ant: how good is counterpoise?
Message-ID: <[e-mail]>
Organization: Organization? Me?
References: <4spjrl$[e-mail]> <4t06ce$[e-mail]>
Date: Mon, 22 Jul 1996 15:40:47 GMT
Lines: 26
Sender: [e-mail]

In article <4t06ce$[e-mail]> [e-mail] (W8JI  Tom) writ
es:
>[e-mail] (David Feldman)
>writes:
>
>>For lower bands, at what point does the body of the car/truck serving as
>>counterpoise become a limiting factor? It seems as the area of the
>vehicle
>>is reduced, there would be a corresponding reduction in efficiency as
>there
>>would be less area carrying differential voltage/current relative to the
>>antenna element itself. Can this be modeled?
>
>I've actually measured F-150 and F-250 trucks here. On 75 meters (~3.8
>MHz), the F150 looked like ~8+ ohms in series with about 700 pF. On 160 it
>was almost 20 ohms R!
>
>The F250 is about two feet longer, and presented just under 8 ohms
>resistance on 75 meters.
>
>Measrements were made over 4 mS/m soil.

Thanks for the interesting observations. That is a helpful way of looking
at the problem. I think in the end it is as important to model the vehicle
body as it is the antenna itself...

73 Dave WB0GAZ [e-mail]


From [e-mail] Sat Jul 27 19:14:08 1996
Path: news2.epix.net!uunet!in2.uu.net!ott.istar!istar.net!news.nstn.ca!newsflash.concordia.ca!newsfeed.pitt.edu!godot.cc.duq.edu!newsgate.duke.edu!zombie.ncsc.mil!linden.fortnet.org!coopnews.coop.net!frii.com!usenet
From: Avatar <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 18 ga random ok?
Date: Sun, 21 Jul 1996 08:43:03 -0700
Organization: Front Range Internet, Inc.
Lines: 12
Message-ID: <[e-mail]>
References: <4ss85t$[e-mail]>
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pdunn wrote:
>
> Is there any reason why I can't use 18 gauge bare stranded copper for a
> random length antenna at 100 watts?
>
> tia
>
>  phil ki0dmNo problem. The only possible problem is some scratching noise in
 recieve
due to flexing of strands rubbing against each other in a wind.

W0MAY



From [e-mail] Sat Jul 27 19:14:09 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-ana-24.sprintlink.net!newsfeed.internetmci.com!howland.reston.ans.net!newsxfer.itd.umich.edu!news2.acs.oakland.edu!newsfeed.concentric.net!news-master!news
From: "Jack R. Brown" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 2m/440 retractable mobile antenna
Date: Mon, 22 Jul 1996 12:54:47 -0400
Organization: Concentric Internet Services
Lines: 6
Message-ID: <[e-mail]>
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Has anyone made a 2m/440 mobile antenna that is retractable? Glass mount
won't load up on my car, magnetic mounts ruin the paint, drilling holes
in the body is out (I live in Michigan-Rust City!), trunk lip mounts
obscure visability, side window mounts bug the other passengers.  If you
have any experience with retractable HAM antennas, please drop me a note
email [e-mail].  Thanks


From [e-mail] Sat Jul 27 19:14:10 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!news.infi.net!imci5!pull-feed.internetmci.com!news.internetMCI.com!newsfeed.internetmci.com!swrinde!cs.utexas.edu!news.ti.com!news.dseg.ti.com!s1236096
From: [e-mail] (Dr. Brendon Holt)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2mtr beam wanted
Date: Tue, 23 Jul 96 13:38:30 GMT
Organization: TI
Lines: 15
Message-ID: <4t2kre$[e-mail]>
References: <4stjtj$[e-mail]>
NNTP-Posting-Host: a0194291c.dseg.ti.com
X-Newsreader: News Xpress 2.0 Beta #0

In article <4stjtj$[e-mail]>, [e-mail] wrote:
>hello I am looking for 2meter beam ant..something the neighbors wont
>notice right away...Would considerer GROVE BEAM..jey I can tell them
>its a TV ant..pls email me at [e-mail] or here at the
>newsgroup    thanks jim
>

Jim,
I tried sending an e-mail to [e-mail] but it bounced.  Give me
your e-mail and I'll send you a plan for a ground plain that works very well.
I am using it on a 1.5-2 W HT to talk to repeaters > 20 miles away.

Regards,
Brendon Holt ([e-mail])
KC5VCW


From [e-mail] Sat Jul 27 19:14:11 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!news.radio.org!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: 30m rotatable dipole on a budget?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <4soj5n$[e-mail]> <[e-mail]>
Date: Sat, 20 Jul 1996 18:34:32 GMT
Lines: 38

In article <[e-mail]> Mike Swaney <[e-mail]
om.net> writes:
>I have some room above a tri-bander at abt 35'.  Since the wire antenna
>is trapped for 40-80-160, I am considering putting a 30m rotatable
>dipole above the tri-bander.  Has anybody else tried putting back-to-back
>fiberglass mobile antennae up for rotatable dipoles and are they a good
>alternative to a full sized monoband wire at the same elevation?

I tried a couple of Hustlers that way once. It sort of worked, but
not as well as a full sized wire. It should be obvious why that's so.
The real question, of course, is whether the advantage of being able
to rotate the antenna broadside to the signal is greater than the
loss incurred by using the shortened dipole. My experience was that
it wasn't.

The notch when the dipole is exactly end on to the signal is fairly
pronounced, but it is so narrow that for signals even slightly off
that line the losses of the shortened dipole overwhelmed the pointing
gain. Just orient the ends of your fixed dipole in directions you don't
care about and it'll do a better overall job.

From what I've read, these shortened whips are only about 10% efficient,
but a full size wire dipole is 90% efficient or better. So you can
see that you have a fairly large deficit to overcome. (Note, I wasn't
set up to confirm that with AB comparisons, and 9.5 db often isn't
that big a deal on HF, but its probably about right, and certainly
a bigger difference than you'll see by being able to orient the dipole
broadside to the signal.)

The only real advantage I see is in being able to put the end on
null toward an interfering station, but 30m usually isn't that
crowded.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Jul 27 19:14:12 1996
Path: news2.epix.net!uunet!inXS.uu.net!tank.news.pipex.net!pipex!oleane!jussieu.fr!math.ohio-state.edu!howland.reston.ans.net!newsfeed.internetmci.com!in2.uu.net!news.ner.bbnplanet.net!cam-news-feed6.bbnplanet.com!news.ipass.net!news
From: [e-mail] (George McCrary)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 30m rotatable dipole on a budget?
Date: Sun, 21 Jul 1996 04:45:31 GMT
Organization: IPass.net
Lines: 16
Message-ID: <[e-mail]>
References: <4soj5n$[e-mail]> <[e-mail]> <[e-mail]>
NNTP-Posting-Host: customs127.ipass.net
X-Newsreader: Forte Agent .99e/32.227

        How's this for budget. Doug (KF4KL) had an old 40M beam given
to him. It was so flimsy he felt it was a bad idea to put it up. After
it laid in the weeds for a couple of years he got the idea of making
a rotatable dipole out of one element. It's fed with balanced feed
line and used with a tuner. It is great on 30, 17 and 12M where he
didn't have a rotatable antenna.

        To top it off, he gave me the other element, I've had it up
for about 2 months, and it's great! The mount that held the element to
the boom holds the dipole to the mast. On my tower it's about 5 feet
above a tribander which is at 40 feet. We have the dipole 90 off the
beam which seems to keep interaction to a minimum. But, you have to
remember to turn 90 degrees off what you want to work.


                                73 DE KQ4QM (George)


From [e-mail] Sat Jul 27 19:14:13 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!news.inc.net!imci5!pull-feed.internetmci.com!news.internetMCI.com!newsfeed.internetmci.com!news.kei.com!news-in.tiac.net!news-old.tiac.net!usenet
From: adamkern <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 40 meter wire beam
Date: 23 Jul 1996 17:52:23 GMT
Organization: The Internet Access Company
Lines: 12
Message-ID: <4t33gn$[e-mail]>
NNTP-Posting-Host: adamkern.tiac.net
Mime-Version: 1.0
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Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.22 (Windows; I; 16bit)

I'm thinking about putting up a 40 meter "inverted v" wire beam,
consisting of a rope as a boom, and then three inverted v wires off the
rope boom.  Can anyone tell me what lengths to cut the wires, and at what
length should I space them along the rope?

Also, any hints on installation are welcome!

73,
Adam Kern
N1TYF
[e-mail]



From [e-mail] Sat Jul 27 19:14:14 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!nntp.primenet.com!newsfeeder.sdsu.edu!news.sgi.com!swrinde!howland.reston.ans.net!newsxfer.itd.umich.edu!aanews.merit.net!ns1.autonet.net!C1098-122
From: [e-mail] (Cyber Millionair)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.policy
Subject: A New " America Online"......$19.96\month Unlimited access!!!
Date: Thu, 25 Jul 96 08:06:56 GMT
Organization: CyberTraders
Lines: 10
Distribution: world
Message-ID: <4t8r1q$[e-mail]>
NNTP-Posting-Host: c1098-122.dialup.autonet.net
X-Newsreader: News Xpress Version 1.0 Beta #2.1
Xref: news2.epix.net rec.radio.amateur.antenna:23402 rec.radio.amateur.digital.misc:16594 rec.radio.amateur.equipment:31317 rec.radio.amateur.policy:35657

Access our network NOW!!!
FREE Windows  Software!! Complete Easy System.!! Automatic Update!!
Full UNLIMITED Internet Access for $19.96 ,Chat, Forums, Classified ,Usenet
Business forums , Family forums,Online games!! and more!!
BETTER THAN  Prodigy , ComuServe and America Online!!

For more Info: Log on my BBS [phone] and download the file "pwr1.txt"
BUT HURRY UP before it is too late!!!
( If the line is busy, try again later )



From [e-mail] Sat Jul 27 19:14:15 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-res.gsl.net!news.gsl.net!hunter.premier.net!news.cais.net!news2.digex.net!news6.digex.net!news.gteais.com!news
From: aor <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Active antenns for Fox Hunt - aor
Date: Wed, 24 Jul 1996 19:23:46 -0400
Organization: gteais-org
Lines: 24
Message-ID: <[e-mail]>
References: <4t0l5o$[e-mail]>
NNTP-Posting-Host: r1p8.gteais.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 3.0b5a (Win95; I)
To: Michael <[e-mail]>

Michael,

We built 60 active direction finders from kits as a club project.
Stephen Douglas sells a kit for about $20 (call and check prices).  I
met him in CA, and again at Dayton this year.  It covers 50-400Mhz, and
plugs into your handheld/scanner.  We have DF'd all kinds of things with
it. You get $20 worth of performance.. but it has been a blast on 2
meters!  I was surprised.

Call him at 916-440-9082.  This will call his beeper and page him.  You
only have 20 seconds, so name and phone number are a must!  Speak quick.

Stephen Douglas, N6TLD
Factory Rep
DF Systems
PO Box 246925
Sacramento, CA 95824-6925


73 and good luck,

Al, NW2M
President, MARC Inc., Maryland
http://www.dsport.com/marc/


From [e-mail] Sat Jul 27 19:14:15 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!news.kei.com!nntp.coast.net!zombie.ncsc.mil!linden.fortnet.org!coopnews.coop.net!frii.com!usenet
From: Avatar <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Antenna Software?
Date: Sat, 20 Jul 1996 16:40:03 -0700
Organization: Front Range Internet, Inc.
Lines: 10
Message-ID: <[e-mail]>
NNTP-Posting-Host: ftc-59.ppp.frii.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
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X-Mailer: Mozilla 2.0 (Win16; U)

I have been out of touch with Ham products for quite awhile. While I have
done some antenna design programming, I hate to reinvent the wheel. Would
someone take the time to list what is available, a short description of
features and a source. If there is a listing elsewhere on the net,
please advise. I'm sure others would appreciate having this information
also. Thanks in advance for your help.

Regards,
W0MAY



From [e-mail] Sat Jul 27 19:14:17 1996
Path: news2.epix.net!uunet!in3.uu.net!psinntp!psinntp!psinntp!psinntp!rosebud.ldp.com!usenet
From: Rolfe Tessem <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: BEST MULTIBAND HF VERTICAL?
Date: Thu, 25 Jul 1996 10:41:10 -0400
Organization: Lucky Duck Productions, Inc.
Lines: 17
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: excalibur.ldp.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 3.0b4 (X11; I; IRIX 5.3 IP22)

[e-mail] wrote:
>
>  I know, I know....a beam is better. BUT I need to find a real good
> multiband vertical...anyone with 1st hand experience please
> comment.

The best ones are traditional ground-mounted 1/4 wavelength verticals,
with 60 or more full-length (1/4 wave) radials. MFJ makes one for
80/40/20 and I'm sure other manufacturers do as well. The MFJ is
top-loaded on 80 and full-size on 40 and 20. Overall height is 33'.

Rolfe
W3VH
--
Rolfe Tessem            |       Lucky Duck Productions, Inc.
[e-mail]           |       96 Morton Street
[phone]          |       New York, NY 10014


From [e-mail] Sat Jul 27 19:14:17 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-res.gsl.net!news.gsl.net!swrinde!howland.reston.ans.net!newsfeed.internetmci.com!aanews.merit.net!server3.mich.com!abs486
From: [e-mail] (Frank Latos)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Broadcast Band (AM) Antenna Plans
Date: Sat, 27 Jul 96 14:32:55 GMT
Organization: Duo Systems Inc.
Lines: 17
Message-ID: <4td903$[e-mail]>
References: <4tcblg$[e-mail]>
NNTP-Posting-Host: pm001-23.dialip.mich.com
X-Newsreader: News Xpress 2.0 Beta #2

In article <4tcblg$[e-mail]>, mbaker <[e-mail]> wrote:
>Where can I find some plans for AM antennas.
>
>Local radio station cancelled favorite talk show. (Bruce Williams)
>

Contact the National Radio Club  (http://wcoil.com:80/~gnbc/).  They publish a

large assortment of manuals and article reprints devoted to this subject.

Try the Antenna Reference Manual (volumes 1 & 2) and the Loop Antenna Design
Guide  for starters.


-----------------------------------------
Frank Latos, Duo Systems Inc.
[e-mail]
-----------------------------------------


From [e-mail] Sat Jul 27 19:14:18 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-res.gsl.net!news.gsl.net!swrinde!newsfeed.internetmci.com!news.compuserve.com!ix.netcom.com!news
From: AC6V <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Broadcast Band (AM) Antenna Plans
Date: Sat, 27 Jul 1996 07:45:03 -0700
Organization: Author
Lines: 30
Message-ID: <[e-mail]>
References: <4tcblg$[e-mail]>
NNTP-Posting-Host: esc-ca1-05.ix.netcom.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-NETCOM-Date: Sat Jul 27  7:44:43 AM PDT 1996
X-Mailer: Mozilla 2.01 (Win95; U)
To: mbaker <[e-mail]>

mbaker wrote:
>
> Where can I find some plans for AM antennas.
>
> Local radio station cancelled favorite talk show. (Bruce Williams)
>
> tnx,
>
> mark (KG7GL)
>
> mailto:[e-mail]


Greetings Mark.
Take a look at "Easy-Up Antennas" by Edward M. Noll, Howard Sams &
Company, ISBN 0-672-22495-x. Some interesting AM Band antennas.

I home brewed a 160M vertical --- 32 feet high with a base-loaded coil
and a sprinkling of radials.  The coil was house wire on a carpet form
to resonant at 160M. To be on the safe side I overwound it and found it
resonated at the AM Broadcast Band -- was pulling AM stations in from
all over!!! Was kinda narrow bandwidth tho Hi Hi.

Good BCBing

Rod
--
Hark for I have hurled my words to the far reaches of the earth!
What King of old could do thus??
..... AC6V


From [e-mail] Sat Jul 27 19:14:19 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-res.gsl.net!news.gsl.net!hunter.premier.net!newsfeed.internetmci.com!news-out.microserve.net!news-in.microserve.net!news
From: Jesse Touhey <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Butternut HF5B wisdom
Date: 24 Jul 1996 11:51:53 GMT
Organization: Microserve Information Systems (800)-380-INET
Lines: 7
Distribution: world
Message-ID: <4t52op$[e-mail]>
References: <[e-mail]> <4t0a61$[e-mail]>
NNTP-Posting-Host: dyn1.frazmtn.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.22 (Windows; I; 16bit)

I have done many tests on the "Butterfly".  In my opinion, it is wishful
thinking to expect 5 dbd gain from this antenna.  The construction is
flimsy, and because of this tuning is very unstable. The design exhibits
a reversal of front to back ratio on different bands.  I have owned and
tested this antenna and thik there is much better
alternatives...73...Jesse (W6KKT) (not speaking for anyone else!)



From [e-mail] Sat Jul 27 19:14:20 1996
Path: news2.epix.net!uunet!in2.uu.net!spool.mu.edu!howland.reston.ans.net!surfnet.nl!sun4nl!sci.kun.nl!usenet
From: sloman@sci'kun.nl (Bill Sloman)
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna,rec.radio.amateur.equipment,ont.forsale,sci.electronics.repair,sci.electronics.equipment,
Subject: Re: CAtalogs
Date: 25 Jul 1996 10:29:14 GMT
Organization: K.U.Nijmegen
Lines: 7
Message-ID: <4t7i9q$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: elpro4.sci.kun.nl
X-Newsreader: WinVN 0.92.6+
Xref: news2.epix.net rec.radio.amateur.homebrew:16257 rec.radio.amateur.antenna:23409 rec.radio.amateur.equipment:31330 ont.forsale:33234 sci.electronics.repair:30045 sci.electronics.equipment:4219

In the UK and most of continental Europe, see Premier Farnell at
http://www.farnell.co.uk/components/compindex.html - you can ask
for their very comprehensive paper catalogue

In the US see http://www.marshall.com/ which seems to have a complete
catalogue on the net. There are others.
                                        Bill Sloman


From [e-mail] Sat Jul 27 19:14:21 1996
Path: news2.epix.net!uunet!in3.uu.net!newsfeed.internetmci.com!news.sgi.com!sdd.hp.com!hp-pcd!news.vcd.hp.com!news
From: Don Huff <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna,rec.radio.amateur.equipment,ont.forsale,sci.electronics.repair,sci.electronics.equipment,sci.electronics.design,sci.electronics.misc
Subject: Re: CAtalogs
Date: Thu, 25 Jul 1996 12:16:03 -0700
Organization: Hewlett-Packard
Lines: 15
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: hpvcldu.vcd.hp.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.02 (X11; I; HP-UX A.09.05 9000/720)
Xref: news2.epix.net rec.radio.amateur.homebrew:16261 rec.radio.amateur.antenna:23422 rec.radio.amateur.equipment:31345 ont.forsale:33258 sci.electronics.repair:30068 sci.electronics.equipment:4226 sci.electronics.design:10276 sci.electronics.misc:8140

A Guy named Moe wrote:
>
> Can people tell me if there are any eletronicComponent retailers on the
> net and where are they and give me some addresses  so I can get free
> catalogs for eletronic components
Moe,


  Do some legwork before posting dozens of posts.  Try READING
MATERIAL first.  Visit your local library or bookstore.  Your many
questions reveal that you have not used readily available sources
of information.

    73,
               Don W6JL


From [e-mail] Sat Jul 27 19:14:22 1996
Path: news2.epix.net!uunet!in3.uu.net!newsfeed.internetmci.com!news.infinet.com!crenshaw!ed.welch
From: [e-mail] (ED WELCH)
Newsgroups: rec.radio.amateur.antenna
Subject: CB Channel 9/19 Freqs
Message-ID: <[e-mail]>
Date: Fri, 26 Jul 96 07:54:00 -0600
Distribution: world
Organization: The Crenshaw County BBS/Luverne, AL/334-335-3968/ CHEAHA!!!
Reply-To: [e-mail] (ED WELCH)
X-Newsreader: PCBoard Version 15.21
X-Mailer: PCBoard/UUOUT Version 1.10
Lines: 13

We monitor CB Channel 9 for the area.  The radio is at our place of
business in the main office....which makes for some noisy
moments.<groan>  What I'm wanting to do is adjust the antenna for the
monitor radio to be resonant for Channel 9.  From what I've found the CB
freqs run from 26.965 to 27.405.  This amount of bandwidth isn't as much
as the Novice 10 meter band so I feel if I get fairly close to the
center of the frequency I'll do fairly well.  Basically, if someone has
the frequency for channel 9, and channel 19 (for my delivery trucks) I'd
greatly appreciate you sharing the info with me.

Thanks,
73, Ed, KF4KRV
Luverne, Alabama


From [e-mail] Sat Jul 27 19:14:23 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.primenet.com!winternet.com!tclbbs.com!jim.hammock
From: [e-mail] (Jim Hammock)
Newsgroups: rec.radio.amateur.antenna
Subject: CB rubber ducky
Date: Sun, 21 Jul 1996 10:18:00 GMT
Message-ID: <[e-mail]>
Organization: The City Lights BBS
Distribution: world
Lines: 20

On 07-16-96 12:05, "TRON DAVIS" <ROND@INTEL was talking to ALL
 about CB rubber ducky:


"D>We use a dozen or so handheld CB's to coordinate our matches at the loc
"D>gun club.  I've been trying to fix up some of the semi-deceased radios.
"D>Does anyone have a source for rubber duck, CB freq, with a BNC connecto
"D>antennas???  Thanks
"D>Please respond via email if you know of any.

        Radio Shack National Parts. Just get the catalog number of a CB they
sell and as for a replacement. And break the fingers of anyone carrying the
radio by the antenna. <G>

73


Jim KI0DN
---
 * PW * Dammit Jim, I'm a Doctor not a sushi chef!


From [e-mail] Sat Jul 27 19:14:23 1996
Path: news2.epix.net!uunet!in3.uu.net!newsfeed.internetmci.com!castle.nando.net!news
From: Dennis / WR4i <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Cushcraft ATB-34  (4-el Tri-Bander)
Date: Tue, 23 Jul 1996 13:14:35 -0700
Organization: Nando.net Public Access
Lines: 9
Message-ID: <[e-mail]>
NNTP-Posting-Host: 152.52.44.53
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.01 (Win16; I)

Hi All..
Just picked up a ATB-34 at a local hamfest as part of a tower deal. Looks
to be a good antenna in its day and was wondering if anyone has used one
and their comments?
Also, I noticed that quite a bit of the hardware is rusting
(U-bolts,etc). I find it hard to believe that any antenna company as big
as Cushcraft would put anything other that stainless on their ants!
Thanks for reading..
Dennis,WR4i


From [e-mail] Sat Jul 27 19:14:25 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!news.cais.net!news.sprintlink.net!news-dc-2.sprintlink.net!usenet.logical.net!news.wizvax.net!news
From: Tom Homewood <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Delta Loop
Date: Tue, 23 Jul 1996 09:13:06 -0700
Organization: Wizvax Communications, Troy, N.Y. 12180 USA
Lines: 12
Message-ID: <[e-mail]>
NNTP-Posting-Host: plp30.vgernet.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.02 (Win16; I)

I recently put up a 30 meter delta loop antenna and it is not performing
as well as I had hoped.  It has the apex up and is fed in the lower
corner through a balun and quarter wave matching transformer.  The bottom
is about 12 feet off the ground.

I am interested in results anyone else has experienced.  The other
antenna I am using on 30 is my 160 meter dipole fed with 450 ohm ladder
line.  In almost every case the 160 meter dipole works much better,
signals are louder.  On WWV there is about a 10 db difference.  Location
is in Western Massachusetts.  Any comments?

Tom K8TH


From [e-mail] Sat Jul 27 19:14:26 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!news.kei.com!news.texas.net!news.sprintlink.net!news-fw-6.sprintlink.net!itnews.sc.intel.com!news
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Delta Loop
Date: Tue, 23 Jul 1996 09:15:46 -0700
Organization: Intel Corp., Chandler, AZ
Lines: 13
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: cmoore.ch.intel.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.01 (Win16; I)

Tom Homewood wrote:
> I recently put up a 30 meter delta loop antenna and it is not performing
> as well as I had hoped.  It has the apex up and is fed in the lower
> corner through a balun and quarter wave matching transformer.  The bottom
> is about 12 feet off the ground.

Hi Tom, this antenna will work a lot better if you turn it upside down, i.e.
make the long horizontal run high rather than 12 ft off the ground. You are
losing a lot of power in the section parallel to the ground. And the way
you are feeding it is not balanced with respect to ground. When you turn
it upside down it will also be better balanced.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)


From [e-mail] Sat Jul 27 19:14:30 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!news.cais.net!news2.cais.com!cais2.cais.com!gttm
From: USCG TELECOMMS <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Delta Loop
Date: Tue, 23 Jul 1996 14:10:10 -0400
Organization: Posted via CAIS Internet <[e-mail]>
Lines: 28
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: cais2.cais.com
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
To: Tom Homewood <[e-mail]>
In-Reply-To: <[e-mail]>



On Tue, 23 Jul 1996, Tom Homewood wrote:

> I recently put up a 30 meter delta loop antenna and it is not performing
> as well as I had hoped.  It has the apex up and is fed in the lower
> corner through a balun and quarter wave matching transformer.  The bottom
> is about 12 feet off the ground.
>
> I am interested in results anyone else has experienced.  The other
> antenna I am using on 30 is my 160 meter dipole fed with 450 ohm ladder
> line.  In almost every case the 160 meter dipole works much better,
> signals are louder.  On WWV there is about a 10 db difference.  Location
> is in Western Massachusetts.  Any comments?
>
Tom:  Nothing wrong with the way you have the loop configured, although
some so-called antenna experts will argue otherwise.  The 160 dipole on 30
meters exhibits somewhat of a cloverleaf pattern (composite) and the
vertical pattern peaks at 30 degrees elevation.  On the other hand, the
loop exhibits a higher takeoff angle with about 4.5 dB less gain than the
160 dipole.  I once had a loop for 80 meters, configured exactly the way
you have yours for 30 meters, with the base only 10' high.  I used this
antenna from Virginia for about 2 years and received over 200 unsolicited
QSL cards from European and South American DX.  I wonder what would have
happened if I would have used a 2 wavelength long dipole instead.

Ron, W4VR



From [e-mail] Sat Jul 27 19:14:31 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.primenet.com!news.asu.edu!aztec.asu.edu!hamop
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Delta Loop - Confused
Date: 21 Jul 1996 20:25:48 GMT
Organization: Arizona State University
Lines: 14
Message-ID: <4su3oc$[e-mail]>
NNTP-Posting-Host: aztec.asu.edu


Les said -
How does the author arrive at 22'10" for the transformer?  According to
my arithmetic, a qurter wave at 40 mtrs. is 10 mtrs., or about 32'9".

Les,
        The American "40 meter band" from 7 MHz to 7.3 MHz is
actually about 42.9 to 41.1 meters wavelennght.
        Solid poly coax has a phase velocity factor of about .66
so, depending on the frequency chosen in the band, a quarter wave
may be very close to the figure 22'10".

Charlie, W7XC
--


From [e-mail] Sat Jul 27 19:14:32 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!fozzie.mercury.net!zombie.ncsc.mil!newsgate.duke.edu!agate!biosci!news.Stanford.EDU!bloom-beacon.mit.edu!newsfeed.internetmci.com!swrinde!cs.utexas.edu!news.sprintlink.net!news-stk-200.sprintlink.net!news.sprintnw.com!usenet
From: Tim Robertson KC7QOM <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Diamond CP-4A Vertical
Date: Fri, 26 Jul 1996 10:16:40 -0700
Organization: A.C.S.
Lines: 10
Message-ID: <[e-mail]>
NNTP-Posting-Host: tddial4.gorge.net
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.02 (Win95; U)
CC: rec.radio.amateur.equipment

Hello to All,
 I recently aquired a Diamond CP-4A Vertical antenna and need some help.
The instructions are written in japanese and my japanese is a little
rusty. Being a new Techplus I'm not sure how to tune the antenna or
attach the coax. Anyone have this antenna that might be able to help me
out? Or maybe even have some instructions written in english?
Thanks in advance
73s
Tim,KC7QOM



From [e-mail] Sat Jul 27 19:14:33 1996
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From: Jim Finney <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Duo-band vs duplexer
Date: Tue, 23 Jul 1996 00:18:21 -0400
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Hello All,

I am debating whether to get a duo-band antenna or a duplexer and use two sepe
rate antennas for mobile
use for my new FT-8000 duo-band rig.

Can anyone comment on the advantages/disadvantages of using a duo-band 2m/440
antenna over using a
duplexer or splitter and seperate antennas.

I am particularly interested in knowing what the tx and rx losses would be wit
h each system.

Thanks,

Jim..  WA5VPW..


-----------------------------------------------------
Jim Finney
[e-mail]
http://users.southeast.net/~jpf
Jacksonville, Florida
-----------------------------------------------------


From [e-mail] Sat Jul 27 19:14:38 1996
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From: [e-mail] (Richard Lamont)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Duo-band vs duplexer
Date: 23 Jul 1996 09:39:05 GMT
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In article <[e-mail]>,
        Jim Finney <[e-mail]> writes:
> Hello All,
>
> I am debating whether to get a duo-band antenna or a duplexer and use two se
perate antennas for mobile
> use for my new FT-8000 duo-band rig.
>
> Can anyone comment on the advantages/disadvantages of using a duo-band 2m/44
0 antenna over using a
> duplexer or splitter and seperate antennas.

I think this is a case where the simplest solution is the best: for
mobile use I 'd go for a separate antenna for each band - just a
quarter wave whip for 2m, and probably the same for 70cm.

Antennas which purport to offer gain rely on a flat ground plain and
the antenna staying vertical for their claimed gain figures. In reality
the ground plane provided by a vehicle is usually not flat, and the
antenna flaps about during motion.

The insertion loss of the diplexer may be small, but it will be smaller
if you don't have one. ;-)

A small point of terminology here - a diplexer (typically) combines
two bands into one antenna. A duplexer (typically) is used to
enable simultaneous transmission and reception within the same band.


--

Richard Lamont
(G4DYA)
[e-mail]


From [e-mail] Sat Jul 27 19:14:39 1996
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From: Dale Mosby <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: ELNEC  modeling - question about source
Date: Thu, 25 Jul 1996 10:19:07 -0700
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I just started playing with ELNEC.  (So far I'm just running the
demo program, but I have the program on order.)

What I would like to do is model some wire antennas that will be
fed with 450 ohm ladder line and used as multi-band antennas
fed with a tuner.  I *think* the program can do this, but I'm
obviously confused when it comes to suppling the source to the
antenna.  As I undertand this, you can model a dipole as a single
wire with the source in the center.  OK, I think of a dipole as
two wires with the source at the junction, but this doesn't seem
to be the way the model works.  With a non-resonant, ladder line
fed dipole I believe that the ladder line will radiate and act
as part of the antenna -- (yes, no ? feel free to clue me in).
I wanted to start with something simple, two 30 foot long wires
set up as a dipole 30 feet above the ground, with two more wires
running out from the center at a 90 degree angle (the ladder line).
(These wires are also 30 feet in the air, so the tuner is assumed
to be up there also -- if I get this working then I'd add more wires
and bring the tuner down near the ground.)
I'll measure the lader line sometime, but for now I assumed .1 foot
spacingfor the ladder line. So the two legs of the dipole are
separated by .1 foot also.

My confusion comes when I want to feed this at the end of the two
parallel wires simulating the ladder line.  Just how do I do this?

To describe an acutal antenna I'd have to figure out the actual
path of the ladder line -- tedious, but possible I suppose.  My
though on this was that I could try and simulate some of the possible
antennas I can put on some property at the coast.  I've got some
constraints from houses, trees, power lines and such.  I could try
running a dipole, delta, or loop (of some not really square shape).
Using ELNEC I'd like to try and make some prediction of efficiency,
SWR, and pattern at the various bands.  Is this even a reasonable
thing to do? I do have a feeling that once the houses and trees
come into effect the behaviour may not be what I expect so I should
just throw out some wire and get on the air assuming that someone,
somewhere will hear me no matter what!  (But like many hams, lots of
the fun of "hamming" is experimenting with things, not just being
on the air).

Thanks for any insights.  73, Dale.   N7PEX     [e-mail]


From [e-mail] Sat Jul 27 19:14:40 1996
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From: [e-mail] (John Kaufmann)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: EZNEC antenna simulation
Date: Thu, 25 Jul 96 16:46:21 GMT
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Gilles Monette <[e-mail]> wrote:
>I am having problems simulating antenna trap for a vertical multi band
>HF antenna.  Does anyone know how to simulate trap with EZNEC.
>
>Gilles


You can model a trap as a load which can be added to a wire using
the EZNEC loads menu.   In this menu, select Laplace coefficients and
then the "P" (parallel R-L-C) option, assuming your trap is a parallel
L-C circuit.  You then enter the R-L-C values for the trap.  For a lossless
trap you want infinite R, so set R to some large value like a megohm
and then enter the L and C values.

73 de W1FV


John Kaufmann
[e-mail]


From [e-mail] Sat Jul 27 19:14:41 1996
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From: Gilles Monette <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: EZNEC simulation with traps
Date: Fri, 26 Jul 1996 14:55:02 -0400
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Thanks for the replies.  The problem in more detail is that by inserting
the traps with the load option, shoes the load ok.
The problem comes when you do the simulation.  To better describe this
let me tell you what I am doing.

I am simulating a trap vertical fo 10,15,20 and 40 meters.
I get a lamda/4 for 29.9 MHz ok with no traps.
Now add a paralle resonant circuit od 1 ohm, 3 uH and 15 pF.
Simulate at 29.9 MHz is ok with and without trap.
Add extra length to get lamda/4 at 21.5 MHz.
This is ok.
Check simulation at 29.9,  Then patern is real mess, does not look like
it doing things right with the traps.

That is what the problem is.

Regards,  Gilles


From [e-mail] Sat Jul 27 19:14:42 1996
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From: [e-mail] (Jay H. Miller)
Newsgroups: rec.radio.amateur.antenna
Subject: Force 12 Antennas Comments
Date: 26 Jul 1996 19:22:02 GMT
Organization: Trinity Graphics Systems
Lines: 11
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Would appreciate comments from anyone with actual experience with a Force
12 model C4.

Please reply via private e-mail.

Thanks.

--
73 de
Jay Miller, KK5IM
reply via email to   [e-mail]


From [e-mail] Sat Jul 27 19:14:43 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 22 Jul 1996 01:32:57 -0400
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Hi Gary,

In article <[e-mail]>, [e-mail]
(Gary Coffman) writes:

>In article <4sik12$[e-mail]> [e-mail] (W8JI  Tom)
>writes:
>>Secondly, it confuses people about the actual operation of a PA. They
are
>>led to believe that maximum efficiency occurs with some wild far-fetched
>>tuning method that causes the tank to present a very low impedance to a
>>transistor, and high impedance to a tube.
>
>Transistors do need to see a low impedance load, and tubes do need to
>see a high impedance load. Z=E^2/P, for identical P, the Z a transistor
>needs to see is much lower than the Z a tube needs to see because the
>collector voltage of the transistor is much lower than the plate voltage
>of the tube. There's nothing at all far-fetched about that. Of course
>the impedance at the transmitter's output connector will be nominally
>something near 50 ohms in either case.

I worded that poorly. What I meant to say was the source impedance at the
output of the PA, as I re-read it I see that I said "presented to the
device".

My point was this... In either a solid state or tube PA, the output
impedance of the device (tube FET or transistor) is determined the
available RF voltage and current at the selected operating conditions. But
the impedance looking BAACK into the entire PA system (after filters) is
absolutely greater than the load impedance if any linearity is to be
expected, and the conjugate of the load impedance if maximum power output
for a given amount of drive is being obtained.

It's incorrect to think a solid state rig presents a low impedance and a
tube a higher impedance at the 50 ohms output port. We basically agree on
everything you said.

>
>Transistors do need to see a low impedance load, and tubes do need to
>see a high impedance load. Z=E^2/P, for identical P, the Z a transistor
>needs to see is much lower than the Z a tube needs to see because the
>collector voltage of the transistor is much lower than the plate voltage
>of the tube. There's nothing at all far-fetched about that. Of course
>the impedance at the transmitter's output connector will be nominally
>something near 50 ohms in either case.
>

We would have to define E and P as:
E = Effective RMS signal voltage.
P = Effective signal power.

NOT as plate voltage and dc input power.

73, Tom


From [e-mail] Sat Jul 27 19:14:44 1996
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From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Mon, 22 Jul 1996 14:40:57 -0700
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Gary Coffman wrote:
> Your main problem is that you're not using the wave model properly.

Given the following with a 100w XMTR and no losses:

XMTR----52ohm coax----1:1 balun----1/2 WL 300 ohm ladder-line----52ohm load

Power delivered to the load = 100(1/2 + 1/4 + 1/8 + 1/16 + ...)

Reflected power = 100(1/2 + 1/4 + 1/8 + 1/16 + ...)

Forward power = 100(1 + 1/2 + 1/4 + 1/8 + 1/16 ...)

This model works with multiple re-reflections and though not perfect, seems
to agree with reality closer than any of the steady-state models that I've
looked at.

73, Cecil, W6RCA, OOTC  (not speaking for my employer)


From [e-mail] Sat Jul 27 19:14:48 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 23 Jul 1996 11:22:16 -0400
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Hi Jeff,
[e-mail](Jeff Anderson) writes:
>   I'm inclined to agree with you, simply because your statement is
>true for class A amps, and so, by extension, it should also true for
>class C amps.

>    Accepting the statement that we'll have maximum power transfer when
>the source impedance of the class C amp is the conjugate of the load
>impedance, my next question is, "OK, so what is this source impedance?"
> And this is the question that I cannot answer.
>    All the literature I've read so far (including Chaffee analysis)
>concern themselves with calculating the load resistance without
>discussing the source impedance of tube/transistor.  The
>equations/techniques for calculating the load impedance seem to work
>just fine without having to know this source impedance, so I'm inclined
>to say, "Who cares?"

In a well designed class C PA, on resistance is negligible or very low
compared to the operating impedance. "Who cares" is a very good answer..

The ohmic resistance of a properly designed generator system is negligible
compared to the source impedance (dynamic resistance) of the generator
caused by the flux or shaft torque limitations.

The source has an impedance that behaves like a conventional resistance,
except it is lossless and doesn't create heat. This "non-dissipating
resistance" dominates the circuit's operation.

>    Well, clearly someone cares.  We have two camps, one claiming there
>is no conjugate match, the other claiming there is.  How do we come to
>a resolution?
>
>    I'd love to see a rigorous mathematical analysis determining the
>source impedance of a class C amp, backed up with verification by
>experiment.  So far I've seen "verification by experiment," but with
>conflicting results (Bruene vs. W8JI).  Tom, you've mentioned that "any
>effort to offer an analysis has been rebuffed with 'Oh, no....not that
>again!'."  Let me state that such an analysis would be great!  And I'm
>sure others in this group would strongly agree.

If you re-read Bruene, you'll see the impedance values were simple
postulations. He could only measure SWR, and not the direction of the
impedance deviation. With the load pull or tapped line metods, you can
tell the direction and magnitude of the impedance change. Our measurements
agree up to the point where he "estimated or rationalized" the impedance's
value from SWR.

Further, if the PA was tuned for maximum efficiency or output power with a
safe amount of drive his results would match mine. The Alpha amplifier
crossed 1:1 SWR at one power level, just as all my tests do (except a
class A amp, it was stable).

When I measured a ICOM 751A, I measured reverse generator standing waves
similar to Bruene's "not matched" results. But remember the methods I used
indicate direction of the output terminal impedance, and it was
higher..not lower.

I also added an outboard antenna tuner, limited drive to a safe value, and
disabled the SWR limit circuit. When I adjusted the tuner for maximum RF
output, efficiency also increased. Looking into the tuner's rig connector,
the tuner looked like a higher impedance than 50 ohms. Looking back into
the output of the tuner while driving a 50 load at full power under the
"matched for maximum power" condition, the impedance looked like 50 ohms
(with the tuner in line).

Source impedance (except for a class A stage) increased as drive was
reduced, and decreased as drive was increased..exactly a Chaffe analysis
indictes. This is exactly what happens in a generator system when field
excitation is varied. The impedance has nothing to do with the conversion
device being a tetrode, triode, or transistor... since it obviously even
applies to a mechanical to electrical generator system.

The point is this, if we conjugately match to the designed impedance of
the device....correct performance is acheived. If we conjugately match the
source impedance in a well designed PA, efficiency and power ouput are
maximized.

In any circuit, maximum power transfer occurs with a conjugate match. If
parasitic losses are low, maximum efficiency also occurs at or very near
that point.

73, Tom


From [e-mail] Sat Jul 27 19:14:50 1996
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From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: Mon, 22 Jul 1996 20:54:26 +0100
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 wrote:
>    I'm not sure this goal is achievable through SPICE (it should be),
>but I'd like to find out.  In between work and life I'm learning
>"PSPICE for WINDOWS" and hope to do this, but I wouldn't mind if
>someone beat me to it (hint hint)!

Intusoft have an application note on modeling Class-C devices using
SPICE - see their Web pages (sri, I don't have the address handy).

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


From [e-mail] Sat Jul 27 19:14:51 1996
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From: [e-mail](Jeff Anderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 24 Jul 1996 13:09:53 GMT
Organization: Netcom
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In <4t4g6h$[e-mail]> [e-mail] (W8JI  Tom)
writes:

>Now think of what it does when the reflected signal is caused by
>reflections. It's synchronized with the signal at the anode, but at
>some unknown phase difference. It simply modifies the load impedance
>seen by the anode.
>
>One thing I haven't measured but I speculate to be true is this. If
>phase delay is long compared to the modulation rate, distortion may be
>created. I suspect that is part of the cause of distortion in linear
>PA's. Mistune the external PA's cathode circuit with a long cable
>between the exciter and the external PA, and system IMD increases.
>
>I wonder what others think of that possibility?
>
>73 Tom

Tom,

    Although the possibility of distortion products caused by
reflections may exist, the existance of such distortion would surprise
me.  And I'll use the following example to explain why:

    What has a tremendously long transmission line (given the
wavelength of operation), and is quite frequently misterminated,
resulting in horrendous reflections?  Answer: a telephone!

    An improperly terminated phone line results in echoes, which,
depending on the length of phone line, can be *very* annoying to a
telephone subscriber.  Do these echoes (or reflections) result in
distortion?

    Annoyance factor aside, the answer is no.  To eliminate such echoes
one often employs a "line echo canceller" for the telephone line side
of a conversation, and if one really wants to get fancy, an "acoustic
echo canceller" for the room side if using a speakerphone (acoustic
echo cancellers are expensive - they are much more difficult to design
than line side cancellers because the impulse response of a room is
MUCH more complex than that of a telephone line).

    One characteristic of echo cancellers is that their operation
degrades in the presence of distortion, and eventually fall apart if
distortion is high enough.  That is, they work by comparing what they
receive to what they've sent out.  If there is correlation between the
input signal and the output, that represents an echo.  If there is no
correlation (and distortion, to an echo canceller, looks like an
uncorrelated signal), then the echo canceller doesn't know what to
cancel - it thinks there are no reflections.  If reflections (echoes)
caused distortion, echo cancellers, by their nature, would just not
work.

    In the case of an RF transmitter I would also be surprised, given
the extremely short length of an RF transmission line compared to the
wavelength of voice, that there would be any effect at all on the
modulation.  If distortion exists, I'd be much more inclined to blame
it on a less than ideal load (due to reflections) causing, perhaps,
increased non-linear operation.

    But who knows?  It's an interesting question that you've posed,
Tom.  Maybe someone has a different insight into it.

    One interesting experiment might be to simply send morse code and
look at the rising and falling waveform edges as load/line length is
varied.  How do they change?  What is their duration?

- Jeff, WA6AHL






From [e-mail] Sat Jul 27 19:14:55 1996
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From: [e-mail](Jeff Anderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 24 Jul 1996 13:37:42 GMT
Organization: Netcom
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In <[e-mail]> Jon Bloom <[e-mail]> writes:
>

>
>I'm sure you would see some such effect if the delay were long enough.
>I'd think, though, that since the frequncies being mixed are the
>current input signal and a delayed version of the input signal, the
>mixing products wouldn't be at classic IM frequencies. In other words,
>you get a mix of the input signal frequencies and whatever frequencies
>were input <delay> seconds ago. Bet the result would be pretty wierd!
>This seems like something that would be quite likely in a video
>system. Wonder if any of the TV folks on the forum have seen anything
>like this?

If the improperly terminated line is rather short, you get ringing on
transitions.  For instance, a black-to-white transition will look like
its followed by a black line (not really black, if viewed on a waveform
monitor, but the eye perceives it this way).  If the line is long
enough, you'll get ghosting (ghosting may be inverted or not, but it's
been a long time since I designed video equipment - I'm no longer
sure).

If I recall, the rule of thumb for delay was roughly 1 ns per foot of
coax.  So, given that a TV horizontal line is approx. 64 usec long, you
can calculate, given a transition on the screen, where its reflection
will appear.

But, if memory serves, I've *never* seen distortion artifacts caused by
reflections.

- Jeff


From [e-mail] Sat Jul 27 19:14:56 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 24 Jul 1996 16:45:08 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 50
Sender: [e-mail]
Message-ID: <4t620k$[e-mail]>
References: <4t57b1$[e-mail]>
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Hi Jeff,

In article <4t57b1$[e-mail]>, [e-mail](Jeff
Anderson) writes:

>Tom,
>
>    Although the possibility of distortion products caused by
>reflections may exist, the existance of such distortion would surprise
>me.  And I'll use the following example to explain why:
>
>    What has a tremendously long transmission line (given the
>wavelength of operation), and is quite frequently misterminated,
>resulting in horrendous reflections?  Answer: a telephone!
>
>    An improperly terminated phone line results in echoes, which,
>depending on the length of phone line, can be *very* annoying to a
>telephone subscriber.  Do these echoes (or reflections) result in
>distortion?
>
>    Annoyance factor aside, the answer is no.

The telephone is a linear device (unless you live in rural Georgia). Like
the class "A" PA, I suspect the returned signal is either dissipated in
the resistance of the linear device or simply "echos" back out again.
Mixing does not occur.

This seems to agree with what I see on the spectrum analyzer when I look
at the signal while injecting a low level reverse generator on a different
frequency.

With a matched class A stage, the "reflected power" disappears somewhere
in the PA without a trace of IMD. If IMD is there, it's buried in the
noise of the transmitter and PA. With a class C amp, I can clearly see new
IMD products that total slightly less than the level of the reverse
injected signal.

Too bad I can't inject enough signal to measure temperature changes in the
class A stage. The class A RF amp I used is a 3CPX5000, the 600 watt
reverse generator applied through a 30 dB pad doesn't bother it much
(nothing else does either, hi). I suspect the reverse generator power of
.6 watt becomes part of the tube's 3-1/2 kW anode dissipation.

I do have some kW medical generators that have 65 uS pulses with 1 uS rise
and fall times. They may work better than a CW transmitter if I could just
understand what we needed to do. Look for multiple pulse echos from both
ends? The problem is they change characteristics when off, since they are
not class A linear PA's.

73, Tom


From [e-mail] Sat Jul 27 19:14:57 1996
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From: [e-mail](Jeff Anderson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 26 Jul 1996 12:49:14 GMT
Organization: Netcom
Lines: 86
Message-ID: <4taesa$[e-mail]>
References: <4t57b1$[e-mail]> <4t620k$[e-mail]>
NNTP-Posting-Host: pax-ca23-12.ix.netcom.com
X-NETCOM-Date: Fri Jul 26  5:49:14 AM PDT 1996

In <4t620k$[e-mail]> [e-mail] (W8JI  Tom)
writes:
>
>With a matched class A stage, the "reflected power" disappears
>somewhere in the PA without a trace of IMD. If IMD is there, it's
>buried in the noise of the transmitter and PA. With a class C amp, I
>can clearly see new IMD products that total slightly less than the
>level of the reverse injected signal.
>

Hi Tom,

I thought about this a bit more (what else is there to do in the
shower?), and I agree with your observations - a class C amp with a
*long* xmission line, unlike a class A amp in a similar situation,
should exhibit distortion.  Here's how I convinced myself:

1.  Let's make a simple model for a non-linear amp:

               V+
             --------
            |        |
            L        C     <---  LC resonant at F1 Hz
            |        |
             --------  <------------
            |
 switch    \                long xmission line with Zo char. imp.
            |--------  <------------
            gnd

The switch is switching at a rate = F1 Hz.  If the xmission line is
infinity long, there will be no reflections and the load looks like the
characteristic impedance, Zo.  A wave of freq. F1 is traveling down the
transmission line.

2.  Now let's stop toggling the switch.  The wave is still traveling
down the line, but nothing new is following it.  Think of it as a
packet of RF energy moving down the line.

3.  Now let's say that the line is not infinitely long, but terminated
and with a length longer, in terms of propogation time, than this
"packet."  The packet reaches the end of the line, and if the
termination is mismatched, some of the energy is reflected back and
eventually arrives back at the amplifier terminals.  Assume the amp is
still doing nothing (switch open), this reflected wave, to us, looks
like a source with an associated source resistance (in a way analogous
to how a receiving antenna models like a source (voltage or current)
with a source resistance).



             --------  <--------------
            |        |        |       |
            L        C       Rs     I Source (at frequency F1)
            |        |        |       |
             --------  <--------------

4.  Now let's say that the switch, upon the return of this packet,
rather than doing nothing, is switching at a new rate F2 (still close
to the LC's resonant frequency).  Combining the first and second
models, I get:



               V+
             --------
            |        |
            L        C
            |        |
             --------  <------------
            |              |        |
 switch    \               R      I Source (frequency F1)
(freq. F2)  |              |        |
            |--------  <------------
            gnd


Hmmm...This looks like a mixer to me, and, depending on the LC's Q, I'd
expect to see mixing components (such as 2F2-F1, etc.) at this amp's
output terminals.

At least, it *seems* to make sense.

Best regards,

- Jeff, WA6AHL


From [e-mail] Sat Jul 27 19:14:58 1996
Path: news2.epix.net!news
From: Dave Flail <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: GAP ant modelization with EZNEC
Date: Wed, 24 Jul 1996 19:38:07 -0400
Organization: epix.net
Lines: 5
Message-ID: <[e-mail]>
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EMPIRICAL DATA:

My Gap Challenger DX-VIII is a better dummy load than my Cantenna.

73! Dave, N3KVF


From [e-mail] Sat Jul 27 19:14:59 1996
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From: [e-mail] (JAMES MCEWEN)
Newsgroups: rec.radio.amateur.antenna
Subject: Getting a wire up a tree
Date: 25 Jul 96 23:46:43 GMT
Organization: ucsd usenet gateway
Lines: 13
Message-ID: <[e-mail]>
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

     Dear Elmer,

     Took your advice to make an inverted V. Tied wire to mouse.
     Placed mouse in tree. Mouse didn't go anywhere.  Placed cat in
     tree as incentive for mouse to move.
     Now have wire with three wraps around top of tree.  Mouse escaped
     and is free, cat won't come down.  Please forward instructions
     for end fed antenna with capacitive top hat, and phone number of
     fire department to retrieve cat.

     Cordially yours
     Joe Novice



From [e-mail] Sat Jul 27 19:15:00 1996
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From: adamkern <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Getting wires up in the trees
Date: 23 Jul 1996 18:04:20 GMT
Organization: The Internet Access Company
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Finally, I'm wondering what's the best way to get wires up in the trees.
 I live near Boston, MA, where there are lots of pines, that are very
tall.  It is possible to climb the trees, but I've heard several ideas
about using a bow and arrow, or just tying rope to a rock and throwing
it.  Any suggestions?

-Adam Kern
N1TYF
[e-mail]



From [e-mail] Sat Jul 27 19:15:01 1996
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From: [e-mail] (Jim Garver)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: 23 Jul 1996 18:48:40 GMT
Organization: Intel Corp., Hillsboro, Oregon
Lines: 37
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References: <4t3474$[e-mail]>
NNTP-Posting-Host: pdx804.intel.com

In article <4t3474$[e-mail]>, adamkern  <[e-mail]> wrote
:
>Finally, I'm wondering what's the best way to get wires up in the trees.
> I live near Boston, MA, where there are lots of pines, that are very
>tall.  It is possible to climb the trees, but I've heard several ideas
>about using a bow and arrow, or just tying rope to a rock and throwing
>it.  Any suggestions?

I've used a bow and arrow, but have observed that a powerful slingshot such
as a Wrist Rocket is just as good or maybe a little better.  Are these devices
no longer allowed in our PC society?  You will not be able to throw or
sling a rock nearly as high or far.  I've used 30-50 lb. bows with a hole
drilled in the arrow's tail and light weight fishing line, 10-20 lbs.
A bow fishing reel would be nice, but I usually lay the line out before
me in a serpentine pattern.
For some of the longer shots where I have to get a line over a lot of
deciduous growth to reach the target conifer, I have considered using
rockets but am afraid of starting fires.

In any case, don't expect the line to stay up long.  I've used all kinds
of poly and nylon ropes.  The summer sun will cook them and the winter
winds are the coup-de-grace.  Expensive ropes like Phillystran(sp?) are
out of the question for the quantity I need.
If you do climb the tree, do not tie anything around the main trunk.  Tie
a pulley to a branch so that you can lower or repair it later without
climbing again.
The tree will swallow the rope and grow over it eventually but may not
continue internal growth past it.  High winds last winter snapped off
the top of my nicest Cedar tree because I choked it with poly rope many
years ago when I didn't know better.
Do tie a pulley to a branch so that you can lower or repair it later without
climbing again.




--
[e-mail]          WA7LDV            I don't speak for Intel


From [e-mail] Sat Jul 27 19:15:02 1996
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From: [e-mail](Glenn Sparks)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: 24 Jul 1996 16:18:48 GMT
Organization: Netcom
Lines: 25
Message-ID: <4t5id8$[e-mail]>
References: <4t3474$[e-mail]>
NNTP-Posting-Host: hou-tx3-05.ix.netcom.com
X-NETCOM-Date: Wed Jul 24  9:18:48 AM PDT 1996

In <4t3474$[e-mail]> adamkern <[e-mail]> writes:
>
>Finally, I'm wondering what's the best way to get wires up in the
trees.
> I live near Boston, MA, where there are lots of pines, that are very
>tall.  It is possible to climb the trees, but I've heard several ideas

>about using a bow and arrow, or just tying rope to a rock and throwing

>it.  Any suggestions?
>
>-Adam Kern
>N1TYF
>[e-mail]
>
Wrist rocket sling shot is my favorite, with a bow fishing spool for
the string.  I use a breakable 2' piece of string next to the weight
(practice casting weight from fishing store) so if it gets stuck I can
break the string.  Then I use braided fishing string to pull the dacron
rope into place.

I've heard in some area's the wrist rocket slingshot is considered a
weapon, so check your local codes.

Glenn Sparks  KI5GY


From [e-mail] Sat Jul 27 19:15:03 1996
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From: [e-mail] (Ted Kell)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: Wed, 24 Jul 1996 10:21:18 -0600
Organization: Me, Myself & I
Lines: 12
Message-ID: <[e-mail]>
References: <4t3474$[e-mail]> <4t5c3h$[e-mail]>
NNTP-Posting-Host: toad.jsc.nasa.gov

What kind of reel do you use?  I have tried the slingshot with an openface
spinning reel and find that the line will not spin off.  The weight goes
out about 10 feet and then reverses direction and returns to whence It
came.  Very exciting, but not much fun.

Instead of the slingshot, I have been filling a plastic 20 oz coke bottle
half full of water.  Then I tie the line to the neck.  I also tie about
3-4 feet of 3/8" rope to the neck.  I then spin the bottle by the rope in
a circle, letting fly at the appropriate (found by experiment) time.  The
bottle, line, and rope (if I am lucky) go over the branch I have selected.

Ted


From [e-mail] Sat Jul 27 19:15:04 1996
Path: news2.epix.net!uunet!in2.uu.net!hunter.premier.net!news.cais.net!news2.cais.com!cais3.cais.com!gttm
From: USCG TELECOMMS <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: Wed, 24 Jul 1996 10:27:10 -0400
Organization: Posted via CAIS Internet <[e-mail]>
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Message-ID: <[e-mail]>
References: <4t3474$[e-mail]>
NNTP-Posting-Host: cais3.cais.com
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
To: adamkern <[e-mail]>
In-Reply-To: <4t3474$[e-mail]>



On 23 Jul 1996, adamkern wrote:

> Finally, I'm wondering what's the best way to get wires up in the trees.
>  I live near Boston, MA, where there are lots of pines, that are very
> tall.  It is possible to climb the trees, but I've heard several ideas
> about using a bow and arrow, or just tying rope to a rock and throwing
> it.  Any suggestions?
>
What I've been using for years is the sling shot method.  Although the bow
and arrow method works, the sling shot is less cumbersome to use.  I have
100' oak trees and make full use of them on a 5 acre lot.  I have a sling
shot, with an arm rest, available from K-Mart in most states for about $8.
I have a casting reel mounted on the side arm.  I use 15 pound
monofilament line with 1 ounce tear drop sinkers.  You can buy everything
at K-Mart or Walmart.  I paint the sinkers blaze orange so they are easy
to see as they come down on the other side of the chosen limb for your
antenna support.  This system has worked for me for the last 25 years.

Ron, W4VR



From [e-mail] Sat Jul 27 19:15:05 1996
Path: news2.epix.net!uunet!in2.uu.net!newsfeed.internetmci.com!news.sprintlink.net!new-news.sprintlink.net!cs.utexas.edu!news.ti.com!newsfeed.mc.ti.com!usenet
From: [e-mail] (Jim Flanders)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: 24 Jul 1996 14:31:13 GMT
Organization: Texas Instruments @ Lewisville
Lines: 32
Message-ID: <4t5c3h$[e-mail]>
References: <4t3474$[e-mail]>
NNTP-Posting-Host: shtip114.dseg.ti.com
Mime-Version: 1.0
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Adam
  3 field days ago, I was working in Reston VA. and joined the Reston
ARA for field day.  One of the Reston amateurs was a real expert in
getting antennas up into a tree.  He used a bow, however, I have also
seen the technique done with a sling shot.  I will try here to
describe his technique.  He put weights an the arrow. He explained
that this allows the arrow to fall from the top of the tree better.
Next - he tied a very thin monofiliment line to the end of the arrow.
The reason for this is to allow the flight of the arrow without the
hinderence of a heavier line. After retreiving the arrow, a heavier
line is hooked to the thin monofiliment. It is pulled up over the
tree.  Finally, the heavier line is hooked to the antenna wire, and
pulled into place.  I know I have left out some nuinces, but practice
will iron those things out. By the way - I still fondly remmember the
Reston ARA hospitality that summer.
Jim W0OOG/5


In article <4t3474$[e-mail]>, [e-mail] says...
>
>Finally, I'm wondering what's the best way to get wires up in the
trees.
> I live near Boston, MA, where there are lots of pines, that are very
>tall.  It is possible to climb the trees, but I've heard several ideas
>about using a bow and arrow, or just tying rope to a rock and throwing
>it.  Any suggestions?
>
>-Adam Kern
>N1TYF
>[e-mail]
>



From [e-mail] Sat Jul 27 19:15:06 1996
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From: [e-mail] (Jon McCombie)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: Tue, 23 Jul 1996 20:39:09 -0400
Organization: The Internet Access Company
Lines: 32
Message-ID: <[e-mail]>
References: <4t3474$[e-mail]>
NNTP-Posting-Host: jonnysmac.tiac.net

In article <4t3474$[e-mail]>, adamkern <[e-mail]> wrote:

>Finally, I'm wondering what's the best way to get wires up in the trees.
> I live near Boston, MA, where there are lots of pines, that are very
>tall.  It is possible to climb the trees, but I've heard several ideas
>about using a bow and arrow, or just tying rope to a rock and throwing
>it.  Any suggestions?

A technique used with excellent results by many in my radio club--
myself included--is the fishing reel and slingshot method. Attach a fairly
hefty fishing sinker to the end of some strong fishing line wound onto a
fishing/casting reel. Put the reel in "cast" mode, then use the slingshot to
propel the weight over the top of the desired tree. Wiggle the line until you
can see the weight dangling through the tree/on the other side. Attach a rope
to the weight, and reel the line in on the fishing reel. Voila! instant
rope-strung-through-tall-tree!

Note: be VERY CAREFUL with this. When the weight leaves the slingshot it is
moving very fast and could very seriously injure someone or something
(like your neighbor's picture window).

You mention that you are near Boston, MA. For legal reasons I explicitly DO NO
T
recommend that you use this method in MA because slingshots are ILLEGAL
in Massachusetts. If you want to do this anyway, IN VIOLATION OF STATE LAW,
you will have to make your own slingshot, borrow one from a friend, or travel
out of state to purchase one (e.g., slingshots are not illegal in New Hampshir
e;
large department stores just over the border will be happy to sell you one).

Have fun!

Jon
N1ILZ


From [e-mail] Sat Jul 27 19:15:07 1996
Path: news2.epix.net!uunet!in2.uu.net!ftpbox!mothost!lmpsbbs!news
From: Bruce Burke <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: Thu, 25 Jul 1996 07:51:24 -0400
Organization: Motorola Inc
Lines: 29
Message-ID: <[e-mail]>
References: <4t3474$[e-mail]> <[e-mail]>
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USCG TELECOMMS wrote:
>
> On 23 Jul 1996, adamkern wrote:
>
> > Finally, I'm wondering what's the best way to get wires up in the trees.
> >  I live near Boston, MA, where there are lots of pines, that are very
> > tall.  It is possible to climb the trees, but I've heard several ideas
> > about using a bow and arrow, or just tying rope to a rock and throwing
> > it.  Any suggestions?
> >
> What I've been using for years is the sling shot method.  Although the bow
> and arrow method works, the sling shot is less cumbersome to use.  I have
> 100' oak trees and make full use of them on a 5 acre lot.  I have a sling
> shot, with an arm rest, available from K-Mart in most states for about $8.
> I have a casting reel mounted on the side arm.  I use 15 pound
> monofilament line with 1 ounce tear drop sinkers.  You can buy everything
> at K-Mart or Walmart.  I paint the sinkers blaze orange so they are easy
> to see as they come down on the other side of the chosen limb for your
> antenna support.  This system has worked for me for the last 25 years.
>
> Ron, W4VR

My last antenna had to go over my 2-story townhouse. I settled on my
fishing pole with the maximum allowed amount of weight allowed for
it attached to the line. One cast and the job was done.

73,

Bruce, WB4YUC


From [e-mail] Sat Jul 27 19:15:08 1996
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From: [e-mail] (Kevin  AstirCS "1U"   KO0B)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: Fri, 26 Jul 1996 11:12:33 -0700 (PDT)
Organization: Aquila Technologies Group, Inc.
Lines: 14
Message-ID: <4tau2n$[e-mail]>
References: <4t3474$[e-mail]> <4t5c3h$[e-mail]> <[e-mail]>
NNTP-Posting-Host: thoreau.aquilagroup.com
X-Newsreader: Forte Free Agent v0.38

[e-mail] (Ted Kell) wrote:

>What kind of reel do you use?  I have tried the slingshot with an openface
>spinning reel and find that the line will not spin off.

With the bow, I used a Penn closed face job.  Not sure the model #...I
remember it had a ceramic eyelet where the line came out.  I think it
was pretty much top or thier closed face line.

Shooting more weight slows things down, and may allow line to come off
nicer.

-KF-



From [e-mail] Sat Jul 27 19:15:09 1996
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From: [e-mail] (Dennis Gabler)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: 26 Jul 1996 12:45:30 GMT
Organization: Microware Systems Corporation, Des Moines, Iowa
Lines: 18
Message-ID: <4taela$[e-mail]>
References: <4t3474$[e-mail]> <4t5c3h$[e-mail]> <[e-mail]> <4t6dcf$[e-mail]>
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In <4t6dcf$[e-mail]> [e-mail] (Ken Kuzenski) write
s:

>Ted, I bought a very cheap and very short (maybe 3 feet) fishing
>rod at K-Mart for about $10.  After 3 years of regular use and
>abuse, I just replaced the reel with a Zebco 202 model, for about
>$6.  This works great for me.  The one problem is holding the rod
>as I'm shooting the weight with the Wrist Rocket.

The Wrist Rocket works great except I just strap the reel to the frame of
the slingshot facing the direction of travel. No muss no fuss :-)



--
Dennis Gabler    --o--------------------------=o=--------------------------o--
                                               |
[e-mail]   KB5HVN_________________|       [e-mail]



From [e-mail] Sat Jul 27 19:15:10 1996
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From: [e-mail] (Dick Boley)
Newsgroups: rec.radio.amateur.antenna
Subject: Glass Mount - Tinted Glass ??
Date: 24 Jul 96 20:01:17 GMT
Organization: ucsd usenet gateway
Lines: 18
Message-ID: <[e-mail]>
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]


I have a dual band galss mount (2m/440) on the side window of a Voyager van.
The glass is tinted
from top to bottom with heavier tint at the top. Ant mounted about 1/3 down
on the window to avoid dense tint area.

However, cannot get it to load up. Obviously suspect the tint. Has anyone
come up with somthing to allow the use of a glass mount on tint (probably
metalic content) ???  Any "hint" ??

Regards,
Dick  N3HKN  Pittsburgh
[e-mail]
Dick Boley
Sales Engineering
Westinghouse Communications
412-247-7756



From [e-mail] Sat Jul 27 19:15:13 1996
Path: news2.epix.net!uunet!in2.uu.net!cs.utexas.edu!news.tamu.edu!news
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: grounding question
Date: 21 Jul 1996 05:12:56 GMT
Organization: Texas A&M University, College Station, Texas
Lines: 47
Message-ID: <4sse8o$[e-mail]>
References: <[e-mail]> <4so4je$[e-mail]> <4soccq$[e-mail]> <4ss8c9$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: 128.194.44.219
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In <4ss8c9$[e-mail]>, [e-mail] (pdunn) writes:
>In article <4soccq$[e-mail]>, [e-mail] says:
>>
>>In <4so4je$[e-mail]>, [e-mail] (Harris) writes:
>>>ED WELCH ([e-mail]) wrote:


>Helluva story! I have read that on boats/ships that if you place a
>grounded wire high above the superstructure that they don't get hit by
>lightning.
>
>Any one heard of this?

But Phil, there's MORE!  I'm a professional broadcast engineer as well!

One of my clients had a station in Lufkin that got hit THREE times on the
power lines like this.

The first two times, they were totaled out by the blasts.  Insurance company
picked up the tab and rebuilt them.

The third time, it completely vaporized the 140 amp main breakers inbound
to the transmitter.  That done, it set fire to the place on the way down the
racks and the wall hunting for and eventually reaching the feed line ground
to go back out to the shunt fed tower.

The stroke was neatly sunk, as have been several of mine at my country
QTH site, by the ANTENNA farm grounds!!!!!

The fire completely burned the site to the ground, leaving only the charred
feed lines out to the neat 120 radial shunt fed tower.

The insurance company refused to pay off on the loss and the station
went dark.

:)

All because the station didn't provide the equivalent sink hole for the
stroke around the perimter of the transmitter as well as out at the tower!

:)

Hams are not the only ones with empty pockebooks for protective costs!

Mike W5WQN as a guest at leviathan.tamu.edu (No mail address there)




From [e-mail] Sat Jul 27 19:15:15 1996
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From: [e-mail] (Mike Cook - AF9Y)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.space
Subject: Helix Antenna Gain Meas and New Receive Tests
Date: 27 Jul 1996 21:18:59 GMT
Organization: Your Organization
Lines: 33
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Xref: news2.epix.net rec.radio.amateur.antenna:23429 rec.radio.amateur.space:7356

         Helix Antenna Gain Meas and New Receive Tests

The test of the 5 foot, no-screen helix prototype at Central States
was most positive. In fact, the gain was over 1 dB higher than the
model predicted.  I will continue using the gain shown by AO for all
Mars Observer link caculations.

I found that the GaAs Fet preamp used in my last series of receive
test had a poor solder joint in the front end which resulted in a
much higher NF than the 0.5 stated.  I reran the receive test and
also factored in the new receive levels expected from the Mars
Observer.  The results were very encouraging.  A -173 dBm signal
level in a 100 deg K system produces an excellent trace using
the 16x integration mode of FFTDSP.  At this setting, the update
rate is once every 8 seconds.  A full screen will require only
30 minutes.

Assuming 0.5 dB coax/combiner loss, two 10ft antennas Helix antennas
would provide 18 dBic. With the new receive levels, I think this
system would provide an excellent chance of detection. In fact, just
two 5 ft Helix should be enough for detection.

With the 16x integration mode, Doppler Chirp correction will not be
necessary. At that integration mode, the display trace will have a
slope showing the Doppler Chirp which should help confirm that it is
from the Mars Observer. A 30 minute period will fill the screen and
the trace will show a linear slope of aprox 100 Hz.

Full details and pictures of the receive test results and the helix
design are available from my webpage at http://www.webcom.com/af9y





From [e-mail] Sat Jul 27 19:15:16 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.mathworks.com!newsfeed.internetmci.com!in3.uu.net!news.interlog.com!news
From: James Brooks <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna,rec.radio.amateur.equipment,sci.electronics.repair,sci.electronics.equipment,sci.electronics.design,sci.electronics.misc
Subject: Re: High and low Frequence Antannas
Date: Sat, 27 Jul 1996 13:19:22 -0700
Organization: Drastic Technologies
Lines: 16
Message-ID: <[e-mail]>
References: <[e-mail]> <4tar39$[e-mail]>
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Bob Wilson wrote:
>
>> A Guy named Moe ([e-mail]) wrote:
>> : Where can i get information on different types of antannas, how to
>>build
>> : them and how they work?
>
> Try the ARRL Handbook.
>
> Bob.

He really should learn to use a search engine.

Patrick Rea




From [e-mail] Sat Jul 27 19:15:17 1996
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From: [e-mail] (UNITOG)
Newsgroups: rec.radio.amateur.antenna
Subject: High Performance Antenna  For 30M
Date: 24 Jul 96 13:22:16 GMT
Organization: ucsd usenet gateway
Lines: 9
Message-ID: <[e-mail]>
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

I need a good performing wire antenna for 30m.  We have one 45ft.high
support (a mahogany tree) at my QTH.  I am considering a diamoned shaped
1 and 1/2 wave loop fed with ladder line at the bottom.  Can I do better ?
Your comments and suggestions will be greatly appreciated :>)

Todd DeWire
HR3TFD




From [e-mail] Sat Jul 27 19:15:17 1996
Newsgroups: rec.radio.amateur.antenna
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From: "Al Koblinski  (W7XA)" <[e-mail]>
Subject: Re: HM IV + TH5 ???
Content-Type: text/plain; charset=us-ascii
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I have used a ham IV at the top (not inside) a tower for 6 years to turn
a 5 element quad on a 8 meter boom with no problems.  I would strongly
suggest that you mount the boom as close as possible to the rotator to
minimize bending stress on the rotator case.
I don't expect you will have any problems that way.
My boom is just a few cm above the top of the rotator.  My antenna is
also quite heavy, maybe 45 kilos.
73, Al




From [e-mail] Sat Jul 27 19:15:18 1996
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From: [e-mail] (Robert G. Strickland)
Newsgroups: rec.radio.amateur.antenna
Subject: How many ferite beads make a balun?
Date: Sat, 20 Jul 1996 20:44:40 GMT
Organization: ServiceTech, Inc.
Lines: 8
Message-ID: <4srk1k$[e-mail]>
NNTP-Posting-Host: regcon.syr.servtech.com
X-Newsreader: Forte Free Agent 1.0.82

I'm building some antenna feed point baluns using Amidon ferite
sleve-beads. They're each about one inch long. How many, more or less,
should I use to make an effective balun for 20-10m. Thanks.

...Robert





From [e-mail] Sat Jul 27 19:15:19 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!nntp.primenet.com!tank.news.pipex.net!pipex!oleane!jussieu.fr!math.ohio-state.edu!uwm.edu!lll-winken.llnl.gov!fnnews.fnal.gov!nntp-server.caltech.edu!news.ridgecrest.ca.us!kusznir
From: [e-mail] (Jim Kusznir)
Subject: Re: How to measure sig.on 2 ant.and use strongest
X-Nntp-Posting-Host: annex030
Message-ID: <[e-mail]>
Sender: [e-mail] (Ridgenet Usenet admin)
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References: <4s8la3$[e-mail]>
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Far out <[e-mail]> wrote:

> I was flipping through a magazine a few years ago at a newstand, and came
> across an article on how to build a gizmo that weighs the signal between
> two antennas, and switches back and forth to the strongest. It was aimed
> at cb users I believe, but now that I have a cellular, I'm thinking I
> should have bought the magazine. What do you think, if I had an antenna
> at either end of my motorhome, would it:
> (A) Give me the the best possible reception
> (B) Give me worse reception
> (C) Do absolutely nothing at all
> If the answer is A does anyone know where I can find the article, or similar
> how to.
>
> Terry

Sounds like a voter to me.  If it is working corectly, it will always
choose the best antenna.  The difficulty is that each antenna must have
its own receaver (to my knolodge), which pretty much rules out use on
cell phones.  It works well for repeaters, though.


--
73 de Jim Kusznir, KE6DWM

[e-mail] (Primary Internet)
ke6dwm@wa6ybn.#soca.ca.usa.noam (Ametuar Radio Packet System only)


From [e-mail] Sat Jul 27 19:15:20 1996
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From: [e-mail] (VoltageS)
Newsgroups: rec.radio.amateur.antenna
Subject: IC-706 Antenna Tuners
Date: 22 Jul 1996 09:48:25 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Sender: [e-mail]
Message-ID: <4t00r9$[e-mail]>
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NNTP-Posting-Host: newsbf02.mail.aol.com

Would appreciate any info , difference between and basic specs on AH-3 and
AT-180.  Thanks


From [e-mail] Sat Jul 27 19:15:21 1996
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From: [e-mail] (VoltageS)
Newsgroups: rec.radio.amateur.antenna
Subject: ICOM IC-706 Antenna Tuner AH-3
Date: 24 Jul 1996 14:44:01 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 3
Sender: [e-mail]
Message-ID: <4t5qth$[e-mail]>
Reply-To: [e-mail] (VoltageS)
NNTP-Posting-Host: newsbf02.mail.aol.com

Does anybody out there know what is the shortest RANDOM LENGTH end fed
wire this tuner will handle on 80 meters?  I would like to get some input
from IC-706/AH-3 users.  Thanks de Gene K2AKV


From [e-mail] Sat Jul 27 19:15:22 1996
Path: news2.epix.net!uunet!in2.uu.net!newsxfer2.itd.umich.edu!newsfeed.internetmci.com!miwok!news.mcn.org!usenet
From: [e-mail] (Dan Richardson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-Pole gain
Date: Sat, 20 Jul 1996 13:45:44 GMT
Organization: LPS Systems
Lines: 74
Message-ID: <4sqr9r$[e-mail]>
References: <4se01v$[e-mail]> <4siunl$[e-mail]> <4sqq30$[e-mail]>
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[e-mail] (Dan Richardson) wrote:

>[e-mail] (W8JI  Tom) wrote:

>>In article <4sc71h$[e-mail]>, [e-mail] (Dan Richardson) writes:

>>>
>>>The same gain as a ╜ wave dipole..... the bottom section (╝ wave
>>>length long) does not radiate...
>>>
>>>Danny, K6MHE

>>Hi Danny,

>>I have one question. **What prevents the stub from radiating?**

>>It's my understanding that any transmission line, including both coaxial
>>or balanced lines, radiate when currents in both conductors are not equal
>>and 180 degrees out of phase.

>>At the top of the stub (which is a two wire transmission line), one
>>conductor hooks to the several hundred ohm element and the other hangs
>>free. Thus the currents in the stub can not be equal, or 180 degrees out
>>of phase, throughout the length of the stub.

>>Since stub currents can not be equal and opposite, the stub must radiate.

>>Tell me where my mistake is please.

>>73 Tom

>Good question Tom,

>The j-pole is really nothing more than an end feed ╜ wave element
>connected to a ╝ wave stub. The lower portion (the  ╝ wave stub) is
>used for matching the feed line (usually coax) which is connected at a
>point on the stub for proper match.

>The lower portion (the ╝ stub) does not radiate for the same reason
>that balance lines do not radiate.  As long as the two conductors 180
>degrees out of phase and are spaced by less than 0.01 wave length
>between them there will be no radiation as the fields from the
>conductors (for all practical purposes) cancels each other.

>To be absolutely correct the lower portion of a J-pole does radiate a
>very small portion. The reason being that the two fields the ╝ wave
>section are not 180% out of phase.. If you consider that one side of
>the ╝ wave stub is connected to the end of a self-resonate ╜ wave
>element is in the neighborhood of 4000 ohms while the other end is
>connected to nothing (infinite impedance) This difference does cause a
>small difference in phase between the two conductors. Because the
>phase is not exactly 180 degrees apart (but very close) a small amount
>of radiation takes place.

>Note however, note that the radiation is the result of the phase not
>being exactly 180 degree apart but something less.

>73- Danny


I wrote too fast.... The radiation is in the stub portion results from
a difference in the current flow not the phase.....

4,000 ohms vs infinite impedance at the stub ends results in a
inbalance if current flow....

I'll proof read better next time...

73 Danny







From [e-mail] Sat Jul 27 19:15:23 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-Pole gain
Date: 23 Jul 1996 11:22:40 -0400
Organization: America Online, Inc. (1-800-827-6364)
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Hi Gary,
In article <[e-mail]>, [e-mail]
(Gary Coffman) writes:

>I think your mistake (if you're making one) is <snip>

>The same is true when we try to assign a finite impedance to the
>current zero point of an antenna. There isn't one, though the
>currents rushing toward and away from the point might appear
>externally to allow us to assign one.

There is no "current zero point" over the length of any pratical antenna,
not even at the open end.  A "current zero point" could only exist if the
antenna was lossless, in that case the reflected current would cancel
forward current and current would indeed reach zero.  But since the
antenna has distributed losses as well as radiation field losses, the
current never reaches zero anywhere.

Current doesn't even reach zero at the very end of a finite cross section
conductor. Current is not zero at the very end of the very last molecule
of the antenna because current makes a transistion into the electric field
at that point.

>This is like trying to take
>a limit on a function at a point of singularity. We can get a
>finite answer, but we have to treat it very carefully in the way
>we give it physical interpretation.

I'll say. And "very carefully" involves research and careful consideration
of the problem. With that in mind:

1.) Jasik, Kraus, Jordan, Bailman, and Kuecklin list the maximum end
impedance of a half wave radiator as a finite value that depends upon the
radiated field, conductor Zo, and losses. The end impedance values range
from a few hundred ohms to a few thousand depending on conductor surge
impedance and radiated field levels.  Are these engineering texts
incorrect?

2.) A half-wave broadcast tower can be end-fed with a L network of modest
component values. Jasik lists real world values of a few hundred to
several hundred ohms. How can this be if current is "zero"?

3.) If the current is zero, voltage is infinite for even one milliwatt of
applied power. How do insulators at broadcast stations stand this power?
Why doesn't the feedpoint of a J-pole arc over to the nearest conductor?
Why doesn't a 1 watt transmitter cause corona problems with such high
(infinite) impedances?

While the reflected current pulse argument sounds convincing, it totally
neglects radiation and resistive effects.

73 Tom


From [e-mail] Sat Jul 27 19:15:24 1996
From: [e-mail] (Claton Cadmus)
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-res.gsl.net!news.gsl.net!hunter.premier.net!news.cais.net!mr.net!news.mr.net!medtronic.com!rosevax!hamlink!fredmail
Newsgroups: rec.radio.amateur.antenna
Subject: J-pole Gain
Message-ID: <[e-mail]>
Date: Fri, 26 Jul 1996 16:06:12
X-FTN-To: [e-mail]
Lines: 23

Tom W8JIT writes to Danny,

W8>It's my understanding that any transmission line, including both coaxial
  >or balanced lines, radiate when currents in both conductors are not equal
  >and 180 degrees out of phase.

This is correct.

W8>At the top of the stub (which is a two wire transmission line), one
  >conductor hooks to the several hundred ohm element and the other hangs
  >free. Thus the currents in the stub can not be equal, or 180 degrees out
  >of phase, throughout the length of the stub.

Here is where you have made your mistake, the half wave dipole section
is also a single conductor transmission line and reflects the impedence
seen at it's open end which is many thousands of ohms, not several
hundred.  It's also equal to that seen at the open end of the stub.
Therefore the matching section is balanced.

73 de  Claton Cadmus,  KA0GKC
 * SLMR 2.1a * Remember, you are unique, just like everyone else!




From [e-mail] Sat Jul 27 19:15:25 1996
Path: news2.epix.net!uunet!in3.uu.net!oronet!usenet
From: [e-mail] (Jim Weir)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-Pole gain
Date: Thu, 25 Jul 1996 14:26:51 GMT
Organization: RST Engineering
Lines: 34
Message-ID: <4t809q$[e-mail]>
References: <4t5l1f$[e-mail]> <4t6m42$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: rst-engr.oro.net
X-Newsreader: Forte Free Agent 1.0.82

[e-mail] (W8JI  Tom) shared the following priceless pearls of
wisdom:

->Perhaps you could describe the details of that antenna, including
the feed
->method you used, since that is critical to the performance of both
->antennas.

That is why I posted the website of the construction details as well
as some scanned photos.


->The question in my mind isn't how much worse than a half-wave the J
pole
->is,

That is my point -- it is within experimental error the same as a half
wave, with the attendant benefits of not having to make either a
ferrite or coax balun to feed it, being grounded for lightning and
p-static, and hell for stout.

 but rather how much (if any) better than a simple 1/4 gp it is.

Dependent on the droop of the radials, I'd expect at least two dB or
so in terrestrial applications, slightly less in airborne.

Jim

Jim Weir VP Engineering | You bet your sweet patootie I speak for the
RST Engineering         | company.  If I don't, ain't nobody gonna.
Grass Valley CA 95945   |
http://www.rst-engr.com | AR Adv WB6BHI--FCC 1st phone---Cessna 182A N73CQ
[e-mail]        | Commercial/CFI-Airplane/Glider-A&P-FAA Counselor



From [e-mail] Sat Jul 27 19:15:26 1996
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From: [e-mail] (Rolfe Tessem)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Kurt, help us please!
Date: 26 Jul 1996 20:07:00 GMT
Organization: Lucky Duck Productions, Inc.
Lines: 17
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In <4t6mc6$[e-mail]>, [e-mail] (W8JI  Tom) writes:
>I've just read the most interesting antenna article I've ever read. August
>CQ, Antennas and Digital communications. I think everyone will enjoy this
>article, especially Kurt N. Sterba. I can't wait 'til he sees it!

(Enjoying tidbits deleted)

Hmmm...and it's getting rather late in the year for the April issue,
isn't it?

Rolfe
W3VH

--
Rolfe Tessem         |     Lucky Duck Productions, Inc.
[e-mail]        |     96 Morton Street
[phone]       |     New York, NY 10014


From [e-mail] Sat Jul 27 19:15:27 1996
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From: Merv Stump <[e-mail]@postoffice.worldnet.att.net>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Kurt, help us please!
Date: 26 Jul 1996 11:23:41 GMT
Organization: AT&T WorldNet Services
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References: <4s0h7j$[e-mail]> <4t6mc6$[e-mail]>
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I was very disappointed that he failed to point out that the "fact" that
the reason isotropic antennas are seldom used by amateurs is they are so
small they are always getting lost.  Regards, Merv



From [e-mail] Sat Jul 27 19:15:30 1996
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Lightning strikes!!!
Date: 21 Jul 1996 23:02:48 GMT
Organization: Texas A&M University, College Station, Texas
Lines: 59
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In <[e-mail]>, [e-mail] (Jim Hammock) w
rites:
>On 07-15-96 23:04, STEVE O'DONNELL <SODONNE was talking to ALL
> about Lightning strikes!!!:
>

> Our dog now has a permanent prescription for valium and is a better
> indicator of thunderstorms than the NWS.

Your dog may be, but when I took the last big hit on the AC mains, I was
asleep in bed.  Note I said WAS.  My gear at the fixed site is in the next
room.  It rolled me out of bed, I don't exactly know if I bolted out or was
blown out.  The air was full of ozone.  It did NOT trip the AC mains breakers,

the power was still hot.  Travelled the entire house on the ground busses I
had so carefully installed everywhere.  Melted down all the ground pins in
many of the receptacles and plug cords.

Of course, wits collected, this isn't the first time for all this, at 3:00 a.m
.,
I'm totalling up what does and does not work....   One has to go on living,
if one is alive.  If you can count up the damage, you made it...

Let's see now.  Three hits at sea as a marine radio op for Texas A&M and
electronics engineer aboard their research vessel.  Radio room is topside on
a converted wood hulled UNS mine sweeper behind the wheel house just
ahead of the stacks.  My car has been hit with me in it - blown left front
tire where the stroke went from the rim to the pavement.  I've taken four
hits I know about in our company Beech Baron's flying hard IFR upstairs.
One hit to a light pole in Houston on the street trying to get out of the mess
.
Four direct or near direct hits at my country fixed site that I know about.

At least three a year direct while on premises as a Chief Engineer at WTAW
in College Station for many years.  I get to thinking about all this whenever
I go outside and hear this tic, tic, tic, tic, .....

The real interesting stuff is when you are sitting in your vehicle outside
SAMS in the parking lot and you hear your BC receiver in the truck going
tic, tic, tic, until it becomes a roar and then BOOM.  I stay in the truck.
All the other fools are running across the parking lot trying to keep
from getting wet.....   Every thirty seconds to a minute, roar becomes
BOOM someplace within a few miles or so....

Use your BC receiver for an alerter - WONDERFUL tool...

:)

Your dog may be paranoid, but I'm not on Vallium....

I hear the facility go click a lot when I am there during the frontal
passages, but I've learned with all the big iron up there, you may as well
just tough it out.

GROUND the stuff as best as you can afford to do.  The rest is useless once
the iron is up there and the ground network is in under it.....

I guess more things are wrought by prayer and grounds than this world
dreams about and most folsk have ever discovered....

:)

Mike W5WQN as a guest at leviathan.tamu.edu (No mail address there)


From [e-mail] Sat Jul 27 19:15:31 1996
Path: news2.epix.net!uunet!in2.uu.net!cs.utexas.edu!bcm.tmc.edu!news.tamu.edu!news
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Lightning strikes!!!
Date: 21 Jul 1996 05:17:52 GMT
Organization: Texas A&M University, College Station, Texas
Lines: 40
Message-ID: <4ssei0$[e-mail]>
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In <[e-mail]>, Clifford Soderback <[e-mail].
net> writes:
>Cecil Moore wrote:
>>
>> [e-mail] wrote:
>> > The ONLY way I've ever seen that is half way safe, is to do the job right
,
>> > starting with a through job of diversion to ground on your antennae,...
>>
>> Hi Mike, How about doing what I do. Disconnect the ladder-line from the
>> banana plugs that lead into the house and toss the feedline 15 yards away
>> from the house? Cheap, easy, effective and at least halfway safe. :-)
>>
>> 73, Cecil, W6RCA, OOTC  (not speaking for my employer)
>
> Cecil:
>        Be sure to unplug your Rx & Tx from the AC line. The AC power
>has a much higher chance of incurring a EMP pulse or a direct hit
>than your antenna. I have had equipment destroyed several miles from
>a hit by surges through the AC line. In one case it actually evaporated
>the AC wire. I don't have much faith in the so called surge protectors,
>but some offer a $25,000 insurance policy which might make the purchase
>worthwhile in a high hit area.
>
>                            Cliff, W7VVA

Check Zero Surge's literature.  The MOV stuff is just about GUARANTEED to
wast anything with a switching power supply for making DC, as well as
virtually every serial port device, external printer and network card box
you have.  It's nice to have the money, but almost guaranteed your have to
have it if, as you are VERY correct, your AC line is the entry point.

Polyphazor has their act together as well.  Check their books...

I have LOTS of vaporized samples of I/O stuff, modems, etc., etc., to
prove it and to show off......


Your antenna farm is only PART of the problem...

Mike W5WQN as a guest at leviathan.tamu.edu  (No mail addresss there)



From [e-mail] Sat Jul 27 19:15:34 1996
Path: news2.epix.net!uunet!inXS.uu.net!nntp.primenet.com!winternet.com!tclbbs.com!jim.hammock
From: [e-mail] (Jim Hammock)
Newsgroups: rec.radio.amateur.antenna
Subject: Lightning strikes!!!
Date: Sun, 21 Jul 1996 10:15:00 GMT
Message-ID: <[e-mail]>
Organization: The City Lights BBS
Distribution: world
Lines: 32

On 07-15-96 23:04, STEVE O'DONNELL <SODONNE was talking to ALL
 about Lightning strikes!!!:

SO>As an aircraft mechanic who maintains a single DC-9 for NASA, I must te
SO>all that there are no absolute insulators for a direct strike! I have
SO>seen glass position light lenses melted and scarred from such encounter
SO>and medium frequency antenna couplers (ADF) blown apart! And those
SO>strikes were above 20,000 feet in clouds. The only sure way to avoid
SO>damage is to DISCONNECT!73, N5LAP

        Disconnect and ground. Our house in NC was a lightning magnet! Five
hits on our 1/2 acre lot in as many years. All were just trees until the last
hit.
        The lightning struck a pine tree in the front yard, came down the
tree 20+ feet, jumped an air gap of fifteen feet to our second story soffit,
went along an aluminum vent and into the bathroom. It blasted a number of
holes in the drywall, the largest 2" in diameter, traveled across the metal
shower curtain rod, and split it's path. One leg went through the other
drywall across a nail in the framing and down the hot (now very hot) water
pipe. The other leg jumped four feet to a towel rod, entered the mirror and
exited the mirror at the two faucet and two light fixtures, burning off the
silver at entrance and exit points. Our dog now has a permanent prescription
for valium and is a better indicator of thunderstorms than the NWS.
        Bunches of stuff was affected, no ham gear (Thank God), but I firmly
believe in disconnecting and grounding. (Also not being in the
bathroom during thunderstorms!)



Jim KI0DN
---
 * PW * Keep the shack warm.. Run radios with tubes !!


From [e-mail] Sat Jul 27 19:15:35 1996
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From: [e-mail] (John DeCicco)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Long Wire or loop antenna
Date: Sun, 21 Jul 1996 05:24:24 GMT
Organization: SoVerNet, Inc.
Lines: 29
Message-ID: <4ssenv$[e-mail]>
References: <01bb6c84.06affba0$53cbc2d0@main> <[e-mail]>
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Gary Watts <[e-mail]> wrote:


>Hello All,

>I'm looking for some ideas for a General Coverage antenna  :-)

>I currently have up a 540 foot loop antenna which has come down
>after being up in the air for a couple of years.
>IT worked great on the lower freqs but a g5rv did better on the higher
>freqs.
>Cant remember specifics frequency ranges tho :-(

Greetings,

I would suggest the loop, fed with 450 ohm ladder line.  100 feet of
coax will cut down the signal that eventually reaches the xcvr
(half?), whereas LL will produce almost no loss, especially at the
lower frequencies.  The loop will work well fed at one point.
However, my 160m loop didn't work well on the highewr freq's.
If you want 30m and higher, ty an extended lazy h (n4pc).  Works great
with ladder line, too.

Have fun,

John, KC1IQ
Brandon, VT




From [e-mail] Sat Jul 27 19:15:36 1996
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From: [e-mail] (Brad K.)
Newsgroups: rec.radio.amateur.antenna
Subject: MFJ Transmitter-Antenna Switch Model-1700B
Date: Sat, 20 Jul 1996 19:47:48 GMT
Organization: bkarthau
Lines: 7
Sender: [e-mail]
Message-ID: <4srd5d$[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: ceres.execpc.com
X-Newsreader: Forte Free Agent 1.0.82

Transmitter-Antenna Switch for sale.

        Common and A-F Outputs for Transmitter.
        Common and 1-6 Inputs for Receiver.

Very well built.  $50 / obo. plus shipping.



From [e-mail] Sat Jul 27 19:15:37 1996
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From: A Guy named Moe <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Modem Information
Date: Thu, 25 Jul 1996 01:12:59 -0700
Organization: **************
Lines: 8
Message-ID: <[e-mail]>
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Xref: news2.epix.net rec.radio.amateur.homebrew:16245 rec.radio.amateur.antenna:23387 rec.radio.amateur.equipment:31299

Does anyone have schematics, comonent lists, layouts of 14.4 kbps or
28.8 kbps modems? any make will do.  I also need information on radio
monems like how they work, detailed explanations, schematics and stuff
like that.   Where are some good places to find information like this on
the 'net??


thanks


From [e-mail] Sat Jul 27 19:15:38 1996
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From: [e-mail] (Michael J. Donohue)
Newsgroups: rec.radio.amateur.antenna
Subject: Need Help With Butternut HF6V-X
Date: Mon, 22 Jul 1996 11:26:34 GMT
Organization: IGS - Information Gateway Services
Lines: 23
Message-ID: <[e-mail]>
NNTP-Posting-Host: ttya01.renc.igs.net
X-Newsreader: Forte Agent .99e/16.227

Hi:
     Just getting around to setting up the Butternut Vertical and the
CPK.  Tuning it seems to be the problem on a few of the bands other
that that all is going ok. However I need some help with the tuning
from anyone who might have some experience with this antenna. I have
played around with the 30m coil for over a day and still no success.
From below I am having problems moving the resonant freq on 3 bands,
here is what I have as of today:

Band    Desired Freq    Actual Freq     VSWR

80m      3762                3762                1.3:1
40m      7075                8200                1.5:1 *
30m     10115              10775               1.1:1 *
20m     14155              14885               1.5:1 *
15m     21242              21242               1.2:1
10m     28750              28750               1.1:1

    Any help and or observations would be greatly appreciated. Tnx

Michael VE3DMJ




From [e-mail] Sat Jul 27 19:15:38 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!tank.news.pipex.net!pipex!nntp.primenet.com!news.cais.net!mr.net!winternet.com!n1ott.istar!ott.istar!istar.net!tor.istar!east.istar!news
From: A Guy named Moe <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Packet Modems
Date: Thu, 25 Jul 1996 14:06:40 -0700
Organization: **************
Lines: 2
Message-ID: <[e-mail]>
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Does  anyone know how they work and were to get inforation on the net.
I can not go to a local book store because there is not one near by.


From [e-mail] Sat Jul 27 19:15:39 1996
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From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re. Non-contaminating jacket
Date: 25 Jul 96 00:12:02 GMT
Organization: ucsd usenet gateway
Lines: 21
Message-ID: <[e-mail]>
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

Ken --

     A cable with a non-contaminating jacket is more suitable for outdoor use
than a 'regular' jacket material.  UV will cause a chemical reaction over
time in a PVC material (normal coax jacket) that will cause the chloride
(polyvinyl chloride, remember?) to leach, or migrate, out of the jacket
towards the middle of the cable.  Over time the chloride will coat each
strand of the braid and will insulate the strands from each other.  The
strands will have continuity from end to end but not from strand to strand.
 This causes SWR and efficiency problems in the coax.  This is a big problem
in locations with lots of sunshine or higher elevations exposed to more UV.
 Here in the Pacific Northwest, it's not as big a problem.

     BTW, you may want to subscribe to Towertalk - the tower and antenna
reflector.  Send a message to [e-mail] with the word
subscribe in the message and you'll get signed up.  Lots of interesting
people with good info available.  See you there!

73,  Steve   K7LXC

    TOWER TECH  -- professional tower supplies and services for amateurs


From [e-mail] Sat Jul 27 19:15:40 1996
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From: [e-mail] (VoltageS)
Newsgroups: rec.radio.amateur.antenna
Subject: SPIDER MULTI-BAND ANTENNAS
Date: 23 Jul 1996 10:37:40 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 2
Sender: [e-mail]
Message-ID: <4t2o3k$[e-mail]>
Reply-To: [e-mail] (VoltageS)
NNTP-Posting-Host: newsbf02.mail.aol.com

I would appreciate some input from anyone using the Spider multi-banders.
Are they efffective, concealable, tuning range?  thanks de gene K2AKV


From [e-mail] Sat Jul 27 19:15:41 1996
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From: [e-mail] (RAMSES1234)
Newsgroups: rec.radio.amateur.antenna
Subject: SR, RF/MICROWAVE DESIGN ENGINEERS WANTED!
Date: 20 Jul 1996 17:56:02 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 17
Sender: [e-mail]
Message-ID: <4srkli$[e-mail]>
Reply-To: [e-mail] (RAMSES1234)
NNTP-Posting-Host: newsbf02.mail.aol.com

M/A-COM PHI is a state-of-the-art designer and manufacturing of RF and
microwave transistors and amplifiers utilizing bipolar and MOSFET
technology. We are looking for creative and technically qualified circuit
design engineers with 5+ years experience in microwave circuit/component
design and applications, with a BSEE or advanced degree.

Microwave power bipolar and MOSFET familiarity is desirable. Our company
offers a competitive compensation and benefits package. Please submit your
resume and salary history in confidence to:

M/A-COM
1742 Crenshaw Blvd.-Torrance, CA 90501
FAX [phone]
VISIT OUR WEB SITE-www.macom-phi.com
Fax: [phone]
e-mail: [e-mail]
EOE/M/F/H/V


From [e-mail] Sat Jul 27 19:15:42 1996
Path: news2.epix.net!uunet!in2.uu.net!01-newsfeed.univie.ac.at!02-newsfeed.univie.ac.at!news.ecrc.de!news.mch.sni.de!news.sni.de!kebsch
From: [e-mail] (Kebsch)
Newsgroups: rec.radio.amateur.antenna
Subject: SWR and matching problems?
Date: 23 Jul 1996 11:20:52 GMT
Organization: Siemens Nixdorf Informationssysteme AG, Paderborn, Germany
Lines: 59
Message-ID: <4t2cik$[e-mail]>
Reply-To: Waldemar Kebsch <[e-mail]>
NNTP-Posting-Host: norman.pdb.sni.de

Hi, I am a German and my English is not the very best, so I am asking
    for your sympathy .. :-)

from time to time we have a very long and interesting discussion here,
what to do and what not to do, if the antenna impedance don't match the
impedance of the feeding line, a 50 ohm coax usually.

We know: A 50 ohm coax feeding line may have an frequency independent
         lenght, if the output impedance of the generator (TX) is 50 ohm
         and the input impedance of the load (antenna) is 50 ohm.

Let say: Our antenna has an input impedance of 37 ohm and we have "tuned"
         the output impedance of our TX with a pi filter (= antenna tuner)
         to 37 ohm; all what we need now is a coax feeding line with an
         impedance of 37 ohm!

Now you are thinking I am kidding you, right? There is no coax with 37 ohm
available! But, as HAM's, we have learned to build everything by ourself,
if it's not available at the next HAM shop. We cut the coax to the
electrical half wave lenght of the resonance frequency of our antenna.
Then this coax line has the same impedance like the TX and the antenna.
You got the message? >>"The same impedance"<<. If your antenna has an
input impedance of i.e. 25 ohm and you have "tuned" the output impedance
of your TX to 25 ohm also, then this coax works like a 25 ohm coax line!

If the mechanical lenght of the coax is to short to connect your antenna to
your radio in your shack, then make the coax exactly 2, 3, 4, 5, .. times
longer, than the prior calculated mechanical length. No problem, it works!

You have a "3-element-3-band beam" for 20m/15m/10m? Don't worry, it works
with one coax cable; it's not necessary to run seperate cables and coax
switches. Calculate the mechanical length for the 20m band and cut the cable
to a length of factor 2, 4, 6, 8, 10, ..

Last question: How to calculate the mechanical lenght? You have to know
the "Shortening Factor" of the coax cable you want to use. Sorry I don't
know the right English word for this parameter, sorry, sorry. If you don't
know this parameter of your coax then your dealer should be able to help.
In almost all cases this parameter has a value in the range of 0.67..0.87.

   len (m)   = (300000 / (2 * f)) * SF

   len (ft.) = (984252 / (2 * f)) * SF

f = frequency in kHz, SF = this misterious "Shortening Factor"

That's it!

73 de Waldemar, DK3VN

PS: In my previous posting, which I have cancelled (!), there was a little
    typo in the formulas ... :-(
--
E-Mail:  [e-mail] .. or .. Packet Radio:  DK3VN @ DB0NOS.#NRW.DEU.EU
Big antennas, high in the sky, are better than small ones, low!          [b9h]

--
E-Mail:  [e-mail] .. or .. Packet Radio:  DK3VN @ DB0NOS.#NRW.DEU.EU
Big antennas, high in the sky, are better than small ones, low!          [b9h]


From [e-mail] Sat Jul 27 19:15:44 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!in3.uu.net!news3.agis.net!agis!NEWS!not-for-mail
From: Bob Lewis <[e-mail]>
Subject: Re: SWR and matching problems?
Message-ID: <[e-mail]>
Date: Thu, 25 Jul 1996 06:45:41 -0400
References: <4t2cik$[e-mail]>
Organization: AA4PB
X-Mailer: Mozilla 2.01 (Win95; U)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 67

Kebsch wrote:
>
> Hi, I am a German and my English is not the very best, so I am asking
>     for your sympathy .. :-)
>
> from time to time we have a very long and interesting discussion here,
> what to do and what not to do, if the antenna impedance don't match the
> impedance of the feeding line, a 50 ohm coax usually.
>
> We know: A 50 ohm coax feeding line may have an frequency independent
>          lenght, if the output impedance of the generator (TX) is 50 ohm
>          and the input impedance of the load (antenna) is 50 ohm.
>
> Let say: Our antenna has an input impedance of 37 ohm and we have "tuned"
>          the output impedance of our TX with a pi filter (= antenna tuner)
>          to 37 ohm; all what we need now is a coax feeding line with an
>          impedance of 37 ohm!
>
> Now you are thinking I am kidding you, right? There is no coax with 37 ohm
> available! But, as HAM's, we have learned to build everything by ourself,
> if it's not available at the next HAM shop. We cut the coax to the
> electrical half wave lenght of the resonance frequency of our antenna.
> Then this coax line has the same impedance like the TX and the antenna.
> You got the message? >>"The same impedance"<<. If your antenna has an
> input impedance of i.e. 25 ohm and you have "tuned" the output impedance
> of your TX to 25 ohm also, then this coax works like a 25 ohm coax line!
>
> If the mechanical lenght of the coax is to short to connect your antenna to
> your radio in your shack, then make the coax exactly 2, 3, 4, 5, .. times
> longer, than the prior calculated mechanical length. No problem, it works!
>
> You have a "3-element-3-band beam" for 20m/15m/10m? Don't worry, it works
> with one coax cable; it's not necessary to run seperate cables and coax
> switches. Calculate the mechanical length for the 20m band and cut the cable
> to a length of factor 2, 4, 6, 8, 10, ..
>
> Last question: How to calculate the mechanical lenght? You have to know
> the "Shortening Factor" of the coax cable you want to use. Sorry I don't
> know the right English word for this parameter, sorry, sorry. If you don't
> know this parameter of your coax then your dealer should be able to help.
> In almost all cases this parameter has a value in the range of 0.67..0.87.
>
>    len (m)   = (300000 / (2 * f)) * SF
>
>    len (ft.) = (984252 / (2 * f)) * SF
>
> f = frequency in kHz, SF = this misterious "Shortening Factor"
>
> That's it!
>
> 73 de Waldemar, DK3VN
>
> PS: In my previous posting, which I have cancelled (!), there was a little
>     typo in the formulas ... :-(
> --
> E-Mail:  [e-mail] .. or .. Packet Radio:  DK3VN @ DB0NOS.#NRW.DEU.
EU
> Big antennas, high in the sky, are better than small ones, low!          [b9
h]
>
> --
> E-Mail:  [e-mail] .. or .. Packet Radio:  DK3VN @ DB0NOS.#NRW.DEU.
EU
> Big antennas, high in the sky, are better than small ones, low!          [b9
h]

This recommendation solves the matching problem at the transmitter BUT
the coax cable still has the SWR and resulting losses.  If SWR is not
too bad then no problem, but if the SWR is high you only fool the
transmitter and yourself.  My opinion - it is much better to make the
antenna 50 ohms so that it matches the impedance of the cable.



From [e-mail] Sat Jul 27 19:15:45 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-res.gsl.net!news.gsl.net!swrinde!cs.utexas.edu!howland.reston.ans.net!news-e2a.gnn.com!pop.gnn.com!KB2UFS
From: [e-mail] (Mike Duda)
Newsgroups: rec.radio.amateur.antenna
Subject: TEST POST
Date: Thu, 25 Jul 1996 00:27:40
Organization: GNN
Lines: 4
Message-ID: <4t6ti6$[e-mail]>
NNTP-Posting-Host: 8-35.client.gnn.com
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
X-GNN-NewsServer-Posting-Date: 25 Jul 1996 04:35:16 GMT
X-Mailer: GNNmessenger 1.3

JUST A TEST

73 DE KB2UFS, Mike



From [e-mail] Sat Jul 27 19:15:45 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news-res.gsl.net!news.gsl.net!hunter.premier.net!news.nl.innet.net!INnl.net!news.be.innet.net!INbe.net!tank.news.pipex.net!pipex!oleane!in2p3.fr!swidir.switch.ch!scsing.switch.ch!ubnsrv.unisource.ch!news
From: [e-mail] (Markus Buehler)
Newsgroups: rec.radio.amateur.antenna
Subject: TET-EMTRON Beam TE-33 ???
Date: Thu, 25 Jul 1996 18:24:28 GMT
Organization: Unisource Business Networks
Lines: 7
Message-ID: <4t8ag6$[e-mail]>
NNTP-Posting-Host: pub01-ppp06.hitline.ch
X-Newsreader: Forte Free Agent 1.0.82

Does anybody out there has informations about the
TET-EMTRON Beam TE-33 or similar antennas
from this company ? Price ?
Any comments are welcome.
Thank's a lot.
HB9CPW  Marc, Switzerland



From [e-mail] Sat Jul 27 19:15:46 1996
Path: news2.epix.net!uunet!inXS.uu.net!newsfeed.internetmci.com!solaris.cc.vt.edu!pelt.ams.vt.edu!user
From: [e-mail] (Ranson J. Pelt)
Newsgroups: rec.radio.amateur.antenna
Subject: Wanted 40-2CD
Date: Mon, 22 Jul 1996 08:11:06 +0000
Organization: Virginia Tech
Lines: 10
Message-ID: <[e-mail]>
NNTP-Posting-Host: pelt.ams.vt.edu

I'm looking for a used 40-2CD, forty meter yagi.  If you have one you want
to sale, please contact me.

Tnx

--
Ranson J. Pelt

[e-mail]
QST de w4wyt


From [e-mail] Sat Jul 27 19:15:47 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-pen-4.sprintlink.net!news.inc.net!uwm.edu!lll-winken.llnl.gov!ames!agate!newsgate.duke.edu!godot.cc.duq.edu!newsfeed.pitt.edu!newsflash.concordia.ca!news.nstn.ca!ott.istar!istar.net!van.istar!west.istar!uniserve!oronet!news.acsu.buffalo.edu!news.drenet.dnd.ca!crc-news.doc.ca!nott!nntp.igs.net!usenet
From: [e-mail] (Stan Sanderson)
Newsgroups: rec.radio.swap,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc
Subject: WTB: H.D. Rotor for 35 sq. ft of antennas
Date: Tue, 23 Jul 1996 12:41:14 GMT
Organization: IGS - Information Gateway Services
Lines: 6
Message-ID: <4t23ev$[e-mail]>
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Xref: news2.epix.net rec.radio.swap:70600 rec.radio.amateur.antenna:23361 rec.radio.amateur.equipment:31244 rec.radio.amateur.misc:105443

Want to buy. An antenna rotor that will handle 35 sq ft of antenna.
73 Stan VA3DS
Email: [e-mail]
Tel: [phone]
Packet: VA3DS@VE3NUU



From [e-mail] Thu Aug 01 21:20:45 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sgi.com!enews.sgi.com!lll-winken.llnl.gov!nntp.coast.net!zombie.ncsc.mil!newsgate.duke.edu!agate!info.ucla.edu!newsfeed.internetmci.com!news1.mnsinc.com!usenet
From: John P Smith <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 160m vertical?
Date: Mon, 29 Jul 1996 23:41:19 -0700
Organization: Monumental Network Systems
Lines: 7
Distribution: inet
Message-ID: <[e-mail]>
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A number of years ago W6SAI had a 160 meter vertical in his book that
consisted of an 80 ft horizontal wire and a 40 ft vertical wire soldered
to its center and dropped straight down and loaded with an inductor at
the base.  Has anyone used this antenna?  Could I instead run coax into
the shack and feed it into a tuner and get good results.
73
John KI4RO...anxiously awaiting winter! HI


From [e-mail] Thu Aug 01 21:20:46 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!cyberspace.com!news1.wtn.mci.net!newsfeed.internetmci.com!newsxfer2.itd.umich.edu!portc01.blue.aol.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 160m vertical?
Date: 30 Jul 1996 13:17:15 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 23
Sender: [e-mail]
Message-ID: <4tlg2r$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: newsbf02.mail.aol.com
X-Newsreader: AOL Offline Reader

In article <[e-mail]>, John P Smith <[e-mail]>
writes:

>
>A number of years ago W6SAI had a 160 meter vertical in his book that
>consisted of an 80 ft horizontal wire and a 40 ft vertical wire soldered
>to its center and dropped straight down and loaded with an inductor at
>the base.  Has anyone used this antenna?  Could I instead run coax into
>the shack and feed it into a tuner and get good results.
>73
>John KI4RO...anxiously awaiting winter! HI
>
>

I've used T antennas like that John. They work about the same as an
Inverted L, but have a little less high angle radiation.

As with any vertical, use a good ground system. The ground is the single
most important key to success,

Good DXing.

Tom


From [e-mail] Thu Aug 01 21:20:47 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!nntp04.primenet.com!news.shkoo.com!nntp.primenet.com!news.cais.net!hunter.premier.net!news-res.gsl.net!news.gsl.net!usenet.eel.ufl.edu!arclight.uoregon.edu!netnews.worldnet.att.net!ix.netcom.com!news
From: Greg Corteville <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 2m/440 Vertical Ant Design Question
Date: Sun, 28 Jul 1996 20:08:35 -0400
Organization: Netcom
Lines: 53
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: war-mi3-14.ix.netcom.com
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X-NETCOM-Date: Sun Jul 28  7:05:48 PM CDT 1996
X-Mailer: Mozilla 3.0b4Gold (Win95; I)

About a year ago I bought an antenna from a vendor at a local ham swap.
 Its a dual band 2 meter/440 vertical antenna.  It is basically #12
copper wire surrounded in CPVC tubing.  He used brazing rod (not
surrounded by PVC) for the ground radials.  The antenna works very well.
 It has almost a 1:1 match across both bands.  The needle barely moves
when measuring.

Now that I'm going off to college, I'd like to build a clone of this
antenna to place on top of the building where the club office is
located.  It would mainly be used to run packet and occasional voice.  I
 can't really disassemble my antenna to see how its put together (its
glued), so I was wondering if somebody could help me fill in the details
for the design...

Here's what I can readily observe:

                        ___   1/2" CPVC Cap
                        | |
                        | |
                        | |  1/2" CPVC Pipe of length 74.5cm
                        | |
                        | |
                        | |
                        / \  1/2"CPVC-3/4" CPVC Blushing
                        | |
                        | |
                        | |  3/4" CPVC Pipe of length 57.4cm
                        | |
                      \ | | /
                       \|_|/    3 Ground Radials
                         |
                         |

The ground radials are of lengths 5 3/8" and 20 1/4" for 70cm and 2m
respectively.  There are 3 ground radials for each band.  They share
common screws that are drilled into the antenna and attach to the
radials via copper nuts.  Now my big question... What is the length of
the main radiating element here?  Is there a coil inside that allows it
to do both bands?  If so, how do I simulate this?  Or is it just a
straight piece of wire (74.5+57.4cm)?  On the original antenna, a piece
of RG-8 coax hung out the bottom as the antenna stub.  I center
conductor is obviously mounted to the radiating element.  But is the
shield of this coax just divided into 3 like sizes and connected to the
same screws that the ground radials are attached to?

I can provide a real picture of my existing antenna if you believe it
would help in answering my question.  Just let me know...

--
-----------------------------------------------------------------------Greg Co
rteville - KB8WFV
Internet     : [e-mail]
WWW Home Page: http://web.msu.edu/user/cortevi5
-----------------------------------------------------------------------


From [e-mail] Thu Aug 01 21:20:48 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!newsfeed.internetmci.com!news.kei.com!nntp.coast.net!news-res.gsl.net!news.gsl.net!usenet.eel.ufl.edu!news.ultranet.com!usenet
From: Rob Bellville <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Company ASA still around?
Date: Tue, 30 Jul 1996 19:59:53 -0700
Organization: Web Page Creation Services
Lines: 50
Message-ID: <[e-mail]>
References: <[e-mail]> <4tjes6$[e-mail]>
NNTP-Posting-Host: dial246.acol.com
Mime-Version: 1.0
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To: [e-mail]

david l. thompson wrote:
>
> Rob Bellville <[e-mail]> wrote:
>
> >I'm wondering if a company called ASA is still around. They manufactured
> >VHF/UHF helicals but I haven't seen any mention of them lately. Anyone got
an
> >address or phone number?
>
> >- Rob
>
> >...........................................................
> > Rob Bellville, N1NTE                           PO Box 515
> > [e-mail]                  Millbury, MA 01527
> >...........................................................
> >     Web Page Creation Services - Internet Consulting
> >           http://www.ultranet.com/~bellvill/
> >...........................................................
>
> ASA (antenna Specialists) became Allen Telecom Group several years
> ago.
>
> Allen Telecom Group
> Antenna Specialists Division
> 30500 Bruce Industrial Parkway
> Cleveland, OH  44139-3996
> 216-349-8400  FAX [phone]
>
> Dave K4JRB
> Editor, 1996 Amateur Radio Mail Order Catalog and Resource Directory
> (ARRL Pubs #5242)


Nope not Antenna Speicalists... ASA. I think they were located in the
Carolinas but not sure. They manufactured and sold amateur antennas only.

Thanks anyways...

- Rob


--


...........................................................
 Rob Bellville, N1NTE                           PO Box 515
 [e-mail]                  Millbury, MA 01527
...........................................................
     Web Page Creation Services - Internet Consulting
           http://www.ultranet.com/~bellvill/
...........................................................


From [e-mail] Thu Aug 01 21:20:49 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.fast.net!netaxs.com!hunter.premier.net!news.cais.net!news.abs.net!ddsw1!news.mcs.net!van-bc!nntp.portal.ca!news.bc.net!info.ucla.edu!agate!howland.reston.ans.net!cs.utexas.edu!news.ti.com!usenet
From: Joe Fitter BV/N0IAT <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Problems-Need Help!!
Date: Mon, 29 Jul 1996 20:08:32 -0700
Organization: Texas Instruments Asia, Taiwan ROC
Lines: 41
Message-ID: <[e-mail]>
References: <4s41uv$[e-mail]>
NNTP-Posting-Host: na01872244.taiwan.ti.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.02 (Win16; I)
To: Brian Watson <[e-mail]>

Brian Watson wrote:
>
> I have a Cushcraft 11 element beam for 2 meters (don't know model or
> anything) but I'm having problems on recieve with it.  I have it pointed
> toward a repeater about 40 miles from my QTH and am only getting about an
> S5 copy on it.  I live in S. Florida so terrain's not the problem.  The
> SWR is pretty flat (the highest is about 1.4:1)  I'm feeding the antenna
> with 50' of RG58/u coax.  Does anyone have any ideas on what I should do
> to figure out what is going wrong.  The problem has just started in the
> last few days.  I know it's not the radio since a repeater less than a
> mile away comes in full scale.  Any help will be greatly appreciated.
>

Well,  for starters check to see if the repeater 40 miles away is
still working to "original spec".   If the repeater has a defective
power amp, or some other failure (antenna, etc) this could explain
the problem.

As for RG-58, I disagree with Cecil to go replace it.  While upgrading to RG-8

or 9913 will improve things, his suggestion does nothing to diagnose your spec
ific
problem of "just started in the last few days".   I take this statement
to mean that the repeater 40 miles away USED to come in much better on your
current configuration of antenna and coaxial cable.   I suspect some moisture
has permeated the coaxial cable, probably where the connector attaches to the
yagi feedpoint.  Also check for loose connectors at both ends (dont use those
cheap pl-259's either ... genuine Amphenol with the UG reducers work best).

just my 10 NT worth.    73,   Joe

p.s.  Cecil...I use RG-58 too....works FB for HF and VHF up to about 75 feet,
and
keeps things tidy and clean.



--
----------------------------------------------------------
Amateur Radio:  BV/N0IAT   Taipei TAIWAN Republic of China

ex.  7J1AOF (Japan)  YU3/N0IAT (Slovenia)  KA0ZDH (Novice)
Licensed Radio Amateur since 1986.  Comments are mine only.
----------------------------------------------------------


From [e-mail] Thu Aug 01 21:20:50 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-fw-6.sprintlink.net!news1.inlink.com!news.starnet.net!spool.mu.edu!howland.reston.ans.net!math.ohio-state.edu!jussieu.fr!oleane!tank.news.pipex.net!pipex!iol!usenet
From: [e-mail] (The Man in the Bog)
Newsgroups: rec.radio.amateur.antenna
Subject: anyone know where to find output "2sc1307"
Date: Wed, 31 Jul 1996 01:10:53 GMT
Organization: Ireland On-Line
Lines: 1
Message-ID: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: dialup-039.athlone.iol.ie
X-Newsreader: Forte Agent .99d/32.182




From [e-mail] Thu Aug 01 21:20:51 1996
Path: news2.epix.net!uunet!in3.uu.net!en.com!usenet
From: mbaker <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Broadcast Band (AM) Antenna Plans
Date: 27 Jul 1996 06:06:40 GMT
Organization: Exchange Network Services
Lines: 10
Message-ID: <4tcblg$[e-mail]>
NNTP-Posting-Host: dial-4.ncweb.com
Mime-Version: 1.0
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Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 1.22 (Windows; I; 16bit)

Where can I find some plans for AM antennas.

Local radio station cancelled favorite talk show. (Bruce Williams)

tnx,

mark (KG7GL)

mailto:[e-mail]



From [e-mail] Thu Aug 01 21:20:55 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!uunet!in2.uu.net!EU.net!usenet2.news.uk.psi.net!uknet!usenet1.news.uk.psi.net!uknet!psinntp!psinntp!psinntp!xetron.com!news
From: [e-mail] (Tim Huster)
Subject: Re: CB Channel 9/19 Freqs
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: timh.xetron.com
Organization: Xetron Corp.
X-Newsreader: WinVN 0.93.14
References: <[e-mail]>
Mime-Version: 1.0
Date: Fri, 26 Jul 1996 18:17:57 GMT
Lines: 34

Citizens Band

        Ch    Freq       Ch    Freq       Ch    Freq       Ch    Freq

         1   26.965      11   27.085      21   27.215      31   27.315
         2   26.975      12   27.105 *    22   27.225      32   27.325
         3   26.985      13   27.115      23   27.255 -    33   27.335
         4   27.005 *    14   27.125      24   27.235 -    34   27.345
         5   27.015      15   27.135      25   27.245 -    35   27.355
         6   27.025      16   27.155 *    26   27.265      36   27.365
         7   27.035      17   27.165      27   27.275      37   27.375
         8   27.055 *    18   27.175      28   27.285      38   27.385
         9   27.065      19   27.185      29   27.295      39   27.395
        10   27.075      20   27.205 *    30   27.305      40   27.405



In article <[e-mail]>, [e-mail] says...
>
>We monitor CB Channel 9 for the area.  The radio is at our place of
>business in the main office....which makes for some noisy
>moments.<groan>  What I'm wanting to do is adjust the antenna for the
>monitor radio to be resonant for Channel 9.  From what I've found the CB
>freqs run from 26.965 to 27.405.  This amount of bandwidth isn't as much
>as the Novice 10 meter band so I feel if I get fairly close to the
>center of the frequency I'll do fairly well.  Basically, if someone has
>the frequency for channel 9, and channel 19 (for my delivery trucks) I'd
>greatly appreciate you sharing the info with me.
>
>Thanks,
>73, Ed, KF4KRV
>Luverne, Alabama




From [e-mail] Thu Aug 01 21:20:56 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!newsfeed.internetmci.com!hunter.premier.net!netnews.worldnet.att.net!ix.netcom.com!news.compuserve.com!news.production.compuserve.com!news
From: Brian Webb <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Discone antenna construction help needed
Date: 31 Jul 1996 03:56:53 GMT
Organization: Umbra Research
Lines: 13
Message-ID: <4tmli5$n7o$[e-mail]>
References: <[e-mail]>

You would connect the coax center to the top ring and the shield
to the skirt.

By the way, did you ever like in Lakewood, CA? I know a family
with your last name there (the eldest son, Howard, was a ham
back in 1969-70).

Hope to work you on 10-meters someday.

Regards,

Brian Webb KD6NRP
Thousand Oaks, CA


From [e-mail] Thu Aug 01 21:20:57 1996
Path: news2.epix.net!uunet!in2.uu.net!interaccess!usenet
From: Robert Mansfield <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: EZNEC simulation with traps
Date: Sat, 27 Jul 1996 00:01:44 -0500
Organization: InterAccess, Chicago's best Internet Service Provider
Lines: 25
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: d127.nwchi.interaccess.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.02 (Win95; I)
To: Gilles Monette <[e-mail]>

Gilles Monette wrote:

 Thanks for the replies.  The problem in more detail is that by inserting
 the traps with the load option, shoes the load ok.
 The problem comes when you do the simulation.  To better describe this
 let me tell you what I am doing.

 I am simulating a trap vertical fo 10,15,20 and 40 meters.
 I get a lamda/4 for 29.9 MHz ok with no traps.
 Now add a paralle resonant circuit od 1 ohm, 3 uH and 15 pF.
                                      ^^^^^^
for a Q of 400 this should be 162k ohm, this is shorting the trap out

 Simulate at 29.9 MHz is ok with and without trap.
 Add extra length to get lamda/4 at 21.5 MHz.
 This is ok.
 Check simulation at 29.9,  Then patern is real mess, does not look like
 it doing things right with the traps.

 That is what the problem is.

 Regards,  Gilles

Bob Mansfield
WA8USR


From [e-mail] Thu Aug 01 21:20:59 1996
Path: news2.epix.net!uunet!in3.uu.net!van-bc!uniserve!usenet
From: [e-mail] (JEFF)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Force 12 Antennas Comments
Date: Sun, 28 Jul 1996 06:12:50 GMT
Organization: UNIServe Online
Lines: 16
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: van0209.tvs.net
X-Newsreader: Forte Agent .99d/32.182

Its not a C-4 , but I have a C-3 up for some time now and its a
fantastic antenna !           Jeff     VE7 GMXOn 26 Jul 1996 19:22:02
GMT, [e-mail] (Jay H. Miller) wrote:

>Would appreciate comments from anyone with actual experience with a Force
>12 model C4.
>
>Please reply via private e-mail.
>
>Thanks.
>
>--
>73 de
>Jay Miller, KK5IM
>reply via email to   [e-mail]



From [e-mail] Thu Aug 01 21:20:59 1996
Path: news2.epix.net!uunet!in3.uu.net!van-bc!uniserve!usenet
From: [e-mail] (JEFF)
Newsgroups: rec.radio.amateur.antenna
Subject: FORCE 12 E-MAIL ADD ?
Date: Sun, 28 Jul 1996 06:14:46 GMT
Organization: UNIServe Online
Lines: 3
Distribution: world
Message-ID: <[e-mail]>
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        Anyone have the  E-Mail add. for force 12 ?

                                 Thanks     ,      Jeff      VE7-GMX


From [e-mail] Thu Aug 01 21:21:00 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 28 Jul 1996 07:08:14 -0400
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Hi Cecil,

In article <[e-mail]>, Cecil Moore
<[e-mail]> writes:

>A couple of years ago, in a thread entitled "Where Does The Power Go",
>I stood alone in believing that a class-A amplifier could re-reflect
>some of the reflected energy and absorb the rest. The answer from the
>experts back then was, by definition "all reflected energy is
>re-reflected and any power absorbed by the amp was never generated."

Whats wrong with that analogy? Being absorbed where it came from is the
same as having never been generated in the first place. With a separate
reverse source, the reverse energy must make a contribution to
dissipation, or replace power supply power (which is the same as being
re-radiated, isn't it?), or be re-radiated. Which of these happens depends
on many things.

>Is the energy that is not re-reflected and "disappears and/or is
absorbed"
>turned into heat? If so, is it dissipated in the amp or the power supply?

>I realize that this energy/power/heat is usually neglible but I am
>interested in that particular component of energy/power/heat, neglible
>though it may be.

I can only postulate. I suspect the power is dissipated as heat, since my
class A  3CPX5000 even makes a good dummy load. I've never consider this
beyond what I've actually seen.

The power certainly goes somewhere, and it does NOT appear as standing
waves on the line when the PA is tuned for maximum power transfer or
efficiency (with a resonably low loss tank).

I suspect some of the missing power in the class C PA that doe not
re-appear as new mixing products turns to heat in the PA also. But that
shouldn't be confused with causing a PA to run hot when the load is
mismatched, because the reverse generator is a non-coherent signal. A
coherent signal from a true reflection would have the effect of simply
modifying the impedance and changing the plate current and voltage.

If the analysis doesn't fit both circuit and wave analysis, it isn't a
good analysis.

73 Tom


From [e-mail] Thu Aug 01 21:21:02 1996
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Gary Coffman)
Subject: Re: forward/reflected power
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <4siroh$[e-mail]> <4sj881$[e-mail]> <[e-mail]> <[e-mail]> <4ss6rd$[e-mail]>
Date: Sun, 28 Jul 1996 09:16:28 GMT
Lines: 62

In article <4ss6rd$[e-mail]> Cecil Moore <w6rca@w
orldnet.att.net> writes:
>[e-mail] (Gary Coffman) wrote:
>>If you start thinking of them as real dissipative loads,
>>you're headed down the path to LA-LA land and not dealing with
>>the real world anymore.
>
>My concern is not the image/dynamic impedance. The real
>dissipative component of a non-superconductive amplifier
>does not equal zero ohms - resistance never equals zero
>in the the real world (so far at room temperature or above).

That's right, Cecil, there are real loss components in there.
In a well designed amp they are tiny compared to the image
and dynamic impedances, so it will be very hard to measure
them using the method you're attempting.

>Reflected current flowing through a non-zero dissipative
>resistance will cause power loss. The total power dissipated
>may go up or down but there will be a component of power loss
>caused by simple I^2R reflection current losses. It may be
>small, but it is there, not in LA-LA land.

That's right, but separating it from the dynamic impedance
is going to be a bear. And separating it from the DC losses
in the device isn't easy either. But still, measuring stack
temperature can give you an idea of the combined DC and RF
losses in the device. For a single tone signal, you could then
note the RMS plate current, remove drive, and adjust the
grid bias to get the same plate current at DC and measure
the difference in stack temperature. The difference would
be representative of the RF loss elements in the device.
Using the CFM flow, you can then calculate the power loss
due to RF loss elements and then use the R = P / I^2
relation to solve for R. In a well designed device, it should
be small.

The vast bulk of any reflected signal will just be absorbed
into, and become part of, the dynamic impedance, which isn't
a loss resistance per se. It is simply the product of the
vector sums of all voltages and currents at the device output
terminal at any given instant. Changes in it simply change
the demand on the DC power supply in proportion to the device
conductance at the instantaneous drive, bias, and plate voltage
conditions of that moment.

If the dynamic impedance could act as a real dissipative load,
then we couldn't build an amplifier with more than 50% efficiency.
But of course we can, so the dynamic impedance to which we
"match" isn't dissipative, and can't serve as a dissipative
load for your "reflected currents". The real loss elements
in the circuit are made as small as possible by the device
designers to enhance efficiency. The fact that operating the
device Class D can yield efficiencies exceeding 90% tells us
that the dissipative elements must be small in comparison to
the dynamic impedance.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Thu Aug 01 21:21:03 1996
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From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: forward/reflected power
Date: 29 Jul 1996 02:51:05 -0400
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In article <[e-mail]>, [e-mail]
(Gary Coffman) writes:

> The real loss elements
>in the circuit are made as small as possible by the device
>designers to enhance efficiency. The fact that operating the
>device Class D can yield efficiencies exceeding 90% tells us
>that the dissipative elements must be small in comparison to
>the dynamic impedance.
>
>Gary

And even RCA had a handle on this with an old plate modulated transmitter
(I wish I could remember the model).

It operated with around 90 percent efficiency by virtue of wave squaring
third harmonic resonators in the anode and grid of the glass insulated
external anode-triode PA.

In article <[e-mail]>, [e-mail]
(Gary Coffman) writes:

>I also agree with you that you want to overcouple the device to
>get best linearity in most cases. That's confirmed by pragmatic
>experience. *Why* that is so is a more complex topic. I'd like to
>see your explanation of why it is true. (My explanation is simple,
>overcoupling shifts the loadline to the right where the device
>response curve is flatter. But that doesn't really explain *why*
>the device's response curve is flatter to the right.)

The distortion becomes pronounced because of voltage saturation in the
device.

Let's remember what happens to the dynamic resistance of the PA as drive
is increased. Dynamic resistance is reduced. With excessive load
impedance, the output device is undercoupled resulting in current
saturation and flat-topping on peaks.
The load impedance at maximum envelope power must never be greater than
the source impedance or the output device will saturate. A little bit of
correct curve in the right area can actually reduce IMD, but abrupt
current saturation kills IMD performance.
>
>I'm unconvinced that looking "BAACK" into the amplifier's output
>port shows us anything but a reflection of the image impedance
>we're presenting to the device (reflected by the device characteristic
>which is the reciprocal of the thing we call dynamic impedance). That
>is a distorting mirror to be sure, but what we see isn't in any
>reasonable sense a load.

Then consider the following carefully, because I originally thought like
you until I tested about 15 different PA's.

1.) If I ignore all other metering except for the flatness of the reverse
signal, I can perfectly "peak" any PA for maximum output (and VERY close
to maximum efficiency)  by only watching the reverse generator's flatness.

2.) As power was reduced in any amplifier (other than a full blown class A
amp) the output port impedance, as seen by the reverse generator,
increased. In the class A amp the impedance remained constant.

Now if the reverse generator was seeing some "random event" caused by a
mirror of something or other, what are the odds this would be repeatable
with both solid state and tube type amps...both grounded grid and grid
driven, and from class C to class A?

Perhaps someone can offer a better explaination. But the very fact the
results are repeatable, and the criteria of a matched reverse generator
always produced correct tuning for maximum power transfer, indicates I am
indeed measuring a parameter related to correct tuning for maximum power
transfer.

73 Tom


From [e-mail] Thu Aug 01 21:21:04 1996
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From: [e-mail] (Joel Mandigo)
Newsgroups: rec.radio.amateur.antenna
Subject: FS: Anli 144/440 mobile mag mount antenna
Date: Mon, 29 Jul 1996 22:07:52 GMT
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        I have an Anli 144/440mhz mag mount antenna for sale, 3/5.5 db gain.
The antenna is apprx. 23" long, and the coax cable (comes w/ PL-259
connector) is apprx 20'. It was hardly used. Reason for selling is I
am going to college. If interested email [e-mail].

73's de KR4FJ
Joel Mandigo
[e-mail]



From [e-mail] Thu Aug 01 21:21:05 1996
Newsgroups: rec.radio.amateur.antenna
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From: [e-mail] (Steve Ellington)
Subject: Re: Gary, help us please!
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: 73 and looking forward to reading your first article,  Steve  K7LXC


I couldn't agree more! Magazine subscriptions are becoming a thing of the
past. We pay for paper, advertising, staff and postage to the tune of $25
per year for what is mostly trash. Here on the internet we have all the
advertising we need, no postage, no paper and now all we need are good,
technical articles.

I really don't believe that (good writers) are in it for the money. After
all, what's a few bucks compared to the satisfaction one gets when he sees
his article in a magazine? Here, one can instantly broadcast their
knowledge to the world at no extra cost to anyone. This is a much higher
calling Gary and all the rest.

Post on usenet don't have to be questions. They can be STATEMENTS;
informative and educational. Let's take full advantage of it! The great
thing about this is being able to respond to an article with questions and
more statements.

Let us upgrade this Usenet by posting some real information, news,
technical articles and give those hamrags a run for their money! 73


:


--
Steve Ellington [e-mail]  Louisville, Ky


From [e-mail] Thu Aug 01 21:21:06 1996
Path: news2.epix.net!uunet!in3.uu.net!newsfeed.internetmci.com!news.campus.mci.net!not-for-mail
From: [e-mail] (Phil Brown)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Getting wires up in the trees
Date: Fri, 26 Jul 1996 20:35:25 GMT
Organization: Mediassociates
Lines: 18
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>>Finally, I'm wondering what's the best way to get wires up in the trees.


I've got lots of tall trees,and currently have a multiband dipole up
in one of them, with the ends in other trees. My problem is not so
much getting the line up over a tall branch as it is dragging the
dipole with attached RG8 through all the branches. I do think I will
wait until winter thins out all the growth before putting up my
planned  160m dipole. How do the rest of you manage it?

73
Phil

Phil Brown N4COD
[e-mail]
Video Producer/Instructor
Like Flowers? Check out our home page at www.tigerweb.com



From [e-mail] Thu Aug 01 21:21:07 1996
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From: [e-mail] (Dick Boley)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ham-Ant Digest V96 #461
Date: 31 Jul 96 11:48:08 GMT
Organization: ucsd usenet gateway
Lines: 14
Message-ID: <[e-mail]>
NNTP-Posting-Host: mail.ucsd.edu
Originator: [e-mail]

Glass Mount Antenna - I had posted a query on a galss mount antenna and
tinted glass. Thanks for all the replies. However, after removing the cover
I discovered nice little sparks jumping about in the tuning mechanisim. Seem
that the proximity of a few sharp points (2 sets) was the problem. By gently
bending the coils and mounting tabs I was able to move them and eliminate
the arcing.Works as well as a 1/4 wave mag mount now.  The unit I am using
is the low-end $39.95 antenna sold by several companies under a house label.

Regards - Dick  N3HKN  Pittsburgh
Dick Boley
Sales Engineering
Westinghouse Communications
412-247-7756



From [e-mail] Thu Aug 01 21:21:08 1996
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From: [e-mail] (pete brunelli)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HELP: Need 2m Mobile Ant
Date: Wed, 24 Jul 1996 13:20:25 GMT
Organization: Connix - The Connecticut Internet Exchange
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[e-mail] (Kevin Webster) wrote:
snip!
>I'm looking for something in the 1/2 wave to 5/8 wave size range (but
>a good 1/4 wave would not be ruled out either).  This antenna will be
>mounted on the trunk of a mid-sized car (either mag or no-hole mount).

>Any suggestions? Any good recommendations on where to get it?

How about a 2M hamstick?  I run a 220 stick and it works very well.
Also very easy to moutn on antyhing that takes 3/8 stud mount.

73




From [e-mail] Thu Aug 01 21:21:12 1996
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From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna,rec.radio.amateur.equipment,sci.electronics.repair,sci.electronics.equipment,sci.electronics.design,sci.electronics.misc
Subject: Re: High and low Frequence Antannas
Date: Wed, 31 Jul 96 18:35:34 GMT
Organization: EZNEC Antenna Software
Lines: 19
Message-ID: <4to8vk$[e-mail]>
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In article
<[e-mail]>,
   "'Cel' M. Mallary" <[e-mail]> wrote:
>Reminds me of a Navy instructor who when asked the same question about a
>Yagi, raised his eyebrows and dryly said " pretty good."  'Course the same
>guy,
>a day or two before, enlightened us about the "1/4 wave ground plane" or
>the "Marconi whip" antenna.  Seems Marconi had been working through a
>summer draught trying to prove a base fed 1/4 wave rod with it's insulated
>base stuck in the ground, would produce a nice 360 deg. toroidal radiation
>pattern.  After a fruitless few days, Marconi threw up is hands and said
>"Aww piss on it".  Well one of his grunts did just that and all of a
>sudden the antenna started working.  And that's the honest to gosh
>beginning of all those little 1/4 wave whips you see on cars nowdays.
>                         ( (-:jm:-) )

So that's what a pissant is.

Roy Lewallen, W7EL


From [e-mail] Thu Aug 01 21:21:13 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!holonet!colossus.holonet.net!agate!info.ucla.edu!nnrp.info.ucla.edu!csulb.edu!news.sgi.com!swrinde!cs.utexas.edu!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!nntp-xfer-1.csn.net!csn!nntp-xfer-2.csn.net!symbios.com!southwind.net!usenet
From: Ken Bessler <[e-mail]>
Newsgroups: rec.ham-radio.swap,alt.radio.scanner,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.dx,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space,fidonet.ham,rec.ham-radio,rec.ham-radio.packet,rec.ham-radio.swap,slac.rec.ham_radio,su.org.ham-radio,swb.lists.linux.hams,rec.radio.swap,tnn.radio.amateur,uwarwick.societies.amateur-radio
Subject: Re: homepage revised
Date: Thu, 01 Aug 1996 00:28:24 -0500
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To: Dave Booth <[e-mail]>
Xref: news2.epix.net alt.radio.scanner:32458 rec.radio.amateur.antenna:23476 rec.radio.amateur.digital.misc:16629 rec.radio.amateur.dx:161 rec.radio.amateur.equipment:31447 rec.radio.amateur.homebrew:16306 rec.radio.amateur.misc:105668 rec.radio.amateur.policy:35734 rec.radio.amateur.space:7369 fidonet.ham:8 slac.rec.ham_radio:63 su.org.ham-radio:294 swb.lists.linux.hams:14 rec.radio.swap:70935 tnn.radio.amateur:68 uwarwick.societies.amateur-radio:27

Dave Booth wrote:
>
> I just revised my homepage if you want to check it out.
> new stuff!
> --
> Dave Booth
>  kc6wfs

I am always ready to surf....However I do need a URL....:-)


From [e-mail] Thu Aug 01 21:21:14 1996
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From: [e-mail] (Gary V. Deutschmann, Sr.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: how to make 10m from CB?
Date: Tue, 30 Jul 1996 05:19:55 GMT
Organization: Inlink
Lines: 19
Message-ID: <4tk681$[e-mail]>
References: <4tg32l$[e-mail]>
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[e-mail] (Ken McCoy) wrote:

>Can one simply clip off a few inches from a base-loaded CB whip to make it
>work for 10m, or is there some returning of the matching coil involved?
>I'm thinking of the 3-4 foot whips.

>Thanks for any info,

>Ken
>KF4BQF
>[e-mail]
I'm running a Mosely A511S 5/8 wave Ground Plane on 10, only shortened
it about 8 inches by sliding the top element down inside the next and
retightening the clamp.

TTUL - 73+ de Gary - KG0ZP





From [e-mail] Thu Aug 01 21:21:14 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!tank.news.pipex.net!pipex!usenet.eel.ufl.edu!news-res.gsl.net!news.gsl.net!portc01.blue.aol.com!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-Pole gain
Date: 28 Jul 1996 07:12:50 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 20
Sender: [e-mail]
Message-ID: <4tfhvi$[e-mail]>
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In article <4tam1u$[e-mail]>, [e-mail] (Jim Weir) writes:

>
>And I'd suggest you check your design.  I've designed, built, and
>written construction articles on J-poles for almost twenty years, and
>if you do them right, the coax is as cold as a brass jockstrap.
>
>

Jock straps aside, the J-poles I built move in that direction if I connect
a groundplane to the bottom of the stub or the feedline where it leaves
the antenna.

My question remains, has anyone else tested a J-pole in a true ground
isolated configuration?

The stub was exactly 1/4 wl electrical length, and the element a 1/2 wl.
Doesn't seem to be an overcomplicated thing to build.

73 Tom


From [e-mail] Thu Aug 01 21:21:16 1996
Newsgroups: rec.radio.amateur.antenna
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.inc.net!uwm.edu!news-res.gsl.net!news.gsl.net!hunter.premier.net!newsfeed.internetmci.com!news.radio.org!wa4mei!ke4zv!gary
From: [e-mail] (Gary Coffman)
Subject: Re: J-Pole gain
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
Organization: Destructive Testing Systems
References: <4sp4mr$[e-mail]> <4t2qo0$[e-mail]>
Date: Sun, 28 Jul 1996 09:37:40 GMT
Lines: 51

In article <4t2qo0$[e-mail]> [e-mail] (W8JI  Tom) writ
es:
>Hi Gary,
>In article <[e-mail]>, [e-mail]
>(Gary Coffman) writes:
>>I think your mistake (if you're making one) is <snip>
>
>>The same is true when we try to assign a finite impedance to the
>>current zero point of an antenna. There isn't one, though the
>>currents rushing toward and away from the point might appear
>>externally to allow us to assign one.
>
>There is no "current zero point" over the length of any pratical antenna,
>not even at the open end.  A "current zero point" could only exist if the
>antenna was lossless, in that case the reflected current would cancel
>forward current and current would indeed reach zero.  But since the
>antenna has distributed losses as well as radiation field losses, the
>current never reaches zero anywhere.
>
>Current doesn't even reach zero at the very end of a finite cross section
>conductor. Current is not zero at the very end of the very last molecule
>of the antenna because current makes a transistion into the electric field
>at that point.

Ok, so if I follow what you're saying, the current standing wave is
biased above zero by an amount proportionate to Rrad+Rloss. Where
Rrad is the result of losses to the radiation field and Rloss is
plain old copper loss. That makes perfect sense, and also demonstrates
why net current (and power) flow is always forward.

My error was in unconsciously assigning the zero axis to the median
amplitude of the current standing wave. In fact, that's correct for
the forward wave and the reverse wave treated *separately*, but we
can't do that. It is their vector sum which sets up the standing
wave which maps the instantaneous flow at every point along the wire,
and which is responsible for the radiation field (magnetic).

That brings up another thought. The energy in the EM field oscillates
between the magnetic field and the electric field. An antenna that
pumps energy into one is the same as pumping energy into the other.
But we seem to only concern ourselves with pumping the magnetic field
when we talk of antennas. We speak of high current nodes of the
standing wave as being the radiation center of the antenna. We
seem to ignore the electric field. Why is that?

Gary

--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Thu Aug 01 21:21:16 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.cdsnet.net!news.sprintlink.net!news-stk-3.sprintlink.net!newsfeed.internetmci.com!howland.reston.ans.net!Germany.EU.net!Dortmund.Germany.EU.net!main.Germany.EU.net!fu-berlin.de!news.belwue.de!news.uni-stuttgart.de!moritz
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-pole Gain
Date: 29 Jul 1996 13:53:46 GMT
Organization: Comp.Center (RUS), U of Stuttgart, FRG
Lines: 29
Message-ID: <4tifpa$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: ipers1.e-technik.uni-stuttgart.de

>W8>At the top of the stub (which is a two wire transmission line), one
>  >conductor hooks to the several hundred ohm element and the other hangs
>  >free.

>Here is where you have made your mistake, the half wave dipole section
>is also a single conductor transmission line and reflects the impedence
>seen at it's open end which is many thousands of ohms, not several
>hundred.

Hi Clanton,

Tom was perfectly correct, and you can find the appropriate
impedance diagram in most antenna engineering handbooks.
The  (unimportant?) datail you forget is that antennas *radiate* and
therefore do not reflect the impedance at their open end back to the
feed point.

73, Moritz DL5UH


  It's also equal to that seen at the open end of the stub.
>Therefore the matching section is balanced.
>
>73 de  Claton Cadmus,  KA0GKC
> * SLMR 2.1a * Remember, you are unique, just like everyone else!
>
>




From [e-mail] Thu Aug 01 21:21:17 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-fw-6.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-stk-3.sprintlink.net!news.texas.net!nntp.primenet.com!uunet!in3.uu.net!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Kurt, help us please!
Date: 28 Jul 1996 03:24:53 -0400
Organization: America Online, Inc. (1-800-827-6364)
Lines: 19
Sender: [e-mail]
Message-ID: <4tf4k5$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: newsbf02.mail.aol.com
X-Newsreader: AOL Offline Reader

In article <[e-mail]>, Charlie Panek
<[e-mail]> writes:

>  "Enjoy" isn't exactly the word I'd use.  I think 'ol Buck had
>best stick to wiring up TNC's.
>
>  Thanks for pointing it out, though.  I usually just skip right
>over his column.
>
>

Perhaps I shouldn't have pointed it out. I initially chuckled about it,
but that was wrong. Everyone makes mistakes, and I'm sure his intentions
were to help people learn something.

I actually feel bad now that I brought it up, since the initial humor wore
off.

73 Tom


From [e-mail] Thu Aug 01 21:21:18 1996
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From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Kurt, help us please!
Date: Wed, 31 Jul 1996 13:12:23 +0100
Organization: IFW Technical Services
Lines: 10
Distribution: world
Message-ID: <Q3YqRCAn20$[e-mail]>
References: <4s0h7j$[e-mail]>
 <4t6mc6$[e-mail]> <4tjdqq$[e-mail]>
 <4tmrva$[e-mail]>
NNTP-Posting-Host: ifwtech.demon.co.uk
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X-Newsreader: Turnpike Version 1.12 <9qI82xurdT5+z2vSgnCPFcKgQL>

Roy Lewallen wrote:
>There is no reason that an explanation must be
>technically wrong in order to be simple or easy to understand.

Darn right!

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


From [e-mail] Thu Aug 01 21:21:19 1996
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From: [e-mail] (John Clifford Wilke)
Newsgroups: rec.radio.amateur.antenna
Subject: Limits on YAGI length?
Date: 29 Jul 1996 20:07:35 GMT
Organization: University of Wisconsin - Milwaukee
Lines: 15
Message-ID: <4tj5m7$[e-mail]>
NNTP-Posting-Host: 129.89.169.1
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Not too long ago there was an article in QST for a 100' long yagi  for
2meters with something like 45 elements, built with rope as the element
supports. The author reported fantastic results.

I tried one at 50' long but with some experimentation I found that past
18 elements (with approx. 35 foot "boom" length) that the gain dropped
off. I used a standard 8 el. quagi design with equal director lengths
and equal .308 wavelength spacing past the 6th director.

I guess I need to run this antenna on some sort of optimizer software but
does anyone know if there are diminishing returns past a certain length?

jw
wb9uai


From [e-mail] Thu Aug 01 21:21:20 1996
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From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Limits on YAGI length?
Date: 31 Jul 1996 14:48:21 GMT
Organization: Comp.Center (RUS), U of Stuttgart, FRG
Lines: 12
Message-ID: <4tnrnl$[e-mail]>
References: <4tj5m7$[e-mail]> <4tln8o$[e-mail]>
NNTP-Posting-Host: ipers1.e-technik.uni-stuttgart.de

>One potential loss of gain when using rope supports for long yagis might
>be rope sag.  You will want to keep all the elements in as straight a
>line as possible.

Interesting topic.

I have been wondering about the adverse effect of boom sag on the gain of
long yagis. take e.g. a 4 wl yagi, how many degrees of total curvature
within the boom will derate the gain by one dB? any simmulations?

73, Moritz DL5UH



From [e-mail] Thu Aug 01 21:21:21 1996
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From: [e-mail](Glenn Sparks)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: MultiBand dipole
Date: 30 Jul 1996 19:54:06 GMT
Organization: Netcom
Lines: 28
Message-ID: <4tlp8u$[e-mail]>
References: <[e-mail]>
NNTP-Posting-Host: hou-tx1-01.ix.netcom.com
X-NETCOM-Date: Tue Jul 30  2:54:06 PM CDT 1996

In <[e-mail]> The Mad Hatter <[e-mail]>
writes:
>
>Hi I'm interrested in making a multiband dipole. I have a plan for one
>called a "Tuned Feeder antenna". It uses 135' wire fed to a balanced
>tuner with 450ohm parallel line. Can anyone tell me how this works as
a
>multiband and what kind of tuner to use.
>

I have used the above with good results, and have also had good results
with a loop antenna fed at one corner with ladder line and a tuner.  I
used what was called a Zepp tuner, with a swinging link to load.

I also have at a beach house where I want to keep things very simple a
"Fan Dipole"  I put up first an 80 meter dipole then added a 40 meter
to the same feedpoint letting it droop down a foot below the 80, and
then added a 20 meter dipole to the same feedpoint letting it droop
down a couple more feet.  I feed it with 50 ohm coax and do not use a
tuner.  Some old timers tell me I should be able to load 15 Meters on
the 40 section but I have made several of them and never have been able
to load 15 on it.  It is simple, cheap, and requires no tuner for the
bands you hang.  The reason you can use the same feedpoint is there is
such a mismatch on the wrong wires that the impedance is so high it is
virtually invisible to the coax at the transmitted frequency.  Since I
only use 80, 40 and 20 it is OK for me.

Glenn Sparks  KI5GY


From [e-mail] Thu Aug 01 21:21:22 1996
Path: news2.epix.net!uunet!in3.uu.net!nntp.primenet.com!news.asu.edu!atkes
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Non-contaminating jacket
Date: 28 Jul 1996 07:04:49 GMT
Organization: Arizona State University
Lines: 33
Message-ID: <4tf3eh$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]
NNTP-Posting-Host: general1.asu.edu
X-Newsreader: TIN [version 1.2 PL2]

I have heard a lot of hams talk about buying non contaminating jacket
coax and all the bad things that happen if you don't, but here is an
excerpt of a letter in Ham Radio Magazine, April 1986, page 9, by
Ronald Steir, W9ICZ, at that time Marketing Director for Belden which
says that all that is nonsense.  He was commenting on a column where
W1JR advised readers to buy only coax with noncontaminating jackets.

Quoting from W9ICZ's letter:
>The difference between contaminating and noncontaminating jackets is
>the amount of plasticizer in the vinyl compound, which the provides
>flexibility at low temperature extremes.  It has been my experience in
>laboratory environments with so-called contaminating jackets that
>circulating ovens at 120 degree C (which is more than adequate
>temperature to drive out plasticizers) after seven days shows only a
>minimal amount of plasticizer migration. Outside of the laboratory
>environment, I personally have not experienced plasticizer migration
>problems with coax, both buried and fully exposed to the elements.
>After eight to 10 years of service, no attenuation increases.
>
>At the same time, I have examined many pieces of coaxial cable in which
>plasticizer migration and/or contamination has been submitted as the
>cause of high attenuation in real-life operation.  To date I have not
>seen a piece of coaxial cable in which that has been the cause of high
>attenuation in real-life operation.  It has always been water and
>moisture getting into the cable.  Water and moisture entry most
>commonly come about from inadequate sealing at the connecto ends of the
>cable and/or cuts or pin holes caused by abrasion of the jacket. Yes, I
>see W1JR's point -- and I have heard the myth many, many times
>throughout my active days as an engineer and in my current position as
>well.

73 Kevin [e-mail]



From [e-mail] Thu Aug 01 21:21:23 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.zeitgeist.net!news.lanminds.com!news.walltech.com!cyberstation.net!usenet
From: [e-mail] (Don Young)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Pager Antenna Help Needed...
Date: Mon, 29 Jul 1996 23:49:48 GMT
Organization: CyberStation, Inc
Lines: 14
Message-ID: <[e-mail]>
References: <4thkqg$[e-mail]>
NNTP-Posting-Host: dialup55.cyberstation.net
X-Newsreader: Forte Agent .99e/16.227

[e-mail] (Marty Albert) wrote:

>Hello, Folks:
>
>I have a problem that I have never dealt with and hope someone out
>there can offer some information...
You might try a small beam pointed at the pager system tower, connect
it to a quarter wave antenna in the house.  Might even put a TV cable
preamp between the beam and the quarter wave.

Just a thought.

73, Don KA2IMX



From [e-mail] Thu Aug 01 21:21:25 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!newsfeed.internetmci.com!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!math.ohio-state.edu!usc!news.cerf.net!hacgate2.hac.com!news.delcoelect.com!usenet
From: [e-mail] (Paul J. Dobosz)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Quadrifilar Antenna's
Date: Wed, 31 Jul 1996 00:25:37 GMT
Organization: Delco Electronics Corp.
Lines: 28
Distribution: usa
Message-ID: <4tm23e$[e-mail]>
References: <[e-mail]> <3v7bqg$[e-mail]> <3vui1b$[e-mail]>
NNTP-Posting-Host: 198.208.19.250

Detailed info is available in the ARRL book Reflections by Walter
Maxwell, W2DU.


Dan Bathker <[e-mail]> wrote:

>[e-mail] (Rane Curl) wrote:
>>
>> In article <[e-mail]>,
>> William Penner <[e-mail]> wrote:
>> >I have been looking for information on the construction of Quadrifilar
>> >antennas for use with GPS.  Does anyone know off-hand where I might find
>> >some discussion on this?  None of the ARRL books seem to have anything.
>> >
>> >Bill Penner, WB7DPF
>> >
>> The ARRL publication _Satellite Experimenters Handbook_ (1990 - still
>> available) contains parameters (in units of wavelengths) for the
>> quadrifilar helical antenna. Some time ago a ham reported in
>> sci.geo.satellite-nav that he had built one from semi-rigid coax
>> for GPS use, and it worked.
>>
>> Rane Curl    N8REG
>>
>>
>Test,test




From [e-mail] Thu Aug 01 21:21:26 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!news-dc-9.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!news.sprintlink.net!news-dc-10.sprintlink.net!news-dc.gsl.net!news.gsl.net!news-res.gsl.net!news.gsl.net!nntp.coast.net!zombie.ncsc.mil!newsgate.duke.edu!agate!info.ucla.edu!newsfeed.internetmci.com!in3.uu.net!intex.net!dstarr.vrcomm.com!dstarr
From: [e-mail] (David A. Starr)
Newsgroups: rec.radio.amateur.antenna
Subject: R-7000, any comments?
Date: Thu, 25 Jul 1996 11:31:24
Organization: Virtual Resources Communications
Lines: 10
Message-ID: <[e-mail]>
NNTP-Posting-Host: 204.255.102.40
X-Newsreader: Trumpet for Windows [Version 1.0 Rev A]

Hi all,

I'm thinking about putting up an R7000 vertical (with the 80 meter kit) and
was wondering if anybody had any comments about the antenna, good or bad.

Thanks,

David Starr
WB9PIF
Plano, TX


From [e-mail] Thu Aug 01 21:21:27 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!news-dc-5.sprintlink.net!news.sprintlink.net!news-dc-9.sprintlink.net!newsfeed.internetmci.com!hunter.premier.net!news1.erols.com![e-mail]
From: Jake Brodsky <[e-mail]>
Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc
Subject: Re: RF attenuation of mirrored glass at 900MHz?
Date: Wed, 31 Jul 1996 13:52:48 -0700
Organization: Wheeeeee!
Lines: 25
Message-ID: <[e-mail]>
References: <[e-mail]>
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Xref: news2.epix.net rec.radio.amateur.misc:105653 rec.radio.amateur.antenna:23473 rec.radio.amateur.digital.misc:16627

John Paul Morrison wrote:
>
> Does anyone know how many dB of loss mirrored office tower glass
> windows have at 900 MHz? Or where I could look it up?
>
> Cell phones work inside the building, so it couldn't be too bad.
>
> I'm guessing between 5 to 10 dB.
>

It depends on what they mirrored the glass with and how conductive
it is.  I ran in to the same problems about five years ago when the
office building they were building at work had that kind of glass.

We experimented at 23 GHz (one of the many microwave links to and
from this building) and discovered an atteunation of about 10 dB.
We decided to do things the right way and erect a radome window on
the penthouse.  It works pretty well.

73,

Jake Brodsky, mailto:[e-mail]
PP-ASEL-IA, Cessna Cardinal N30946, Based @ MD24
Amateur Radio Station AB3A
"Beware of the massive impossible!"


From [e-mail] Thu Aug 01 21:21:28 1996
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From: "Anthony R. Gold" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Sommer ants at Dayton 96?
Date: Tue, 30 Jul 96 03:40:04 GMT
Organization: Microvest Limited, New York
Lines: 18
Distribution: na
Message-ID: <[e-mail]>
References: <4tgudl$[e-mail]>
Reply-To: [e-mail]
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X-Mail2News-Path: tgold.dialup.access.net

In article <4tgudl$[e-mail]>
           [e-mail] "Rick Kissell" writes:

> Can anyone tell me (a) if Sommer Antenna Company was at Dayton '96 and (b) i
f
> they had a sale on?

a) Yes, they were in their usual location in the oval hall which has
audience seating around the edge (basketball arena?).

b) I didn't notice any `sale' on their beams but they may have been
offering some sort of introductory pricing on their new verticals.

Regards,
--
   Tony - G3SKR / AA2PM                  email: [e-mail]
                                                [e-mail]
                                        packet: g3skr@n0ary.#nocal.ca.usa.na


From [e-mail] Thu Aug 01 21:21:31 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!crawford.com!news.sprintlink.net!news-fw-6.sprintlink.net!arclight.uoregon.edu!news.dacom.co.kr!nntp.coast.net!netnews.worldnet.att.net!newsadm
From: Jim Hughes <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Sommer ants at Dayton 96?
Date: Wed, 31 Jul 1996 21:35:07 +0000
Organization: AT&T WorldNet Services
Lines: 30
Message-ID: <[e-mail]>
References: <4tgudl$[e-mail]>
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X-Mailer: Mozilla 2.01 (Win16; I)

Rick Kissell wrote:
>
> Can anyone tell me (a) if Sommer Antenna Company was at Dayton '96 and (b) i
f
> they had a sale on?
>
> TNX ES 73,
>
> Rick WB9GYTRick...

Give carefull consideration to this antenna before you buy.  I have put
up several of the Sommer beams. While the performance and construction of
the antenna is good, the support (or lack thereof) does not exist.  The
design is in constant flux.  Of the beams I have assembled and put up
there were no two identical,  The instructions were never consistant.
Parts were missing.  In some cases the hams who purchased the beams had
difficult time in getting the parts shipped.  Some had to resort to
driving down to Orlando to get the parts.  Then when they tried to
install the parts they quickly found that the design had changed and the
parts would not fit.  You cannot get Sommer to return phone calls for
support after the sale.  We have one ham here in the area that has been
waiting for over three years for parts so he can put the thing together.
 He has given up and purchased a Mosley.

Suggest you consider the after purchase support before you buy.  Stick
with a well proven manufacturer.  Unless you have the money to burn you
are not going to get much more bang for the buck.

Jim

[e-mail]


From [e-mail] Thu Aug 01 21:21:33 1996
Path: news2.epix.net!news.sprintlink.net!news-dc-2.sprintlink.net!news.sprintlink.net!new-news.sprintlink.net!newsreader.sprintlink.net!imci3!imci4!newsfeed.internetmci.com!miwok!news.mcn.org!usenet
From: [e-mail] (Dan Richardson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SWR and matching problems? - coax.jpg (0/1)
Date: Sun, 28 Jul 1996 13:07:45 GMT
Organization: LPS Systems
Lines: 24
Message-ID: <4tfs2l$[e-mail]>
References: <4t2cik$[e-mail]> <[e-mail]> <4tajh9$[e-mail]>
NNTP-Posting-Host: an1-men-a29.mcn.org
X-Newsreader: Forte Free Agent 1.0.82

[e-mail](Glenn Sparks) wrote:




>One of my old elmers who thought he was the worlds formost expert on
>feedline (only use coax if there is absolutely no way to use ladder
>line was his first advice) had a mobile setup where the antenna
>impedance was about 25 ohms.  Since the transmitter he had would load
>to 25 he used 2 strands of RG-8 to the antenna claiming since it was
>parallel the result was a 25 ohm match.  I didn't beleive this to be
>the case, but was only 14 at the time and didn't mention it.  I haven't
>heard anything along these lines before or since, any comments?

>Glenn Sparks

Check HF Antennas for all locations by L. A. Moxon, G6XN page37.

You could parallel two 72 ohm coax cables and have a 36 ohm
transmission line.

Danny, K6MHE




From [e-mail] Thu Aug 01 21:21:33 1996
Path: news2.epix.net!uunet!in3.uu.net!netnews.worldnet.att.net!ix.netcom.com!news
From: [e-mail] (Tim Hynde)
Newsgroups: rec.radio.amateur.antenna
Subject: TV antenna for 190MHz
Date: 26 Jul 1996 20:09:10 GMT
Organization: Netcom
Lines: 9
Message-ID: <4tb8l6$[e-mail]>
References: <4t97a3$[e-mail]> <4t9crh$[e-mail]>
NNTP-Posting-Host: pon-mi2-22.ix.netcom.com
X-NETCOM-Date: Fri Jul 26  3:09:10 PM CDT 1996


I am looking to reccomend an antenna for a friend who is trying to get
channel 9 out of Windsor, Ont. He is just outside of the fringe and I
thought perhaps a Yagi cut to the channel freq may be better than a
typical log periodic TV antenna. Keeping in mind the antenna is for one
specific channel. Plenty of space to work with. Channel 9 should be
around 190MHz.

Any thoughts?


From [e-mail] Thu Aug 01 21:21:35 1996
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From: [e-mail](Glenn Sparks)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: TV antenna for 190MHz
Date: 30 Jul 1996 19:46:06 GMT
Organization: Netcom
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In <4tb8l6$[e-mail]> [e-mail] (Tim
Hynde) writes:
>
>
>I am looking to reccomend an antenna for a friend who is trying to get

>channel 9 out of Windsor, Ont. He is just outside of the fringe and I
>thought perhaps a Yagi cut to the channel freq may be better than a
>typical log periodic TV antenna. Keeping in mind the antenna is for
one
>specific channel. Plenty of space to work with. Channel 9 should be
>around 190MHz.
>
>Any thoughts?

I grew up in the North of Kansas, almost everyone had 3 antennas
stacked, a channel 2 pointed southwest, a channel 4 pointed North and a
channel 12 pointed Southeast.

When rotators became cheap many went to single yagi, unless they had
multiple TV sets.

I would probably find the 2m Quagi construction plans from the ARRL
antenna handbook a few years ago and scale it down.  If there are no
other channel 9's the area, the directivity isn't so critical, you
could do with a less directional and add a mast mounted pre-amp.

Glenn Sparks  KI5GY


From [e-mail] Thu Aug 01 21:21:36 1996
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From: [e-mail] (Bill Hetzel)
Newsgroups: rec.ham-radio,rec.ham-radio.swap,alt.ham-radio.fm,alt.ham-radio.hf,alt.ham-radio.vhf-uhf,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur,rec.radio.amateur.misc,rec.radio.amateur.swap
Subject: Where to find swinging/locking mobile antenna base
Date: Tue, 30 Jul 1996 13:03:37
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Xref: news2.epix.net rec.radio.amateur.antenna:23462 rec.radio.amateur.equipment:31418 rec.radio.amateur.misc:105635

Where can i find a mobile antenna base that will easily swing down 90 degrees
to lie flat along the roof?

I want to mount it outside the drivers window, on the gutter or roof, and be
able to reach out the window to lay the antenna flat as necessary.

I am sure i have seen something like this.  It was some kind of ball-joint
with detents at 90 deg. to hold the antenna in place.

It should be able to hold a standard 5/8 wave 2-m antenna.

I need to get this soon for an upcoming road trip.  Thanks much for any help
in finding this antenna.

Bill Hetzel
[e-mail]
510-632-5670
(please respond by email, as my news connection is flakey)





From [e-mail] Thu Aug 01 21:21:37 1996
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From: [e-mail] (Workshop)
Newsgroups: rec.radio.amateur.antenna
Subject: Wire antenna length&impedance ?
Date: 31 Jul 1996 11:35:34 GMT
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I'm not sure if this is the correct group but here goes
What is the best length for a piece of wire that is bieng used as an antenna?
It is to be used on one of these simple single transistor transmitters,that ju
st
has a capacitor connected to the transistors collector and to a piece of wire.
There is no proper feed line etc.
Should I use 1/4 ,1/2 , 1 wavelength?
Also:What is the "approx"(as it would depend on wire thickness & lots of other
factors) impedance of a piece of wire 1/4,1/2 or 1 wavelength long.
Hope I have not been to vague.
Cheers
Robin