World of Ham Radio 1997/WOHR97_AmSoft_(1997-02-01).iso/usenets/1996_05/_antenna.txt

Text File | 1997-02-01 | 493KB | 13,269 lines

The World of Ham Radio CD-ROM



From [e-mail] Fri May 03 12:10:20 1996
From: Ted F <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 2 meter Beam
Date: Wed, 01 May 1996 11:26:07 -0400
Message-ID: <[e-mail]>

This might be a stupid question, but i'll ask anyway.  In the April issue of 7
3 on page
54 there is an article about a 3 element direct connect beam antenna that is e
asy to
construct.  The only question I have is, what type of transmission line to use
 with it.
 The way it looks in the pictures, I am guessing twin lead ladder line.  Coax
would be
better for me as I have a surplus of rg-8 I can use.  Thanks in advance for yo
ur help.
Ted F.
N3SQY


From [e-mail] Fri May 03 12:10:21 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 50 ohms from ladder-line
Date: 30 Apr 1996 23:14:01 -0700
Message-ID: <4m6vf9$[e-mail]>
References: <4m48b6$[e-mail]>

[e-mail] (Cecil A. Moore~) wrote:
>Think of it. A perfect 50 ohm match using a single variable
>capacitor from my junk box. Who said balanced antenna tuners
>were expensive and complicated?

Got some more data. The 50 ohm (actually 1/50 S) unit conductance
circle on a 300 ohm Smith chart is drawn through points 0+j0 and
0.167+j0, a rather small circle close to the current maximum points.
That means a single parallel reactance placed within 0.013
wavelengths of the current maximum will result in a perfect 50
ohms for any 300 ohm ladder-line SWR above 6:1  I've done it for
10m-20m with a single 20-200pf variable capacitor.

73, Cecil, KG7BK, OOTC




From [e-mail] Fri May 03 12:10:22 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 50 ohms from ladder-line
Date: 30 Apr 1996 23:24:02 -0700
Message-ID: <4m7022$[e-mail]>
References: <4m48b6$[e-mail]> <[e-mail]>

Larry Deering <[e-mail]> wrote:
>       I hope that you are using a 1:1 balun between the xmtr and balanced
>line, or do you have a balanced output from the xmtr?

Just a plain old bead choke. Don't have any RF-in-the-shack
problems.

73, Cecil, KG7BK, OOTC




From [e-mail] Fri May 03 12:10:23 1996
From: [e-mail] (Paul Love)
Newsgroups: rec.radio.amateur.antenna
Subject: 6 metre J Pole
Date: 1 May 96 09:13:59 GMT
Message-ID: <[e-mail]>


>Date: Thu, 25 Apr 1996 01:35:30 GMT
>From: [e-mail] (Gary V. Deutschmann, Sr.)
>Subject: 6 meter J- Pole

>[e-mail] (Michael W. Smith II) wrote:

>It seems that there is a lot of action/questions about J poles....I'm
>looking to build a 6 meter jpole.  There are some articles about
>construction, but there are in the 1950's magazines.  I was wondering
>if anyone had built a 6 meter j pole and could give me some ideas on
>how to build one, or some starting dimensions.  Thanks alot!!

>73's
>N5TGL
>Michael W. Smith II

>I use a mirror image J on 6-m....
>By using a simple solenoid, I can flip it from vertical to horizontal.

>Plans available on my web page http://www.inlink.com/~raiar

>TTUL - 73+ de Gary - KG0ZP

------------------------------
Michael there are dimensions in most ARRL Antenna handbooks, and Gary's
suggestion is interesting. I have been having a discussion about this
same topic on the HAM_TECH fido conf. and the suggestion was made that
they are so cheap to build you could mount one horizontally off the side
on your tower mounted at the bottom "U"  but facing out that way---> ,
without upsetting the radiation pattern of the antenna. With one cut
for the top FM band and another for the SSB DX end you get the best of
both world cheaply, but Gary's suggestion goes one step further.

73 & Have Fun.....Paul VK4XD.




***************************************************************************
*  E-Mail : [e-mail]     |   AMPRNET:[e-mail]  *
*  AX25: vk4xd @ vk4rzb.#bne.qld.aus.oc |   IP     :[44.136.138.118]      *
***************************************************************************




From [e-mail] Fri May 03 12:10:24 1996
From: [e-mail] (Gary V. Deutschmann, Sr.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 6 metre J Pole (UPDATE)
Date: Thu, 02 May 1996 17:27:36 GMT
Message-ID: <4marg9$[e-mail]>
References: <[e-mail]>

Did an experiment last weekend.

Built a combination 6-meter mirror image J-Pole combining both
vertical and horizontal elements.

I stumbled across a couple of double T-Fittings, actually an X-Fitting
with T in the center, made of brass for a couple of bucks each.

My evil mind concocted a double mirrored-J, thus I built it.

As it turned out, I had to use two pieces of 59U coax, exactly 1/2
wavelength long, one to the vertical and one to the horizontal
transformer.  These two pieces of coax were joined and then any length
of 50 ohm coax can be used for the trip back to the shack.

It took about 10 tries at feeding this monstrosity before I hit on the
combination that gave me less than 1.2-1 SWR.  The antenna operates
vertically and horizontally at the same time.

I don't have any technical data on it yet, but in comparison to the
single mirrored image J-Pole.  The received signal on the combo vs the
vertical from our local repeater was 1.5 S units higher.  The received
signal on the combo vs the horizontal was only 1 S unit higher, but
our repeater is vertical.

A QSO with a ham about 30 miles away on a horizontal dipole, showed
the following.
Received signal on the new combo antenna was a full 10 over S 9.
Received signal on the vertical mirrored-J was only 6 S units.
Switching it to horizontal raised the received signal to 8.5 S units.

Transmitting at 20 watts my signal was received at 15 over S 9 using
the combo antenna.
The vertical was only received at 5 S units and the
horizontal was received at 9 S units.

Feeding the combo with a single feedline to the vertical, showed no
improvement over a regular mirrored vertical-J.

Once the Co-Phasing harness was built, installed and tuned for lowest
SWR, the difference was dramatic enough to mention it here.

TTUL - 73+ de Gary - KG0ZP
http://www.inlink.com/~raiar







From [e-mail] Fri May 03 12:10:25 1996
From: [e-mail] (FORREST GEHRKE)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Modeling Sof
Message-ID: <[e-mail]>
Date: Wed, 01 May 96 11:14:00 -0300
Distribution: world
Reply-To: [e-mail] (FORREST GEHRKE)
References: <[e-mail]>

CM> >OS/2?  What's that? =8~}
CM> Hi Jim, isn't that an old obsolete operating system like CPM? :-)

 * RM 1.3 02583 * Windows95? Been There,..Done That,..2 Years Ago!!... OS/2


From [e-mail] Fri May 03 12:10:26 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Theory Question
Date: Wed, 01 May 1996 14:18:46 GMT
Message-ID: <4m7rrd$[e-mail]>
References: <4l80tb$[e-mail]> <4ltst7$[e-mail]> <[e-mail]> <4m0veu$[e-mail]> <4m2ps4$[e-mail]>

[e-mail] () wrote:


>>We have proven that faster than light communications occurs.

>>We have proven that EM waves do not follow straight lines and
>>cannot propagate through nothing.

>Wrong news group, Cecil,

>Take it to alt.scifi.weird.

>73, Moritz DL5UH


Perhaps this will explain some curious phenomena...


Administratium
World's Heaviest Element Discovered

The heaviest element known to science was recently discovered by
University
of Adelaide physicists.  The element, tentatively named Administratium
has no proton and no electrons and thus has atomic weight of 0.

However, it does have one neutron, 12 assistant neutrons, 70
vice-neutrons
and 161 assistant vice-neutrons.  This gives it an atomic mass of 244.
These 244 particles are held together in a nucleus by a strong force
that
involves the continuous exchange of meson-like particles called
morons.

Since it has no electrons, Administratium is inert.  However, it can
be
detected chemically as it impedes every reaction it comes into contact
with.
According to researchers, in one experiment, a minute amount of
Administratium was added to a reaction, which took four days to
complete.
Without Administratium, the reaction ordinarily took less than one
second.

Administratium has a normal half-life of approximately three years, at
which
time it does not actually decay, but instead undergoes a
reorganisation in
which assistant neutrons, vice neutrons and assistant vice-neutrons
exchange
places.  Preliminary studies show that the atomic number actually
increase
after reorganisation.

Research indicates that Administratium occurs naturally in the
atmosphere,
but it tends to concentrate in artificial structures build on lower
tender
such as government agencies and universities.  It can usually be found
in
the newest, best appointed and best maintained buildings.

Scientists warn that Administratium is known to be toxic and recommend
plenty of red and white fluids and bed rest after exposure to even low
levels of the element.





73/DX


           C. Dean Norris
      Amateur Radio Station K7NO
      e-mail to [e-mail]
    http://www.syspac.com/~dnorris/



From [e-mail] Fri May 03 12:10:28 1996
From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Theory Question
Date: Wed, 1 May 1996 09:13:52 +0100
Distribution: world
Message-ID: <[e-mail]>
References: <4l80tb$[e-mail]>

Cecil Moore wrote:
>
>It follows that if two sub-atomic particles can communicate with
>each other instantaneously no matter what distance is between them,
>then our "reality" does not originate locally.
>
>Since space itself is curved, how do you propose to prove a line
>is straight? Your ruler isn't even straight.
>
>Don't look now, but Newton's Laws have a built in error. As a matter
>of fact, every time you make a measurement, you make an error.
>
All those statements may well be correct. But in everyday life -
including electronics and radio engineering - those effects are totally
negligible.

At the beginning of this century it would have been quite reasonable to
"believe in" simple physical laws - Newton, Maxwell etc. That is no
longer reasonable because we now know that they break down at the very
large (astronomical) or very small (atomic) scales.

Instead we have to create an imaginary ring-fence around our everyday
experience. "In Here", the old laws still apply; straight lines are
straight, and the length of a ruler doesn't vary if you look harder at
it. Maxwell's equations work In Here, just as well as they always did,
and so too do Newton's Laws and the laws of Thermodynamics.

"Out There", none of that may be true; but In Here it doesn't matter.

I think it's important to remember that this is an In Here newsgroup.
Antennas don't come anywhere near the ring-fence. They are complicated
and sometimes difficult to understand, but that's something different.

So if we still can't explain every single aspect of our antennas, let's
not blame Maxwell, Kirchhoff or Ampere. It's strictly our problem.


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


From [e-mail] Fri May 03 12:10:29 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Auto Tuner vs Multiband Vertical
Date: 1 May 1996 23:04:08 GMT
Message-ID: <4m8ql8$[e-mail]>
References: <[e-mail]> <4lno77$[e-mail]> <4m4gqd$[e-mail]> <4m52gd$[e-mail]>

[e-mail] (Ignacy Misztal) wrote:

>I agree that the impedance variations can be extreme, but they are not
>unmanageable.
>
>Ignacy Misztal              Ham radio: NO9E, SP8FWB

Hi Ignacy, and now the $64 question (I'm old enough to remember the $64
question on AM radio).

Do you know what your impedance variations are? If not, how can you
possibly know if you have managed them properly? I was losing half
my power on 75m. I was still "getting out" and "having fun".

It is possible to get lucky and achieve a good match by accident without
knowing anything or measuring anything, but not very likely. The impedance
at your balun is easy to measure using a $13 Ladder-Lizard from TechnoLogic
Concepts and IMO is well worth knowing for sure.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Fri May 03 12:10:30 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Auto Tuner vs Multiband Vertical
Date: 1 May 1996 14:39:33 GMT
Message-ID: <4m7t36$[e-mail]>
References: <[e-mail]> <4lgmjn$[e-mail]> <[e-mail]> <4lm11v$[e-mail]> <4lmtc3$[e-mail]> <4m4glj$[e-mail]>

[e-mail] (WB3U) wrote:

>Louis Varney has already laid claim to
>102', so maybe you should try, say, 84' and see what happens.  ;)

I personally like the 20m EDZ length of 88' for an all-band HF antenna.
I've been concentrating on 102' because it is so popular.

88, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Fri May 03 12:10:32 1996
From: Gary Cavie <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Formula For J-Poles
Date: Tue, 30 Apr 1996 22:40:40 +0100
Message-ID: <[e-mail]>
References: <[e-mail]>

Buster wrote:
>
> Any one have formula's for J-Pole construction.
>
> I have plenty of dimensions, just want the raw formula's for
> future reference
>
> How to calculate the radiator & matching stub lengths.
>
> Most importantly, how to calculate where to feed the antenna
> from the short at the bottom?
>
> What I'm looking to do is build J-poles for different bands, and
> possibly out of materials with different velocity factors.  My big
> hurry up project is a 6m Twin-Lead J-Pole.  It'd be great for field
> day.  Just toss one end up in the tree.
>
> I have plenty of construction articles on J-Poles, unfortunately
> they don't tell you how they came up with the numbers.  They just
> say measure, cut, solder.
>
> Thanks
>
> Buster, KC7KMJ, DM42
> Tucson, AZ

Whilst on the subject of J-poles, can anyone give me the dimensions for a
J-pole centred on 145.500 MHz, made from 15mm copper pipe and yorkshire
fittings. I know there was a design for it in the September 1994 issue of
Practical Wireless, but this is the one copy which appears to have gone
missing from my file.

Many thanks

Gary, G7SJF
Tiptree, England
[e-mail]


From [e-mail] Fri May 03 12:10:33 1996
From: [e-mail] (Stan Nowak)
Newsgroups: rec.radio.amateur.antenna
Subject: High gain antenna for cellular phone
Date: 1 May 1996 00:16:08 GMT
Distribution: world
Message-ID: <4m6ag8$[e-mail]>

I need a high gain yagi antenna for the cell phone band. If any one knows
who make one I would appreciate the info :)


Brad - ve7qbn



From [e-mail] Fri May 03 12:10:34 1996
From: [e-mail] (Alan Burgstahler)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: High gain antenna for cellular phone
Date: Wed, 01 May 1996 13:57:03 GMT
Message-ID: <4m7qja$[e-mail]>
References: <4m6ag8$[e-mail]>

[e-mail] (Stan Nowak) wrote:

>I need a high gain yagi antenna for the cell phone band. If any one knows
>who make one I would appreciate the info :)

They're commerciall available.  At work we've bought some from Tessco, which
is a two-way radio supplies supplier, however I don't remember the brands of t
he
yagis.  Tessco can be found at http://www.tessco.com.   No connection to me
except at work we're a satisfied customer.

Alan Burgstahler - WA6AWD - Kent, WA, USA



From [e-mail] Fri May 03 12:10:35 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Modeling a ferrite bead in Eznec
Date: Wed, 01 May 96 16:31:19 GMT
Message-ID: <4m83ik$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>,
   Robert Mansfield <[e-mail]> wrote:
>Hi to all
>
>I need info on how to model a clip on ferrite bead(s) on a guy wire (the
>backstay on my sailboat) in Eznec. I want to try some antenna experments,
>but I need to breakup the guy wire resonance on 20 meters. I want to test
>this in Eznec first since I can only put the beads on when I have the mast
>stepped which is once a year. Thanks in advance.
>
>Bob Mansfield
>WA8USR
>s/v Shadow Dancer

It would be modeled as a "load". You'll either have to measure the bead's
impedance or get its impedance at the frequency of operation from the
bead's manufacturer. The impedance could be primarily inductive, primarily
resistive, or in between, depending on the frequency and type of ferrite.

Roy Lewallen, W7EL




From [e-mail] Fri May 03 12:10:35 1996
From: "Clark A. Townsend" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: TA-33Jr Antenna
Date: Wed, 01 May 1996 13:52:27 -0700
Message-ID: <[e-mail]>

The wind surface area is 5.7 sq. ft. according to Mosley catalog
Clark, K8CZM


From [e-mail] Fri May 03 12:10:36 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The Coax Mentality
Date: 30 Apr 1996 23:05:02 -0700
Message-ID: <4m6uue$[e-mail]>
References: <4m0rpa$[e-mail]> <4m4gon$[e-mail]>

[e-mail] (WB3U) wrote:
>   [e-mail] (Cecil A. Moore~) wrote:
>>Ladder-Line Mentality: It's easy to make measurements
>>along a transmission line without disturbing anything.
>How long does this take?

It takes a leisurely hour per band. All you do is find a current
maximum and a current minimum. Dividing those two readings gives
you the SWR which you can draw as a circle on a Smith chart. The
current maximum is the low purely resistive point and the current
minimum is the high purely resistive point on that very same SWR
circle. Since it's a halfwavelength around the Smith chart and you
know the length of your ladder-line, you know the antenna impedance
and the impedance at the transmitter.

>That means it requires (ugh) math.  Tell me again, where do I get one
>of those coax meters?

Sorry, it doesn't work on coax which is good enough reason not to use
it. A voltmeter and a calculator is all you need in addition to the
Ladder-Lizard from TechnoLogic Concepts, [e-mail]
My application note avoids Smith charts altogether relying instead
on tables.

>>Ladder-Line Mentality: Cutting and trying is inexpensive
>>and easy. It as easy as twist-ties. Splicing is as easy
>>as using butt lug connectors.
>This could get expensive around the ten-thousandth splice.

I have only two splices in 72 ft of ladder-line and they happened
before I knew what I was doing.

>McCoy says the best length is the one that reaches from the antenna to
>the shack.  What impedance is that?

Sorry to say, Lew is one of the nicest guys I know but he is wrong
on that one. A random length of feedline is almost never the best.
If you locate a current node, a 50 ohm point is always less than
0.013 wavelength away for any 300 ohm ladder-line SWR over 6:1.

>I like this idea.  What happens when you use a 0 pF cap like the
>other guy was asking about?

Jack, I just tried a 0 pf cap and nothing happened. I think I'll
ask for my money back if I can find it. :-)

73, Cecil, KG7BK, OOTC




From [e-mail] Fri May 03 12:10:37 1996
From: [e-mail] (Thomas Clarke)
Newsgroups: rec.radio.amateur.antenna
Subject: Vertical Zepp?
Date: 1 May 1996 18:44:25 GMT
Message-ID: <4m8be9$[e-mail]>
Reply-To: [e-mail]

I've been thinking about the advantages of a vertical, but
the problem of a good ground system seemed insurountable.

Then I thought of trying something like a vertical zepp.
End feed a vertical 1/2 wave dipole with open wire line.
I think this would work without a ground system.
I've even been thinking about supporting a thin wire with
a balloon or a kite to get 80m or even 160m coverage without a
tall tower.

Has this been tried?  Is there a catch 22?
I can't find anything like it in the ARRL antenna book.

Thanks.

Tom Clarke KE4VFH


From [e-mail] Fri May 03 12:10:38 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Vertical Zepp?
Date: 2 May 1996 18:44:04 GMT
Message-ID: <4mavpk$[e-mail]>


Tom Clarkewrote -
Then I thought of trying something like a vertical zepp.
End feed a vertical 1/2 wave dipole with open wire line.
I think this would work without a ground system.
I've even been thinking about supporting a thin wire with
a balloon or a kite to get 80m or even 160m coverage without a
tall tower.

My recent posting in reply assumed Tom was going to ground one side
of the balanced line at the anttenna.

        I now think Tom was proposing hoisting the antenna AND
feed line so as to be a sort of inverted true Zepp.

Tom,
        As with almost any unbalanced load, there will be some
radiation from the open wire balanced feed line.  However I should
expect it to be less than that when a hrizontal half wave is end
fed by open wire feeders because in this case the feeders are
roughly in line with the antenna instead of perpendicular to it.
So there is less coupling between the antenna and the line.
        You did not propose a specific line length.  It appears
that the height of the antenna will be determined by the line
length.  You shoud investigate the resulting pattern since it
changes with antenna height
        There will also be some deviation from the pattern caused
by the radiation from the feed line as mentioned above.

Charlie, W7XC
--


From [e-mail] Sat May 04 15:45:04 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: 2m/70cm base station antenna
Date: Fri, 03 May 1996 13:07:11 -0700
Message-ID: <[e-mail]>

Hi,

I have tried to find an article with information about
building a 70cm/2m base station gp-antenna. What I am
after is an omnidirectional system with a considerable
gain over 1/4lambda gp and that needs only one coax.
Diamond has many different models on market but how to
build one yourself?

Anyone can help me with this?

Hannu/OH6MAZ
[e-mail]


From [e-mail] Sat May 04 15:45:05 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Electric half-wavelenght xmition lines...
Date: 3 May 1996 17:10:17 GMT
Message-ID: <4mdelp$[e-mail]>
References: <[e-mail]>

[e-mail] wrote:
: Hi all:
: Some days ago I'd posted a msg. asking if it's valid take antenna
: measurements (HF range) using a RX Noise Bridge conectet to a antenna
: trhu a electric half-wavelenght transmition line.
: This particular line lenght (and it's multiples) will be "transparent" to
: complex impedances?

If the line has zero loss, then the impedance at one end of a half-wave
piece of line will be exactly reflected to the other end.  If you want
to take into account line loss, you can use standard line formulas.  The
result of loss is always that the impedance seen at the transmitter end
of the n*half-wavelength line will be the same phase angle as the load
but of a magnitude (slightly) closer to the line impedance.  Think of a
Smith chart.  A half wavelength along lossless line runs you around one
full circle, centered on the line impedance normalized to the center of
the chart.  If the line has loss, the path becomes a spiral, in toward
the center as you move away from the load, but still a full 360 degrees
for 1/2 wavelength along the line.

--
Cheers,
Tom
[e-mail]


From [e-mail] Sat May 04 15:45:06 1996
From: [e-mail]@adobe.com (David Mitchell)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ethernet Cable
Date: 3 May 1996 15:56:58 GMT
Message-ID: <4mdaca$[e-mail]>
References: <[e-mail]>

Cougercat ([e-mail]) wrote:
: I have heard that Ethernet cable makes good transmitting coax.  What is the
: impedance of the Ethernet cable  (the orange stuff) and how much power can
: it handle?

: Thanks

: Please reply to :

: [e-mail]



: Jeff

The impedence of Ethernet coax is 52 ohms and the thick stuff (orange or
yellow) can handle the legal limit. It gets lossy in the VHF and UHF bands
despite the foam dialectric and double shield, and the outer sheath will
deteriorate when exposed to sunlight. Beware of used Thicknet cable, as it
may have "vampire tap" holes in it. These let in moisture, small insects,
etc. and can make impedence matching a real challenge.

Saludos,
 .david.
--
David Mitchell
Adobe Systems Incorporated  [e-mail]
Bainbridge Ometepe Sister Islands Association  [e-mail]
Amateur Radio AB7DM & YN5NPM  [e-mail]
 *Organic, Shade-grown Fair-traded Coffee at http://www.bosia.org*



From [e-mail] Sat May 04 15:45:07 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Modeling a ferrite bead in Eznec
Date: 1 May 1996 08:49:49 -0400
Message-ID: <4m7mld$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, Robert Mansfield
<[e-mail]> writes:

>Hi to all
>
>I need info on how to model a clip on ferrite bead(s) on a guy wire (the
>backstay on my sailboat) in Eznec. I want to try some antenna experments,
>but I need to breakup the guy wire resonance on 20 meters. I want to test
>this in Eznec first since I can only put the beads on when I have the
mast
>stepped which is once a year. Thanks in advance.
>
>Bob Mansfield
>WA8USR

I would insert a load at the point in question that has the correct series
resistance and inductance for the bead and frequency you are using.

The resistance and inductive values vary with frequency (and can even go
capacitive).

I have measured and logged the data from dozens of common beads. I'm not
sure the manufacturers aways have that data available, but you can try
them.

73 Tom


From [e-mail] Sat May 04 15:45:08 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Problems modelling linearly loaded dipole & beam!
Date: Thu, 02 May 96 22:59:27 GMT
Message-ID: <4mbema$[e-mail]>
References: <4lgn5r$[e-mail]>

In article <4lgn5r$[e-mail]>, [e-mail] (Rob Frohne) wrote:
>I have been trying to model KLM's linearly loaded rotatable dipole.  I
found the impedance
>to match just fine experimentally, but I can't seem to make the simulation
agree.  I'm
>using NEC2 and I've used up to 350 elements for just this dipole.  The
resonance doesn't
>seem to occur at the right place.  If I use around 50 elements the
reactance is about 10%
>more negative (from -180 ohms to -200 ohms); the resistance seems to have
converged to about
>what I expect.  Has anyone else had any experience with modelling linear
loaded antennas.

I'm not familiar with the particular antenna, but if the entire antenna
isn't made from wire or tubing of one diameter, NEC-2 won't give completely
accurate results. The error will manifest itself chiefly as an inaccurate
reactance. This is a known shortcoming of NEC-2. For best accuracy with
differing-diameter conductors, make the segment length as LONG as possible.
This is contrary to intuition, but the problem is aggravated by short
segment length-to-diameter ratios near the junctions of dissimilar-diameter
wires.

The error is large enough to throw the pattern (particularly the nulls)
badly off if parasitic elements have wires of more than one diameter. EZNEC
and NEC-Wires have a built-in correction for some special cases, such as
full-length Yagi elements, using an equivalent single-diameter conductor
based on a method in Dave Leeson's book _Physical Design of Yagi Antennas_.
However, it's valid only for straight elements with a length near 1/2
wavelength, such an in full-size Yagis, and not for "linearly loaded"
elements.

Roy Lewallen, W7EL


From [e-mail] Sat May 04 15:45:10 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Radiation resistance
Date: 3 May 1996 18:49:40 GMT
Message-ID: <4mdkg4$[e-mail]>


Richard,

        Here is a fairly simple approximation of Rr seen at
the center feedpoint of a horizontal dipole (possibly either
not loaded, inductively loaded at any point or end capacity
loaded; in freespace and assuming sinusoidal current
distribution.
        This Rr will vary with height above earth on a
curve of Rr vs height oscillating about the free space value
as a damped sinusoid approaching the free space value at
great heights and decreasing with height below about .2
wavelength height to some small value at zero height.
        Note:  Rr does NOT include earth loss, copper loss
of the wire or loss resistance of any loading coils.  Earth
loss is generally negligible at heights above about .2
wavelengths.


        Rr = 70 (sin L1 + cosL1(1 - cosL2)/sinL2)) ^2

Where:
L1 = angular length of section below loading coil
L2 = angular length of section above loading coil.
        angular length = .366 h f
                Where      h = length in feet of each side of
the     dipole         and     f = frequency in MHz.

        This equation applies to any loading coil position
including loading at the feedpoint (L1 = 0) and purely
capacitive end loading where L2 = 0.
        Coil loss resistance reflected to the feedpoint will
be approximately    Rc cos^2 L1 Where Rc is the loss
resistance of the coil.         But because the current
distribution is not quite sinusoidal, the actual value will be
somewhat greater.
        This loss resistance from copper loss of the antenna wire (usually negligible

for otherwise high efficiency very short antennas), coil loss and earth loss a
r
to form the input impedance of the antenna center feedpoint.

        Charlie, W7XC
--


From [e-mail] Sat May 04 15:45:11 1996
From: "Thomas W. Castle" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Sale
Date: Fri, 3 May 1996 01:52:58 -0400
Message-ID: <[e-mail]>
Reply-To: "Thomas W. Castle" <[e-mail]>

Hi Tom here... I have for sale 2 Regency 16ch programable mobiles.
They have 30W output, keyboard programable, mobile mtg brackets,
power cords, mics & all paperwork... They have programming switch
added to back of radio for on the fly re-programming.

They have been set-up for Emergency service rigs 140Mhz - 180Mhz.
broad banded, running 25W at the moment, an working in the 2 mtr
band. Type Accepted... So should be usable in other services as well.
They have scan, priority, skip, monitor & Tx & Rx pls <programable>
built in. It can have 2 different PL's <1 tx & 1 rx>...

Still with their original boxes, never pressed into service...
Tested to check functions on 2 mtrs... <We can guarenty they work.>
Area has gone 800Mhz trunked... <Reason for selling>


Will sell one or both, $235.00 each shipped.... Both for $450.00...

Contact me via e-mail or thru packet KD4QHH@K4DPZ.#Gnsvl.Fl.USA.NA.

Tnx De Tom 73






From [e-mail] Sat May 04 15:45:12 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The Coax Mentality
Date: 2 May 1996 18:39:04 GMT
Message-ID: <4mavg8$[e-mail]>
References: <4m8ehm$[e-mail]> <4m8usl$[e-mail]>

[e-mail] (Tom Bruhns) wrote:

>you can probe the voltage in a coaxial line by inserting detectors at
>intervals along the line.  You don't need a lot of them; four at fixed
>locations, a known propagation time apart, should be plenty.  If you choose
>the separations correctly, the four should cover the whole HF part of the
>spectrum.  You can use a computer to measure the voltages and calculate the
>same sorts of things you are suggesting for open wire line.

Hi Tom, sounds messy compared to absolute non-intrusion into the ladder-
line. Inductive coupling is all that is needed for ladder-line measurements.
It would be interesting to hear from anyone who has done the above with coax
and/or are willing to try it in the future.

>I think there continue to be appropriate places to use coax, and
>appropriate places to use balanced lines.  I appreciate your food for
>thought, but it's not going to make me go out and replace the
>coax feeding my unbalanced antennas that already match the 50 ohm line
>quite well.  And I don't think you were suggesting that anyway.

I'm not anti-coax. It's great for 50 ohm unbalanced antennas and mobile
stuff. My remarks are aimed at HF hams who already use ladder-line but
don't know how to make very simple measurements in order to know everything
about their antenna system. I'm designing a remote control for a non-resonant
ladder-line fed dipole here at Intel because the 70 ft of transmission line
between the roof and the shack needs to be coax. The remote controller will
ensure a perfect 50 ohm match into the coax.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Sat May 04 15:45:14 1996
From: P Tyers <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Two beams on one feedline ?
Date: Fri, 03 May 1996 16:11:43 +1100
Message-ID: <[e-mail]>
References: <4lm0n3$[e-mail]> <4lr1vq$[e-mail]> <4mb3hj$[e-mail]>

Brian Williams wrote:
>
> In article <4lr1vq$[e-mail]>,
> [e-mail] says...
>
> >In article <4lm0n3$[e-mail]>,
> >Pat Masterson <[e-mail]> wrote:
>
> >> I want to use two 440 beams to link two packet nodes. All
>                  ~~~~~~~~~~~~~         ~~~        ~~~~~
> >>that is available to me are standard, 50 ohm antennas. How
> >>can I connect them to one radio, presenting a decent
>                         ~~~~~~~~~
> >>impedance load? Is there a trick with matching sections of
> >>coax I can use? Thanks. -pat

> I believe he's looking for the proper way to take both beams (pointed
> in two directions for covering two different areas (beams between those
> two areas) and using one radio, not two.
>
>  I think that
> using a length of 50 ohm coax from the radio to a T-coupler and using
> two equal lengths (maybe not critical if antennas are pointing in
> seperate directions) of 75 ohm coax between the other two connectors of
> the coupler to the antennas.

Almost right!
Use two lengths of 75 ohm coax which are ODD (1,3,5
etc)quarter wave multiples (remember the velocity factor -
roughly 0.66 - when calculating the quarter wavelengths).
These act as transformers 50 ohms to 100 ohms and by
paralleling the 100 ohm impedances the radio sees 50 ohms
again.

Generally the arrangement for stacking is half wave vertical
of horizontal seperation and one quarter wave plus one three
quarter wave cable section. For pointing in two directions
I'd assume any mixture of odd quarter wave sections would do.
But dont ask me what the resultant pattern would look like !!

--
P Tyers, Tel. [phone]
AARnet: [e-mail]
CSnet: [e-mail]    HAM: VK3KTS
MAIL: Telstra Research Laboratories,P.O. Box 249,
      Clayton,VICTORIA 3168,AUSTRALIA


From [e-mail] Sat May 04 15:45:15 1996
From: "George J. Molnar" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Want to know differenses between SB200 and SB201 ??
Date: Fri, 03 May 1996 18:29:18 -0600
Message-ID: <[e-mail]>
References: <4m7efv$[e-mail]>
Reply-To: [e-mail]
To: Martin Rask <[e-mail]>

Martin Rask wrote:
>
> Could anyone tell med the differenses between Heathkit SB200 amp and the
> Heathkit SB201 ???
>
The 201 didn't have 10m coverage as sold by Heathkit. The 200 did.
I suspect most 201's in the field today have been modified "back"
into 200's, though.

--
George J. Molnar
Highlands Ranch, Colorado
Amateur Radio: KF2T@N0QCU.#NECO.CO.USA.NOAM
http://www.interealm.com/p/gmolnar/index.html


From [e-mail] Sat May 04 15:45:25 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Grid Driven 4-1000
Date: 3 May 1996 13:12:40 -0400
Message-ID: <4mdeq8$[e-mail]>
References: <4mccop$[e-mail]>

Hi All,

The correct AB1 formula for a simple shunt grid resistance is: R=
Eg^2 / 2Pdrv

A 50 ohm L pad can be calculated using ohm's law: .707bias / sqrt(p/50) =
Rgrid.  The input series R would of course be: 50 - Rgrid = Rs

With 90 watts and 56 volts of bias,  30 ohms of grid-cathode shunt
resistance fed by a series 20 ohm resistor would provide both proper grid
resistance and exciter loading.

Years ago I ran a pair of grid driven 4-1000A tubes, but scrapped the idea
because of tuning and adjustment difficulties. AB1 grid driven amplifiers
are tough to tune correctly, even the slightest amount of grid current or
improper loading makes them poor IMD performers.

I eventually tried to run the 4-1000A's in the Collins circuit used in the
30L1, but was unsucessful due to less than sufficient catode to anode
shielding. The only circuit that worked well was conventional grounded
grid with screen and grid bias applied. There was some slight performance
improvement over no screen or grid bias in grounded grid.

As with any tetrode, screen regulation and grid current in both grids was
critical. As time passed I scrapped the 4-1000's in favor of a grounded
grid triode. IMD performance and ease of adjustment improved greatly with
this move.

Looking back on it all, there was almost no advantage for all the effort
in building the screen and bias supply in the cathode driven 4-1000
configuration, althought it was easy to use and relatively clean even when
slightly mistuned. The thing I wanted awas more power gain, but gain
barely increased over a conventional grounded grid circuit with no screen
or grid bias voltages.

The grid driven configuration gave greatly improved power gain, but was
pretty fussy to tune properly on SSB. The largest problem was creation of
IMD even when scope and meters appeared correct. I think the Collins
circuit (used in the 30S1 4CX1000 amp) would have been the best circuit
but the poor screen grid shielding in the 4-1000A's made regeneration a
problem.

There are pros and cons to every circuit, and I guess the best choice
depends on user goals. But the 4-1000A is a far cry from the 4CX1000 in
operation and stability.

73 Tom


From [e-mail] Sat May 04 15:45:26 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Information Needed!
Date: 3 May 96 02:39:58 GMT
Message-ID: <[e-mail]>

Hi all.

I still looking for information at the following items:

- CELLULAR PHONE PWR MODULE, LABELED FMC080802-20, REMOVED FROM A
  NEC CELL-PHONE.
- 2SC1251, A NEC TRANSISTOR (SUPOSE TO BE A CLASS A UHF DRIVER, I THINK
  I SAW IT AT SOME MOTOROLLA DATABOOK SOME YR AGO)
- IF THERE IS ANY CODE TO SMD TRANSISTOR AND DIODES/MIXERS SIMILLAR
  TO THE ONE WE USE TO SMD (CAPACITORR AND RESISTORS).
- ANY SOURCE FOR SAW-FILTERS, 455KHZ OR 10.7MHZ, 40khz BW(NOAA/GOES/
  METEOSAT DEVIATION).
- HRPT INFORMATION/SOFTWARE SOURCES.
- PATCH ANTENNAS THEORY (AND THEIRS YAGI-LIKE ASSEMBLY, SUCH AS USED TO
  MMDS LNBY COMBINATION)

AND MORE:

- ANY RESULTS USING STANDARD TVRO KU-BAND FEEDERS AT 10.25GHz ASSOCIATED
  TO THOSE 0.6...2.4 METER DISHES(0,33...0.36 F/D)?
- HOME-MADE FERRITE CIRCULATOR TO IN A 10.25GHz WAVEGUIDE: TO ALLOW MO-
  DIFIED KU-BAND LNB AND GUNNPLEXER CONECTION(DUAL-PORT...)?
- ANY SUGESTION TO BUILD A 1.2/2.4GHz DIRECTIONAL COUPLERS, STRIP-LINE
  ON PCB + SMA CONN + SMD BALANCE RESISTORS (-20...-30dB COUPLING
  FACTOR)? MAY BE A MODEL 43 PLUS THE CORRECT PLUG-IN DETECTORS...BUT
  HERE? THE DETECTOR WILL BE A TEKTRONIX 2714 SPECTRUM ANALYZER!

  THANKS IN ADVANCE!

73 - Marcus Ramos - [e-mail] - Sao Paulo - Brasil


From [e-mail] Sat May 04 15:45:27 1996
From: [e-mail] (Bob Duckworth)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need Phone In-Use Light
Date: 2 May 1996 16:01:17 -0400
Message-ID: <4mb4ad$[e-mail]>
References: <[e-mail]> <[e-mail]>

In article <[e-mail]>,
 <[e-mail]> wrote:
>
>In Article<[e-mail]>, <[e-mail]>
>writes:
>
> > Does anyone a nifty circuit for a phone in-use indicator. The
>indicator
> >
>JADE Electronics makes one just as you described.  Its a kit
>for $11.00.  A bit expensive but you only need to buy one
>and clone the rest...
>73
>Scott
>

Or you can put a diac in each line.
If one phone is off hook, there won't be enough
voltage to turn on the diacs at the other phones on.
The end result being that you can only use one phone
at a time.
-bob

--
Bob Duckworth Consulting, 960 Ralph McGill Blvd. Atlanta GA 30306-4447
bobs' address is [e-mail]    404-888-0389(V) 892-2301(FAX)
Buy Sell Trade Surplus Computer Electronics Datacom Telecom since 1981.
Fax or email your list for a fast cash offer. Watch for listserv catalog.


From [e-mail] Sat May 04 15:45:28 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (SARUMAN)
Subject: Schematic for DTMF decoder
Message-ID: <[e-mail]>
Date: Sat, 4 May 1996 00:05:15 GMT

Hi all, anyone have a schematic for a DTMF decoder? I'm looking for something
with a LCD display to Translate and show DTMF's. Thanx


<tsb>
                               Midgard Graphics
           3D Animation and Special FX for the hobbyist videographer
                          Email: [e-mail]

--
          Drop into #amigacafe on IRC's undernet for a chat sometime

--

<tsb>

                     A man of many hobby's master of none.




From [e-mail] Sat May 04 15:45:29 1996
From: [e-mail] (Douglas R Davis)
Newsgroups: rec.radio.amateur.homebrew
Subject: Some Antenna Trim Caps
Date: 3 May 96 07:09:36 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>


Antenna Trim Caps
10-90pF, 50V trim cap used to match antennas in auto radios, CB'ss,
transceivers, etc., 15/16" tall
X 1/2" wide with a 6-32 mounting hole. Stock# 0823-VC, 4?$1.00

Marlin P. Jones
P O Box 12685
Lake Park FL 33403-0685

407-848-8236
Order FAX 1-800-4 FAX YES


From [e-mail] Tue May 07 19:37:03 1996
From: "Don P. Wittlich" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: (no subject)
Date: Mon, 29 Apr 1996 19:29:03 -0700
Message-ID: <[e-mail]>

subscribe




From [e-mail] Tue May 07 19:37:04 1996
From: [e-mail] (Mark Moulding)
Newsgroups: rec.radio.amateur.antenna
Subject: Ant Element Keepers - Need Source
Date: Mon, 06 May 1996 04:12:03 GMT
Message-ID: <4mju2n$[e-mail]>
Reply-To: [e-mail]


I decided to do a mod to a 432 Mhz antenna and find that I am going to
need to replace the element keepers as well!  These are the type used
by cushcraft and M2, I think.  For 3/16th dia elements.

Anyone know a good source for these?

Thanks, 73, Mark, KE7NS





From [e-mail] Tue May 07 19:37:05 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: antenna impedance bridge wanted!!!
Date: 5 May 1996 18:27:02 -0700
Message-ID: <4mjkh6$[e-mail]>
References: <4mfn08$[e-mail]>

[e-mail] wrote:
>Does anybody know where can I find an Antenna Bridge

If you can use ladder-line, your antenna bridge will cost
almost nothing. Email me for details.

73, Cecil, KG&BK (W6RCA soon), OOTC




From [e-mail] Tue May 07 19:37:06 1996
From: [e-mail] (D. Deming)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Question
Date: Mon, 06 May 1996 09:40:00 -0400
Message-ID: <ddeming-060596094000@129.15.42.22>
References: <ddeming-030596080413@129.15.42.22>

In article <ddeming-030596080413@129.15.42.22>,
[e-mail] (D. Deming) wrote:

> I know this newsgroup is for RADIO, but maybe someone can help
> me with this question.
>
> I have what appears to be a VHF antenna on the roof of my house
> left by the previous owner.  Works great, but absolutely no
> UHF reception.
>

Thanks to everyone who helped me on this question.  However,
the problem turned out to be my own stupidity.  After
some more testing, the problem appeared to be confined
to our 2 modern Sony tvs.  The antenna worked greate with
my 30-year-old Sony.  I called Sony and they reminded me
to turn off the "cable" switch.  I did, and now everything
works.

Thanks again.


From [e-mail] Tue May 07 19:37:07 1996
From: [e-mail] (Edward French)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Theory Question
Date: Sat, 04 May 1996 09:28:06 -0500
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]>




> Maxwell is deservedly honoured for providing us a calculating engine that
> correctly models real observations in electromagnetics. That we users of
> his work have neglected to re-jig or replace the concepts to provide a
> consistent model, is a sad admission that maybe we have not the ability.
>
> out there to whom Maxwell might even have invited out for an evening
> intellectual jam session. Maybe if I lurk this group long enough....
>
>        Thanks in advance for allowing this mischief.
>        Hmm.. I just *know* you are going to make me regret it.
>
> 73's + Regards to all
>
> G4WNT
>
> --
> Graham Seale

graham,
how did mr.maxwell live?...what's earliest record of vector math concept?

thanks and take care

--
hug the day


From [e-mail] Tue May 07 19:37:08 1996
From: [e-mail] (MARKTAINT)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Any opinions on 2-Element "Butterfly" Beam antenna?
Date: 5 May 1996 23:24:43 -0400
Message-ID: <4mjrdr$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (MARKTAINT)

I had the Butternut Butterfly beam antenna up for about two years until I
moved. I only had it up about 25 feet and only ran it barefoot so it
wasn't perhaps a true picture of what the antenna is capable of. I
had/have mixed feelings about the antenna.  On the one hand, I was able to
make a number of DX contacts to various parts of the world with it and
having the five band capability is very nice.  On the other hand, I had
hoped to make contacts with my brother-in-law in Papua New Guinea and was
never really able to do that with him. I was able to make some contacts
into VK and ZL land though so I'm not sure the difference . Perhaps he was
in a more difficult area to reach.

I found it to be a fairly difficult antenna to assemble and tune as well.
It was definately *not* one where you put color coded screws in the slots
and that's it.

I couldn't confirm the gain figures quoted by the company and I also
couldn't tell you whether a vertical would be better.

Like I said, I have mixed feelings about the antenna. If you're looking
for a small, easy to turn antenna, with 5 band capability, the Butternut
could work very well for you.  If you're looking to be able to work lots
of DX, then you might not be very happy with it.


From [e-mail] Tue May 07 19:37:10 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Auto Tuner vs Multiband Vertical
Date: 4 May 1996 19:42:01 -0700
Message-ID: <4mh4hp$[e-mail]>
References: <4mf19i$[e-mail]>

[e-mail] (CHARLES J. MICHAELS) wrote:

>Cecil,
>       Correction on previous posting (Ooops, used .2 dB per 100
>feet )
>       A 40 meter dipole of 66.45 feet of #12 copper wire
>(resonant at 7.15 MHz) 40 feet above medium quality earth has an
>input impedance of 1.694 - j 2354.8 at 1.9 MHz according to
>EZNEC.
>       If fed by 100 feet of 450 ohm open wire line having the
>suggested attenuation factor of .02 dB per 100 feet, the line loss will
>be about 5.86 dB which means that 17.06% of the power input to
>the line reaches the antenna.  Hardly MOST.

Charlie is having trouble with his newsreader and sent me an email
to point out my fuzzy logic. I was assuming that 50 ft of line had
half the loss of 100 ft of line. That's only true with matched-line
losses. When reflections are present, 50 ft of line has more losses
than 100 ft of line. Thanks Charlie, for setting me straight.

However, I know a way around the problem. If the second 50 ft has
less losses than the first 50 ft, just use the second 50 ft instead
of the first 50 ft. :-)

73, Cecil, KG7BK (W6RCA soon), OOTC




From [e-mail] Tue May 07 19:37:10 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Auto Tuner vs Multiband Vertical
Date: 5 May 1996 18:02:01 GMT
Message-ID: <4miqep$[e-mail]>


Cecil said -
Hi Ignacy, I can tell you're not a purist. :-) What you may not
realize (QST may not realize it either) is that it is possible
to radiate most of your 160M power from a 40m dipole if you
get your transmission line losses low enough. If you use open-
wire transmission line, the matched-line loss is about 0.02 dB
per 100 ft on 160m. You can stand a gigantic SWR before you
lose "most" of your power in the open-wire line. Notice, I said
open-wire rather than ladder-line.

73, Cecil, KG7BK (W6RCA soon), OOTC



Cecil,
        Correction on previous posting (Ooops, used .2 dB per 100
feet )
        A 40 meter dipole of 66.45 feet of #12 copper wire
(resonant at 7.15 MHz) 40 feet above medium quality earth has an
input impedance of 1.694 - j 2354.8 at 1.9 MHz according to
EZNEC.
        If fed by 100 feet of 450 ohm open wire line having the
suggested attenuation factor of .02 dB per 100 feet, the line loss will
be about 5.86 dB which means that 17.06% of the power input to
the line reaches the antenna.  Hardly MOST.
        Even with a 50 foot line, 5.35 dB or 29.17% at antenna.

Charlie, W7XC
--


From [e-mail] Tue May 07 19:37:12 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Auto Tuner vs Multiband Vertical
Date: 5 May 1996 18:40:03 -0700
Message-ID: <4mjl9j$[e-mail]>
References: <4mf0ci$[e-mail]> <4mhnqs$[e-mail]>

[e-mail] (WB3U) wrote:
>The dipole I'm using is much longer than that, but on various
>bands I'm sure the SWR is at least as high as in the example.

Hi Jack, don't assume that. Any center-fed longer than 3/8th
wavelength will not get much above an SWR of 10:1 when fed
with 450 ohm ladder-line. After all, 450x10=4500 ohms. However,
when an antenna gets shorter and shorter down from 3/8th
wavelength, the SWR goes up and up (to infinity with an iso-
tropic. :-) First, find out what your SWR really is and then
decide whether to worry about it or not. A 22:1 SWR with 450
ohm ladder-line can be around 10k ohms at the antenna. It's
when the resistance doesn't go up with the reactance that you
have to worry. That happens at less than 3/8th WL.

In short, things go to heck at less than 3/8 wavelength on a
center-fed. If you are longer than 3/8 WL, you probably don't
have anything additional to worry about. I say "additional"
because you worry too much already. :-)

73, Cecil, KG7BK (W6RCA soon) OOTC




From [e-mail] Tue May 07 19:37:13 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Belden address
Date: 6 May 1996 17:22:05 GMT
Message-ID: <4mlcft$[e-mail]>
Reply-To: [e-mail]

Western Regional Sales Office
2955 E. Main Street, Suite 300
Irvine, CA 92714
1-800-BELDEN-1
[e-mail] or HTTP://www.inna.net/Stevens


From [e-mail] Tue May 07 19:37:13 1996
From: [e-mail] (Chris Valliant)
Newsgroups: rec.radio.amateur.antenna
Subject: Best Antenna for Apartment ?
Date: 6 May 1996 22:30:21 GMT
Message-ID: <4mluht$[e-mail]>



        I live in a small apartment, but the landlord won't let me put an
antenna on the roof. Does anyone know of a good antenna that I can mount
on the window sill ? I have thought about putting up one without his
knowledge, but that wouldn't be right. Any idea's would be greatly
apreciated. Oh yea, this is for the 10 M band (forgot to add that in).

        Thanks in advance
                Chris



From [e-mail] Tue May 07 19:37:15 1996
From: "John D. Farr" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Sun, 05 May 1996 02:26:11 -0500
Message-ID: <[e-mail]>
References: <4mg9ar$[e-mail]>

WB3U wrote:
>
> Lately, I've been thinking about stringing a wire vertical from
> a tree and installing a good radial system underneath.  However,
> there's a wildlife problem that's threatening to thwart my plans.
>
> During the last two winters, I have been beseiged by an invasion
> of moles.  The runners they create in the yard and the many mole
> hills make it impossible to consider radials.  I still have to
> cut what's left of the grass, and there's no question that the
> moles' activity will push any wires I install up to the surface.
>
> So far I've tried the following with little or no success:
>
>     Smoke bombs and poison pellets designed for this purpose
>     Traps designed to kill the mole when it tunnels underneath
>     Flooding the tunnels with a garden hose
>     Filling the tunnels with exhaust fumes from my car
>     900 VAC at 1 Amp delivered into the ground by aluminum stakes
>       placed 20 feet apart
>     Elmer Fudd impressions (lawn chair and shotgun)
>
> The most successful was the AC votage.  That seemed to drive them
> away if I applied it intermittantly over a period of several days.
> They always return quickly though, and for obvious reasons I can't
> leave the current on indefinitely (or unattended).
>
> Does anyone know a solution for this problem?  My last thought is
> to try a much higher votage, but the current consumption of
> continuously-applied AC becomes enormous above about 1 KV.  If
> I build a voltage tripler or quadrupler and use it to charge a
> bank of capacitors, is there a way to discharge the caps into the
> ground at timed intervals?  Any other ideas?
>
> 73,
> Jack  WB3U


I have a cat that has developed a taste for moles.  I have no problems
with them like some of my neighbors.  Best of all, my cat brings me the
best parts!

73, John


From [e-mail] Tue May 07 19:37:16 1996
From: [e-mail] (robert bowman)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: 6 May 1996 00:05:00 GMT
Message-ID: <4mjfnc$[e-mail]>
References: <4mg9ar$[e-mail]>

In article <4mg9ar$[e-mail]>, [e-mail] (W
B3U) says:
>During the last two winters, I have been beseiged by an invasion
>of moles. Does anyone know a solution for this problem?

ferrets


From [e-mail] Tue May 07 19:37:17 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: 6 May 1996 18:16:11 GMT
Message-ID: <4mlflb$[e-mail]>
References: <4mg9ar$[e-mail]>

Jack,

I *HAD* a mole problem.  I rectified it with several cheap
battery-powered AM radios.

#1 Tune them to a local rock station with a good signal.
      (needs to be rock-n-roll, moles like classical and country)
#2 Turn 'em up fairly loud.
#3 Stick 'em in heavy plastic bags.
#4 Bury them where you have the problem.

The batteries usually last a week or more, and by then the moles
have "moved on" to greener pastures.  Sounds silly, but it works!

Bill Young
[e-mail]
KB0UZQ


From [e-mail] Tue May 07 19:37:18 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Sun, 05 May 96 20:10:13 GMT
Message-ID: <4mj1t1$[e-mail]>
References: <4mg9ar$[e-mail]>

Get yourself an "Out-O-Sight" brand mole trap or clone. It's shaped like a
couple of horseshoes spring-loaded together. I've used one for years, and
trapped a couple of dozen moles with it. It has never failed to catch a
mole. (Occasionally one will trip the trap without being caught but I get
'em eventually.)

Roy Lewallen, W7EL


From [e-mail] Tue May 07 19:37:19 1996
From: Chuck Vaughn <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Mon, 06 May 1996 09:13:07 -0800
Message-ID: <[e-mail]>
References: <4mg9ar$[e-mail]>

WB3U wrote:
>
> Lately, I've been thinking about stringing a wire vertical from
> a tree and installing a good radial system underneath.  However,
> there's a wildlife problem that's threatening to thwart my plans.
>
If you have enough vertical room you might consider a vertical
dipole. I put together a 30/40m trapped one with capacitive hats
that is only 35' long for a friend who had about 40' of vertical
space. I've been surpised at how much DX he's been able to work,
even on 40m. It's really a pretty good antenna for only a wire
and no radials required!

Chuck - AA6G


From [e-mail] Tue May 07 19:37:20 1996
From: Jake Brodsky <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: Sun, 05 May 1996 23:17:26 -0700
Message-ID: <[e-mail]>
References: <[e-mail]> <4mg98q$[e-mail]>

WB3U wrote:
>
>    [e-mail] wrote:
>
> >Given: a 'dipole' is rated at at 2.13 dbi.  Does this apply for
> >transmit only, or does it include receive also?
>
> Yes, it includes receive.
>
> >The ARRL defines a dipole as a half-wavelength fed at the center.
> >Define dipole.  Define feed.
>
> There was a discussion here awhile back on this.  I personally
> consider any antenna with two physical poles to be a dipole, but
> not everyone agrees with that.  Some believe that to qualify as
> a dipole, the antenna must also have two electrical poles, that
> is, it must be resonant.
>
> When used as a noun, "feed" is the power made available to
> the load.  It is sometimes also used to describe the method
> of delivering that power.
>
> >Here are my conditions for a 'half-wavelength dipole':
> >
> >A. A dipole of 'average' wire size, and 'average' physical length
> >which brings it into resonance.  Feed is one side hot(coax center),
> >and the other side is not hot(coax shield or ground).
>
> This won't create a true dipole unless a balun is used or unless
> the transmission line is a length that prevents RF current from
> flowing back down the line on the outside of the shield.
>
> >B. A dipole of 'average' wire size, and 'average' physical length
> >which brings it into resonance.  Feed is balanced ladder
> line(300/450 etc.)  Both halves of the dipole are driven.
>
> This will create a dipole, although with certain deviations from
> a theoretical model due to practical considerations.
>
> >C. A dipole of very thin(<50 gauge) wire, fed as in A.  Length
> >approaches free space length.
>
> Not a true dipole.
>
> >D. A dipole of very thin(<50 gauge) wire, fed as in B.  Length
> >approaches free space length.
>
> The RF resistance of extremely small wire will reduce the gain.
>
> >E. A dipole of very thick (i.e. 2 inch diameter) wire, fed as in A.
> >The length now is very short physically.
>
> Not a true dipole.
>
> >F. A dipole of very thick (i.e. 2 inch diameter) wire, fed as in B.
> >The length now is very short physically.
>
> Generally speaking (and ignoring factors such as losses in the
> matching network), gain will be close to that of the dipole in B.
>
> >G. A dipole as in A, but balun fed(toroid sleeve) so that both sides
> >are radiating and receiving.  Applies to C and E also.
>
> This simply creates a true dipole.
>
> >Which of these 'dipole' antennas will give the 2.13 dbi figure?
>
> Maybe none.  Assuming that only the power actually delivered to
> the feedpoint of the antenna is considered, the gain will vary
> with height above ground and soil conditions.  If the power at
> the output of the transmitter is the reference, system gain will
> vary with losses in the matching network (if any), transmission
> line and balancing device.
>
> >There will be a measurable difference between a thin and thick
> >wire. Is there a difference?  Does the cross-sectional area of the
> >thin wire equal the cross-sectional area of the thick wire?
>
> Cross-sectional area is not a factor.  Due to skin effect,
> surface area is the dimension that will affect RF resistance.
>
> >How many db's gain or loss does G have over A?
>
> That's impossible to know.  Current flowing down the outer shield
> in A will rob the antenna proper of current and will skew the
> radiation pattern.
>
> >With these things in mind, how much of dbd gain does YOUR antenna
> >have?
>
> Not enough.  ;)
>
> 73,
> Jack  WB3U

Jack, I think you're missing something here.  The dipole he's referring
to is the THEORETICAL dipole.  It is a mathematic model with wires that
have zero resistance, negligible size, it assumes a center, balanced
feed, and each half is 1/4 wave.  Yes, this *theoretical* dipole will
have the 2.13 dB gain compared to an isotropic radiator.  I remember
computing the antenna patterns of such a dipole in my EE studies at
the Johns Hopkins University's Electricity and Magnetism class.  It's
been over six or seven years since I did it and the math wasn't exactly
pleasant.  I don't think I could (or should) repeat it here.

Jake Brodsky, AB3A, <[e-mail]>
"Beware of the massive impossible!"


From [e-mail] Tue May 07 19:37:21 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: 7 May 1996 04:20:07 GMT
Message-ID: <4mmj1n$[e-mail]>


Roy said -
There's one more thing about the 2.15 dBi dipole. It's in free space. This
makes it as much a fictitious antenna as an isotropic radiator.


        Oh no.  Graham doesn't believe in *displacement current* and
now Roy says that the isotropic radiator is FICTITIOUS.  Next someone
will say that there is NO SANTA CLAUS and NO EASTER BUNNY.

Charlie, W7XC
--


From [e-mail] Tue May 07 19:37:22 1996
From: Alan Huckerby <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Distance between two 2M antennas operating simultaneously?
Date: Sun, 5 May 1996 15:14:43 +0100
Distribution: world
Message-ID: <[e-mail]>
References: <4me36u$[e-mail]>

In article <4me36u$[e-mail]>, David Negaard
<[e-mail]> writes
>I'm thinking about operating two 2M radios on two (probably not widely
>separated) frequencies.  One will be a Mitrek set up to operate 9600
>bps packet, and the other may be set up to operate 1200 bps packet or
>FM voice.
>
>My question is, how far apart do the antennae need to be in order to
>avoid problems?
>

----CUT
>--
A good rule of thumb is 2 Lambda (around 4mts/13feet in your case), thats
vertical on the mast/support.
Regards
--
Alan Huckerby  (G8HJL - Lapsed!)



From [e-mail] Tue May 07 19:37:24 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Electric half-wavelenght xmition lines...
Date: 4 May 1996 01:01:18 GMT
Message-ID: <4mea8u$[e-mail]>
References: <[e-mail]> <4me6ie$[e-mail]>
Reply-To: [e-mail]

In <4me6ie$[e-mail]>, [e-mail] writes:
>In <[e-mail]>, [e-mail] writes:
>>Hi all:
>>Some days ago I'd posted a msg. asking if it's valid take antenna
>>measurements (HF range) using a RX Noise Bridge conectet to a antenna
>>trhu a electric half-wavelenght transmition line.
>>This particular line lenght (and it's multiples) will be "transparent" to
>>complex impedances?
>>What will occur with the SWR at the line? I'll have an "isolated path"
>>from XMTR and antenna?
>>If I use a transmatch at the transmitter site, an electric half-walelenght
>>transmition line, and any antenna, this transmatch will "see" the load
>>as-is? And the SWR at the transmition line?
>>Any help?
>>Thanks. Marcus Ramos. [e-mail] - Sao Paulo - Brasil
>
>
> Marcus,
> I think you are making a correct assumption that an electrical half-waveleng
th
>should be transparent. Using a noise bridge is a fairly accurate method of en
suring
>the half wave length.
>                                               Jim WD9AHF
>
>There is a copy of COAX2.EXE on the latest QRZ CD-ROM that will let you
>graphically see the difference between physical and electrical lengths by
>frequency. The program requires OS/2 Warp to run.



From [e-mail] Tue May 07 19:37:25 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Electric half-wavelenght xmition lines...
Date: 3 May 1996 14:34:17 GMT
Message-ID: <4md5h9$[e-mail]>
References: <[e-mail]>

[e-mail] wrote:
>If I use a transmatch at the transmitter site, an electric half-walelenght
>transmition line, and any antenna, this transmatch will "see" the load
>as-is? And the SWR at the transmition line?

Hi Marcus, neglecting losses, transmission line impedances repeat every
half wavelength. Losses include any nearby objects that might upset the
current balance in ladder-line. So measurements made a half-wavelength
from the antenna reflect the antenna impedance minus losses in the
transmission line. Whether one considers transmission line losses neglible
or not depends on the required accuracy of the measurements. With an 'S'
unit being 3-6 dB, I personally consider 1 dB of loss to be neglible
although one can readily measure that amount of loss.

You can measure or estimate the matched-line loss in a transmission line.
You can then calculate the expected additional loss from standing waves.
You can then factor this loss into your measurements if you consider them
not neglible.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Tue May 07 19:37:26 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Electric half-wavelenght xmition lines...
Date: 3 May 1996 23:52:18 GMT
Message-ID: <4me67j$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

In <[e-mail]>, [e-mail] writes:
>Hi all:
>Some days ago I'd posted a msg. asking if it's valid take antenna
>measurements (HF range) using a RX Noise Bridge conectet to a antenna
>trhu a electric half-wavelenght transmition line.
>This particular line lenght (and it's multiples) will be "transparent" to
>complex impedances?
>What will occur with the SWR at the line? I'll have an "isolated path"
>from XMTR and antenna?
>If I use a transmatch at the transmitter site, an electric half-walelenght
>transmition line, and any antenna, this transmatch will "see" the load
>as-is? And the SWR at the transmition line?
>Any help?
>Thanks. Marcus Ramos. [e-mail] - Sao Paulo - Brasil



From [e-mail] Tue May 07 19:37:28 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Electric half-wavelenght xmition....re:...
Date: 6 May 96 00:00:29 GMT
Message-ID: <[e-mail]>

Rich Griffiths <[e-mail]> wrote:
>You now have many answers to these questions that all basically confirm
>one another.

>But remember that a line can be an electrical half-wavelength (or a
>multiple of a half-wavelength) at only one frequency.  You won't be
>able to count on its "transparency" across a very wide band, like 80 m.

Ok Rich, it's true! This aproach came to discussion between me and
another ham here some time ago. We're considering any method to take
measurements remotely. The last option should be a kind of RX noise
bridge that we can mount (and control!) remotely, to be installed at the
prototypes feed point.
   In my real situation, as I wrote at some answer concerning such
question, I'm placed at a vy. urbanized area (according to the hams here
in Sao Paulo, I got the worse place in the town to radio works! - I got
it!). But I still doing some antenna tests and checking the softwares
predictions against the real world. At least concerning impedances.
   The other thing I have in mind for such 1/2WL xmition line is that
having a "random" wire outside I'll transfer the "Z" to inside the shack.
I knew abt. bandwidht limits. But again, in my real situation, at least
at some portion of each band I'll have any kind of "transparency" and
"shielding".
   Take a 75 ohm CATV coaxial cable(I work for a CATV MSO here).
Somewhere I read(1980 Ham Radio Magazine, some broadband coaxial baluns..
. article) that the high the coax Z, the broader the xformer. And the
ideia is to use a 7.08MHz 1/2WL line to 40 and add(or subtract) small
cable pieces to got some 1/2WL multiple at different frequencies. At the
ends of this line, some kind of "RF coils", like 1:1 balun, to isolate
the xmition line. At least the intention is to shield the path between
the transmatch and antenna - the neighbours will love it!.
   Thanks for the comments and best regards.

Marcus Ramos - [e-mail] - Sao Paulo - Brasil.


From [e-mail] Tue May 07 19:37:29 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ethernet Cable
Date: 6 May 1996 20:07:23 GMT
Message-ID: <4mlm5r$[e-mail]>
References: <[e-mail]> <[e-mail]> <4mg3ki$[e-mail]>

[e-mail] (Gorsline Family) wrote:
>Given its an indoor cable (fire rated FT4/FT6...), will the orange jacket tak
e
>outside abuse (weather, UV, etc.)?

It is *not* UV protected and lasts less than a year in the sun around Phoenix.

If one has unused ethernet cable and UV protects it, it's a pretty good HF/VHF

cable especially if it's free. I've used it inside old garden hoses.

73, Cecil, KG7BK, OOTC (not speaking for my employer)




From [e-mail] Tue May 07 19:37:29 1996
From: William Osborne <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Force 12 Log Periodic Antennas?
Date: 6 May 1996 13:42:58 GMT
Message-ID: <4mkvl2$[e-mail]>
References: <4mg63j$[e-mail]>

I called and ask about these and I was given a sales pitch as to why it
is so difficult to get LP's to work ask described in the books!  I think
the mention of LP's in their catolog is to get you not to buy one!

--
William P. Osborne, AA5ZQ
[e-mail]
214-883-2974




From [e-mail] Tue May 07 19:37:30 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help: 6m Dipole Ant
Date: Fri, 3 May 96 01:56:06 -0500
Message-ID: <[e-mail]>
References: <4lp20o$[e-mail]> <4m5gpa$[e-mail]>

Doug D <[e-mail]> writes:

>A 5/8 Vertical would be 11 feet, 0 inches long.

That is not correct!


From [e-mail] Tue May 07 19:37:31 1996
From: [e-mail] (Brian Williams)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help: 6m Dipole Ant
Date: 6 May 1996 17:51:21 GMT
Message-ID: <4mle6p$[e-mail]>
References: <4lp20o$[e-mail]> <4m5gpa$[e-mail]> <[e-mail]>

In article <[e-mail]>, [e-mail] says...
>Doug D <[e-mail]> writes:
>>A 5/8 Vertical would be 11 feet, 0 inches long.

>That is not correct!
Then what is it?  (Approx)

Brian



From [e-mail] Tue May 07 19:37:32 1996
From: [e-mail] (Brian Longwell)
Newsgroups: rec.radio.amateur.antenna
Subject: HF Mobile Antenna type/placement
Date: 6 May 1996 02:54:05 GMT
Message-ID: <[e-mail]>

I've been trying out a few different HF antenna options and wanted to get some

opinions.  My car is a Chevy Blazer.  So far, I have focused on antennas
mounted on the roof rather than the side or the hitch.  My somewhat
questionable field strenth measurements have been made using 4 different
antennas all on 75 meters: 1) Hamstick, 2) Hustler center loaded Super
Resonator ~9' tall, 3) Hustler Super Resonator with shorter mast ~6' tall, 4)
Home made base loaded with 4" diameter coil/#14 wire and 9' total hight.

The Hamstick and the shortened Hustler performed about the same.  The
full-size hustler gave about 2.5 gain over the Hamstick, and the base loaded
antenna (!) was about .5 db better than the full-size Hustler.  The reason
must be due to the higher Q of the homemade coil.

The Hamstick is easiest to deal with on the roof, but the full-size Hustler is

totally unmanagable.  The base loaded version was workable, except I did find
myself temporarily loading up to a few overpasses on the highway.  If I chop
off another 6", I should be OK.  I would like to try the highly recommended
screwdrivers, but these are definitly not roof-top type antennas.

My question is, what degradation in performance might be expected in mounting
a full-size Hustler or screwdriver on the back side (with the base 2~2.5'
below the roof line) of the Blazer.

The screwdriver is appealing for its remote tune ability.  The homemade base
loaded version is appealing because I have concocted a remote raise/lower
contraption to get me through tolls, cities, parking garages, etc.   The base
of the antenna is near the back on a pivit.  I used a power window motor to
crank it up/down.  When down, it lays on the roof, looking like I'm off for
some fishing rather than the giant bumper car look.

Thanks for the feedback.

Brian
WB2DSH


From [e-mail] Tue May 07 19:37:33 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (George L. Hiscox)
Subject: Re: HF Mobile Antenna type/placement
Message-ID: <[e-mail]>
References: <[e-mail]>
Date: Mon, 6 May 1996 16:14:56 GMT

[e-mail] (Brian Longwell) wrote:

>I've been trying out a few different HF antenna options and wanted to get som
e
>opinions.  My car is a Chevy Blazer.  So far, I have focused on antennas
>mounted on the roof rather than the side or the hitch.  My somewhat
>questionable field strenth measurements have been made using 4 different
>antennas all on 75 meters: 1) Hamstick, 2) Hustler center loaded Super
>Resonator ~9' tall, 3) Hustler Super Resonator with shorter mast ~6' tall, 4)
>Home made base loaded with 4" diameter coil/#14 wire and 9' total hight.

<------------------------WHACK------------------------->

Brian,

There is an EZNEC model of a Chevy Blazer (blazer.zip) available for anonymous
ftp from   emclab.ee.umr.edu/pub/aces/NEC/EZNEC_FILES .   Using the vehicle
model,  you can then  model your various antennas in different mounting
locations and get a good idea of what results to expect.

The EZNEC software is available from Roy Lewallen, W7EL, who also posts to thi
s
newsgroup.   I have found it very useful and a whole lot of fun to use.

73/George



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

[Finger [e-mail] for PGP Public Key]



From [e-mail] Tue May 07 19:37:34 1996
From: [e-mail] (Dan Tang)
Newsgroups: rec.radio.amateur.antenna
Subject: HF Vertical
Date: Fri, 3 May 1996 22:37:00 -0500
Message-ID: <[e-mail]>

Can some one please tell me if an hf vertical antenna install on the roof
(with radials) works as good as it install on the ground (with radials)?


From [e-mail] Tue May 07 19:37:35 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Steve Ellington)
Subject: Re: HF Vertical
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]>
Date: Mon, 6 May 1996 22:59:13 GMT

Works good on roof if radials base of vert is up at least 1/4 wave from
roof peak. Otherwise, expect interaction with house wiring and RFI
problems. Also expect birds to set on wire and poop on roof. This leaves
large, white X on roof which marks your house for even larger birds.



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


From [e-mail] Tue May 07 19:37:36 1996
From: Chuck Vaughn <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Vertical
Date: Mon, 06 May 1996 09:02:44 -0800
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]>

George J. Molnar wrote:
>
> Dan Tang wrote:
> >
> > Can some one please tell me if an hf vertical antenna install on the roof
> > (with radials) works as good as it install on the ground (with radials)?
>
> It'll probably work a bit better, presuming you install a good-quality
> set of radials on the roof.

And not only that, but you can get the impedance closer to 50 ohms
by sloping the radials down.

Chuck - AA6G


From [e-mail] Tue May 07 19:37:38 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Horizontal HF loops
Date: Sat, 04 May 1996 14:44:59 GMT
Message-ID: <4mfqhs$[e-mail]>
References: <[e-mail]> <[e-mail]> <4lteku$[e-mail]>

[e-mail] (GreenThumb) wrote:

>Rolfe Tessem <[e-mail]> wrote:

>>Monty Wilson wrote:
>>>
>>> A friend of mine is experimenting with horizontal HF loops.  He
>>> built one to resonate on 80, thinking he could use it on any multiple
>>> of the principal frequency.


>>Rolfe
>>W3VH

>About 8 years ago, I installed a 75M horizontal loop.  I used it not
>only for amateur use, but also for Navy/MC MARS.  The first evening I
>went on 4515 MARS, they asked me to turn off the amplifier.  The loop
>does indeed tend to exhibit the "straight up, straight down" effect on
>lower frequencies, to some extent.  But my "killer" footprint on 4515
>was basically the middle third of the US (I'm in Illinois).  What is
>NOT generally known (but was exposed in a very good article complete
>with charts in QST, I believe it was - and if I can find the article
>again I'll let you know) is that on higher frequencies, the horizontal
>loop is an EXTREMELY good DX antenna, especially when mounted
>relatively low.  My loop was at 25 feet, and if you look at a copy of
>my log during the time I used this antenna, running usually abt 50
>watts, occasionally but rarely up to 300 watts, you can see the
>concrete results.  Apparently when mounted in this way, the loop is
>basically multiple wavelengths, and the charts show INCREDIBLE
>low-angle radiation.



Here is my experience:

A while ago, I found on page 5-16 of The ARRL Antenna Book a
description of the Loop Skywire.
Since I have a lot of space, i upscaled it to a full size 160 meters
loop.

From 7 mhz up, the results are astounding. I use a FD4 windom for
comparison, and my loop is from 12 to 24 feet high suspended between
trees in a forest.
on 14 mhz, switching from the FD4 to the loop makes the noise
disappear and the signal to pop up as if the preamp was on.

the reports are jumping from 549 to 599 constantly.

the cost was near to nothing, and the line is just a 25 feet of rg213
directly connected to the corner of thel loop. the line is so short
than any matching will be useless.

try it!

ik4yng paolo




From [e-mail] Tue May 07 19:37:40 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Horizontal HF loops
Date: Sat, 04 May 1996 14:44:50 GMT
Message-ID: <4mfqhj$[e-mail]>
References: <[e-mail]> <[e-mail]> <4lteku$[e-mail]>

[e-mail] (GreenThumb) wrote:

>Rolfe Tessem <[e-mail]> wrote:

>>Monty Wilson wrote:
>>>
>>> A friend of mine is experimenting with horizontal HF loops.  He
>>> built one to resonate on 80, thinking he could use it on any multiple
>>> of the principal frequency.


>>Rolfe
>>W3VH

>About 8 years ago, I installed a 75M horizontal loop.  I used it not
>only for amateur use, but also for Navy/MC MARS.  The first evening I
>went on 4515 MARS, they asked me to turn off the amplifier.  The loop
>does indeed tend to exhibit the "straight up, straight down" effect on
>lower frequencies, to some extent.  But my "killer" footprint on 4515
>was basically the middle third of the US (I'm in Illinois).  What is
>NOT generally known (but was exposed in a very good article complete
>with charts in QST, I believe it was - and if I can find the article
>again I'll let you know) is that on higher frequencies, the horizontal
>loop is an EXTREMELY good DX antenna, especially when mounted
>relatively low.


Here is my experience:

On the 17th edition of the Antenna Book, at page 5-16, there is a
description of the Loop Skywire.

I simply upscaled it to a double size, 160 meters long loop, and I use
it on every band from 160 meters up.

The rig is a ICOM 781, 150W, with internal tuner; the loop is
installed at a quite low height, suspended between the trees in a
forest (average, 12 feet to 20 feet) and was made resonating at 7.05
mhz, where the ROS is still about 4:1 due to an unfavorable resistance
(maybe 200 Ohm).

Since my rig is about 15 feet directly below one corner of the loop, i
forgot the ROS and simply connected some RG213 directly to the loop
corner, shield to one side and wire to the other.
At the beginning, i tried to use a balun, but it works better without
it, and the line is so short than the ROS does nothing bad (virtually
no attenuation).

From 7 mhz up, the results are astounding. I have a Windom F4D as a
comparison, and switching between the windom and the loop at 14 MHZ is
umbeliable: the noise disappears, and the signal pops out. On DX
stations, I get 599 against a 559 on the FD4.

Assuming the space is available (the footprint is 150 X 150 feet) the
cost is so cheap that everybody should try it!!!

Quite soon I will try to clip it to the original 80 meters lenght. I
just want to see the difference; all of the wire is now suspended
through pulleys, so it's a two hours job anyway!

By The Way!!! Does anybody knows where I can buy a surplus Antenna
Bridge, like the General Radio? I need it, and I will pay top cash!!

73, from IK4YNG





From [e-mail] Tue May 07 19:37:41 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Horizontal HF loops
Date: Sun, 05 May 96 17:00:44 GMT
Message-ID: <4miqss$[e-mail]>
References: <[e-mail]> <[e-mail]> <4lteku$[e-mail]> <4mfqhj$[e-mail]>

   [e-mail] wrote:

>On the 17th edition of the Antenna Book, at page 5-16, there is a
>description of the Loop Skywire.

I missed the earlier posts in this discussion, but I'm interested
in that antenna also.  Do you know why the Antenna Book says not
to use a balun?  What prevents coax feedline radiation?

>I simply upscaled it to a double size, 160 meters long loop, and I
>use it on every band from 160 meters up.
>
>The rig is a ICOM 781, 150W, with internal tuner; the loop is
>installed at a quite low height, suspended between the trees in a
>forest (average, 12 feet to 20 feet) and was made resonating at 7.05
>mhz, where the ROS is still about 4:1 due to an unfavorable
>resistance (maybe 200 Ohm).

If I build one of these, it will also be for 160M and the
installation will be almost identical to yours.  The wire will
have to run through the woods and be suspended on trees.  However,
my feedline is much longer, about 100', so I'm concerned about loss.
I use ladder line, but even so, extremely high SWR can create
significant loss on a line this long.

>Since my rig is about 15 feet directly below one corner of the loop,
>i forgot the ROS and simply connected some RG213 directly to the loop
>corner, shield to one side and wire to the other.

Is the feedpoint impedance of these antennas more moderate across
the bands than a random dipole?  If the loop is cut for 160M like
yours, how significant is the SWR on the other bands, particularly
those that are not an integral multiple of the fundamental?  What
have you measured for SWR on the various bands?

>At the beginning, i tried to use a balun, but it works better without
>it, and the line is so short than the ROS does nothing bad (virtually
>no attenuation).

What characteristic improved when the balun was removed?

73,
Jack  WB3U


From [e-mail] Tue May 07 19:37:42 1996
From: [e-mail] (Bill Poston)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: HOW DO U CONNECT COAX TO QUAD????????
Date: Sun, 05 May 1996 02:47:42 GMT
Message-ID: <[e-mail]>

I am attempting to homebrew a quad antenna. I have read Cubical Quad
Antennas by W6SAI and the ARRL Antenna Book. Neither answers my question.

How do I connect one coax feedline to the multiple loops on the driven
element?

Please explain in detail so that a dummy can understand.

Thanks in advance for your help.


Email would be appreciated.


Bill N4BVS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bill            <[e-mail]>
Marietta, Ga.
================== THIS TOO, SHALL PASS ==================


From [e-mail] Tue May 07 19:37:43 1996
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
From: Monty Wilson <[e-mail]>
Subject: Re: HOW DO U CONNECT COAX TO QUAD????????
Message-ID: <[e-mail]>
Date: Mon, 6 May 1996 21:07:06 GMT
References: <[e-mail]>

[e-mail] (Bill Poston) wrote:
>I am attempting to homebrew a quad antenna. I have read Cubical Quad
>Antennas by W6SAI and the ARRL Antenna Book. Neither answers my question.
>
>How do I connect one coax feedline to the multiple loops on the driven
>element?
>
>Please explain in detail so that a dummy can understand.

I believe you just tie them together:

                /----------------\
                |                |
                |   /---------\  |
                |   |         |  |
                |   |         |  |
                |   |  /---\  |  |
                |   |  |   |  |  |
                |   |  |   |  |  |
                |   |  |   |  |  |
                |   |  \   /  |  |
                |   |   | |   |  |
                |   |   | |   |  |
                |   \---+ +---/  |
                |       | |      |
                \-------+ +------/
                        | |
                        \-O
                          H
                          H
--
.........Monty.
[e-mail]




From [e-mail] Tue May 07 19:37:45 1996
From: Edward Lawrence <eal>
Newsgroups: alt.binaries.pictures.erotica.amateur.female,alt.binaries.erotic.senior-citizens,alt.binaries.pictures.erotic.senior-citizens,alt.binaries.pictures.erotica.breasts,alt.binaries.pictures.erotics.breasts,alt.binaries.pictures.voyeurism,alt.freemasonry,alt.masonic.members,alt.banjo.clawhammer,alt.binaries.sounds.midi,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.misc,alt.appalachian,alt.binaries.clip-art,k12.ed.music,alt.sex.fat,rec.sex,alt.consumers.sweepstakes,sci.numerology
Subject: Re: Looking for info on numerology
Date: 6 May 1996 12:56:57 GMT
Message-ID: <4mksup$[e-mail]>
References: <4lp7o9$[e-mail]> <[e-mail]>

Why are you posting this material to rec.amateur.antennas?   This is about as
far off topic as you can get . Please don't do it again.



From [e-mail] Tue May 07 19:37:46 1996
From: "George J. Molnar" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need plans for HF antenna
Date: Sun, 05 May 1996 07:08:16 -0600
Message-ID: <[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]
To: Francois Meehan <[e-mail]>

Francois Meehan wrote:
>
> Is there a WEB site where I can find plans, design for HF antenna on the
> Web or anywhere on the net?
>
Exactly what KIND of HF antenna?? I'm not sure of any
general-information sources, but you might want to to a search
on "antennas" and "HF" or "ham", etc.

I've got a page full of search engine forms at:
http://www.interealm.com/p/gmolnar/webtools.html

73
--
George J. Molnar
Highlands Ranch, Colorado
Amateur Radio: KF2T@N0QCU.#NECO.CO.USA.NOAM
http://www.interealm.com/p/gmolnar/index.html


From [e-mail] Tue May 07 19:37:47 1996
From: [e-mail] (FORREST GEHRKE)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: OFC and OOTC
Message-ID: <[e-mail]>
Date: Sun, 05 May 96 13:28:00 -0300
Distribution: world
Reply-To: [e-mail] (FORREST GEHRKE)
References: <4m9c73$[e-mail]>

RL> >I have been noticing Roy Lewallen's signature of OFC. . . >of Old
RL> Farts Club . . .

RL> Oh, no. Is THAT what it stands for???

Roy, It could also stand for Old Fogies Club.  But people
born in 1946 still qualify! ;-)

I must admit, I like my rendition better. But it's your
club; tell us your name for it.  Hmmm....

--k2bt

 * RM 1.3 02583 * Old age isn't so bad when you consider the alternative.


From [e-mail] Tue May 07 19:37:48 1996
From: Matteo Montanari <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: only test
Date: Mon, 06 May 1996 19:03:28 +0200
Message-ID: <[e-mail]>

only test



From [e-mail] Tue May 07 19:37:49 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Q: Matching to an extreme high impedance
Date: 7 May 1996 05:58:51 -0700
Message-ID: <4mnheb$[e-mail]>

Hello,

I need to match a source of 50ohms to a load of approx. 100kohms
or even higher in parallel with a capacitance of 10nF at frequencies
up to 30MHz and power levels up to 1kW.
The matching network needs to have a loaded Q that can be freely chosen.
Any suggestions?

Thanks in advance & 73 de G/ON4BAA, Serge


From [e-mail] Tue May 07 19:37:49 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Q: Matching to an extreme high impedance
Date: Tue, 07 May 96 20:28:48 GMT
Message-ID: <4mobnr$[e-mail]>
References: <4mnheb$[e-mail]>

In article <4mnheb$[e-mail]>,
   [e-mail] wrote:
>Hello,
>
>I need to match a source of 50ohms to a load of approx. 100kohms
>or even higher in parallel with a capacitance of 10nF at frequencies
>up to 30MHz and power levels up to 1kW.
>The matching network needs to have a loaded Q that can be freely chosen.
>Any suggestions?
>
>Thanks in advance & 73 de G/ON4BAA, Serge

You might try connecting the load to a grounded parallel-resonant circuit
and the source to a tap on the inductor (or use a capacitive divider for
the capacitor, with the source to the capacitor "tap"). Vary the loaded Q
by changing the L/C ratio.

Roy Lewallen, W7EL


From [e-mail] Tue May 07 19:37:50 1996
From: [e-mail] (robert bowman)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: questions on loop antenna
Date: 4 May 1996 14:19:44 GMT
Message-ID: <4mfp20$[e-mail]>
References: <4mcfb2$[e-mail]>

In article <4mcfb2$[e-mail]>, [e-mail] (Zacharias L
iangas) says:
>To my surprise the antenna did not show resonace  with capacitor  but
>inly without capacitor  and at the first 2-3 wounds !
>Its results were s not so satisfactory for me as the LOwe HF150  in
>its ATT position, together with 8 m of RG 59 and clips to the
>antenna's zero and 2 nd  wound showed lower signals than of mine AIWA
>J150

if i am reading this correctly, you are connecting the HF150 directly
across the loop? if so, this may be your problem. try link coupling
the receiver with a one or two turn loop. the other alternative is
using a FET circuit from the loop to drive the receiver. this doesn't
have to amplify, it just presents a very high input impedance to the loop,
to keep the Q high and give you sharp tuning.




From [e-mail] Tue May 07 19:37:51 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Radiation resistance
Date: 3 May 1996 21:29:15 GMT
Message-ID: <4mdtrb$[e-mail]>


Richard,
        Note restriction to 90 degree each-side-limit and
resistive component of input impedance only added to
my previous posting.
        Here is a fairly simple approximation of Rr seen
at the center feedpoint of a horizontal dipole (possibly
either not loaded, inductively loaded at any point or end
capacity loaded; in freespace and assuming sinusoidal
current distribution.
        This Rr will vary with height above earth on a
curve of Rr vs height oscillating about the free space
value as a damped sinusoid approaching the free space
value at great heights and decreasing with height below
about .2 wavelength height to some small value at zero
height.
        Note:  Rr does NOT include earth loss, copper
loss of the wire or loss resistance of any loading coils.
Earth loss is generally negligible at heights above about
.2 wavelengths.


        Rr = 70 (sin L1 + cosL1(1 - cosL2)/sinL2)) ^2

Where:
L1 = angular length of section below loading coil
L2 = angular length of section above loading coil.
        angular length = .366 h f
                Where      h = length in feet of each side
of the  dipole         and     f = frequency in MHz.
                Maximum overall angular length (L1 +
L2) is 90 degrees per side.
        This equation applies to any loading coil position
including loading at the feedpoint (L1 = 0) and purely
capacitive end loading where L2 = 0.
        Coil loss resistance reflected to the feedpoint will
be approximately    Rc cos^2 L1 Where Rc is the loss
resistance of the coil.         But because the current
distribution is not quite sinusoidal, the actual value will
be somewhat greater.
        This loss resistance from copper loss of the
antenna wire (usually negligible except for otherwise
high efficiency very short antennas), coil loss and earth
loss are added to Rr to form the input resistance
component of impedance of the antenna center
feedpoint.
        If the antenna is not resonant there will be a reactive component in addition

resistive component.
--


From [e-mail] Tue May 07 19:37:53 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Small loop over a lossy earth
Date: 3 May 1996 13:05:49 -0400
Message-ID: <4mdedd$[e-mail]>
References: <4man2s$[e-mail]>

Hi Michele,

In article <4man2s$[e-mail]>, Michele Piscopo
<[e-mail]> writes:

>Hi guys,
>I' m searching for information about the efficiency of small loop
>antennas when located near a lossy earth.
>
>I believe that, being the near field essentially magnetic, and being the
>losses due to almost the only electric fields, the small loop antennas
>can work also at little heights without inducing appreciable losses in
>the ground...

Do not count on that. The small loop is also lossy because magnetic
coupled losses are also high in poor soil, plus the "electromagnetic wave"
effect is the same even with a small loop.

>An exact study of the electromagnetic problem could be done using the
>Sommerfeld integrals to evaluate the field in the ground and integrating
>the quantity  S * abs(E) in the lower half-space (where S is the ground
>conductivity and abs(E) is the modulus of the electric field).

>Anyway I would like to know if someone tried to make a comparison
>between a conventional antenna and a small loop or, better, if someone
>tried to evaluate the efficiency of the small loop over a lossy earth as
>function of the height h using a numerical antenna simulator (just as
>NEC...).

I found in field strength measurements a small vertical loop near soil
here (around 4 mS/m) was about 4 dB down at high wave angles compared to
the same antenna at the same height (one loop diameter) over a good
groundplane, and efficiency dropped rapidly as the antenna was placed near
earth.

There seem to be very few ways to get something for nothing.

73 Tom




From [e-mail] Tue May 07 19:37:54 1996
From: Michele Piscopo <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Small loop over lossy earth.
Date: 6 May 1996 11:07:26 GMT
Message-ID: <4mkmhe$[e-mail]>

Hi guys,
I' m searching for informations about the efficiency of small loop
antennas when located near a lossy earth.

I believe that, being the near field essentially magnetic, and being the
losses due to almost the only electric fields, the small loop antennas
can work also at little heights without inducing appreciable losses in
the ground...

An exact study of the electromagnetic problem could be done using the
Sommerfeld integrals to evaluate the field in the ground and integrating
the quantity  S * abs(E) in the lower half-space (where S is the ground
conductivity and abs(E) is the modulus of the electric field).

Anyway I would like to know if someone tried to make a comparison
between a conventional antenna and a small loop or, better, if someone
tried to evaluate the efficiency of the small loop over a lossy earth as
function of the height h using a numerical antenna simulator (just as
NEC...).





From [e-mail] Tue May 07 19:37:55 1996
From: [e-mail] (David L. Thompson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: SOMMER antenna
Date: Sun, 05 May 1996 00:56:38 GMT
Message-ID: <4mh1bq$[e-mail]>
References: <4m60p7$[e-mail]>
Reply-To: [e-mail]

[e-mail] (Marco Magnano) wrote:

>73's to all the Ham in this newsgroup.

>Is there any of you who has been testing or currently using the DJ2UT SOMMER
>multi band no trapped beam?
>I would like to know how it works.
>In the advertisment it looks very good.

>Best luck and good DX
>IT9WPO Marco Magnano
>[e-mail]

Marco...I know two hams that use the antenna (XP807) with very good
results.   Bob, N4VZ lives near Atlanta and Bill KM1E in Maine.  Bill
had a 2 or 3 part article in the DX magazine 2 years ago on selecting
the antenna.   Wish you had that article.

Only bad thing I hear is it is more difficult to put together than
many beams.   I have a KT34XA and it cannot more difficult than that!

Another antenna I think is very good is the Fritzel Dx 506 poly beam
with 2el on 10, 17, 12 and 3 el on 20, 15. and 10.  HE does use traps.

Dave K4JRB



From [e-mail] Tue May 07 19:37:56 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The Coax Mentality
Date: 6 May 1996 19:31:01 -0700
Message-ID: <4mmcl5$[e-mail]>
References: <4m8ehm$[e-mail]> <4m8usl$[e-mail]> <4mavg8$[e-mail]> <[e-mail]> <4megu5$[e-mail]> <4mksr7$[e-mail]>

Edward Lawrence <eal> wrote:
>So the feed line radiates and gives me an 'extra' vertical component. So what
?
>How is that a 'mortal sin'?   This is an honest question, not by any means a
>flame.  Thought I would make that 'perfectly clear".   WA5SWD

Hi Edward, that statement was my wierd sense of humor poking
fun at some purists who consider certain aspects of ham radio
as a religion. Guess I should have added a :-)

73, Cecil, KG7BK (W6RCA soon), OOTC




From [e-mail] Tue May 07 19:37:57 1996
From: [e-mail] (MARKTAINT)
Newsgroups: rec.radio.amateur.antenna
Subject: What ladder line to use
Date: 4 May 1996 09:55:19 -0400
Message-ID: <4mfnk7$[e-mail]>
Reply-To: [e-mail] (MARKTAINT)

I'm considering stepping into (for me) uncharted waters and putting up an
antenna using ladder line. My question is this: Does it make any
difference which line I would use?  300 ohm and 450 ohm wire seem to be
the most common although I read about 600 ohm feedline fairly regularly..
Are these lines used for specific purposes or can they be used in any
application.  I'm considering several possible antennas including
center-fed dipoles as well as loop antennas.

Thanks for any help you can give me with this question.
73,
Mark Taintor, N0YRW


From [e-mail] Tue May 07 19:37:57 1996
From: [e-mail] (Jeremy Boot)
Newsgroups: rec.radio.amateur.antenna
Subject: WWW Pages
Date: Sun, 05 May 1996 18:18:40 GMT
Message-ID: <[e-mail]>
Reply-To: [e-mail]

The local server programme which processes forms has thrown a wobbly
this weekend, so if I've missed anyone's messages, please be patient.

        http://www.innotts.co.uk/~asperges/

The pages are still functioning fine however and have been recently
updated. If you haven't visited yet, do please drop by.

73 de
Jeremy G4NJH
[e-mail]
[Am Radio, SWL pages: http://www.innotts.co.uk/~asperges/ ]



From [e-mail] Sun May 12 18:01:35 1996
From: [e-mail] (Parf)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: "Patch" Antennas?
Date: 11 May 1996 22:09:14 -0400
Message-ID: <4n3h8a$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (Parf)

The antenna you describe sounds more like a bogner. It used disc parasites
and a traditional horn exciter w/ a 1/4 W probe.
The patch antenna was in QST- December issues have a yearly index.

73,  Dale WA2YPY


From [e-mail] Sun May 12 18:01:36 1996
From: Shabanov Sergey <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 2.4 GHz antennas
Date: 8 May 1996 12:38:34 GMT
Message-ID: <4mq4ka$[e-mail]>

Help anybody!

Where I can buy hi-gain (over 11dB) omni-directional
trans-rec. antenna for WaveLAN 2.4 GHz?


Sergey Shabanov
Rosnet-International


From [e-mail] Sun May 12 18:01:37 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: Wed, 08 May 96 16:11:57 GMT
Message-ID: <4mql67$[e-mail]>
References: <4mq4ka$[e-mail]>

Post / CC by Mail

   Shabanov Sergey <[e-mail]> wrote:

>Help anybody!
>
>Where I can buy hi-gain (over 11dB) omni-directional
>trans-rec. antenna for WaveLAN 2.4 GHz?
>
>
>Sergey Shabanov
>Rosnet-International

Andrew Corporation sells omnidirectional transmit antennas for MMDS
(2.5 - 2.7 MHz) and MDS (2.1 MHz) that meet this specification.  I'm
sure they can provide one tuned for 2.4 GHz.  Roughly speaking, these
antennas sell for approximately $10,000.

Andrew Corp. (U.S. callers): 800-255-1479

73,
Jack  WB3U


From [e-mail] Sun May 12 18:01:38 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: 10 May 1996 17:50:06 GMT
Message-ID: <4mvvke$[e-mail]>
References: <4mq4ka$[e-mail]> <[e-mail]>

>Maybe antenna theory has advanced beyond me.  To show 11dB of gain over
>any lossless omni-directional system and remain omni-directional seems
>beyond the physics of passive systems.  You will have to use amplifiers.


Tony,

Look how the term "omnidirectional" is defined: it commonly refers only
to the azimuth. If you squash the pattern's elevational extention,
you have an omnidirectional antenna with gain.

Unlike many amateur (mystery) desighns, e.g. minibeams, ground planes
without ground plane  et.c, they are widely used in commercial
applications and work.

73, Moritz DL5UH




From [e-mail] Sun May 12 18:01:39 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Christopher E. Brown)
Subject: Antenna Design Info
Message-ID: <577cc$11230.2ad@NEWS>
Date: Tue, 07 May 1996 10:18:48 GMT
Keywords: Antenna


        Hello all, looking for some antenna info.

        First off, jpoles, operation of.  How much of a loss of transmit
gain comes from operating a j-matched monopole with no ground plane?

        Second, colinear elements, vertical stacking of.  What are the gain
figures with the different methods?  Heard everything from 1.8db (shorted
stub delay line 1 - 2 inch spacing) to 2.9db (phasing coil 1/4 wave spacing).

        Also the delay sections, should they always be 90deg (1/2wave)?
Or does one need a shorter delay on say stacked 5/8 wave elements?

Any info would be of great help.

Thanks

BTW: Please CC: a copy to [e-mail], the news server is a bit stupid
right now.


--
----------------------------------------------------------------------------
Christopher E. Brown          WL7CLA          Lostnet Systems Administration

                      <[e-mail]>
----------------------------------------------------------------------------

REAL PORTION of Microsoft Windows code:

        while (memory_available)        {
                eat_major_portion_of_memory (no_real_reason);
                if (feel_like_it)
                        make_user_THINK (this_is_an_OS);
                gates_bank_balance++;
        }
----------------------------------------------------------------------------



From [e-mail] Sun May 12 18:01:40 1996
From: aor <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Location*
Date: Sun, 05 May 1996 07:53:38 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>

Jerry Boyd wrote:
>
> If anyone on here has access to TA or some other means of answering my
> question (direct via [e-mail]) I'd really appreciate it.  I'm
> moving to a new QTH and am involved in HF Contests and DXing.  New QTH
> is at about 1900 feet elevation.  Obstructions I am concerned about are:
> Mountain peaks of 5100-5900 feet about 8 miles away from my QTH and
> smaller peaks of 2800-3400 feet 2 1/2 - 3 miles away.  Fortunately these
> are all within about 90 degrees leaving 270 degrees unobstructed.  Part
> of the obstructed path is straight over the North Pole.  Unfortunately,
> the other is to JA.  Problem?!?!
>
> Any info/thoughts appreciated
>
> Jerry Boyd
> KG6LF

Jerry,

The mountain peaks that you describe are far
enough away that they appear to be below 8-10
degrees from your radio horizion.  For your
signal to "hit" this, you need to be higher
than 2 wavelength high on the frequency in
use.  For 20 meters, this means a
tower/antenna combo higher than 120 feet.
If your 1900' QTH raises you higher, then
the mountains are really only 3-6 degrees
above your horizion, then you would need
to be 300' up!!!  Big beams at 75-90' will
work great.  10 Meters may be the only band
with a take-off angle low enough to be a
(slight) problem.  Serious contesters use
stacks of antennas with a BLU antenna switch
(Both, Lower, Upper).  On some band conditions,
you may want to run the lower antenna for
better skip, top-only, or both for a very-low
take-off angle when needed.  Read-up on the
Yagi Antenna Handbook from ARRL.  There are
chapters dealing with antenna height and
stacking for serious performance.  I use
this book for antenna design and stacking
performance.

73,

Al, NW2M  President, MARC

http://www.dsport.com/marc/


From [e-mail] Sun May 12 18:01:41 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Tuner Baluns
Date: Wed, 08 May 96 02:20:46 GMT
Message-ID: <4mp4fl$[e-mail]>
References: <4mm0v0$[e-mail]>

Post / CC by Mail

   Jonathan Helis <[e-mail]> wrote:

>Currently, I am using an antenna tuner that is a homebrew L-C network
>with a single wire input.  It was designed for end-fed single wire
>antennas.  I would like to make a 4:1 balun for this tuner so I can
>feed it with twinlead.  How to wind a balun is in the ARRL Handbook.
>It looks easy, but I can't find anything suitable to wind it on.
>
>The Amidon catalog has tordoids in it like the diagram in the ARRL
>Handbook.  Has anyone ever done anything like this?  What were your
>results?  I plan to run not more than 100 watts out of a Kenwood
>TS-140S, into a small loop.

Hi Jon,

First, there are two spreadsheets on my FTP site that might help
you design a balun if you have Excel 4.0 for Windows or something
compatible.  The files are labeled Toroid.xls and Flux2.xls.  The
FTP site is:  ftp.microserve.com/popaccts/h/jackl/

The general rule of thumb when using Toroid.xls is that the the total
XL of the winding should be four to five times the impedance of the
circuit.  Also, for toroids at the FT-240 size, the number of turns
should probably be limited to ten or twelve to avoid excessive inter-
winding capacitance.  Finally, one of the best baluns consists of
bifilar turns, wound on the toroid in a manner that creates a current
balun.  In this configuration, each winding is in series with one
conductor of the line.

That said, a balun needs to be used in a circuit that presents the
input and output impedance the balun is designed for, within
reasonable limits.  Although the type of system you're planning is
widely used, it doesn't meet that qualification.

In order to assure balance and maximum transfer of power, you will
need to use either A) a balanced tuner like a Match Box instead of
the balun, or B) a technique employing variable line length with a
tunable (simple) L/C network ahead of the balun.  The latter will
present the balun with a non-reactive load near its desired load
impedance.

Cecil Moore (KG7BK) has posted quite a few articles here regarding
the latter technique and has written application notes.  Those notes
are being published by the company that makes the "Ladder Lizard", an
inexpensive device for determining SWR, impedance and power on ladder
line.  The company's name is TechnoLogic Concepts and their e-mail
address is:  [e-mail]

You might want to write and see if the notes are available yet.
Maybe Cecil will jump in here with more details.  ;)

73,
Jack  WB3U


From [e-mail] Sun May 12 18:01:43 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Tuner Baluns
Date: 7 May 1996 22:07:02 -0700
Message-ID: <4mpa5m$[e-mail]>
References: <4mm0v0$[e-mail]> <4mp4fl$[e-mail]>

[e-mail] (WB3U) wrote:
>You might want to write and see if the notes are available yet.
>Maybe Cecil will jump in here with more details.  ;)

Hi Jack, as far as I know, Don, KE6AJH, has information ready
to email and is ready to ship. Just don't believe him when he
says the Ladder-Lizard is better than sex. :-)

I might explain the final solution (hi hi) here at my QTH. On
a transmission line a little bit closer to the transmitter from
the current maximum is what I call the PC point, where a single
parallel capacitor will cause a Z0 match. If it happens at the
transmitter, Z0 = 50 ohms and I call it the PC-50 point. So at
the transmitter, I have a 20-200pf variable cap with the ability
to switch in other fixed capacitors (thanks Tom). Capacitors are
the only reactances that I use to achieve a 1:1 SWR on all
frequencies on all HF bands. No lossy coils. How is it possible?

If you can't bring the capacitor to a current maximum, then bring
the current maximum to the capacitor. Outside my shack window, I
have three relays that switch in 32 ft, 16 ft, and 8 ft sections
of ladder-line. In the same box with my variable capacitor, I have
three switches that will switch in 4 ft, 2 ft, and 1 ft sections
of ladder-line. It's easy to see that I can vary my transmission
line by 76 to 76+63=139 ft. I always use the shortest possible
amount of transmission line to cut down on losses.

That's my ultimate (so far) balanced matching system.

73, Cecil, KG7BK (W6RCA soon), OOTC




From [e-mail] Sun May 12 18:01:44 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Tuner Baluns
Date: 11 May 1996 17:56:16 GMT
Message-ID: <4n2kc0$[e-mail]>


Cecil said -
Of course, I realize this is the old stub-matching approach that my
Elmer taught to me 45 years ago. But everything has come together
in an easy-to-implement fashion. The only reason that I can think
of why this is not the most popular matching system for balanced
lines is people don't know about it or don't realize how easy it
is to implement. I didn't mean to imply that this was anything new.

Cecil,
        The same can be said about the Series Section Tranformer.
some seem to think of only the quarter wave section which only
by chance yields a required input impedance for a given termination
and small choices of available line Zo.  The series section
transformer can use often available line Zo to get a wider range
of impedances of input and termination.

Charlie, W7XC
--


From [e-mail] Sun May 12 18:01:45 1996
From: [e-mail] (Richard Lutz)
Newsgroups: rec.radio.amateur.antenna
Subject: AS 1181 UR  Millitary antenna
Date: 8 May 1996 22:11:26 GMT
Message-ID: <4mr66e$[e-mail]>

Sure would like to know the specs on this one, looks like:  abt 6 in diameter,

4 foot long tube of fiberglass with a stacked set of tuned tubes inside. it
checks out well at 146.00  at about 1.6 swr but I wold like to know more.
thanks in advance for any e mail or post back here..

73... KD4SEV

[e-mail]



From [e-mail] Sun May 12 18:01:46 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Auto Tuner vs Multiband Vertical
Date: 7 May 1996 06:31:00 -0700
Message-ID: <4mnjak$[e-mail]>
References: <4mf0ci$[e-mail]> <4mhnqs$[e-mail]> <4mjl9j$[e-mail]> <4ml4ni$[e-mail]> <4mn4b3$[e-mail]>

[e-mail] (WB3U) wrote:
>Why doesn't MiniNec agree with this?  I've tried a number of
>theoretical combinations of frequency and lengths above 3/8
>wave.  Like you say, the resistive component isn't too bad,
>but the result often shows reactive impedances near 2,000 ohms
>on one or more bands.

Hi Jack, I didn't intend to disagree with MiniNec. If you take
a Smith chart and draw two 450 ohm SWR circles, e.g. one at 3:1
and one at 20:1, the impedances from dipoles greater than 3/8 WL
will lie outside the inner circle and inside the outer circle, a
donut distribution of impedances. When the resistance is near
minimum or maximum, the reactance is near minimum. When the
resistance is mid-range, the reactance is high. A 50+j2000
impedance does not result in a "massive" SWR. As long as the
dipole length is greater than about 3/8 WL, the resistance and
reactance tend to follow a tracking pattern round and round
inside the donut.

When the dipole length becomes about 3/8 WL and less, the resistance
and reactance stop tracking. The resistance goes down and down and
the capacitive reactance goes up and up so you get impedances like
1-j5000 resulting in a "massive" SWR. The antenna impedance breaks
out of the donut and heads for 0-j(infinity). I would define
"massive" as an SWR greater than about 50:1 with 450 ohm ladder-
line. If you thought I was disagreeing with MiniNec, we probably
didn't agree on the definition of "massive" SWR.

73, Cecil, KG7BK (W6RCA soon), OOTC




From [e-mail] Sun May 12 18:01:46 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Auto Tuner vs Multiband Vertical
Date: 7 May 1996 16:56:01 -0700
Message-ID: <4monuh$[e-mail]>
References: <4mo6m3$[e-mail]>

CHARLES J. MICHAELS <[e-mail]> wrote:

:       By the way I posted a correction to the posting you
: referenced.  I also calculated for 50 feet.  Still less than
: half reached antenna.  Cecil says use a shorter line,  and chooses
: one.

Hi Charlie, one can always build a taller house. :-)

73, Cecil, KG7BK (W6RCA soon), OOTC



From [e-mail] Sun May 12 18:01:48 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Auto Tuner vs Multiband Vertical
Date: Tue, 07 May 96 08:06:16 GMT
Message-ID: <4mn4b3$[e-mail]>
References: <4mf0ci$[e-mail]> <4mhnqs$[e-mail]> <4mjl9j$[e-mail]> <4ml4ni$[e-mail]>

   Cecil Moore <[e-mail]> wrote:

>Only below about 3/8 wavelength does the antenna impedance of a
>dipole cause massive SWRs in a 450 ohm ladder-line fed system.
>Longer than 3/8 wavelength, the 450 ohm SWR won't be higher than
>about 20:1 giving a pure resistance at a current maximum of greater
>than 22 ohms, not a bad match.

Why doesn't MiniNec agree with this?  I've tried a number of
theoretical combinations of frequency and lengths above 3/8
wave.  Like you say, the resistive component isn't too bad,
but the result often shows reactive impedances near 2,000 ohms
on one or more bands.

73,
Jack  WB3U


From [e-mail] Sun May 12 18:01:48 1996
From: "Anthony R. Gold" <[e-mail]>
Newsgroups: uk.radio.amateur,rec.radio.amateur.antenna,rec.radio.amateur.misc
Subject: Re: Beam Heading Info
Date: Mon, 06 May 96 13:19:45 GMT
Message-ID: <[e-mail]>
References: <[e-mail]> <4mi8fo$[e-mail]>
Reply-To: [e-mail]

In article <4mi8fo$[e-mail]>
           [e-mail] "Walt Davidson" writes:


>               There is also a list along these lines in the RSGB
> "Amateur Radio Operating Manual", with the origin at London, England.

Thanks for this pointer and I'll follow it up.  Maybe I'll also be told how
to operate. It's must be about time I learned :-)

Regards,
--
   Tony - G3SKR / AA2PM                  email: [e-mail]
                                                [e-mail]
                                        packet: g3skr@n0ary.#nocal.ca.usa.na


From [e-mail] Sun May 12 18:01:49 1996
From: [e-mail]  (Jim Reisert AD1C)
Newsgroups: uk.radio.amateur,rec.radio.amateur.antenna,rec.radio.amateur.misc
Subject: Re: Beam Heading Info
Date: 11 May 1996 15:30:42 GMT
Message-ID: <4n2br2$[e-mail]>
References: <[e-mail]> <4mi8fo$[e-mail]> <4mn2gt$[e-mail]>
Reply-To: [e-mail] (Jim Reisert AD1C)

E-mail me your latitude and longitude and I'll send you a printout in return
E-mail.

73 - Jim AD1C

--
Jim Reisert <[e-mail]>
http://www.tiac.net/users/ad1c/



From [e-mail] Sun May 12 18:01:51 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (David Feldman)
Subject: Re: Best Antenna for Apartment ?
Message-ID: <[e-mail]>
References: <4mluht$[e-mail]> <[e-mail]>
Date: Wed, 8 May 1996 15:57:17 GMT

In article <[e-mail]> Zack Lau <[e-mail]> writes:
>Chris Valliant wrote:
>>
>>         I live in a small apartment, but the landlord won't let me put an
>> antenna on the roof. Does anyone know of a good antenna that I can mount
>> on the window sill ? I have thought about putting up one without his
>> knowledge, but that wouldn't be right. Any idea's would be greatly
>> apreciated. Oh yea, this is for the 10 M band (forgot to add that in).
>
>The 10M band isn't in the best shape for DXing at this part of the
>sunspot cycle, though you can work some surprising contacts if you
>are patient and don't mind days on end without useful propagation.

Try 75! I lived in an apartment in Southern California. _I_ didn't bother
telling the landlord... I ran about 120' of fine guage wire out the window
to the parking garage across the alley. Ran a KW phone. Lots of fun except
when the window sill caught on fire a few times. Never did tell the landlord.

All in fun, you see...

73 Dave WB0GAZ [e-mail]


From [e-mail] Sun May 12 18:01:52 1996
From: [e-mail] (Gary Bishop)
Newsgroups: rec.radio.amateur.antenna
Subject: Coax or 450 ladder line
Date: 6 May 96 13:45:58 GMT
Message-ID: <19960506134557504.AAA74@LOCALNAME>



I plan on building a 1/2 dipole for 12, 17, and 30.  Going to have different
wire

lengths for each of the bands ie: 1/2 wave per band.  Is there an advantage in

using ladder line over coax or vice versa.   Thank you.


Brian Sarkisian   KG8CO   e-mail:    [e-mail]



From [e-mail] Sun May 12 18:01:53 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Coax or 450 ladder line
Date: 7 May 1996 14:38:24 GMT
Message-ID: <4mnn90$[e-mail]>
References: <19960506134557504.AAA74@LOCALNAME>

[e-mail] (Gary Bishop) wrote:
>
>
>I plan on building a 1/2 dipole for 12, 17, and 30.  Going to have different
>wire lengths for each of the bands ie: 1/2 wave per band.  Is there an advant
age
>in using ladder line over coax or vice versa.   Thank you.

Hi Gary, If you don't understand transmission lines, IMO play it safe and
use coax. If you do understand transmission lines, ladder-line has some
definite advantages like the ability to transform impedances without
appreciable losses.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Sun May 12 18:01:53 1996
From: Richard Kiefer <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Coax or 450 ladder line
Date: Wed, 08 May 1996 20:16:56 -0700
Message-ID: <[e-mail]>
References: <19960506134557504.AAA74@LOCALNAME>

Gary Bishop wrote:
>
> I plan on building a 1/2 dipole for 12, 17, and 30.  Going to have different
> wire
>
> lengths for each of the bands ie: 1/2 wave per band.  Is there an advantage
in
>
> using ladder line over coax or vice versa.   Thank you.
>
> Brian Sarkisian   KG8CO   e-mail:    [e-mail] Brian,

I think you should definately use coax.  I have found the commonly
available ladder line to be VERY lossy with measurments on my HP network
analyzer.  Much more lossy than good quality coax.  I do not know why
everyone thinks balanced transmission line is so great.  In addition,
coax is probably more quiet, or less likely to pick up local magnetic
coupled noise from computer monitors, motors, microprocessors in
household applicances, etc.  You can probably get away without a balun if
you bring the coax off the center in a symetrical manner and do not have
to much stuff around the antenna.  Good luck.

Dick Kiefer, K0DK


From [e-mail] Sun May 12 18:01:54 1996
From: [e-mail] (J. L. Blanton)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.space
Subject: Coaxial and/or Counterwound Helix Antennas
Date: Wed, 08 May 1996 22:42:30 -0800
Message-ID: <[e-mail]>

I'm thinking about building some circularly polarized antennas for Oscar
use (145 & 435 MHz).  Has anyone tried installing a 435 MHz helix
coaxially inside a 145 MHz helix?  Or would there be too much interaction?

In a related question, has anyone tried building counterwound helices for
the same frequency band on a common framework for left and right circular
polarizations (but separately fed, of course)?

If anyone can point me to some references in these two areas I'd really
appreciate it.  Thanks.

Lee, WA8YBT/6


From [e-mail] Sun May 12 18:01:55 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.space
Subject: Re: Coaxial and/or Counterwound Helix Antennas
Date: 10 May 1996 07:01:14 GMT
Message-ID: <4mupjq$[e-mail]>
References: <[e-mail]>

>In a related question, has anyone tried building counterwound helices for
>the same frequency band on a common framework for left and right circular
>polarizations (but separately fed, of course)?

Lee,

For the same amount of material / weight / wind load a cross yagi
is better.

73, Moritz DL5UH



From [e-mail] Sun May 12 18:01:57 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Thu, 09 May 1996 00:13:56 GMT
Message-ID: <4mrdb5$[e-mail]>
References: <4mg9ar$[e-mail]> <4mlflb$[e-mail]> <[e-mail]>

Jake Brodsky <[e-mail]> wrote:

>[e-mail] wrote:
>>
>> Jack,
>>
>> I *HAD* a mole problem.  I rectified it with several cheap
>> battery-powered AM radios.
>>
>> #1 Tune them to a local rock station with a good signal.
>>       (needs to be rock-n-roll, moles like classical and country)
>> #2 Turn 'em up fairly loud.
>> #3 Stick 'em in heavy plastic bags.
>> #4 Bury them where you have the problem.
>>
>> The batteries usually last a week or more, and by then the moles
>> have "moved on" to greener pastures.  Sounds silly, but it works!
>>
>> Bill Young
>> [e-mail]
>> KB0UZQ

>Where are the smileys?  Assuming the small chance that you're serious,
>have you tried this? What did your neighbors think?  And please tell
>us what gave you the notion to try such a silly thing!  I wonder if
>People for the Ethical Treatment for Animals has anything to say about
>this... :->

>Jake Brodsky, AB3A, <[e-mail]>
>"Beware of the massive impossible!"


I was fighting gophers (not the Minnesota type) for a long time.  PETA
found out that I has caused the demise of some small number of these
critters and have forced me to pay retribution.  This comes in the
form of gopher food, scientifically tested for flavor and growth
advantage,

Now the gophers walk into the house and demand fresh cut veggies and
Iced tea (Arizona style).  Getting hard to cope.....



           C. Dean Norris
      Amateur Radio Station K7NO
      e-mail to [e-mail]
    http://www.syspac.com/~dnorris/



From [e-mail] Sun May 12 18:01:58 1996
From: aor <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Wed, 08 May 1996 12:19:29 -0400
Message-ID: <[e-mail]>
References: <4mg9ar$[e-mail]>

WB3U wrote:
>
> Lately, I've been thinking about stringing a wire vertical from
> a tree and installing a good radial system underneath.  However,
> there's a wildlife problem that's threatening to thwart my plans.
>
> During the last two winters, I have been beseiged by an invasion
> of moles.  The runners they create in the yard and the many mole
> hills make it impossible to consider radials.  I still have to
> cut what's left of the grass, and there's no question that the
> moles' activity will push any wires I install up to the surface.
>
> So far I've tried the following with little or no success:
>
>     Smoke bombs and poison pellets designed for this purpose
>     Traps designed to kill the mole when it tunnels underneath
>     Flooding the tunnels with a garden hose
>     Filling the tunnels with exhaust fumes from my car
>     900 VAC at 1 Amp delivered into the ground by aluminum stakes
>       placed 20 feet apart
>     Elmer Fudd impressions (lawn chair and shotgun)
There has been significant modeling which shows
that an elevated radial system of 4-6 wires up can
give you the same performance as a 64 burried wire
field.  On 80 meters, the radials need only be up
15' feet, slightly less for the higher bands.  The
radials are tuned, (ie 1/4 wave + 5%), and you have
have multiple bands.

I do not know what your tree-field looks like, but
4-6 elevated radials up 10' or so may fit the bill,
and keep the critters at bay!!!

73,

Al NW2M


From [e-mail] Sun May 12 18:02:00 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Thu, 09 May 96 13:05:00 PDT
Message-ID: <[e-mail]>
References: <4mg9ar$[e-mail]>  <4mlflb$[e-mail]>


In Article<4mlflb$[e-mail]>, <[e-mail]> write:
> Path: li.net!news5.ner.bbnplanet.net!news.ner.bbnplanet.net!howland.reston.a
ns.net!news.cac.psu.edu!news.math.psu.edu!chi-news.cic.net!news.suba.com!news
> From: [e-mail]
> Newsgroups: rec.radio.amateur.antenna
> Subject: Re: Critters
> Date: 6 May 1996 18:16:11 GMT
> Organization: Suba Communications
> Lines: 17
> Message-ID: <4mlflb$[e-mail]>
> References: <4mg9ar$[e-mail]>
> NNTP-Posting-Host: 206.29.114.19
> X-Newsreader: SPRY News 3.03 (SPRY, Inc.)
>
> Jack,
>
> I *HAD* a mole problem.  I rectified it with several cheap
> battery-powered AM radios.
>
> #1 Tune them to a local rock station with a good signal.
>       (needs to be rock-n-roll, moles like classical and country)
> #2 Turn 'em up fairly loud.
> #3 Stick 'em in heavy plastic bags.
> #4 Bury them where you have the problem.
>
> The batteries usually last a week or more, and by then the moles
> have "moved on" to greener pastures.  Sounds silly, but it works!
>
> Bill Young
> [e-mail]
> KB0UZQ

Be careful - I tried this once - it did eliminate the moles, but I found
my lawn infested with teenagers...  :-)

KD2FT



From [e-mail] Sun May 12 18:02:00 1996
From: [e-mail] (Larry M. Weissman, X6946)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: 8 May 1996 21:40:43 GMT
Distribution: world
Message-ID: <4mr4cr$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

John D. Farr wrote:

> I have a cat that has developed a taste for moles.  I have no problems
>with them like some of my neighbors.  Best of all, my cat brings me the
>best parts!

>73, John

Can I rent your cat for a weekend John?

Larry - AD3Y


From [e-mail] Sun May 12 18:02:01 1996
From: [e-mail] (Brian Williams)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Diamond 2m 5/8 mobile antenna (for so239 mount)
Date: 10 May 1996 18:42:46 GMT
Message-ID: <4n02n6$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] says...

>Hi:  Does anyone know who manufacturers the Diamond 2m 5/8 mobile whip
>with the pl 239 fitting.
...  text cut here  ...
>Thanks,

>Sal

Sal, Diamond is the manufacturer (or distributor for US market) from
Japan.   Most Diamond, Comet, and some Anli antennas are made to fit
the SO-239 connector mounts.  H.R.O. and R.E.S. and most ham radio
stores sell these products.  If you can not find a store near you,
then let me know and I'll give you an address and phone number of
several stores when I get home.

Brian



From [e-mail] Sun May 12 18:02:03 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: Wed, 08 May 96 19:15:16 GMT
Message-ID: <4mqrpu$[e-mail]>
References: <[e-mail]> <4mg98q$[e-mail]> <4mp7ga$[e-mail]>

In article <4mp7ga$[e-mail]>,
   [e-mail] (WB3U) wrote:
>I'm confused.  Two people have mentioned that my reply to the dipole
>inquiry was incomplete/incorrect because A) the 2.13 dBi dipole is
>only theoretical, and B) the 2.13 dBi dipole is in free space.
>
>So, I went back and looked at my post.  This is what I found:
>
>>This will create a dipole, although with certain deviations from
>>a theoretical model due to practical considerations.
>
>>the gain will vary with height above ground and soil conditions.
>
>Was there something about the way I structured my reply that
>caused these statements to be overlooked?
>
>73,
>Jack  WB3U

Your statements weren't overlooked; speaking as one of the posters in
question, I just felt that an adequate explanation required more
elaboration.

A dipole in free space has a gain in its best directions of about 2.15 dBi.
If a ground is placed under it, several important (interrelated) things
happen. First, the average strength of the entire field increases 3 dB
because the energy is now concentrated in a hemisphere rather than being
radiated in all directions. Second, energy reflects from the ground and
adds to the energy being radiated directly, modifying the pattern and gain.
Third, the feedpoint impedance of the antenna changes because of
interaction of the field with ground. This in turn changes the strength of
the field from the antenna. The net result is a field strength which is
several dB greater than that of a free-space dipole (and a very different
pattern), for any antenna height over ground of any real conductivity. And,
unless you're miles above the Earth, any dipole you construct will be over
ground, not in free space.

To me, these constitute major differences between a dipole in free space
and one over ground, more than "certain deviations. . due to practical
considerations" and "[variation] with height above ground and soil
conditions". I apologize if I misinterpreted your statements.

Roy Lewallen, W7EL


From [e-mail] Sun May 12 18:02:03 1996
From: [e-mail] (Jari Jokiniemi)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: 09 May 1996 04:38:10 GMT
Message-ID: <[e-mail]>
References: <4mmj1n$[e-mail]>


Well, there is no such thing as a 2.15 dBi dipole in the real world
of amateur HF communications due to the ground which we can not get
rid off. So what? Let us compare the dipole and a 7 dBd yagi over the real
ground at the same height. That yagi does indeed beat the dipole with
the great margin of 7 dBd. Who cares how much the gain is in dBi?
--
Jari Jokiniemi, [e-mail], OH2MPO, OH3BU
Tekla Oy, Koronakatu 1, 02210 Espoo, 90-8879 474


From [e-mail] Sun May 12 18:02:04 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: 10 May 1996 05:18:02 GMT
Message-ID: <4mujia$[e-mail]>


Jari said -
Jari said -
That yagi does indeed beat the dipole with
the great margin of 7 dBd. Who cares how much the gain is in dBi?

Jari,
        If it is understood that you are only comaring the gain
at the peak of the lobe then there is no problem.
        But when you start to compare other pattrts/// parts of
the pattern, it is not always clear whether you are comparing
those parts with the dipole pattern parts at the same coordinates
or if you are referenceing it to the peak of the dipole lobe.

Charlie, W7
XC
--


From [e-mail] Sun May 12 18:02:05 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Electric half-wavelenght xmition....re:...
Date: 6 May 1996 18:52:43 GMT
Message-ID: <4mlhpr$[e-mail]>
References: <[e-mail]>

[e-mail] wrote:

>At least the intention is to shield the path between
>the transmatch and antenna - the neighbours will love it!.

Hi Marcus, I can't tell if your antenna is balanced or unbalanced,
resonant or non-resonant.

Your intended shielding will probably be achieved with a resonant
half-wave dipole fed by coax with a 1:1 balun at the antenna.

If your antenna plus balun is not perfectly unbalanced, you will
likely get feedline radiation.

If your antenna is non-resonant, you will likely lose a lot of
power in the coax due to reflections.

It's just not a good idea to use coax on a non-resonant length
antenna.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Sun May 12 18:02:06 1996
From: "John C. Sanders" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: External Antenna for Nokia Handheld Cell Phone on Sailboat?
Date: Tue, 07 May 1996 19:52:16 -0700
Message-ID: <[e-mail]>

My boss has a Nokia handheld cellular phone and a sailboat he likes to
sail in and around Casco Bay, Maine. The cell phone is 1.6 watts. He's
asking me if he can attach an external antenna to this phone, the antenna
to be mounted at some suitably high spot, like maybe atop the mast. We
believe that there may be a so called car kit available for the phone
that includes an external antenna connector (BNC).
Question: Will the installation of the antenna atop the mast and
connected to the phone via cable provide improved reception or would this
be a waste of time and money unless he also went for a 3 watt booster
kit. The point is he has this phone and doesn't want to get another phone
(account) just for the boat.

Thanks,

John


From [e-mail] Sun May 12 18:02:07 1996
From: Darrell Barabash <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Familiar with this antenna book?
Date: Sat, 11 May 1996 23:29:12 -0500
Message-ID: <[e-mail]>
References: <4msfs7$[e-mail]>

KC8CGX wrote:
> Anyone familiar with this book: "Antenna Engineering
> Handbook, Second Edition", Ed by R.C. Johnson & H. Jasik,
> pub by McGraw-Hill.

This is a very good, practical book that covers many types of antenna
systems. It gets into the theory but not too deep. You can get it for
$12.95? Don't even give that a second thought -- get it. At full retail
it's more than worth it.


From [e-mail] Sun May 12 18:02:08 1996
From: Jack McClain <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Field Day wire antenna hints needed
Date: Tue, 07 May 1996 07:44:43 -0400
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]> <4mlgmf$[e-mail]>

John Hughes wrote:
>
> > For a number of years our Field Day stations consisted of erecting
> > tri-band beams on portable 75 foot towers for the high bands and various
> > dipoles or double extended Zepps for 40 and 80 Meters...even tried a
> > G5RV one year!
> >
> > BUT - the last three years we've abandoned those antennas in favor of
> > Horizonal loops. (I should have started with the fact that we operate in
> > class 2B - One SSB station and one CW station)
> >
> > It's so simple if you have any sort of supports to put up as big a loop
> > as you have room for and as high as you can get it. Works well even at
> > 25 feet. We feed ours with 450 ohm ladder line and use a tuner
> > (Transmatch) to match the transceiver. This antenna works well on all
> > bands, so well we don't even miss the beam for 10-15-20.
> >
> > 73, Jack [e-mail]
>
> Loops/ladderline sound gud, but tell us where did you all get the 75ft
> portable towers????
>
> 73


Surplus trailer-mounted fold-over 75' towers! Originally used for
microwave site selection tests for microwave routes. Fiber Optics
technology had made the towers surplus!
73, de AE4Q


From [e-mail] Sun May 12 18:02:09 1996
From: [e-mail] (Brian Williams)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Field Day wire antenna hints needed
Date: 10 May 1996 18:31:38 GMT
Message-ID: <4n022a$[e-mail]>
References: <4mlgmf$[e-mail]> <4mlu8q$[e-mail]> <[e-mail]>

In article <[e-mail]>, [e-mail] says...
>Not exactly in My ham budget!

>Cheers.
>Jim, WU0I


>[e-mail] wrote:

>> In article <4mlgmf$[e-mail]>, John Hughes writes:
>> >Loops/ladderline sound gud, but tell us where did you all get the 75ft
>> >portable towers????
>> >73

I have a friend with a military style guyed crank up that's about 50ft.
I'd buy it myself but really can't justify it to my wife.  If you or a
club is interested, the cost is almost 1/10 the 75ft unit mentioned
earlier.

Brian



From [e-mail] Sun May 12 18:02:10 1996
Newsgroups: rec.radio.amateur.antenna
From: Marilyn Swartz <[e-mail]>
Subject: FM Antenna Question
Message-ID: <[e-mail]>
Date: Tue, 07 May 1996 02:41:45 -0700

Sorry that this isn't a question about esoteric antenna theory, but here
goes:

I recently bought an R-95 Yamaha receiver to listen to FM stations.  I
am using the simple wire-loop antenna that came with the receiver.
However, as I live very close to a radio tower (Sutro tower in San
Francisco), it is very difficult to get certain stations because of the
interferance--they come in, but with a lot of static and only after
moving the antenna around a lot.

Would getting a better antenna help, and if so, which one?  The people
at Good Guys, where I bought the receiver, only reccommend the Terk
brand antennas they have availiable.  I would prefer to use an indoor
antenna if possible, however--but it seems that my problem is mainly
antenna selectivity, not sensitivity, so I doubt a large antenna would
do anything.

Thank you very much in advance for your help.



From [e-mail] Sun May 12 18:02:11 1996
From: [e-mail] (Mike Fink)
Newsgroups: rec.radio.amateur.antenna
Subject: Help on cutting radials for 225-400Mhz,what length?
Date: 6 May 1996 22:06:32 GMT
Message-ID: <4mlt58$[e-mail]>

I bought a quarterwave   groundplane from RS and want to trim the
3 radials and 1 vertical element for monitoring military air. Can
someone recommend a good length to trim them too,and what frequency
is best to use 225,300,400Mhz in choosing the length.

Thanks Mike



--
 --------------------------------------------------------------------------
|Mike Fink                                  Support the right to bear arms |
|[e-mail]                                                          |
|http://www.shadow.net/~mikef                                              |
 --------------------------------------------------------------------------


From [e-mail] Sun May 12 18:02:12 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Vertical
Date: 6 May 1996 22:22:46 GMT
Message-ID: <4mlu3m$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, Chuck Vaughn writes:

>George J. Molnar wrote:
>>
>> Dan Tang wrote:
>> >
>> > Can some one please tell me if an hf vertical antenna install on the
roof
>> > (with radials) works as good as it install on the ground (with
radials)?
>>
>> It'll probably work a bit better, presuming you install a good-quality
>> set of radials on the roof.
>
>And not only that, but you can get the impedance closer to 50 ohms
>by sloping the radials down.
>
>Chuck - AA6G

I used to have a Cushcraft AP8A mounted on my chiney.  I had VERY good luck
with it.  Good performance for both domestic and DX contacts.  Really
enjoyed it.  Good luck.
Al, KE6BER/1, [e-mail]



From [e-mail] Sun May 12 18:02:14 1996
From: Garth Wiscombe <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Vertical
Date: 9 May 1996 02:03:21 GMT
Distribution: world
Message-ID: <4mrjp9$atm@NEWSnewsNeWsnEwS>
References: <[e-mail]> <4mlu3m$[e-mail]>
To: [e-mail]

[e-mail] wrote:
>In article <[e-mail]>, Chuck Vaughn writes:
>
>>George J. Molnar wrote:
>>>
>>> Dan Tang wrote:
>>> >
>>> > Can some one please tell me if an hf vertical antenna install on the
>roof
>>> > (with radials) works as good as it install on the ground (with
>radials)?
>>>
>>> It'll probably work a bit better, presuming you install a good-quality
>>> set of radials on the roof.
>>
>>And not only that, but you can get the impedance closer to 50 ohms
>>by sloping the radials down.
>>
>>Chuck - AA6G
>
>I used to have a Cushcraft AP8A mounted on my chiney.  I had VERY good luck
>with it.  Good performance for both domestic and DX contacts.  Really
>enjoyed it.  Good luck.
>Al, KE6BER/1, [e-mail]
>

Just a note:
You may want to check with the manufature of your particular vertical to
see if the radials are longer with the roof top mount than the ground
mounting.  For example I have the AV5 and the radials for the 80 meter
band are 6 feet longer for the roof mount than ground.  My installation
instructions came with the information for both ground and roof mounting.
 The comment of coming closer to 50 ohms because of angle are also very
true and are discussed in brief in the installation instructions that I
have for my antenna.

Have Fun.
--
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                              *   *    *   *   *
Garth Wiscombe, KA7MHN  /\  /\ *    *   /  /    /  Office     801 265-5057
Salt Lake City         /  \/  \ /\     ----/\---   Cellular   801 631-8675
Utah  84119-6032      /\   \   \  \   /  / || /    Home       801 967-3236
USA                  /  \   \   \  \       ||      FAX        [phone]
                    /    \   \   \  \      ||      E-mail  [e-mail]
                             73 de Garth KA7MHN

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++




From [e-mail] Sun May 12 18:02:15 1996
From: Siegfried Rambaum <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: High SWR Help
Date: Fri, 10 May 1996 14:52:42 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>

On 8 May 1996, Steve Lee wrote:

> Here's what he's doing. He has a Cobra 148F and a Firestik 2 antenna.

Humm ... this sounds, as if your friend only installed half the antenna.
The other half of that antenna would be the car; the Firestick and the
car give a complete antenna system (i.e. form a groundplane) .... I
guess, he would need to add radials like it is the rule for each decent
groundplane.

> He can't have an outdoor antenna where he is at. So, he mounted the
> antenna in his attic. The antenna is 3 feet tall just below his roof
> inside the attic. He's using 50 feet of RG58 coax , new from Radio
> Shack. This is a mobile style antenna, but he is using his radio as a base
                   ******************** here you say it yourself...


From [e-mail] Sun May 12 18:02:16 1996
From: [e-mail] (Dan Halbert)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Horizontal HF loops
Date: 6 May 96 21:17:17 GMT
Message-ID: <halbert.831417437@halite>
References: <[e-mail]> <[e-mail]> <4lteku$[e-mail]> <4mfqhj$[e-mail]> <4mjua9$[e-mail]>

>[Continuing a thread about how good horizontal loops are]
>... Only reason I don't still have it up is that the
>...trees kept rubbing thru the wire and I got tired of fixing it.

I have held up my loops by running the wire (12/13 gauge solid or
stranded copper) through stainless steel marine pulleys that have
nylon wheels. They don't rust, and the wire is free to slide back and
forth in the wind. The pulleys themselves are held up by nylon cord
over tree limbs.

It can be a nuisance to thread the wire through all the pulleys. Some
marine pulleys have removable wheels (sheaves?). On others I have
drilled out the rivet that holds the wheel and replaced it with a
stainless bolt and nut.

Dan Halbert, KB1RT


From [e-mail] Sun May 12 18:02:18 1996
From: P Tyers <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: HOW DO U CONNECT COAX TO QUAD????????
Date: Fri, 10 May 1996 14:08:58 +1100
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]>

Monty Wilson wrote:
>
> [e-mail] (Bill Poston) wrote:
> >I am attempting to homebrew a quad antenna. I have read Cubical Quad
> >Antennas by W6SAI and the ARRL Antenna Book. Neither answers my question.
> >
> >How do I connect one coax feedline to the multiple loops on the driven
> >element?
> >
> >Please explain in detail so that a dummy can understand.
>

Have another read of Cubical Quads. What you actually end up
doing is producing a multiple gamma match, one for each loop.
Of course they interact to all heck while being adjusted.I
seem to recall that the preferred order of adjustment was
from smallest loop to largest loop for minimum interaction -
BUT I COULD BE TOTALLY WRONG ON THIS.

 Another source of information is a series of articles
published in the Wireless Institute of Australia magazine
"Amateur Radio" about 15 +/- 5 years ago on multiband quads
which had several column inches on the care and feeding of
these gamma matches.

Hope this helps!

--
P Tyers, Tel. [phone]
AARnet: [e-mail]
CSnet: [e-mail]    HAM: VK3KTS
MAIL: Telstra Research Laboratories,P.O. Box 249,
      Clayton,VICTORIA 3168,AUSTRALIA


From [e-mail] Sun May 12 18:02:20 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: HOW DO U CONNECT COAX TO QUAD????????
Date: 11 May 1996 05:45:45 GMT
Message-ID: <4n19i9$[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]>
Reply-To: [e-mail]

In <[e-mail]>, P Tyers <[e-mail]> writes:
>Monty Wilson wrote:
>>
>> [e-mail] (Bill Poston) wrote:
>> >I am attempting to homebrew a quad antenna. I have read Cubical Quad
>> >Antennas by W6SAI and the ARRL Antenna Book. Neither answers my question.
>> >
>> >How do I connect one coax feedline to the multiple loops on the driven
>> >element?
>> >
>> >Please explain in detail so that a dummy can understand.
>>
>
>Have another read of Cubical Quads. What you actually end up
>doing is producing a multiple gamma match, one for each loop.
>Of course they interact to all heck while being adjusted.I
>seem to recall that the preferred order of adjustment was
>from smallest loop to largest loop for minimum interaction -
>BUT I COULD BE TOTALLY WRONG ON THIS.
>
> Another source of information is a series of articles
>published in the Wireless Institute of Australia magazine
>"Amateur Radio" about 15 +/- 5 years ago on multiband quads
>which had several column inches on the care and feeding of
>these gamma matches.
>
>Hope this helps!
>
>--
>P Tyers, Tel. [phone]
>AARnet:        [e-mail]
>CSnet: [e-mail]    HAM: VK3KTS
>MAIL: Telstra Research Laboratories,P.O. Box 249,
>      Clayton,VICTORIA 3168,AUSTRALIA

You're right on target!  Highest to lowest frequency.

It takes some juggling.

However, once done, the match stays done.

I've used the gamma match feed system on quads (and virtually everything
else I can reasonably adapt it to.  It works on the quads VERY well.

Another tip.  In stead of chasing all over heck and back for big variable
capacitors as you get down to 40 and 80 meter quads, use a chunk of RG-8
coax cable as a capacitor.  It has capacity and a nice hefty dialectric that
will let you use the inner conductor as one arm of a capacitor and the
outer shield as the other arm.  You get it too long by a foot or so for the
total capacity you need.  You whackem off an inch or so at a time at lower
power to trim away the capacitance.  You use a much smaller air variable
for the trimmer.

When done, presto, BIG heavy cap for 40 and 80 meter versions heap cheapo.

Be sure to trim away some of the braid and leave an inch or so of the inner
conductor and insulation extended to avoice arcing at high power....

Tape the end up to excude water.

Smile all the way to the bank.

:)

Mike W5WQN as a guest at leviathan.tamu.edu (No mail address there)



From [e-mail] Sun May 12 18:02:21 1996
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
From: "Al Koblinski  (W7XA)" <[e-mail]>
Subject: Re: HOW DO U CONNECT COAX TO QUAD????????
Message-ID: <[e-mail]>
To: [e-mail]
References: <[e-mail]>
Date: Thu, 9 May 1996 23:56:14 GMT

I use a 1:1 balun for each loop (Bencher, but any brand is OK).
Where needed I used a coax matching section to match.
On 20mtr, my 3 el on 26' boom was 49 ohms so no matching was needed for
50 ohm coax.
Ditto for 5 el on 15 mtrs with same boom.
10 meters, 5 elements came out to near 90 ohms impedence and I used a
section of 75 ohm coax between the balun and the 50 ohm feedline.
Each element is fed seperately through a switchbox.
I have used a variety of other feed methods in the past, such as gamma
matching (cumbersome) and found that the simple balun approach works
great and is mechanically the most simple.
73, Al




From [e-mail] Sun May 12 18:02:22 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: ISOTRON Antenna Information
Date: 8 May 1996 14:15:21 GMT
Message-ID: <4mqa9p$[e-mail]>
References: <4mogau$[e-mail]>

[e-mail] wrote:
>Any information will be greatly apreciated. TIA.

Hi Barry, IMO you would be a lot better off running $10 worth of
wire in your attic. Have you seen any radiation efficiency specs
on the Isotrons?

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Sun May 12 18:02:23 1996
From: [e-mail] (Barry LaZar)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: ISOTRON Antenna Information
Date: Thu, 9 May 1996 06:34:43 +1000
Message-ID: <[e-mail]>
References: <4mogau$[e-mail]> <4mqa9p$[e-mail]>

In article <4mqa9p$[e-mail]> Cecil Moore <[e-mail]
m> writes:
>From: Cecil Moore <[e-mail]>
>Subject: Re: ISOTRON Antenna Information
>Date: 8 May 1996 14:15:21 GMT

>[e-mail] wrote:
>>Any information will be greatly apreciated. TIA.

>Hi Barry, IMO you would be a lot better off running $10 worth of
>wire in your attic. Have you seen any radiation efficiency specs
>on the Isotrons?

>73, Cecil, KG7BK, OOTC  (not speaking for my employer)
>

Cecil,
        Thanks for the response. All I know about the antenna(s) is what I have read
in a couple of 73 articles. 73

/Barry, K3NDM


From [e-mail] Sun May 12 18:02:23 1996
From: Erik Finskas OH2LAK <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Looking for a 50MHz/145MHz dualband GP
Date: Tue, 07 May 1996 17:07:26 +0100
Message-ID: <[e-mail]>

Is there available any ground plane antennas for 50MHz/145MHz??

Or if you have building instructions, how to make one, could you please
mail me!

Erik
--
Erik Finskas M1AAJ & OH2LAK
Email [e-mail]
      [e-mail]
University of Portsmouth, UK
Department of Electric and Electronic Engineering


From [e-mail] Sun May 12 18:02:26 1996
From: [e-mail] (Mica Sanders)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Mobile Antenna for 27Mhz
Date: Tue, 07 May 1996 20:12:39 +0300
Message-ID: <[e-mail]>
References: <4kpti6$[e-mail]> <[e-mail]> <4lsa7q$[e-mail]>

In article <4lsa7q$[e-mail]>, [e-mail] wrote:

> aor <[e-mail]> wrote:
> >[e-mail] wrote:
> >>
> >> I am trying to build a beam type of antenna for a 27Mhz mobile. Does
> >> anyone have any models of this or ideas??? Even if you have formulas or
> >> theory I would be very interested.
> >>
> >> Thanks
> >
> >
> >One of the easiest ways to do this is by using two
> >antennas and phasing them.  One example would be to
> >buy two 9' whip antennas and mount them 9' feet
> >apart (1/4 wave on 27 MHz).  Feed them in phase by
> >using two equal runs of (odd 1/4 wave) 75 ohm coax
> >from a tee-connector on your radio.  The pattern
> >will be broadside to the two antennas.  With about
> >3db of gain over a single antenna.
> >
> >You see truck drivers with two antennas, you don't
> >see the phasing harness, and the pattern favors the
> >front and back (broadside) by 3 db (double your
> >radiated power) at the expense of side radiation
> >(end-fire).  The principles are the same.
> >
> >There are a lot of other things to consider
> >assuming you can put two antennas 9' apart on a
> >car, have good grounding, and a good ground plane.
> >There are other methods by using 90 degrees phasing
> >and 1/4 wave spacing...  but that is another story.
> >This resembles a 2-3 element beam pattern.
> >
> >It is a lot of fun to do, 75 ohm coax is cheap, and
> >one centrally mounted antenna is usually better
> >than multiple antennas for 99% of the population.
> >Besides, how did you plan on turning this "beam"
> >???  Hi Hi
> >
> >For 30 bucks, order the ARRL Antenna Handbook and
> >read up on the subject.
> >
> >See ya,
> >
> >Al  NW2M
>
> Thanks for the info. I'll look into that. I had heard that you can make
> one of the antennas the hot and another the ground or backdoor.
> Suppossedly the backdoor should act like a reflector.

Al,

I invested in the ARRL Antenna Book (several years ago) and (IMHO) found
it to be of minimal value except in low band antenna designs. It is sorely
lacking in phasing harness design and applications. I have yet to find a
formula (or person) to describe how Decibel Products (premier supplier of
commercial antennas) phases multiple folded dipoles (as many as 16 on
UHF). I built an 8 dipole 465 MHZ unit using a DB-420 as a model and it
performed exceptionally well (VSWR 1.05). I did not consider
frequency/cable Velocity factor when building the harness but made sure
that all 8 elements were fed using equal line lenghts from the feedpoint
(total of 7 "tees" including feedpoint which was positioned at the center
of the array). IMHO, it would seem logical that if the RF signal arrived
at each element at the same time, all elements would resonate "in-phase"
and the way to accomplish this is by equal lenghts of coax to each element
from the feedpoint. Could you lend some insight on why the cable lenghts
have to be in multiples of the frequency (even if center fed?), and what
the "odd multiple" does for the design?

Thanks,

Paul WNQN319


From [e-mail] Sun May 12 18:02:27 1996
From: [e-mail] (George Micros)
Newsgroups: rec.radio.amateur.antenna
Subject: Need help! Fm Antenna and dipole construction.
Date: 10 May 1996 00:52:48 GMT
Message-ID: <4mu410$[e-mail]>

I am looking for any plans for an FM Antenna or co-linear antenna with at
least four dipoles. Need dipole distances and anything that might help me
build it, (mathematical types will do). For use with a 500W fm transmitter.
(for now).
Any help will be appreciated.
If possible please e-mail me at [e-mail]



From [e-mail] Sun May 12 18:02:28 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PVC Core to build 2.4Ghz loop yagi?
Date: 7 May 1996 08:10:44 GMT
Message-ID: <4mn0i4$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>,
Mick Henniger <[e-mail]> wrote:
>The word around here is that ~ 24 db gain is required of the antenna

Well, a miror of abt. 4 feet in diameter will get you there. worth
considering.

>1. Loop yagi build on 1.5 inch diameter PVC pipe.
>   Dimensions scaled from 1.2Ghz loop yagi in VHF/UHF handbook.
>   Not placed on metal boom, just the PVC.

The problem is the scaling. since all dimensions are interdependent,
there is a fair chance that it will not work in the end. Better to find a
2.3 GHz design.

>2. Helical antenna, wound on 1.5 inch diameter PVC pipe.
>   Dimensions scaled from 1.2Ghz helical antenna in VHF/UHF handbook.
>   No center support, just the PVC.

You can test the PVC in the microwave oven. Some are lossy and some are not.
There will also be some detuning by the dielectric constant
For the same gain a loop yagi is more compact.

>   How do I match 140 <--> 75?

use two antennas paralell. one can be righthand and the other lefthand
to get vert. pol.

>3. A collinear which is must a vertical wire with stubs (1/4 wave out and
>   1/4 wave back) every half wavelength.

with 24 dB??

73, Moritz DL5UH



From [e-mail] Sun May 12 18:02:29 1996
From: [e-mail] (Gerry Lavallee)
Newsgroups: rec.radio.amateur.antenna
Subject: Question-railroad antennae
Date: 10 May 1996 04:38:44 GMT
Message-ID: <[e-mail]>

I was wondering if someone could enlighten me.
I am a rail fan and have noticed different radio antennae on locomotives.
I am curious why different shapes are required as the frequencies used by
railroads are in the same bandwidth (around 160 megahertz)
I understand how a "whip" antenna radiates out a signal & captures a signal.
I have an idea why a base plane is used underneath a whip antenna.

Anyway, in the past & now in the present I have seen;
1. An antenna shaped like a gong type bell
2. "    "        "     "  a railing along the loco hood (induction?)
3. "    "        "     "  a fire cracker
4. "    "        "     "  an ice skate (called "Sinclair" type)
5. "    "        "     "  a tin can

The Sinclair type is almost universally used in Canada but in the states
the antennae used seem almost random, even on the same railroad


From [e-mail] Sun May 12 18:02:30 1996
From: "Michael C. Maguire" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Request for Info on M2 Antenna Controller
Date: 7 May 1996 18:48:39 GMT
Message-ID: <4mo5u7$[e-mail]>

I have a Model RC2800-PRK Dual Controller from a company called M2 or M-square
d
(depending on how you read the logo).  The controller connects to an az/el
mount suitable for coarse pointing of a helical antenna for satellite tracking
.
Unfortunately, I do not have a complete manual set for either the controller o
r
the az/el drives.  Does anyone have contact information for either M2 or a
sales rep for M2?  Any combination of corporate address, phone, fax, email or
WWW address would be appreciated.

Thanks in advance.  Regards, mcm

--
Michael C. Maguire
Systems Engineer
Earthwatch Inc. - http://www.digitalglobe.com/
Tel: [phone]  Fax: [phone]  Email: [e-mail]



From [e-mail] Sun May 12 18:02:30 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (CB Smith)
Subject: Rogers Antenna System
Message-ID: <[e-mail]>
Date: Sun, 12 May 1996 00:19:19 GMT

Does anyone have details on this antenna ?
Apparently built by the US military in the 1930's and is static-free.

Any ideas ?

de Brian ve3ex
[e-mail]




From [e-mail] Sun May 12 18:02:31 1996
From: [e-mail] (Clint Bradford)
Date: 07 May 96 19:38:00
Newsgroups: rec.radio.amateur.antenna
Subject: Sale
Message-ID: <[e-mail]>





>>Hi Tom here... I have for sale 2 Regency 16ch programable mobiles.

INTERNET TIP #4 -

If the Conference/Newsgrou doesn't have the word, "SALE," in its
title, it is probably inappropriate to post FOR SALE messages in it.

There -IS- a very active FOR SALE area for you on the same system you
posted this message. Please prepare for a little flack from those who
will not-as-gently-as-I-have remind you of the Conference Posting rules.


[e-mail]
... ATTENTION to Details BBS - 909-681-6221 - REACT/GMRS/AMATEUR RADIO
---
 * TLX v4.00 *
 * wcECHO 4.1 ~ AR-Net: ATTENTION to Details * Mira Loma, CA * 909-681-6221
--
|Fidonet:  Clint Bradford 1:2619/228
|Internet: [e-mail]
|
| Standard disclaimer: The views of this user are strictly his own.



From [e-mail] Sun May 12 18:02:32 1996
From: [e-mail] (BillV21572)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: shortend radials
Date: 9 May 1996 02:02:45 -0400
Message-ID: <4ms1q5$[e-mail]>
References: <4mqp0u$[e-mail]>

I've got 4 little kids and a dog, and if I laid my radials out directly on
the surface of the lawn, they would hand me a ball of wire at the end of
one weekend. Unfortunately, I have a "multi-use" backyard, and even though
Daddy loves his hobby, my kids don't love me <that> much  ;)
Bill ka9hln

Bill Vanstralen  KA9HLN  St. Paul, MN  [phone]  [e-mail]


From [e-mail] Sun May 12 18:02:33 1996
From: [e-mail] (Gary Hosler - KN0Z)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Shunt load a tower
Date: Wed, 08 May 1996 13:45:19 GMT
Message-ID: <4mq8or$[e-mail]>
References: <[e-mail]>

[e-mail] (Anthony Simons) wrote:

>Hello all,  Where can I find the best info on shunt loading a tower.  I have
>a ROHN BX-64 (64' self supporting) with a 3 Ele tri-bander with a dual band
>2m/70cm vertical on top.  The tower is grounded on all three legs with an 8'
>rod with 1/2 copper tubing to each leg.  I would like to use the system on
>40/80 Meters.  Any and all suggestions appreciated.
>                                       Thanks & 73,  de Anthony KC8BK

Sorry to have taken so long to respond to your post but I knew I had
an article stashed away on a similiar installation.  The August 1990
issue of CQ Magazine had an article (on page 46) by Gary Nichols -
KD9SV, and Lynn Gerig - WA9GFR.  The article described shunt feeding a
70 foot tower with a TH6-DXX on top.  Sounds like a VERY similiar
instalation to what your are proposing, and this article also included
the 160M Top Band.  I plan to shunt feed my 100 foot Rohn 25G (with 15
feet of mast out the top) this Summer in preperation for the
Fall/Winter season on Top Band.  Good luck on your project.

                        73 & GUD DX OM  de KN0Z  Gary in Wyoming, MN

Opinions expressed herein are my own and may not represent those of my employe
r.


From [e-mail] Sun May 12 18:02:34 1996
From: Edward Lawrence <eal>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The Coax Mentality
Date: 6 May 1996 12:55:03 GMT
Message-ID: <4mksr7$[e-mail]>
References: <4m8ehm$[e-mail]> <4m8usl$[e-mail]> <4mavg8$[e-mail]> <[e-mail]> <4megu5$[e-mail]>

Cecil Moore <[e-mail]> wrote:
>Larry Deering <[e-mail]> wrote:
>:      Are you going to use a balun between the coax and the ladder line?
>
>Hi Larry, does a bear ---- in the woods? :-) Anytime one has
>an intersection between balanced and unbalanced RF currents
>one should (I want to say must) use a balun of some sort
>even if it is a number of turns of coax which is probably
>what I will use, honoring the KISS principle. Ten loops
>of coax make a reasonable 1:1 HF balun/choke (somebody
>correct me if that's not enough turns for 80m).
>
>50 ohms unbalanced to 50 ohms balanced is usually not a
>match unless both ends are floating and my ends are not
>floating. :-) If one doesn't use a balun of some sort,
>one has feedline radiation - a mortal sin for hams.
>-----------------------------------------------------------------------------
--
>kg7bk                                     __  __     ____  ___       ___ ____
>[e-mail]                       /__)/__) / / / / /_  /\  / /_    /
>                                        /   / \  / / / / /__ /  \/ /___  /
>
>
Cecil, You obviously have a good background on antenna theory.  However I
would like to know WHY freedline radiation is a "mortal sin", other than the
possibility of RF in the Shack.  If I am using a dipole, I obviously don't car
e
much about directivity.  In any event, in the real world other metallic object
s
in the area will distort the pattern anyway! (Assuming  a city lot
installation.)

So the feed line radiates and gives me an 'extra' vertical component. So what?
How is that a 'mortal sin'?   This is an honest question, not by any means a
flame.  Thought I would make that 'perfectly clear".   WA5SWD



From [e-mail] Sun May 12 18:02:35 1996
From: Edward Lawrence <eal>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: The Coax Mentality
Date: 8 May 1996 12:59:24 GMT
Message-ID: <4mq5rc$[e-mail]>
References: <4m8ehm$[e-mail]> <4m8usl$[e-mail]> <4mavg8$[e-mail]> <[e-mail]> <4megu5$[e-mail]> <4mksr7$[e-mail]> <4mped3$[e-mail]>

Good answer, Jack!  Well phrased, and to the point.  Your conclusion seems to
be that coax feedline radiation is not necessaraly 'bad', but seldom is good.
If you read Cecil's reply to me, you also read that his original statement
about
it being a 'mortal sin' was a jest aimed at the purists who expound theory
without truly understanding what they are talking about. :)
I think I like your answer better than any I have heard yet!



From [e-mail] Sun May 12 18:02:37 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Very small Antennas
Date: 8 May 1996 18:29:28 GMT
Message-ID: <4mqp68$[e-mail]>
References: <[e-mail]>

Doug Person ([e-mail]) wrote:

: Now I want to reduce a 40 meter antenna to about 25 ft.  That's all the spac
e I
: have, if I want 40, it must fit in the 25 foot available in the attic.  I gu
essed
: lucky with the 20.  How can I calculate the loading coils for the compact 40
?
: I made one using aluminum tubing and fiberglass coil forms hoping to have so
mething
: I can run my 600 amplifier into.  My guess was way off - 16ft #14 on 1.25od
form and
: about 10 ft of 1" tubing per leg - resonates at 9.745.  I can continue to mo
dify
: deminsions until I get it right - but that is a a lot of attic climbing.  An
y
: suggestions?

Yes, my standard reference for just this sort of thing is an old "Ham
Radio" magazine article by Joseph Boyer, "The Antenna-Transmission Line
Analog."  It was in the April and May, 1977, issues.  It goes into exactly
how to make good engineering-accuracy calculations of loading coils
anywhere along the antenna, and gives you a lot of appreciation for how
linear antennas work, and why one loading-coil position is better than
another.  Since you likely will have trouble finding these issues of
Ham Radio, I have a standing offer to send photocopies of the article
for a SASE and photocopy costs.  It's 24 pages, including some relevant
pages of one of the references which plots antenna impedance versus length
and wire diameter (necessary info to fully use the Boyer article).  Send
me email if interested.


(Design of very short vertical + matching network deleted.)

: Here's the bottom line:  I have no education in this stuff.  I'm just guessi
ng at what works.
: Does this really do something or am I just tuning a coax longwire?  Can I do
 anything to improve
: this concept?  Anyone have suggestions, thoughts, ideas, anything at all the
y wish to contribute?

I'm impressed that it looks like basically a pretty decent design for easy
duplication by hams.  Things to consider:  the feedpoint impedance of a
very short antenna is a very small resistance in series with quite a bit of
capacitive reactance.  That means you need a lot of current to get
radiation (from the low resistance), and a high voltage, to get the current
through the capacitive reactance.  It's hard to make a low loss matching
network for that; pay attention to anything that will be lossy.  Look up
info on optimum coil geometry.  Avoid insulations at the high impedance
points which might be lossy (hint:  Teflon or polystyrene are much, much
less lossy than Nylon).  Provide _some_ kind of reasonably low loss
ground system (several heavy radial wires across the roof?), and make the
actual antenna radiator as long as you can (to raise the resistance) and
as large diameter as you can (to cut losses from the high current flowing
on the surface of the antenna).  (Another hint:  the matching network, if
it's low loss, will be rather high Q, which implies narrow bandwidth.  If
you are getting much bandwidth, it's a clue that you have a lot of
losses besides the radiation from the antenna...)

I'd like to encourage you to keep learning.  You are making some good
early guesses, and with some understanding behind the guesses, you will
probably come up with some really neat -- and reasonably efficient --
designs.

--
Cheers,
Tom
[e-mail]


From [e-mail] Sun May 12 18:02:38 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Very small Antennas
Date: Thu, 09 May 96 09:25:09 GMT
Message-ID: <4msdjf$[e-mail]>
References: <[e-mail]> <4mqp68$[e-mail]>

In article <4mqp68$[e-mail]>,
   [e-mail] (Tom Bruhns) wrote:

> [lots of excellent advice]. . .

>. . . (hint:  Teflon or polystyrene are much, much
>less lossy than Nylon). . .

I was looking in some references recently for other low-loss materials, and
polypropylene looks from the specs to be very good also. And it has a
relatively low dielectric constant. One big minus is that it's very
susceptible to UV deterioration, so I wouldn't use it outside for an
extended period unless you can keep the sunlight off of it. Does anyone
have any experience with it as a high-quality insulator or have any
information that would confirm or refute the premise that it's good?

(This is the stuff you can buy at any discount store as "floating rope".)

Roy Lewallen, W7EL


From [e-mail] Sun May 12 18:02:40 1996
From: [e-mail] (Graham Seale)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Very small Antennas
Date: Thu, 09 May 1996 20:38:39 GMT
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

In message <[e-mail]> Doug Person wrote:

> I have made a 20 meter dipole that is 22 ft instead of the usual 33 ft to
> fit between two conveniently located trees.  This gives me a second antenna
> for 20, 90 degrees from the original favoring north/south signals.  I used s
ome
> pvc pipe and about 8 ft of #14 insulated stranded wire close wound to make a
> loading coil for each leg - mounted more or less in the legs center.  With 1
00
> watts it works great.  SWR on the full size 20 is under 2:1 edge to edge. On
 the
> loaded 20 I loose about 100 khz of bandwidth and otherwise find it comparabl
e.

Hi Doug

Before you get too entangled in dissipating the highest current
contributions from your antenna in loading coils, try a very simple
approach. An antenna shorter than resonance will still deliver
radiation energy, but will appear capacitive at the feedpoint. To
match a feed to it you need to add inductance to tune out the
capacitive component leaving you with something like a unity power
factor. This "matcher" is your loading coil.

My instinct would be to duck the need for such lossy narrow band
things. I would leave the full 33ft of wire in the dipole, but
arrange the middle 22ft to be horizontal, and let 5.5 feet dangle
down vertically at each end. If this be inconvenient, then fold
back the 5.5 foot dangly into a loop back to the support insulator.
Do not let the high voltage end connect back to support point.

The idea is to force the current to go the distance down the wire
the full 33ft. The folded back bit is the beginnings of an *end*
loading coil, and will affect the resonant length a bit, but we
resist madly making it any more of a loading coil than we absolutely
have to. This way, you only mourn the loss of the very little
contributions from the ends. If they dangle down, they provide a
little vertical component. If you fold them back, the folded part
cancels some in the descending part anyway.

In practice you will probably find you can fold up the ends of a
resonant dipole with very little effect on the tuning, but do it as
you would any new dipole - start with a bit extra splaying off the
ends, and tune it to resonance by cutting off some inches each side
and checking the resonance with a dip meter/noise bridge or somesuch.

73's G4WNT

--
Graham Seale


From [e-mail] Sun May 19 13:42:55 1996
From: [e-mail] (Parf)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: "Patch" Antennas?
Date: 11 May 1996 22:09:14 -0400
Message-ID: <4n3h8a$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (Parf)

The antenna you describe sounds more like a bogner. It used disc parasites
and a traditional horn exciter w/ a 1/4 W probe.
The patch antenna was in QST- December issues have a yearly index.

73,  Dale WA2YPY


From [e-mail] Sun May 19 13:42:56 1996
From: Shabanov Sergey <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: 2.4 GHz antennas
Date: 8 May 1996 12:38:34 GMT
Message-ID: <4mq4ka$[e-mail]>

Help anybody!

Where I can buy hi-gain (over 11dB) omni-directional
trans-rec. antenna for WaveLAN 2.4 GHz?


Sergey Shabanov
Rosnet-International


From [e-mail] Sun May 19 13:42:57 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: Wed, 08 May 96 16:11:57 GMT
Message-ID: <4mql67$[e-mail]>
References: <4mq4ka$[e-mail]>

Post / CC by Mail

   Shabanov Sergey <[e-mail]> wrote:

>Help anybody!
>
>Where I can buy hi-gain (over 11dB) omni-directional
>trans-rec. antenna for WaveLAN 2.4 GHz?
>
>
>Sergey Shabanov
>Rosnet-International

Andrew Corporation sells omnidirectional transmit antennas for MMDS
(2.5 - 2.7 MHz) and MDS (2.1 MHz) that meet this specification.  I'm
sure they can provide one tuned for 2.4 GHz.  Roughly speaking, these
antennas sell for approximately $10,000.

Andrew Corp. (U.S. callers): 800-255-1479

73,
Jack  WB3U


From [e-mail] Sun May 19 13:42:58 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: 10 May 1996 17:50:06 GMT
Message-ID: <4mvvke$[e-mail]>
References: <4mq4ka$[e-mail]> <[e-mail]>

>Maybe antenna theory has advanced beyond me.  To show 11dB of gain over
>any lossless omni-directional system and remain omni-directional seems
>beyond the physics of passive systems.  You will have to use amplifiers.


Tony,

Look how the term "omnidirectional" is defined: it commonly refers only
to the azimuth. If you squash the pattern's elevational extention,
you have an omnidirectional antenna with gain.

Unlike many amateur (mystery) desighns, e.g. minibeams, ground planes
without ground plane  et.c, they are widely used in commercial
applications and work.

73, Moritz DL5UH




From [e-mail] Sun May 19 13:42:59 1996
From: [e-mail] (J. L. Blanton)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: Sat, 11 May 1996 11:48:48 -0800
Message-ID: <[e-mail]>
References: <4mq4ka$[e-mail]> <[e-mail]> <4mtfa8$[e-mail]> <[e-mail]>

In article <[e-mail]>, [e-mail]
wrote:

> Perhaps you live in a two-dimentional world.  The array you described
> sounds very far from omni-directional to me.

For many practical applications the world IS two-dimensional, unless you
need to communicate with aircraft or satellites.  An omni antenna in
azimuth can certainly have gain.

Lee, WA8YBT/6


From [e-mail] Sun May 19 13:43:00 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2m/70cm base station antenna
Date: Mon, 13 May 1996 02:22:00 GMT
Message-ID: <4n7ckd$[e-mail]>
References: <[e-mail]>

[e-mail] wrote:

>Hi,

>I have tried to find an article with information about
>building a 70cm/2m base station gp-antenna. What I am
>after is an omnidirectional system with a considerable
>gain over 1/4lambda gp and that needs only one coax.
>Diamond has many different models on market but how to
>build one yourself?

>Anyone can help me with this?

>Hannu/OH6MAZ
>[e-mail]

Have you thought of using a multiband j-pole.  They're very easy to
build and you can find the design in recent ARRL handbooks.  Check
them out at your nearest library.

David, N3NGB
 P.S.  I have measured the gain of my two meter j-pole to have 6db
gain over a 2m ground plane.




From [e-mail] Sun May 19 13:43:01 1996
From: [e-mail] (Ross Alexander)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2m/70cm base station antenna
Date: 13 May 1996 18:51:14 GMT
Message-ID: <4n80b2$[e-mail]>
References: <[e-mail]> <4n7ckd$[e-mail]>

>[e-mail] wrote:

>>Hi,

>>I have tried to find an article with information about
>>building a 70cm/2m base station gp-antenna. What I am
>>after is an omnidirectional system with a considerable
>>gain over 1/4lambda gp and that needs only one coax.
>>Diamond has many different models on market but how to
>>build one yourself?

>>Anyone can help me with this?

>>Hannu/OH6MAZ
>>[e-mail]

Your requirements are stringent, aren't they?  You are asking
for

        dual banded
        ground plane
        omnidirectional
        significant gain (which I choose to mean "+6dBd".)
        vertical polarization (this is implicit in the reference to Diamond)

Discarding the "ground plane" requirement as irrelevant, about the
only thing that fits the bill is a pair of colinears sharing a
feedline.  Get a plan for a 2m colinear, build it, then multiply all
the dimensions by 146/435 and build another.  Use a duplexer to split
the feed if necessary.

regards,
Ross ve6pdq
--
Ross Alexander, ve6pdq  --  [phone]  --  [e-mail]


From [e-mail] Sun May 19 13:43:03 1996
From: [e-mail] (eric_augenstein)
Newsgroups: rec.radio.amateur.antenna
Subject: 3-band scanner antenna
Date: 14 May 1996 10:04:25 GMT
Message-ID: <[e-mail]>

Hi all,
I`m a scanner-freak with no money,for my job (TV-news editor) I need a base
antenna like a discone.
Does anybody have the measurement`s to build it myself ????
Thanx
Jim Wilson
[e-mail]


From [e-mail] Sun May 19 13:43:03 1996
From: Wayne Shanks <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 3-band scanner antenna
Date: Tue, 14 May 1996 13:44:31 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>
To: eric_augenstein <[e-mail]>

eric_augenstein wrote:
>
> Hi all,
> I`m a scanner-freak with no money,for my job (TV-news editor) I need a base
> antenna like a discone.
> Does anybody have the measurement`s to build it myself ????
> Thanx
> Jim Wilson
> [e-mail]


The ARRL antenna handbook hase formulas and data tables for just such a
thing.  Try the local publick library

Wayne S


From [e-mail] Sun May 19 13:43:04 1996
From: Lennart Nilsson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 80/40/15mtr para dipole
Date: 18 May 1996 14:31:35 GMT
Message-ID: <4nkn07$[e-mail]>
References: <4n6jar$[e-mail]>
To: [e-mail]

[e-mail] wrote:
>Has anyone had any experience at building an 80/40/15 mtr parallel dipole (wh
ere the 40 meter radiator doubles as a 15 mtr radiator=
). Any advice as to feedlines and
>lengths would be appreciated. Thanks.

I have used parallell dipoles for 80 and 40 m with the ends of
the shorter dipole spaced about 3 meters from the longer one. I
had to make the 80 m section longer than calculated and the 40 m
section shorter. Resonance frequencies will depend on how much
spacing you allow between the dipoles, so it is a cut and try
process to tune it. The best feedline is 75 ohms coax or
twinlead. On 15 m resonance will be at the high end of the band.
You can lower it by adding small wires hanging down from the 40 m
antenna wire at the voltage maximum, which should be about 3,5 m
from the center insulator. This hardly affects 40 m resonance.
73 de Lennart, SM5DFF.




From [e-mail] Sun May 19 13:43:05 1996
From: Ewan Ross McLeod <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 80mtr loop (cloud warmer)
Date: 17 May 1996 10:09:08 GMT
Message-ID: <4nhj84$[e-mail]>
References: <4ngmqn$[e-mail]>
To: [e-mail]

Yes, plenty experience with antenna type u mention.
For regional comms out to 300-400km mount 1/4 wavelength off real gnd.
That might be asking too much but closer to ground increases gnd losses
but has trade-off of reduced pick-up of manmade noise.  We frequently
just lay it out across the top of dry grass abt 1mtr off gnd and they
perform well.  Also more immune to skewing from ionosphere so less fading
through cross polarisation than with dipoles.
73s
Ewan



From [e-mail] Sun May 19 13:43:06 1996
From: Edward Lawrence <eal>
Newsgroups: rec.radio.amateur.antenna
Subject: Aluminiun Foil for Apartment Ground Plane?
Date: 17 May 1996 11:24:49 GMT
Message-ID: <4nhnm1$[e-mail]>

Ok, This may indeed be a 'wild hair'.  Has anyone tried putting
Aluminum foil UNDER the carpet in an upper story apartment to  act as a local
HF ground plane?  It looks like I am going to be stuck in apartments for a few
years, and I would like to get a decent antenna in an apartment.

Can anyone recommend a good book on apartment antennas?   WA5SWD



From [e-mail] Sun May 19 13:43:07 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Tuner Baluns
Date: Wed, 08 May 96 02:20:46 GMT
Message-ID: <4mp4fl$[e-mail]>
References: <4mm0v0$[e-mail]>

Post / CC by Mail

   Jonathan Helis <[e-mail]> wrote:

>Currently, I am using an antenna tuner that is a homebrew L-C network
>with a single wire input.  It was designed for end-fed single wire
>antennas.  I would like to make a 4:1 balun for this tuner so I can
>feed it with twinlead.  How to wind a balun is in the ARRL Handbook.
>It looks easy, but I can't find anything suitable to wind it on.
>
>The Amidon catalog has tordoids in it like the diagram in the ARRL
>Handbook.  Has anyone ever done anything like this?  What were your
>results?  I plan to run not more than 100 watts out of a Kenwood
>TS-140S, into a small loop.

Hi Jon,

First, there are two spreadsheets on my FTP site that might help
you design a balun if you have Excel 4.0 for Windows or something
compatible.  The files are labeled Toroid.xls and Flux2.xls.  The
FTP site is:  ftp.microserve.com/popaccts/h/jackl/

The general rule of thumb when using Toroid.xls is that the the total
XL of the winding should be four to five times the impedance of the
circuit.  Also, for toroids at the FT-240 size, the number of turns
should probably be limited to ten or twelve to avoid excessive inter-
winding capacitance.  Finally, one of the best baluns consists of
bifilar turns, wound on the toroid in a manner that creates a current
balun.  In this configuration, each winding is in series with one
conductor of the line.

That said, a balun needs to be used in a circuit that presents the
input and output impedance the balun is designed for, within
reasonable limits.  Although the type of system you're planning is
widely used, it doesn't meet that qualification.

In order to assure balance and maximum transfer of power, you will
need to use either A) a balanced tuner like a Match Box instead of
the balun, or B) a technique employing variable line length with a
tunable (simple) L/C network ahead of the balun.  The latter will
present the balun with a non-reactive load near its desired load
impedance.

Cecil Moore (KG7BK) has posted quite a few articles here regarding
the latter technique and has written application notes.  Those notes
are being published by the company that makes the "Ladder Lizard", an
inexpensive device for determining SWR, impedance and power on ladder
line.  The company's name is TechnoLogic Concepts and their e-mail
address is:  [e-mail]

You might want to write and see if the notes are available yet.
Maybe Cecil will jump in here with more details.  ;)

73,
Jack  WB3U


From [e-mail] Sun May 19 13:43:08 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Tuner Baluns
Date: 7 May 1996 22:07:02 -0700
Message-ID: <4mpa5m$[e-mail]>
References: <4mm0v0$[e-mail]> <4mp4fl$[e-mail]>

[e-mail] (WB3U) wrote:
>You might want to write and see if the notes are available yet.
>Maybe Cecil will jump in here with more details.  ;)

Hi Jack, as far as I know, Don, KE6AJH, has information ready
to email and is ready to ship. Just don't believe him when he
says the Ladder-Lizard is better than sex. :-)

I might explain the final solution (hi hi) here at my QTH. On
a transmission line a little bit closer to the transmitter from
the current maximum is what I call the PC point, where a single
parallel capacitor will cause a Z0 match. If it happens at the
transmitter, Z0 = 50 ohms and I call it the PC-50 point. So at
the transmitter, I have a 20-200pf variable cap with the ability
to switch in other fixed capacitors (thanks Tom). Capacitors are
the only reactances that I use to achieve a 1:1 SWR on all
frequencies on all HF bands. No lossy coils. How is it possible?

If you can't bring the capacitor to a current maximum, then bring
the current maximum to the capacitor. Outside my shack window, I
have three relays that switch in 32 ft, 16 ft, and 8 ft sections
of ladder-line. In the same box with my variable capacitor, I have
three switches that will switch in 4 ft, 2 ft, and 1 ft sections
of ladder-line. It's easy to see that I can vary my transmission
line by 76 to 76+63=139 ft. I always use the shortest possible
amount of transmission line to cut down on losses.

That's my ultimate (so far) balanced matching system.

73, Cecil, KG7BK (W6RCA soon), OOTC




From [e-mail] Sun May 19 13:43:09 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Tuner Baluns
Date: 11 May 1996 17:56:16 GMT
Message-ID: <4n2kc0$[e-mail]>


Cecil said -
Of course, I realize this is the old stub-matching approach that my
Elmer taught to me 45 years ago. But everything has come together
in an easy-to-implement fashion. The only reason that I can think
of why this is not the most popular matching system for balanced
lines is people don't know about it or don't realize how easy it
is to implement. I didn't mean to imply that this was anything new.

Cecil,
        The same can be said about the Series Section Tranformer.
some seem to think of only the quarter wave section which only
by chance yields a required input impedance for a given termination
and small choices of available line Zo.  The series section
transformer can use often available line Zo to get a wider range
of impedances of input and termination.

Charlie, W7XC
--


From [e-mail] Sun May 19 13:43:10 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna Tuner Baluns
Date: 13 May 1996 14:46:01 -0700
Message-ID: <4n8aip$[e-mail]>
References: <4n2kc0$[e-mail]>

CHARLES J. MICHAELS <[e-mail]> wrote:

:         The same can be said about the Series Section Tranformer.
: some seem to think of only the quarter wave section which only
: by chance yields a required input impedance for a given termination
: and small choices of available line Zo.  The series section
: transformer can use often available line Zo to get a wider range
: of impedances of input and termination.

Hi Charlie, think about a variable length series section
transformer and what one could do with it.

------------------------------------------------------------------------------
-
73, Cecil                                 __  __     ____  ___       ___ ____
[e-mail]                       /__)/__) / / / / /_  /\  / /_    /
                                        /   / \  / / / / /__ /  \/ /___  /
------------------------------------------------------------------------------
-


From [e-mail] Sun May 19 13:43:11 1996
From: [e-mail] (Richard Lutz)
Newsgroups: rec.radio.amateur.antenna
Subject: AS 1181 UR  Millitary antenna
Date: 8 May 1996 22:11:26 GMT
Message-ID: <4mr66e$[e-mail]>

Sure would like to know the specs on this one, looks like:  abt 6 in diameter,

4 foot long tube of fiberglass with a stacked set of tuned tubes inside. it
checks out well at 146.00  at about 1.6 swr but I wold like to know more.
thanks in advance for any e mail or post back here..

73... KD4SEV

[e-mail]



From [e-mail] Sun May 19 13:43:12 1996
From: [e-mail]  (Jim Reisert AD1C)
Newsgroups: uk.radio.amateur,rec.radio.amateur.antenna,rec.radio.amateur.misc
Subject: Re: Beam Heading Info
Date: 11 May 1996 15:30:42 GMT
Message-ID: <4n2br2$[e-mail]>
References: <[e-mail]> <4mi8fo$[e-mail]> <4mn2gt$[e-mail]>
Reply-To: [e-mail] (Jim Reisert AD1C)

E-mail me your latitude and longitude and I'll send you a printout in return
E-mail.

73 - Jim AD1C

--
Jim Reisert <[e-mail]>
http://www.tiac.net/users/ad1c/



From [e-mail] Sun May 19 13:43:13 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (David Feldman)
Subject: Re: Best Antenna for Apartment ?
Message-ID: <[e-mail]>
References: <4mluht$[e-mail]> <[e-mail]>
Date: Wed, 8 May 1996 15:57:17 GMT

In article <[e-mail]> Zack Lau <[e-mail]> writes:
>Chris Valliant wrote:
>>
>>         I live in a small apartment, but the landlord won't let me put an
>> antenna on the roof. Does anyone know of a good antenna that I can mount
>> on the window sill ? I have thought about putting up one without his
>> knowledge, but that wouldn't be right. Any idea's would be greatly
>> apreciated. Oh yea, this is for the 10 M band (forgot to add that in).
>
>The 10M band isn't in the best shape for DXing at this part of the
>sunspot cycle, though you can work some surprising contacts if you
>are patient and don't mind days on end without useful propagation.

Try 75! I lived in an apartment in Southern California. _I_ didn't bother
telling the landlord... I ran about 120' of fine guage wire out the window
to the parking garage across the alley. Ran a KW phone. Lots of fun except
when the window sill caught on fire a few times. Never did tell the landlord.

All in fun, you see...

73 Dave WB0GAZ [e-mail]


From [e-mail] Sun May 19 13:43:14 1996
Distribution: world
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Big DK3
From: [e-mail] (Randal Olds)
Message-ID: <[e-mail]>
Date: Thu, 16 May 1996 06:37:00 -0640

EL>Yes.  I have on on my Dodge Caravan, but have replaced the 66 inch whip wit
h
EL>a 102 in whip.  Works better.  If you have a copy of the construction artic
l
EL>I
EL>would appreciate a copy, as I have mis-placed mine, and others want to buil
d
EL>one.  E-mail me if you have it, and I will send a SASE.

Yes I have a copy of the article.
I made one of the screwdriver antennas, 2" copper pipe, Mounted on a
1992 ford aerostar van. It didn't work well on 10m or 75m bad swr. I
used the (1000pf adj) on 75m and (500pf adj) on 40m. It did put out a
nice signal on 20m and 40m, lots of good reports. I'm in the process of
making a smaller version to cover 10-40m, out of 1-1/4 and 1-1/2 copper
pipe. I also found a place in NY that has a 64-1 gear reduction 12Vdc
motor, found it in NUTS & VOLTS mag.. This motor is much smaller than
the screwdriver. I just hope it has enough power for the job.

KD8NV
---
 * SLMR 2.1 * ScrewDriver antennas = BIG signal


From [e-mail] Sun May 19 13:43:17 1996
From: "William E. Sabin" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Coax cable shielding - Help please
Date: Sun, 12 May 1996 11:13:25 -0700
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]>

William E. Sabin wrote:
>
> >When the bottom end of the coax (underneath the groundplane) is fed to
> >an analyzer the output is in the region of -40 to -60 dBm maximum
> >(falling with increasing frequency, and with many notches falling
> >into the noise floor).
>
> The outside of the shield of the coax has an electric field induced
> along its length which is "induced" by the antenna. A "boundary
> relation" in electromagnetics says that an electric field that is
> tangential to the boundary between two regions is the same in both
> regions. This means that if the coax is perfect the same electric field
> exists on the inside of the shield, inside the dielectric and also on
> the center conductor of the coax.  If the coax were perfect, the voltage
> measured at the analyzer and also at the 50 Ohm termination would be
> zero because the two E fields would cancel perfectly. But because of
> dielectric and other imperfections the cancellation is not complete.
> Even a solid shielded coax would behave the same way, but maybe with
> less imperfection.
>
> Bill


Followup from Bill:

I set up an experiment to test the explanation that I presented. I will
describe the experiment:

1) I used a piece of 50 Ohm coax 3 feet long.
2) The left end has terminal SL (shield left) and CL (center lead left)
3) The right end has terminals SR and CR.
4) Connect a 10 MHz sig gen, hot lead to SL, Gnd lead to SR. This
   establishes an electric field and a current along the braid of the
   coax.
5) Connect a 50 Ohm voltmeter between CR and SR. This is the analyzer
   that was mentioned.
6) Connect a 50 Ohm resistor between CL and SL. This is the top-end
   termination that was mentioned.
7) Measure the voltage between SR and CR. It was 40 dB below the sig gen
   voltage. There is almost no current flow in the center lead.
8) Disconnect the 50 Ohm resistor that is between SL and CL. The
   voltmeter reading now becomes just a few dB less than the sig gen
   voltage. This voltage is due to capacitive coupling.
9) Re-connect the 50 Ohm resistor between SL and CL.
10) Because the sig gen current flows only on the braid, its H field
   exists *only* on the outside of the coax and not inside. Therefore
   the coupling to the center wire is due entirely to the electric field.
11) The electric field on the shield and the electric field on the center
    lead *cancel* both at the voltmeter and at the termination.
12) This situation is exactly like the direction finder loop. The braid
   of the coax does not constitute a "shorted turn", therefore it is
   transparent to the electric field.

Bill


From [e-mail] Sun May 19 13:43:18 1996
From: "William E. Sabin" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Coax cable shielding - Help please
Date: Thu, 16 May 1996 18:20:00 -0700
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>

Graham Seale wrote:
>
> In message <[e-mail]> "William E. Sabin" wr
ote:
>
> > I also have a suggestion. If you can find some RF absorption material to
> > wrap around the coax, I believe that would be more helpful than anything.
> > The additional screen sounds to me like a non-solution.
>
> Hmm.. Yes, I agree it can help. In my case the only materials allowed in
> were expanded polystyrene because the carbon-loaded "Transorb" started to
> smoke.
>
> I still believe the Faraday shield is too effective to be ignored, even if
> there are some structures that (confusingly) appear not to be shielded.
>
> A copper shield (pipe say) with its base set onto the grounded metal wall,
> forces a boundary condition. You cannot measure any e-fields within the pipe
> more than a couple of diameters from the open end, (unless you get to
> frequencies where the hole diameter is a viable aperture). Just because you
> put a coax up it is not going to change things. If you let the terminated
> end stick out clear into the chamber, you will pick up something.
>
> As far as I know, this is because no part of the coax is expected to help
> the walls of the chamber enforce the boundary condition. Even without a
> "outer Faraday shield", a coax does quite well provided you take care to
> keep it isolated from the "ground".
>
> A more serious problem is the severe distorting effect the shield would
> have to the field inside the GTEM. In this case, absorber seems to have
> clear advantages.
>
> 73's G4WNT
>
> --
> Graham Seale


Thank you for your comments,Graham, and your ideas are certainly worth
tryimg.

Bill


From [e-mail] Sun May 19 13:43:19 1996
From: Richard Kiefer <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Coax or 450 ladder line
Date: Wed, 08 May 1996 20:16:56 -0700
Message-ID: <[e-mail]>
References: <19960506134557504.AAA74@LOCALNAME>

Gary Bishop wrote:
>
> I plan on building a 1/2 dipole for 12, 17, and 30.  Going to have different
> wire
>
> lengths for each of the bands ie: 1/2 wave per band.  Is there an advantage
in
>
> using ladder line over coax or vice versa.   Thank you.
>
> Brian Sarkisian   KG8CO   e-mail:    [e-mail] Brian,

I think you should definately use coax.  I have found the commonly
available ladder line to be VERY lossy with measurments on my HP network
analyzer.  Much more lossy than good quality coax.  I do not know why
everyone thinks balanced transmission line is so great.  In addition,
coax is probably more quiet, or less likely to pick up local magnetic
coupled noise from computer monitors, motors, microprocessors in
household applicances, etc.  You can probably get away without a balun if
you bring the coax off the center in a symetrical manner and do not have
to much stuff around the antenna.  Good luck.

Dick Kiefer, K0DK


From [e-mail] Sun May 19 13:43:20 1996
From: [e-mail] (J. L. Blanton)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.space
Subject: Coaxial and/or Counterwound Helix Antennas
Date: Wed, 08 May 1996 22:42:30 -0800
Message-ID: <[e-mail]>

I'm thinking about building some circularly polarized antennas for Oscar
use (145 & 435 MHz).  Has anyone tried installing a 435 MHz helix
coaxially inside a 145 MHz helix?  Or would there be too much interaction?

In a related question, has anyone tried building counterwound helices for
the same frequency band on a common framework for left and right circular
polarizations (but separately fed, of course)?

If anyone can point me to some references in these two areas I'd really
appreciate it.  Thanks.

Lee, WA8YBT/6


From [e-mail] Sun May 19 13:43:21 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.space
Subject: Re: Coaxial and/or Counterwound Helix Antennas
Date: 10 May 1996 07:01:14 GMT
Message-ID: <4mupjq$[e-mail]>
References: <[e-mail]>

>In a related question, has anyone tried building counterwound helices for
>the same frequency band on a common framework for left and right circular
>polarizations (but separately fed, of course)?

Lee,

For the same amount of material / weight / wind load a cross yagi
is better.

73, Moritz DL5UH



From [e-mail] Sun May 19 13:43:22 1996
From: Rich Griffiths <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Code Speed Change:  Help Needed
Date: Sat, 11 May 1996 12:13:21 -0400
Message-ID: <[e-mail]>
References: <4n0ick$[e-mail]>

[e-mail] wrote:
<snip>
>
>         I propose that the only code speed requirement for Hams in the
> U.S. be 5 wpm.<snip>

I surely don't want to see this happen.

And why is this item cluttering the antenna newsgroup?
There's already a newsgroup dedicated to policy.

Rich   W2RG


From [e-mail] Sun May 19 13:43:23 1996
From: [e-mail] (robert bowman)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Code Speed Change:  Help Needed
Date: 14 May 1996 04:58:25 GMT
Message-ID: <4n93th$[e-mail]>
References: <4n0ick$[e-mail]>

In article <4n0ick$[e-mail]>, [e-mail] says:
>        I propose that the only code speed requirement for Hams in the
>U.S. be 5 wpm.  Classes of hams could still be distinguished by
>different levels of written tests.
>Is anyone interested in helping me put together such an effort before
>the F.C.C.?

Len Winckler, of _Ham Radio and More_ fame, flogged this horse on his
program. at last report, he had about 200 responses. either nobody is
interested, or nobody listens to his program.


From [e-mail] Sun May 19 13:43:23 1996
From: [e-mail] (FORREST GEHRKE)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Communications Quarterly
Message-ID: <[e-mail]>
Date: Wed, 15 May 96 13:16:00 -0300
Distribution: world
Reply-To: [e-mail] (FORREST GEHRKE)
References: <4n6bfd$[e-mail]>

JM> I've seen this pub referred to by several people ion the list, would
JM> someone please give me an address?  I think I want to see about a
JM> subscription.

Terry Littlefield, Editor
Communications Quarterly
P.O. Box 465
Barrington, NH 03825

Tell her I sent you! ;-)
--k2bt

 * RM 1.3 02583 * Win'95 fixpak #1:13 disks+new drivers (also known as "os/2")


From [e-mail] Sun May 19 13:43:25 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Thu, 09 May 1996 00:13:56 GMT
Message-ID: <4mrdb5$[e-mail]>
References: <4mg9ar$[e-mail]> <4mlflb$[e-mail]> <[e-mail]>

Jake Brodsky <[e-mail]> wrote:

>[e-mail] wrote:
>>
>> Jack,
>>
>> I *HAD* a mole problem.  I rectified it with several cheap
>> battery-powered AM radios.
>>
>> #1 Tune them to a local rock station with a good signal.
>>       (needs to be rock-n-roll, moles like classical and country)
>> #2 Turn 'em up fairly loud.
>> #3 Stick 'em in heavy plastic bags.
>> #4 Bury them where you have the problem.
>>
>> The batteries usually last a week or more, and by then the moles
>> have "moved on" to greener pastures.  Sounds silly, but it works!
>>
>> Bill Young
>> [e-mail]
>> KB0UZQ

>Where are the smileys?  Assuming the small chance that you're serious,
>have you tried this? What did your neighbors think?  And please tell
>us what gave you the notion to try such a silly thing!  I wonder if
>People for the Ethical Treatment for Animals has anything to say about
>this... :->

>Jake Brodsky, AB3A, <[e-mail]>
>"Beware of the massive impossible!"


I was fighting gophers (not the Minnesota type) for a long time.  PETA
found out that I has caused the demise of some small number of these
critters and have forced me to pay retribution.  This comes in the
form of gopher food, scientifically tested for flavor and growth
advantage,

Now the gophers walk into the house and demand fresh cut veggies and
Iced tea (Arizona style).  Getting hard to cope.....



           C. Dean Norris
      Amateur Radio Station K7NO
      e-mail to [e-mail]
    http://www.syspac.com/~dnorris/



From [e-mail] Sun May 19 13:43:28 1996
From: aor <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Wed, 08 May 1996 12:19:29 -0400
Message-ID: <[e-mail]>
References: <4mg9ar$[e-mail]>

WB3U wrote:
>
> Lately, I've been thinking about stringing a wire vertical from
> a tree and installing a good radial system underneath.  However,
> there's a wildlife problem that's threatening to thwart my plans.
>
> During the last two winters, I have been beseiged by an invasion
> of moles.  The runners they create in the yard and the many mole
> hills make it impossible to consider radials.  I still have to
> cut what's left of the grass, and there's no question that the
> moles' activity will push any wires I install up to the surface.
>
> So far I've tried the following with little or no success:
>
>     Smoke bombs and poison pellets designed for this purpose
>     Traps designed to kill the mole when it tunnels underneath
>     Flooding the tunnels with a garden hose
>     Filling the tunnels with exhaust fumes from my car
>     900 VAC at 1 Amp delivered into the ground by aluminum stakes
>       placed 20 feet apart
>     Elmer Fudd impressions (lawn chair and shotgun)
There has been significant modeling which shows
that an elevated radial system of 4-6 wires up can
give you the same performance as a 64 burried wire
field.  On 80 meters, the radials need only be up
15' feet, slightly less for the higher bands.  The
radials are tuned, (ie 1/4 wave + 5%), and you have
have multiple bands.

I do not know what your tree-field looks like, but
4-6 elevated radials up 10' or so may fit the bill,
and keep the critters at bay!!!

73,

Al NW2M


From [e-mail] Sun May 19 13:43:30 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: Thu, 09 May 96 13:05:00 PDT
Message-ID: <[e-mail]>
References: <4mg9ar$[e-mail]>  <4mlflb$[e-mail]>


In Article<4mlflb$[e-mail]>, <[e-mail]> write:
> Path: li.net!news5.ner.bbnplanet.net!news.ner.bbnplanet.net!howland.reston.a
ns.net!news.cac.psu.edu!news.math.psu.edu!chi-news.cic.net!news.suba.com!news
> From: [e-mail]
> Newsgroups: rec.radio.amateur.antenna
> Subject: Re: Critters
> Date: 6 May 1996 18:16:11 GMT
> Organization: Suba Communications
> Lines: 17
> Message-ID: <4mlflb$[e-mail]>
> References: <4mg9ar$[e-mail]>
> NNTP-Posting-Host: 206.29.114.19
> X-Newsreader: SPRY News 3.03 (SPRY, Inc.)
>
> Jack,
>
> I *HAD* a mole problem.  I rectified it with several cheap
> battery-powered AM radios.
>
> #1 Tune them to a local rock station with a good signal.
>       (needs to be rock-n-roll, moles like classical and country)
> #2 Turn 'em up fairly loud.
> #3 Stick 'em in heavy plastic bags.
> #4 Bury them where you have the problem.
>
> The batteries usually last a week or more, and by then the moles
> have "moved on" to greener pastures.  Sounds silly, but it works!
>
> Bill Young
> [e-mail]
> KB0UZQ

Be careful - I tried this once - it did eliminate the moles, but I found
my lawn infested with teenagers...  :-)

KD2FT



From [e-mail] Sun May 19 13:43:31 1996
From: [e-mail] (Larry M. Weissman, X6946)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Date: 8 May 1996 21:40:43 GMT
Distribution: world
Message-ID: <4mr4cr$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

John D. Farr wrote:

> I have a cat that has developed a taste for moles.  I have no problems
>with them like some of my neighbors.  Best of all, my cat brings me the
>best parts!

>73, John

Can I rent your cat for a weekend John?

Larry - AD3Y


From [e-mail] Sun May 19 13:43:32 1996
From: [e-mail] (FORREST GEHRKE)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Critters
Message-ID: <[e-mail]>
Date: Wed, 15 May 96 13:21:00 -0300
Distribution: world
Reply-To: [e-mail] (FORREST GEHRKE)
References: <4n6bfd$[e-mail]>

RL> Get yourself an "Out-O-Sight" brand mole trap or clone. It's shaped
RL> like a couple of horseshoes spring-loaded together. I've used one
RL> for years, and trapped a couple of dozen moles with it. It has never
RL> failed to catch a mole. (Occasionally one will trip the trap without
RL> being caught but I get 'em eventually.)

The Animal Rights people have you in their sights! ;-)

--k2bt

 * RM 1.3 02583 * OS/2: too powerful to be Windows, too easy to be Unix


From [e-mail] Sun May 19 13:43:33 1996
From: [e-mail] (Jim Flanders)
Newsgroups: rec.radio.amateur.antenna
Subject: DDRR antenna - reference: RE flagpole antennas
Date: 16 May 1996 15:36:13 GMT
Message-ID: <4nfi1d$[e-mail]>

When I answered the article - flagpole antenna - many people emailed
me with a question on what is a DDRR antenna. See ARRL Antenna manual
page 6-9.DDRR is short for Directional Discontinuity Ring Radiator.
First described in Electronics, Jan 1993.  Later research described in
July 1972 by W2WAM.  Imagine the antenna as a small ring insulated just
above a ground plane.  Distance above the ground plane is 0.0069 wave
length.  Ring diameter is 0.078 wavelength. The coax feedpoint is 0.25
of distance above ground plane.  The far end from the feed is tuned
with a capacitor to ground. The diameter of the conductor is large; i.e
40 meters is 2 inches.  I recently built one for 40 meters, and it is
mounted to look like a car carrier on top of my VAN.  I had a muffler
shop bend and weld the 2" pipe. It is first mounted on a plywood frame
that is covered with copper screen. A motor (from tanner electronics)
tunes the capacitor. The whole thing is topped with a fibreglass cover,
and the unit is demountable from the van, and can be operated while
placed on my outshed. Size of the plywood is 5' X 11'.
Jim W0oog/5 in Plano on 147.180



From [e-mail] Sun May 19 13:43:33 1996
From: [e-mail] (Brian Williams)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Diamond 2m 5/8 mobile antenna (for so239 mount)
Date: 10 May 1996 18:42:46 GMT
Message-ID: <4n02n6$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] says...

>Hi:  Does anyone know who manufacturers the Diamond 2m 5/8 mobile whip
>with the pl 239 fitting.
...  text cut here  ...
>Thanks,

>Sal

Sal, Diamond is the manufacturer (or distributor for US market) from
Japan.   Most Diamond, Comet, and some Anli antennas are made to fit
the SO-239 connector mounts.  H.R.O. and R.E.S. and most ham radio
stores sell these products.  If you can not find a store near you,
then let me know and I'll give you an address and phone number of
several stores when I get home.

Brian



From [e-mail] Sun May 19 13:43:35 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: Wed, 08 May 96 19:15:16 GMT
Message-ID: <4mqrpu$[e-mail]>
References: <[e-mail]> <4mg98q$[e-mail]> <4mp7ga$[e-mail]>

In article <4mp7ga$[e-mail]>,
   [e-mail] (WB3U) wrote:
>I'm confused.  Two people have mentioned that my reply to the dipole
>inquiry was incomplete/incorrect because A) the 2.13 dBi dipole is
>only theoretical, and B) the 2.13 dBi dipole is in free space.
>
>So, I went back and looked at my post.  This is what I found:
>
>>This will create a dipole, although with certain deviations from
>>a theoretical model due to practical considerations.
>
>>the gain will vary with height above ground and soil conditions.
>
>Was there something about the way I structured my reply that
>caused these statements to be overlooked?
>
>73,
>Jack  WB3U

Your statements weren't overlooked; speaking as one of the posters in
question, I just felt that an adequate explanation required more
elaboration.

A dipole in free space has a gain in its best directions of about 2.15 dBi.
If a ground is placed under it, several important (interrelated) things
happen. First, the average strength of the entire field increases 3 dB
because the energy is now concentrated in a hemisphere rather than being
radiated in all directions. Second, energy reflects from the ground and
adds to the energy being radiated directly, modifying the pattern and gain.
Third, the feedpoint impedance of the antenna changes because of
interaction of the field with ground. This in turn changes the strength of
the field from the antenna. The net result is a field strength which is
several dB greater than that of a free-space dipole (and a very different
pattern), for any antenna height over ground of any real conductivity. And,
unless you're miles above the Earth, any dipole you construct will be over
ground, not in free space.

To me, these constitute major differences between a dipole in free space
and one over ground, more than "certain deviations. . due to practical
considerations" and "[variation] with height above ground and soil
conditions". I apologize if I misinterpreted your statements.

Roy Lewallen, W7EL


From [e-mail] Sun May 19 13:43:35 1996
From: [e-mail] (Jari Jokiniemi)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: 09 May 1996 04:38:10 GMT
Message-ID: <[e-mail]>
References: <4mmj1n$[e-mail]>


Well, there is no such thing as a 2.15 dBi dipole in the real world
of amateur HF communications due to the ground which we can not get
rid off. So what? Let us compare the dipole and a 7 dBd yagi over the real
ground at the same height. That yagi does indeed beat the dipole with
the great margin of 7 dBd. Who cares how much the gain is in dBi?
--
Jari Jokiniemi, [e-mail], OH2MPO, OH3BU
Tekla Oy, Koronakatu 1, 02210 Espoo, 90-8879 474


From [e-mail] Sun May 19 13:43:36 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: 10 May 1996 05:18:02 GMT
Message-ID: <4mujia$[e-mail]>


Jari said -
Jari said -
That yagi does indeed beat the dipole with
the great margin of 7 dBd. Who cares how much the gain is in dBi?

Jari,
        If it is understood that you are only comaring the gain
at the peak of the lobe then there is no problem.
        But when you start to compare other pattrts/// parts of
the pattern, it is not always clear whether you are comparing
those parts with the dipole pattern parts at the same coordinates
or if you are referenceing it to the peak of the dipole lobe.

Charlie, W7
XC
--


From [e-mail] Sun May 19 13:43:37 1996
From: "John D. Farr" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: dipole vs dipole gain
Date: Wed, 08 May 1996 01:24:39 -0500
Message-ID: <[e-mail]>
References: <[e-mail]> <4mg98q$[e-mail]> <[e-mail]> <4mklk6$[e-mail]>

Roy Lewallen wrote:
>
> In article <[e-mail]>,
>    Jake Brodsky <[e-mail]> wrote:
> >Jack, I think you're missing something here.  The dipole he's referring
> >to is the THEORETICAL dipole.  It is a mathematic model with wires that
> >have zero resistance, negligible size, it assumes a center, balanced
> >feed, and each half is 1/4 wave.  Yes, this *theoretical* dipole will
> >have the 2.13 dB gain compared to an isotropic radiator.  I remember
> >computing the antenna patterns of such a dipole in my EE studies at
> >the Johns Hopkins University's Electricity and Magnetism class.  It's
> >been over six or seven years since I did it and the math wasn't exactly
> >pleasant.  I don't think I could (or should) repeat it here.
> >
> >Jake Brodsky, AB3A, <[e-mail]>
> >"Beware of the massive impossible!"
>
> There's one more thing about the 2.15 dBi dipole. It's in free space. This
> makes it as much a fictitious antenna as an isotropic radiator. Even a very
> high real dipole won't have a pattern or gain remotely resembling that of
> the theoretical free space dipole -- the gain of the real dipole will
> typically be several dB greater. It's no trick at all to put a dipole in
> your back yard which has 4-5 dBd gain, where dBd is dB relative to a
> free-space dipole (0 dBd = 2.15 dBi).
>
> Roy Lewallen, W7EL


Indeed, indeed.  You also need to look at the direction of the main
lobe. You might get 4-5 dBd gain, but if the main lobe is straight up,
it don't do much good! Antenna height is critical.

John KC4ZXX


From [e-mail] Sun May 19 13:43:38 1996
From: Darrell Barabash <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Familiar with this antenna book?
Date: Sat, 11 May 1996 23:29:12 -0500
Message-ID: <[e-mail]>
References: <4msfs7$[e-mail]>

KC8CGX wrote:
> Anyone familiar with this book: "Antenna Engineering
> Handbook, Second Edition", Ed by R.C. Johnson & H. Jasik,
> pub by McGraw-Hill.

This is a very good, practical book that covers many types of antenna
systems. It gets into the theory but not too deep. You can get it for
$12.95? Don't even give that a second thought -- get it. At full retail
it's more than worth it.


From [e-mail] Sun May 19 13:43:39 1996
From: [e-mail] (Matt C. Brinkhoff)
Newsgroups: rec.radio.amateur.antenna
Subject: Feed 10M & 2M antennas with one feedline?
Date: 14 May 1996 00:12:08 GMT
Message-ID: <4n8j4o$[e-mail]>

I would like to know if anyone has used a single feedline for two antennas.
I am wondering if I can feed my 10M dipole and 2M turnstyle with the same
coax and use a duplexor at the rig for satellite work.  If it is possible,
does it matter which antenna is closer to the rig?  What impact does the
distance between the two antennas have?  Would it be possible to feed three
antennas in this fashion?  (10M/2M/430)?

Thanks.

--
Matt C. Brinkhoff, KB0RXC
[e-mail]
http://incolor.inetnebr.com/mbrinkho
Lincoln, Nebraska [EN10]


From [e-mail] Sun May 19 13:43:40 1996
From: Jack McClain <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Field Day wire antenna hints needed
Date: Tue, 07 May 1996 07:44:43 -0400
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]> <4mlgmf$[e-mail]>

John Hughes wrote:
>
> > For a number of years our Field Day stations consisted of erecting
> > tri-band beams on portable 75 foot towers for the high bands and various
> > dipoles or double extended Zepps for 40 and 80 Meters...even tried a
> > G5RV one year!
> >
> > BUT - the last three years we've abandoned those antennas in favor of
> > Horizonal loops. (I should have started with the fact that we operate in
> > class 2B - One SSB station and one CW station)
> >
> > It's so simple if you have any sort of supports to put up as big a loop
> > as you have room for and as high as you can get it. Works well even at
> > 25 feet. We feed ours with 450 ohm ladder line and use a tuner
> > (Transmatch) to match the transceiver. This antenna works well on all
> > bands, so well we don't even miss the beam for 10-15-20.
> >
> > 73, Jack [e-mail]
>
> Loops/ladderline sound gud, but tell us where did you all get the 75ft
> portable towers????
>
> 73


Surplus trailer-mounted fold-over 75' towers! Originally used for
microwave site selection tests for microwave routes. Fiber Optics
technology had made the towers surplus!
73, de AE4Q


From [e-mail] Sun May 19 13:43:41 1996
From: [e-mail] (Brian Williams)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Field Day wire antenna hints needed
Date: 10 May 1996 18:31:38 GMT
Message-ID: <4n022a$[e-mail]>
References: <4mlgmf$[e-mail]> <4mlu8q$[e-mail]> <[e-mail]>

In article <[e-mail]>, [e-mail] says...
>Not exactly in My ham budget!

>Cheers.
>Jim, WU0I


>[e-mail] wrote:

>> In article <4mlgmf$[e-mail]>, John Hughes writes:
>> >Loops/ladderline sound gud, but tell us where did you all get the 75ft
>> >portable towers????
>> >73

I have a friend with a military style guyed crank up that's about 50ft.
I'd buy it myself but really can't justify it to my wife.  If you or a
club is interested, the cost is almost 1/10 the 75ft unit mentioned
earlier.

Brian



From [e-mail] Sun May 19 13:43:42 1996
From: Lan Administrator <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Flag Pole Antenna
Date: 14 May 1996 15:08:05 GMT
Message-ID: <4na7km$[e-mail]>

Greetings all.

I am getting ready to relocate to another town and I am afraid that the
covenants in the neighborhoods are not accomodating to towers.  I have
been researching different types of "stealth" antennas and have decided
that a flag pole antenna would be the most asthetically (sp?)
pleasing, and for the neighborhood watch dogs to deny it would be
unpatriotic.

My questions are: are there any readers that have experience with these
types of antennas?  Or do you have any other ideas? I have looked at
Isoloops, dipoles attached to the facia, attic wires, .....

I have a good idea how to make a concealed groundplane for the flag pole
(the XYL loves gardening), so that is not a problem.

please email responses to [e-mail]

TIA de KC5GWA
Bren Doreck
tryin' to get over the 10wpm hump



From [e-mail] Sun May 19 13:43:43 1996
Newsgroups: rec.radio.amateur.antenna
From: Marilyn Swartz <[e-mail]>
Subject: FM Antenna Question
Message-ID: <[e-mail]>
Date: Tue, 07 May 1996 02:41:45 -0700

Sorry that this isn't a question about esoteric antenna theory, but here
goes:

I recently bought an R-95 Yamaha receiver to listen to FM stations.  I
am using the simple wire-loop antenna that came with the receiver.
However, as I live very close to a radio tower (Sutro tower in San
Francisco), it is very difficult to get certain stations because of the
interferance--they come in, but with a lot of static and only after
moving the antenna around a lot.

Would getting a better antenna help, and if so, which one?  The people
at Good Guys, where I bought the receiver, only reccommend the Terk
brand antennas they have availiable.  I would prefer to use an indoor
antenna if possible, however--but it seems that my problem is mainly
antenna selectivity, not sensitivity, so I doubt a large antenna would
do anything.

Thank you very much in advance for your help.



From [e-mail] Sun May 19 13:43:44 1996
From: Dave <[e-mail]>
Newsgroups: rec.antiques.radio+phono,rec.radio.amateur.antenna,rec.radio.amateur.homebrew,rec.radio.shortwave,rec.radio.swap
Subject: For Sale- Rider Manuals & SAMS
Date: 18 May 1996 13:57:17 GMT
Message-ID: <4nkkvt$fqt$[e-mail]>

Hello Friends,

I have several Rider Perpetual troubleshooting manuals for Radio
and Televisions for sale. I also have a nearly complete set of
SAMS Photofact of the month series until the year 1991. This from
my Father's business which I closed a few years ago. The overall
condition of the Rider manuals are good, as well as most of the
sams folders. If you have any interest in all or part of these
sets, please respond by E-Mail to [e-mail] , OR
[e-mail]

Thanks for your time

Dave Skalish


From [e-mail] Sun May 19 13:43:44 1996
From: [e-mail] (David Black)
Newsgroups: rec.radio.amateur.antenna
Subject: Foxhunt antenna?
Date: 16 May 1996 16:48:19 GMT
Message-ID: <4nfm8j$[e-mail]>

I'm looking for information on how to build foxhunt/T-hunt
handheld antennas for 2m, 440 and 1.2. We have some creative
people here in the Bay Area who've sent along some idears,
and I'm told there is a book by the ARRL available too.

I'd like to build something that's small enough to use while driving
around in a car, while attached to an HT.

Cheers,

Dave KE6AJC


From [e-mail] Sun May 19 13:43:46 1996
From: [e-mail] (Brian Williams)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Re: Glass mount on "shaded" window
Date: 13 May 1996 20:51:15 GMT
Message-ID: <4n87c3$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] says...

>Hello all,
>Does anybody have any experience with the "patterned" sun shade at the
>top of the rear window of
>GM cars (mine is a 92 Chev Corsica)?
>Thanks
> --Louis

I was told by the manufacturer of the antenna (Larsen) to avoid the
patterned area.  I used the area where the heater wires are about two
inches below the bottom of the pattern and stratled the heater wires
with the antenna coil plate horizontal (parallel to the wires).  I did
this on my Chevy Lumina which I believe is the same style glass as the
Corsica and it performed well.  After about 1-1/2 years, the glue started
to seperate on the outside antenna, so I reglued it using contact cement
and it was fine until I returned the vehicle (company car).  Be careful
to check the mounting regularly and DON'T exceed the power capability.

Brian - N6ZAU



From [e-mail] Sun May 19 13:43:47 1996
From: [e-mail] (JMhilliard)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Help - Offshore vessel has antenna proble
Date: 17 May 1996 10:41:22 -0400
Message-ID: <4ni36i$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (JMhilliard)

Bill, do you have a chart of the HF SSB channels/frequencies?
I would like to listen, but cannot find a chart anywhere!



Mark Hilliard, N2HHR
Formally: [e-mail]
[e-mail]


From [e-mail] Sun May 19 13:43:48 1996
From: [e-mail] (Brian Prendergast)
Newsgroups: rec.radio.amateur.antenna
Subject: Help needed
Date: Tue, 14 May 1996 12:19:14 -0500
Message-ID: <[e-mail]>

Here the situation, I'm just starting in on this radio thing and I'm having
a problem figuring out what is best.  I started with a couple of 49 MHZ
radio shat in pocket communicators so I could play paintball and talk to
another member of my team at the same time.  I quickly found out that the
refs use the same frequency and that the rang and clearity wasn't that
good.  I nneded something that would work better since I didn't have time
to play around with things while I was playing paintball.  I also tryed to
use these in the car since we travel in multiple cars a lot and I thought
it would be nice to be able to talk to each other.  At any rate this didn't
work.  I returned them and figured I would give a CB a shot.  It started
out really good, then I realized that the CB (a hand held one) would be
great for paintball, but not very good for the car since it picked up every
little electronic devise in my car, since I have a stereo well over $1000
and an alarm to guard it along with a radar detector to watch for police oh
and I can't forget about the pager and cell phone.  Anyway you get the
point, I'm into electronics.  So now I hear all about these HAM radios, and
VHF.  How far can they reach and what kinds are the best, how much do they
cost, where can I get them, are there a lot of people using them?  You get
the idea, I have no clue about them.  I know I need a licencse and that's
about it.  Some one has been a great help to me so far, any more help would
be greatly appreciated.  I am extreamly interested in what the benefits are
off having the VHF as opposed to the CB.  Well please get back to me, one
of the more important things is cost and range.  I want to creat a docking
station for it for my home and for my pickup truck.  I am very interested
on how far people think they can go.  Please email me at
[e-mail] with any help.  I don't read these all the time
so I would probibly miss any resonse to this.  Thanks for any help at
all......


From [e-mail] Sun May 19 13:43:49 1996
From: [e-mail] (pete brunelli)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Mobile Magnetic Mount
Date: Fri, 17 May 1996 13:06:07 GMT
Message-ID: <4nhtn0$[e-mail]>
References: <[e-mail]>

[e-mail] wrote:

>Can anyone give me feedback on using any type of HF antenna with the
>extra large multi-pad magnetic mounts?  Bob AA2UV
>([e-mail])

I have had varied results, though typically bad.  One problem will be
getting a decent connection to ground.  The magmount alone is a poor
approximation of a ground connection.  A hardpoint connection to the
chassis would help alot.  Even if it "tunes" ok, the efficiency will
be extra-miserable.

The big H pattern mounts are a big improvement, especially at hwy
speeds.  I have had my outbacker blow off at about 60mph and it was
pretty hair-raising.

GL




From [e-mail] Sun May 19 13:43:50 1996
From: F. Kevin Feeney <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Mobile Magnetic Mount
Date: 17 May 1996 15:24:10 GMT
Distribution: world
Message-ID: <4ni5mq$[e-mail]>
References: <4nhtn0$[e-mail]>

In article <4nhtn0$[e-mail]> pete brunelli, [e-mail]
writes:
>[e-mail] wrote:
>
>>Can anyone give me feedback on using any type of HF antenna with the
>>extra large multi-pad magnetic mounts?  Bob AA2UV
>>([e-mail])
>
>I have had varied results, though typically bad.  One problem will be
>getting a decent connection to ground.  The magmount alone is a poor
>approximation of a ground connection.  A hardpoint connection to the
>chassis would help alot.  Even if it "tunes" ok, the efficiency will
>be extra-miserable.
>
>The big H pattern mounts are a big improvement, especially at hwy
>speeds.  I have had my outbacker blow off at about 60mph and it was
>pretty hair-raising.
>
>GL
>
>

All the ones I've looked at, even the H mount types, don't have much of a
connection to ground - and you need that for the antenna to perform well.
I finally built my own. I started with a 14 inch square aluminum plate
laid flat on the roof to get enough capacitance to ground. Bigger would
be better - I scaled it up from the amount of area typical for a 10/11
meter whip, and then doubled that. The plate is countersunk on the bottom
for screws that go up into two wood rails that run over the top to
magnets on the outsides of the plate. I use some washers to take up the
gap from the top of the magnets (bottom of the rails) to the plate so
it's pushed down firmly on the roof.

I put a bud box in the middle of it, a little forward of center, and
mounted an RS ball mount on that. Inside the box is a switch to switch in
various caps at the base for matching on the lower bands. The coax is
routed out the rear of the box and down into the car via a doorsill.

I use hamsticks on it (on top of a dodge caravan) and get good reports on
40 meters on up, often complimented on the strength of the signal. I
attribute that mostly to a better than average ground connection for the
antenna compared to the other mag mounts they hear. My 2:1 bandwidth is
narrower than others see, also an indication that my ground losses are
probably lower.

It's been in service for about 5 years on and off now. I have to replace
the RS ball every now and then, and the switch needs to be redone also.
It's only been knocked off the roof once, and that was a low tree limb at
45 mph that hit the fiberglass part of the whip and really did a job on
things. Cracked the RS ball base along with damage to the hamstick. But
on more normal encounters, I just hear a big "Boing!" typically. I
routinely drive through the local 'McBarnyards Golden Starches' which
just clears the fiberglass portion of the hamstick and folds the whip
right back - and it's never come unstuck. It's never come unstuck due to
wind.

Total cost was probably about $30, get some big magnets with cups that
you can screw to at a hamfest, use 1x2's for the rails, and I think I got
the bud box at RS although there are probably sturdier ones. I mounted
the box with the U shaped section screwed to the plate, and then stood
the outer U, with the flanges along the sides that help stiffen it, on
top of it, replacing the original screws with brass ones after they
rotted out.

The best thing would be to get a direct low Z connection to ground, but
that isn't always an option. This was my answer to it. Your milage may
vary.

On a side note, when there's no antenna on the ball, it's amazing how
many people thinks it's some kind of 5th wheel trailer hitch. Coming home
from a hamfest once when it was on my VW Rabbit, I was hysterical as
someone joined our group on simplex and asked about the '5th wheel hitch
on the roof of the rabbit. ' Some of my travelling companions had him
convinced that I towed a 25 foot rig with the thing, and still got 32
MPG.  I think next they were going to sell him some beachfront property
on mars!

73 de Kevin, WB2EMS      "When I was a child, mommy told me not to talk
to strangers. Now
that I'm a ham, it's my hobby!"


From [e-mail] Sun May 19 13:43:51 1996
From: Garth Wiscombe <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Vertical
Date: 9 May 1996 02:03:21 GMT
Distribution: world
Message-ID: <4mrjp9$atm@NEWSnewsNeWsnEwS>
References: <[e-mail]> <4mlu3m$[e-mail]>
To: [e-mail]

[e-mail] wrote:
>In article <[e-mail]>, Chuck Vaughn writes:
>
>>George J. Molnar wrote:
>>>
>>> Dan Tang wrote:
>>> >
>>> > Can some one please tell me if an hf vertical antenna install on the
>roof
>>> > (with radials) works as good as it install on the ground (with
>radials)?
>>>
>>> It'll probably work a bit better, presuming you install a good-quality
>>> set of radials on the roof.
>>
>>And not only that, but you can get the impedance closer to 50 ohms
>>by sloping the radials down.
>>
>>Chuck - AA6G
>
>I used to have a Cushcraft AP8A mounted on my chiney.  I had VERY good luck
>with it.  Good performance for both domestic and DX contacts.  Really
>enjoyed it.  Good luck.
>Al, KE6BER/1, [e-mail]
>

Just a note:
You may want to check with the manufature of your particular vertical to
see if the radials are longer with the roof top mount than the ground
mounting.  For example I have the AV5 and the radials for the 80 meter
band are 6 feet longer for the roof mount than ground.  My installation
instructions came with the information for both ground and roof mounting.
 The comment of coming closer to 50 ohms because of angle are also very
true and are discussed in brief in the installation instructions that I
have for my antenna.

Have Fun.
--
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                              *   *    *   *   *
Garth Wiscombe, KA7MHN  /\  /\ *    *   /  /    /  Office     801 265-5057
Salt Lake City         /  \/  \ /\     ----/\---   Cellular   801 631-8675
Utah  84119-6032      /\   \   \  \   /  / || /    Home       801 967-3236
USA                  /  \   \   \  \       ||      FAX        [phone]
                    /    \   \   \  \      ||      E-mail  [e-mail]
                             73 de Garth KA7MHN

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++




From [e-mail] Sun May 19 13:43:52 1996
From: Siegfried Rambaum <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: High SWR Help
Date: Fri, 10 May 1996 14:52:42 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>

On 8 May 1996, Steve Lee wrote:

> Here's what he's doing. He has a Cobra 148F and a Firestik 2 antenna.

Humm ... this sounds, as if your friend only installed half the antenna.
The other half of that antenna would be the car; the Firestick and the
car give a complete antenna system (i.e. form a groundplane) .... I
guess, he would need to add radials like it is the rule for each decent
groundplane.

> He can't have an outdoor antenna where he is at. So, he mounted the
> antenna in his attic. The antenna is 3 feet tall just below his roof
> inside the attic. He's using 50 feet of RG58 coax , new from Radio
> Shack. This is a mobile style antenna, but he is using his radio as a base
                   ******************** here you say it yourself...


From [e-mail] Sun May 19 13:43:53 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Steve Ellington)
Subject: Re: Horizontal HF loops
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <4lteku$[e-mail]> <4mfqhj$[e-mail]> <4mjua9$[e-mail]> <[e-mail]>
Date: Mon, 13 May 1996 20:39:08 GMT

I have tried using things like eyebolts and insulators but even the
softest wire won't pull through them with a lot of effort. The pully idea
sounds great as long as they swivel and the wire doesn't jump off and jam
beside the pulley.



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


From [e-mail] Sun May 19 13:43:56 1996
From: P Tyers <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: HOW DO U CONNECT COAX TO QUAD????????
Date: Fri, 10 May 1996 14:08:58 +1100
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]>

Monty Wilson wrote:
>
> [e-mail] (Bill Poston) wrote:
> >I am attempting to homebrew a quad antenna. I have read Cubical Quad
> >Antennas by W6SAI and the ARRL Antenna Book. Neither answers my question.
> >
> >How do I connect one coax feedline to the multiple loops on the driven
> >element?
> >
> >Please explain in detail so that a dummy can understand.
>

Have another read of Cubical Quads. What you actually end up
doing is producing a multiple gamma match, one for each loop.
Of course they interact to all heck while being adjusted.I
seem to recall that the preferred order of adjustment was
from smallest loop to largest loop for minimum interaction -
BUT I COULD BE TOTALLY WRONG ON THIS.

 Another source of information is a series of articles
published in the Wireless Institute of Australia magazine
"Amateur Radio" about 15 +/- 5 years ago on multiband quads
which had several column inches on the care and feeding of
these gamma matches.

Hope this helps!

--
P Tyers, Tel. [phone]
AARnet: [e-mail]
CSnet: [e-mail]    HAM: VK3KTS
MAIL: Telstra Research Laboratories,P.O. Box 249,
      Clayton,VICTORIA 3168,AUSTRALIA


From [e-mail] Sun May 19 13:43:57 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: HOW DO U CONNECT COAX TO QUAD????????
Date: 11 May 1996 05:45:45 GMT
Message-ID: <4n19i9$[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]>
Reply-To: [e-mail]

In <[e-mail]>, P Tyers <[e-mail]> writes:
>Monty Wilson wrote:
>>
>> [e-mail] (Bill Poston) wrote:
>> >I am attempting to homebrew a quad antenna. I have read Cubical Quad
>> >Antennas by W6SAI and the ARRL Antenna Book. Neither answers my question.
>> >
>> >How do I connect one coax feedline to the multiple loops on the driven
>> >element?
>> >
>> >Please explain in detail so that a dummy can understand.
>>
>
>Have another read of Cubical Quads. What you actually end up
>doing is producing a multiple gamma match, one for each loop.
>Of course they interact to all heck while being adjusted.I
>seem to recall that the preferred order of adjustment was
>from smallest loop to largest loop for minimum interaction -
>BUT I COULD BE TOTALLY WRONG ON THIS.
>
> Another source of information is a series of articles
>published in the Wireless Institute of Australia magazine
>"Amateur Radio" about 15 +/- 5 years ago on multiband quads
>which had several column inches on the care and feeding of
>these gamma matches.
>
>Hope this helps!
>
>--
>P Tyers, Tel. [phone]
>AARnet:        [e-mail]
>CSnet: [e-mail]    HAM: VK3KTS
>MAIL: Telstra Research Laboratories,P.O. Box 249,
>      Clayton,VICTORIA 3168,AUSTRALIA

You're right on target!  Highest to lowest frequency.

It takes some juggling.

However, once done, the match stays done.

I've used the gamma match feed system on quads (and virtually everything
else I can reasonably adapt it to.  It works on the quads VERY well.

Another tip.  In stead of chasing all over heck and back for big variable
capacitors as you get down to 40 and 80 meter quads, use a chunk of RG-8
coax cable as a capacitor.  It has capacity and a nice hefty dialectric that
will let you use the inner conductor as one arm of a capacitor and the
outer shield as the other arm.  You get it too long by a foot or so for the
total capacity you need.  You whackem off an inch or so at a time at lower
power to trim away the capacitance.  You use a much smaller air variable
for the trimmer.

When done, presto, BIG heavy cap for 40 and 80 meter versions heap cheapo.

Be sure to trim away some of the braid and leave an inch or so of the inner
conductor and insulation extended to avoice arcing at high power....

Tape the end up to excude water.

Smile all the way to the bank.

:)

Mike W5WQN as a guest at leviathan.tamu.edu (No mail address there)



From [e-mail] Sun May 19 13:43:58 1996
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
From: "Al Koblinski  (W7XA)" <[e-mail]>
Subject: Re: HOW DO U CONNECT COAX TO QUAD????????
Message-ID: <[e-mail]>
To: [e-mail]
References: <[e-mail]>
Date: Thu, 9 May 1996 23:56:14 GMT

I use a 1:1 balun for each loop (Bencher, but any brand is OK).
Where needed I used a coax matching section to match.
On 20mtr, my 3 el on 26' boom was 49 ohms so no matching was needed for
50 ohm coax.
Ditto for 5 el on 15 mtrs with same boom.
10 meters, 5 elements came out to near 90 ohms impedence and I used a
section of 75 ohm coax between the balun and the 50 ohm feedline.
Each element is fed seperately through a switchbox.
I have used a variety of other feed methods in the past, such as gamma
matching (cumbersome) and found that the simple balun approach works
great and is mechanically the most simple.
73, Al




From [e-mail] Sun May 19 13:43:59 1996
From: [e-mail] (David Voges)
Newsgroups: rec.radio.amateur.antenna
Subject: Info required for Telescoping mast
Date: Mon, 13 May 1996 17:02:19 GMT
Message-ID: <4n70t7$[e-mail]>
Reply-To: [e-mail]

Hi

I have a telescopic mast (pump-up type) which has the name CLARKE
engraved on it.
Can someone tell me where I can find information on this mast ?.
I need to service it and and also replace all the O-rings.





From [e-mail] Sun May 19 13:44:00 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: ISOTRON Antenna Information
Date: 8 May 1996 14:15:21 GMT
Message-ID: <4mqa9p$[e-mail]>
References: <4mogau$[e-mail]>

[e-mail] wrote:
>Any information will be greatly apreciated. TIA.

Hi Barry, IMO you would be a lot better off running $10 worth of
wire in your attic. Have you seen any radiation efficiency specs
on the Isotrons?

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Sun May 19 13:44:01 1996
From: [e-mail] (Barry LaZar)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: ISOTRON Antenna Information
Date: Thu, 9 May 1996 06:34:43 +1000
Message-ID: <[e-mail]>
References: <4mogau$[e-mail]> <4mqa9p$[e-mail]>

In article <4mqa9p$[e-mail]> Cecil Moore <[e-mail]
m> writes:
>From: Cecil Moore <[e-mail]>
>Subject: Re: ISOTRON Antenna Information
>Date: 8 May 1996 14:15:21 GMT

>[e-mail] wrote:
>>Any information will be greatly apreciated. TIA.

>Hi Barry, IMO you would be a lot better off running $10 worth of
>wire in your attic. Have you seen any radiation efficiency specs
>on the Isotrons?

>73, Cecil, KG7BK, OOTC  (not speaking for my employer)
>

Cecil,
        Thanks for the response. All I know about the antenna(s) is what I have read
in a couple of 73 articles. 73

/Barry, K3NDM


From [e-mail] Sun May 19 13:44:02 1996
From: [e-mail] (Gary V. Deutschmann, Sr.)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-pole vs. half wave dipole.
Date: Thu, 16 May 1996 21:55:40 GMT
Message-ID: <4ng8j6$[e-mail]>
References: <4mnq2r$[e-mail]> <4mnu2v$[e-mail]>

[e-mail] () wrote:

>>Thinking of putting up simple vertical for 6M. The J-pole was initial choice

>>but then I wondered if the 1/4 wave, non-radiating, matching section was
>>really worth the trouble. How much better is the J-pole than a simple 1/2 wa
ve
>>dipole fed with 75 ohm coax and a ferrite decoupler on the outside of the co
ax
>> at the feed point?

>Hi John,

>The J-pole better? definitely not. First the 1/4 wave section radiates to
>some extent, because one side is loaded by tha antenna and it is not
>strictly symmetrical, and this degrades antenna gain. Second in a J-pole the

>impdeance is transformed to very high values at the feed point, which in
>most cases will introduce extra losses. Third, you need to worry about
>a symmetric feed with both antennas, else the feed line radiates.

>The J-pole is am electrically poor design, but it has its followers.
>Fortunately it is our privilege to be irrational.

>73, Moritz DL5UH


Not everyone has room for a counterpoise!

TTUL
Gary





From [e-mail] Sun May 19 13:44:03 1996
From: [e-mail] (James S. Gozzo)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Re: Larsen glass mount antennas
Date: Thu, 16 May 1996 08:17:51 -0500
Message-ID: <[e-mail]>
References: <5e7cc$11271c.2ce@NEWS> <[e-mail]>

I've had a Larsen 2m glass mount since 1989.  The antenna works fine and
the adhesive has been great.  When I got a new car I removed the antenna
(much work with acetone, a putty knive and lots of elbow grease) and wrote
to Larsen about how to re-install the antenna.  They sent me a
re-installation kit gratis - contained the glass cleaner, the double-sided
adhesive and isntructions.

Follow the instructions and make sure the mounting surface is clean and
dry.  I've never had a problem with the adhesive coming loose.

73, es cul
Jim, WG1Y

p.s. I have no connection with Larsen.  They just seem to be a good company.

--
Jim Gozzo
[e-mail]


From [e-mail] Sun May 19 13:44:04 1996
From: [e-mail] (George Deamicis)
Newsgroups: rec.radio.amateur.antenna
Subject: Long Wire
Date: 18 May 1996 17:14:10 GMT
Distribution: world
Message-ID: <4nl0h2$[e-mail]>

I have the oppittunity to run two long wires about thiry feet up. One
would be approx 175 to 200 feet the other about 120 feet. I can use
either #12 or 14 insulated wire. I 'm using a ICOM 736 with an auto tune
and I also have a MFJ
948. I have access to Belded 8214 and some twin lead. I would like to
operate 80 and 160 my questions is what problems will I run into, should
I invest in anothe balun? and most importanly any suggestions or ideas?
Thanks.

73 GEORGE
N1JGE




From [e-mail] Sun May 19 13:44:05 1996
Newsgroups: rec.radio.amateur.antenna
From: Monty Wilson <[e-mail]>
Subject: Re: Looking for plans for a small QRP tuner
Message-ID: <[e-mail]>
Date: Thu, 16 May 1996 14:53:24 GMT
References: <4nek5v$[e-mail]> <4neogk$[e-mail]>

The thing you want to watch out for in QRP work is the
addition of too many reactive components that cancel
each other out, giving you a great match but using up
what little power you have in the tuner.  I heard at a
Dayton forum several years ago that you can build a
very simple matching device just by putting the braid
straight through and attaching the center conductors
to either end of an air variable.  This only works if
the antennas in question are on the long side; ie., if
the only reactance to be compensated is inductive rather
than capacitive.  For example, he described a dipole cut
for the bottom end of 80, and for 75 work you just open
the air variable a little.  But you can only have this
luxury if you are at liberty to cut your antennas a little
long.

This raises an interesting question (well maybe interesting):
if you put 20w into a tuner but only get 5w out of it, does
it still count as QRP?

--
.........Monty.
[e-mail]





From [e-mail] Sun May 19 13:44:06 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: MFJ 10 Band Antenna performance?
Date: Mon, 13 May 96 15:11:37 GMT
Message-ID: <[e-mail]>
References: <4mq4ka$[e-mail]> <[e-mail]>

Is anyone familiar with the performance of the MFJ-1798 Half-wave vertical
antenna with coverage from 75/80 40,30,20,17,15,12,10,6 & even 2 meters?

Thanks,
Ben Johnson, KF4JEB




From [e-mail] Sun May 19 13:44:08 1996
From: [e-mail] (Mica Sanders)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Mobile Antenna for 27Mhz
Date: Tue, 07 May 1996 20:12:39 +0300
Message-ID: <[e-mail]>
References: <4kpti6$[e-mail]> <[e-mail]> <4lsa7q$[e-mail]>

In article <4lsa7q$[e-mail]>, [e-mail] wrote:

> aor <[e-mail]> wrote:
> >[e-mail] wrote:
> >>
> >> I am trying to build a beam type of antenna for a 27Mhz mobile. Does
> >> anyone have any models of this or ideas??? Even if you have formulas or
> >> theory I would be very interested.
> >>
> >> Thanks
> >
> >
> >One of the easiest ways to do this is by using two
> >antennas and phasing them.  One example would be to
> >buy two 9' whip antennas and mount them 9' feet
> >apart (1/4 wave on 27 MHz).  Feed them in phase by
> >using two equal runs of (odd 1/4 wave) 75 ohm coax
> >from a tee-connector on your radio.  The pattern
> >will be broadside to the two antennas.  With about
> >3db of gain over a single antenna.
> >
> >You see truck drivers with two antennas, you don't
> >see the phasing harness, and the pattern favors the
> >front and back (broadside) by 3 db (double your
> >radiated power) at the expense of side radiation
> >(end-fire).  The principles are the same.
> >
> >There are a lot of other things to consider
> >assuming you can put two antennas 9' apart on a
> >car, have good grounding, and a good ground plane.
> >There are other methods by using 90 degrees phasing
> >and 1/4 wave spacing...  but that is another story.
> >This resembles a 2-3 element beam pattern.
> >
> >It is a lot of fun to do, 75 ohm coax is cheap, and
> >one centrally mounted antenna is usually better
> >than multiple antennas for 99% of the population.
> >Besides, how did you plan on turning this "beam"
> >???  Hi Hi
> >
> >For 30 bucks, order the ARRL Antenna Handbook and
> >read up on the subject.
> >
> >See ya,
> >
> >Al  NW2M
>
> Thanks for the info. I'll look into that. I had heard that you can make
> one of the antennas the hot and another the ground or backdoor.
> Suppossedly the backdoor should act like a reflector.

Al,

I invested in the ARRL Antenna Book (several years ago) and (IMHO) found
it to be of minimal value except in low band antenna designs. It is sorely
lacking in phasing harness design and applications. I have yet to find a
formula (or person) to describe how Decibel Products (premier supplier of
commercial antennas) phases multiple folded dipoles (as many as 16 on
UHF). I built an 8 dipole 465 MHZ unit using a DB-420 as a model and it
performed exceptionally well (VSWR 1.05). I did not consider
frequency/cable Velocity factor when building the harness but made sure
that all 8 elements were fed using equal line lenghts from the feedpoint
(total of 7 "tees" including feedpoint which was positioned at the center
of the array). IMHO, it would seem logical that if the RF signal arrived
at each element at the same time, all elements would resonate "in-phase"
and the way to accomplish this is by equal lenghts of coax to each element
from the feedpoint. Could you lend some insight on why the cable lenghts
have to be in multiples of the frequency (even if center fed?), and what
the "odd multiple" does for the design?

Thanks,

Paul WNQN319


From [e-mail] Sun May 19 13:44:08 1996
From: [e-mail] (George Micros)
Newsgroups: rec.radio.amateur.antenna
Subject: Need help! Fm Antenna and dipole construction.
Date: 10 May 1996 00:52:48 GMT
Message-ID: <4mu410$[e-mail]>

I am looking for any plans for an FM Antenna or co-linear antenna with at
least four dipoles. Need dipole distances and anything that might help me
build it, (mathematical types will do). For use with a 500W fm transmitter.
(for now).
Any help will be appreciated.
If possible please e-mail me at [e-mail]



From [e-mail] Sun May 19 13:44:09 1996
From: [e-mail] (Jim Bromley, W5GYJ)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need source for antenna elements
Date: 14 May 1996 01:59:03 -0700
Message-ID: <4n9i0n$[e-mail]>
References: <4n3b03$[e-mail]>
Reply-To: [e-mail]

[e-mail] (History67) wrote:

>Can anyone tell me who carries alum, copper, or brass rods suitable for
>use in the construction of 2 meter beam antennas?  I have resorted to coat
>hangers and old car antennas for my first few, but this will not due for
>permanant uses.

I have found that small-diameter brass and steel rods can be found at
model-airplane hobby shops.  The steel is referred to a "piano wire",
is strong and flexible, but is not stainless so it needs to be
painted.  Just a hint.


Jim Bromley, W5GYJ
Glendale, Arizona



From [e-mail] Sun May 19 13:44:10 1996
From: Doyle <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need source for antenna elements
Date: Tue, 14 May 1996 07:35:43 -0400
Message-ID: <[e-mail]>
References: <4n3b03$[e-mail]> <4n9i0n$[e-mail]>

Jim Bromley, W5GYJ wrote:
>
> [e-mail] (History67) wrote:
>
> >Can anyone tell me who carries alum, copper, or brass rods suitable for
> >use in the construction of 2 meter beam antennas?  I have resorted to coat
> >hangers and old car antennas for my first few, but this will not due for
> >permanant uses.
>
> I have found that small-diameter brass and steel rods can be found at
> model-airplane hobby shops.  The steel is referred to a "piano wire",
> is strong and flexible, but is not stainless so it needs to be
> painted.  Just a hint.
>
> Jim Bromley, W5GYJ
> Glendale, Arizona----------------------------------------
reply from jim KD4HUR IN FLORIDA
        John : check out your local welding supply house, I use aluminum
welding rod for most of my 2 and 440 antennas at very reasonable cost
also, they can be had in most diamaters you would usually want.
        Other metals brass , stainless ect are also avail this way...
                73' KD4HUR


From [e-mail] Sun May 19 13:44:11 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need source for antenna elements
Date: 16 May 1996 01:54:26 GMT
Message-ID: <4ne1si$[e-mail]>
References: <4n3b03$[e-mail]> <4n9i0n$[e-mail]>
To: news:4n9i0n$[e-mail]

[e-mail] (Jim Bromley, W5GYJ) wrote:
>[e-mail] (History67) wrote:
>
>>Can anyone tell me who carries alum, copper, or brass rods suitable for
>>use in the construction of 2 meter beam antennas?  I have resorted to coat
>>hangers and old car antennas for my first few, but this will not due for
>>permanant uses.
>
>I have found that small-diameter brass and steel rods can be found at
>model-airplane hobby shops.  The steel is referred to a "piano wire",
>is strong and flexible, but is not stainless so it needs to be
>painted.  Just a hint.
>
>
>Jim Bromley, W5GYJ
>Glendale, Arizona
>
Jim...I have found that for antenna elements the aluminum tubing found
in hardware stores that is used to hold up clothes lines is perfect.
It comes in 7 ft lengths, and cost less than $2 each.  Cut of the "U"
shaped wire at the end thats ment to hold up the line.  May be a tad big
for 2M but is great for 6 and lower

Norm  N8RGR



From [e-mail] Sun May 19 13:44:12 1996
From: RJD <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: No CODE No CW on HF
Date: Sun, 12 May 1996 09:48:05 -0400
Message-ID: <[e-mail]>
References: <4n3ugh$[e-mail]>

[e-mail] wrote:
>
>  I might propose a rule change that says ... "If you want to operate
> CW on the HF bands you must first pass a code test to update your
> license.  HOWEVER if you do NOT intend to operate CW then you do NOT
> need to take or pass a code test."
>
> [e-mail]

I'm sorry - are you referring to Ham Radio, or the proposed "Personal
Radio Service"?  I'm sure Radio Shack, KenComSu would support you
wholeheartedly.  So, I'm sure, would Technics, Pioneer, Sanyo, JVC, and
anyone else who might have a vested interest in selling LOTS of HF rigs
to unqualified "PRSers".

I'm tired of everything being dummied down in this country.  After
memorizing the code, it took me just 45 minutes of receiving practice to
pass the 5 WPM Novice code test.  It just isn't that hard.

Lets keep SOME standards in this country.  God knows, the written test
has become a joke.

RJD


From [e-mail] Sun May 19 13:44:13 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: No CODE No CW on HF
Date: 13 May 1996 02:03:37 -0400
Message-ID: <4n6jbp$[e-mail]>
References: <[e-mail]>

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

>I'm tired of everything being dummied down in this country.  After
>memorizing the code, it took me just 45 minutes of receiving practice to
>pass the 5 WPM Novice code test.  It just isn't that hard.
>
>Lets keep SOME standards in this country.  God knows, the written test
>has become a joke.
>
>RJD

Amen to that. The exams are all much easier now than they were earlier,
including the code test.

Look at what has happened to the USA edge on education thanks to  "dumbing
down" our schools.

It seems the easier something is made, the more people whine about making
it easier still. What's wrong with showing the little effort required?

73 Tom


From [e-mail] Sun May 19 13:44:14 1996
From: [e-mail] (Burch Akin)
Newsgroups: rec.radio.amateur.antenna
Subject: Opinion?
Date: Mon, 13 May 1996 13:57:10 GMT
Message-ID: <4n7f4m$[e-mail]>

I am going to be moving to a new location soon.  I have found an area
that has no antenna restrictions.  The only problem I see is there is
a big warehouse/building to the west of me.  It is about 1/3 of a mile
away.  All the other directions from the house are free from any tall
structures within a couple of miles.  Does anyone have an opinion
about how this structure will effect my singal?  I opperate mainly on
6 meters, 2 meters, 222, 432 and 1296.  My antennas will be up about
50' or so and I really don't know the height of the building.  I am
hoping that my take-off angle will be overcome the building.  I live
on the west coast of Florida and the only thing I can work west of me
is on the other side of the Gulf which takes some type of special
conditions (tropo, e-skip, etc.)  Any opinions would be greatly
appreciated.

KE4ZQV




From [e-mail] Sun May 19 13:44:15 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Opinion?
Date: 14 May 1996 11:21:26 GMT
Message-ID: <4n9qbm$[e-mail]>
References: <4n7f4m$[e-mail]>

>Does anyone have an opinion
>about how this structure will effect my singal?

Noone who has not  seen the building will really be able to help you there.
As a rough guideline, if the building is higher than your antenna, on 50
the attenuation will be not too serious, but 1296 gets wiped out much in the
same way as light.

73, Moritz DL5UH


From [e-mail] Sun May 19 13:44:16 1996
From: [e-mail] (Gerry Lavallee)
Newsgroups: rec.radio.amateur.antenna
Subject: Question-railroad antennae
Date: 10 May 1996 04:38:44 GMT
Message-ID: <[e-mail]>

I was wondering if someone could enlighten me.
I am a rail fan and have noticed different radio antennae on locomotives.
I am curious why different shapes are required as the frequencies used by
railroads are in the same bandwidth (around 160 megahertz)
I understand how a "whip" antenna radiates out a signal & captures a signal.
I have an idea why a base plane is used underneath a whip antenna.

Anyway, in the past & now in the present I have seen;
1. An antenna shaped like a gong type bell
2. "    "        "     "  a railing along the loco hood (induction?)
3. "    "        "     "  a fire cracker
4. "    "        "     "  an ice skate (called "Sinclair" type)
5. "    "        "     "  a tin can

The Sinclair type is almost universally used in Canada but in the states
the antennae used seem almost random, even on the same railroad


From [e-mail] Sun May 19 13:44:17 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (David Chamberlin SLIP/PPP)
Subject: Re: R7000?
Message-ID: <[e-mail]>
References: <4nhqhe$[e-mail]>
Date: Sat, 18 May 1996 02:53:45 GMT

I saw the R7000 today at Dayton. All I can tell you is that it appears to
be heavier in construction. The traps are enclosed now and look more
substantial but who knows? That's a lot of bux for a vertical.


Roger J. Buffington; AB6WR ([e-mail]) wrote:
: Has anyone used the new Cushcraft R7000?  I'm curious as to how it
: performs.  I'm also interested in knowing how it handles high power at a
: near 100% duty cycle, as for SSTV or digital operations (Amtor/Pactor/RTTY).

: The R-7 was notorious for blowing traps at even modest power levels. (The
: R5 does not suffer from this problem, in my experience.)  Did the R7000
: cure this problem?

: And how is performance?  Anyone compare it to other verticals?

: Roger J. Buffington
: AB6WR
: 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."




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


From [e-mail] Sun May 19 13:44:17 1996
From: Rich Griffiths <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Radio Shack Tandy Coax any good?
Date: Thu, 16 May 1996 12:29:33 -0400
Message-ID: <[e-mail]>
References: <[e-mail]> <4ndvve$[e-mail]>

David L. Thompson wrote:
>
> "John T. Young" <[e-mail]> wrote:
>
> >Anyone have any opinions on the quality of Tandy RG8/U coax compared to
> >the other main brands such as Belden, etc.? Thanks de John, KI7JB
>
> According to my contacts at Tandy HQ in Dallas the RS coax since the
> early 90's is 96% braid and close to Belden etc.  I use their RG8 on
> two antennas with good success.  They also have a parts division Tandy
> national Parts.
>
> Dave K4JRB

I bought RG-58 and RG-59 from RS a couple of years ago that couldn't
have been more than 60% coverage.

I haven't checked the RG-8, but then "Fool me once, shame on you ...."
I won't make that mistake again.

I don't fault RS on everything, as some do.  I think they do sell some
good stuff.  But coax is not on the list.


Rich W2RG


From [e-mail] Sun May 19 13:44:18 1996
From: [e-mail] (Brian D. Stevens)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Request comments - Larson mag-mounts
Date: 16 May 1996 15:04:43 GMT
Message-ID: <4nfg6b$[e-mail]>
References: <4ndrjl$[e-mail]>


: I am requesting comments about Larson Antenna mag-mounts.  I have
: experienced with two different NMO-MM mag-mounts that corroded inside and
: became disconnected (electrically) from the capacitive coupling surface
: on the base - resulting in high SWR.  Anyone else experience this?

Mine kept falling off at highway speeds and were destroyed before
they had time to corrode.

B


From [e-mail] Sun May 19 13:44:19 1996
From: "Michael C. Maguire" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Request for Info on M2 Antenna Controller
Date: 7 May 1996 18:48:39 GMT
Message-ID: <4mo5u7$[e-mail]>

I have a Model RC2800-PRK Dual Controller from a company called M2 or M-square
d
(depending on how you read the logo).  The controller connects to an az/el
mount suitable for coarse pointing of a helical antenna for satellite tracking
.
Unfortunately, I do not have a complete manual set for either the controller o
r
the az/el drives.  Does anyone have contact information for either M2 or a
sales rep for M2?  Any combination of corporate address, phone, fax, email or
WWW address would be appreciated.

Thanks in advance.  Regards, mcm

--
Michael C. Maguire
Systems Engineer
Earthwatch Inc. - http://www.digitalglobe.com/
Tel: [phone]  Fax: [phone]  Email: [e-mail]



From [e-mail] Sun May 19 13:44:20 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (CB Smith)
Subject: Rogers Antenna System
Message-ID: <[e-mail]>
Date: Sun, 12 May 1996 00:19:19 GMT

Does anyone have details on this antenna ?
Apparently built by the US military in the 1930's and is static-free.

Any ideas ?

de Brian ve3ex
[e-mail]




From [e-mail] Sun May 19 13:44:21 1996
From: Ed Guzis <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: RS telescoping masts?
Date: 13 May 1996 03:54:25 GMT
Message-ID: <4n6bph$[e-mail]>
References: <4n54i5$[e-mail]>


>
>Does anyone out there have any personal experience with those telescoping
>masts from Radio Shack?
>
>TNX ES 73,
>
>Rick WB9GYT
>Milwaukee, WI

Rick,  Suggestion --- buy one 10 feet longer than you need and discard
the top section -- the Radio Shack push ups are a little light duty --
using only the lower sections helps.


Regards,

Ed Guzis W9TW



From [e-mail] Sun May 19 13:44:22 1996
From: [e-mail] (Clint Bradford)
Date: 07 May 96 19:38:00
Newsgroups: rec.radio.amateur.antenna
Subject: Sale
Message-ID: <[e-mail]>





>>Hi Tom here... I have for sale 2 Regency 16ch programable mobiles.

INTERNET TIP #4 -

If the Conference/Newsgrou doesn't have the word, "SALE," in its
title, it is probably inappropriate to post FOR SALE messages in it.

There -IS- a very active FOR SALE area for you on the same system you
posted this message. Please prepare for a little flack from those who
will not-as-gently-as-I-have remind you of the Conference Posting rules.


[e-mail]
... ATTENTION to Details BBS - 909-681-6221 - REACT/GMRS/AMATEUR RADIO
---
 * TLX v4.00 *
 * wcECHO 4.1 ~ AR-Net: ATTENTION to Details * Mira Loma, CA * 909-681-6221
--
|Fidonet:  Clint Bradford 1:2619/228
|Internet: [e-mail]
|
| Standard disclaimer: The views of this user are strictly his own.



From [e-mail] Sun May 19 13:44:22 1996
From: [e-mail] (Clint Bradford)
Date: 11 May 96 02:00:00
Newsgroups: rec.radio.amateur.antenna
Subject: Sale
Message-ID: <[e-mail]>





>>Hi Tom here... I have for sale 2 Regency 16ch programable mobiles.

INTERNET TIP #4 -

If the Conference/Newsgrou doesn't have the word, "SALE," in its
title, it is probably inappropriate to post FOR SALE messages in it.

There -IS- a very active FOR SALE area for you on the same system you
posted this message. Please prepare for a little flack from those who
will not-as-gently-as-I-have remind you of the Conference Posting rules.


[e-mail]
... ATTENTION to Details BBS - 909-681-6221 - REACT/GMRS/AMATEUR RADIO
---
 * TLX v4.00 *
 * wcECHO 4.1 ~ AR-Net: ATTENTION to Details * Mira Loma, CA * 909-681-6221
--
|Fidonet:  Clint Bradford 1:2619/228
|Internet: [e-mail]
|
| Standard disclaimer: The views of this user are strictly his own.



From [e-mail] Sun May 19 13:44:23 1996
From: [e-mail] (BillV21572)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: shortend radials
Date: 9 May 1996 02:02:45 -0400
Message-ID: <4ms1q5$[e-mail]>
References: <4mqp0u$[e-mail]>

I've got 4 little kids and a dog, and if I laid my radials out directly on
the surface of the lawn, they would hand me a ball of wire at the end of
one weekend. Unfortunately, I have a "multi-use" backyard, and even though
Daddy loves his hobby, my kids don't love me <that> much  ;)
Bill ka9hln

Bill Vanstralen  KA9HLN  St. Paul, MN  [phone]  [e-mail]


From [e-mail] Sun May 19 13:44:24 1996
From: Lennart Nilsson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: shunt fed crank up? vs inverted L?
Date: 13 May 1996 10:33:28 GMT
Message-ID: <4n735o$[e-mail]>
References: <4mqv8l$[e-mail]>
To: [e-mail]

I would start with she shunt feed. Why not use a length of old
detoriated coax cable, RG-8 or RG-11, using the shield as a fat
conductor. Connect to the tower at the top below the rotor and
let the coax run down through holes in isolating material
attached to one ft spacers. When the tower is all the way up you
can tighten the bottom end of the coax to a feedthrough isolator
and have the matching components in a waterproof box. You will
get impedance transformation because the gamma "rod" is much
thinner than the tower. Expect several hundred ohms on 160 m, and
that will keep your ground losses down. I have had such an
arrangement on a 65 ft fixed tube mast loaded with a 2 el Quad.
Don=B4t forget radials!
73 de Lennart, SM5DFF



From [e-mail] Sun May 19 13:44:26 1996
From: [e-mail] (Gary Hosler - KN0Z)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Shunt load a tower
Date: Wed, 08 May 1996 13:45:19 GMT
Message-ID: <4mq8or$[e-mail]>
References: <[e-mail]>

[e-mail] (Anthony Simons) wrote:

>Hello all,  Where can I find the best info on shunt loading a tower.  I have
>a ROHN BX-64 (64' self supporting) with a 3 Ele tri-bander with a dual band
>2m/70cm vertical on top.  The tower is grounded on all three legs with an 8'
>rod with 1/2 copper tubing to each leg.  I would like to use the system on
>40/80 Meters.  Any and all suggestions appreciated.
>                                       Thanks & 73,  de Anthony KC8BK

Sorry to have taken so long to respond to your post but I knew I had
an article stashed away on a similiar installation.  The August 1990
issue of CQ Magazine had an article (on page 46) by Gary Nichols -
KD9SV, and Lynn Gerig - WA9GFR.  The article described shunt feeding a
70 foot tower with a TH6-DXX on top.  Sounds like a VERY similiar
instalation to what your are proposing, and this article also included
the 160M Top Band.  I plan to shunt feed my 100 foot Rohn 25G (with 15
feet of mast out the top) this Summer in preperation for the
Fall/Winter season on Top Band.  Good luck on your project.

                        73 & GUD DX OM  de KN0Z  Gary in Wyoming, MN

Opinions expressed herein are my own and may not represent those of my employe
r.


From [e-mail] Sun May 19 13:44:26 1996
Newsgroups: rec.radio.amateur.antenna
From: John Van <[e-mail]>
Subject: Simple 17M 3ele Yagi
Message-ID: <[e-mail]>
Date: Sat, 18 May 1996 13:53:44 GMT

Can anyone give me a simple design layout for a 3ele 17M antenna? I've
looked thru my past issues of QST and all I find are multi-band 12-17 or
those requiring Traps.....Not what I'm looking for.

Thanks in advance for any help........John / N1ONM



From [e-mail] Sun May 19 13:44:27 1996
From: Edward Oros <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Simple 17M 3ele Yagi
Date: Sat, 18 May 1996 10:51:39 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>

Yes...

Try
             http://www.4w.com/ham/antenna

you can have an antenna designed there.


Ed-- AC3L



John Van wrote:
>
> Can anyone give me a simple design layout for a 3ele 17M antenna? I've
> looked thru my past issues of QST and all I find are multi-band 12-17 or
> those requiring Traps.....Not what I'm looking for.
>
> Thanks in advance for any help........John / N1ONM


From [e-mail] Sun May 19 13:44:28 1996
From: William R Liporace <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: TH6 Info
Date: Thu, 16 May 1996 10:24:46 -0400
Message-ID: <[e-mail]>

Is there a number for Telex/HyGain ??
I would like to check out prices of their SS hardware for the TH6 or
maybe an upgrade kit to a TH7.  I am getting ready for that first tower
project and I want everything to be ready to go up.
TNX 73 Will KB2HUN

William Liporace KB2HUN          [e-mail]
325 Mountain Street              KB2HUN @ K2TR (yccc packet cluster)
Albany, NY 12209                 KB2HUN @ WA2PVV (NEDA)
518-449-1397 home                518-471-2837



From [e-mail] Sun May 19 13:44:29 1996
From: aor <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Tracking Line Noise * one solution !
Date: Sun, 12 May 1996 15:28:17 -0400
Message-ID: <[e-mail]>
References: <4n2p31$[e-mail]>
To: "Henry B. Smith" <[e-mail]>

>
> I want to track down some line noise.
>
> I have seen the power company folks using a receiver with a small yagi.
>
> Anybody know what frequency they use for tracking noise?  What kind of
> receiver is best for tracking line noise?
>
> Smitty, NA5K
> --
> Henry Smith ([e-mail])


Henry,

We had the power company come to one of our meetings
to discuss this subject.  It was a packed house!!!

They have a tool, which is on the end of a 10' PVC
tube, that has two sensors on the top.  One is a
microphone and the other a simple AM detector.
All powered by an internal battery, so nothing
conductive comes even close to the operator.

The sound travels down this tube to the operator
who can 'hear' what's going on.  Really neat!!

I use a simple $10 AM radio tuned to 530 AM.  Each
power pole has a gound wire running into the soil.
I hold the radio next to the ground wire, and on
really bad poles, you hear lots of noises.  I simply
record the number stamped on the pole and make a
telephone call to the interference staff at the
power company.


73, and best of luck.

Al NW2M


From [e-mail] Sun May 19 13:44:30 1996
From: [e-mail] (Darrell kimball)
Newsgroups: rec.radio.amateur.antenna
Subject: variable capacitor
Date: Tue, 14 May 1996 14:39:35 GMT
Message-ID: <[e-mail]>

anyone know where I can buy or "get" a 3 section, 100 pf variable
capacitor? High voltage not needed.Thanks
E-Mail [e-mail]


From [e-mail] Sun May 19 13:44:31 1996
From: Miguel Angel Simoes Santiago <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Vertical 40M antenne
Date: Mon, 13 May 1996 19:07:03 +0000
Message-ID: <[e-mail]>

Is it possible to use my tower as a 1/4 Lambda vertical
antenna?

        I was thinking to match impedance with a GAMMA Match, but I'm
not really sure it will work.

        Any suggestions?



                /  /  /
               /  /| /
                   |
                   |
                   |
                   |
                   |
                   ||
                   || GAMMA
-------------------/
   Gound Radials
     sticked on the earth


                               Miguel Santiago CT2GDD
                                   [e-mail]


From [e-mail] Sun May 19 13:44:32 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Very small Antennas
Date: 8 May 1996 18:29:28 GMT
Message-ID: <4mqp68$[e-mail]>
References: <[e-mail]>

Doug Person ([e-mail]) wrote:

: Now I want to reduce a 40 meter antenna to about 25 ft.  That's all the spac
e I
: have, if I want 40, it must fit in the 25 foot available in the attic.  I gu
essed
: lucky with the 20.  How can I calculate the loading coils for the compact 40
?
: I made one using aluminum tubing and fiberglass coil forms hoping to have so
mething
: I can run my 600 amplifier into.  My guess was way off - 16ft #14 on 1.25od
form and
: about 10 ft of 1" tubing per leg - resonates at 9.745.  I can continue to mo
dify
: deminsions until I get it right - but that is a a lot of attic climbing.  An
y
: suggestions?

Yes, my standard reference for just this sort of thing is an old "Ham
Radio" magazine article by Joseph Boyer, "The Antenna-Transmission Line
Analog."  It was in the April and May, 1977, issues.  It goes into exactly
how to make good engineering-accuracy calculations of loading coils
anywhere along the antenna, and gives you a lot of appreciation for how
linear antennas work, and why one loading-coil position is better than
another.  Since you likely will have trouble finding these issues of
Ham Radio, I have a standing offer to send photocopies of the article
for a SASE and photocopy costs.  It's 24 pages, including some relevant
pages of one of the references which plots antenna impedance versus length
and wire diameter (necessary info to fully use the Boyer article).  Send
me email if interested.


(Design of very short vertical + matching network deleted.)

: Here's the bottom line:  I have no education in this stuff.  I'm just guessi
ng at what works.
: Does this really do something or am I just tuning a coax longwire?  Can I do
 anything to improve
: this concept?  Anyone have suggestions, thoughts, ideas, anything at all the
y wish to contribute?

I'm impressed that it looks like basically a pretty decent design for easy
duplication by hams.  Things to consider:  the feedpoint impedance of a
very short antenna is a very small resistance in series with quite a bit of
capacitive reactance.  That means you need a lot of current to get
radiation (from the low resistance), and a high voltage, to get the current
through the capacitive reactance.  It's hard to make a low loss matching
network for that; pay attention to anything that will be lossy.  Look up
info on optimum coil geometry.  Avoid insulations at the high impedance
points which might be lossy (hint:  Teflon or polystyrene are much, much
less lossy than Nylon).  Provide _some_ kind of reasonably low loss
ground system (several heavy radial wires across the roof?), and make the
actual antenna radiator as long as you can (to raise the resistance) and
as large diameter as you can (to cut losses from the high current flowing
on the surface of the antenna).  (Another hint:  the matching network, if
it's low loss, will be rather high Q, which implies narrow bandwidth.  If
you are getting much bandwidth, it's a clue that you have a lot of
losses besides the radiation from the antenna...)

I'd like to encourage you to keep learning.  You are making some good
early guesses, and with some understanding behind the guesses, you will
probably come up with some really neat -- and reasonably efficient --
designs.

--
Cheers,
Tom
[e-mail]


From [e-mail] Sun May 19 13:44:34 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Very small Antennas
Date: Thu, 09 May 96 09:25:09 GMT
Message-ID: <4msdjf$[e-mail]>
References: <[e-mail]> <4mqp68$[e-mail]>

In article <4mqp68$[e-mail]>,
   [e-mail] (Tom Bruhns) wrote:

> [lots of excellent advice]. . .

>. . . (hint:  Teflon or polystyrene are much, much
>less lossy than Nylon). . .

I was looking in some references recently for other low-loss materials, and
polypropylene looks from the specs to be very good also. And it has a
relatively low dielectric constant. One big minus is that it's very
susceptible to UV deterioration, so I wouldn't use it outside for an
extended period unless you can keep the sunlight off of it. Does anyone
have any experience with it as a high-quality insulator or have any
information that would confirm or refute the premise that it's good?

(This is the stuff you can buy at any discount store as "floating rope".)

Roy Lewallen, W7EL


From [e-mail] Sun May 19 13:44:36 1996
From: [e-mail] (Graham Seale)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Very small Antennas
Date: Thu, 09 May 1996 20:38:39 GMT
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

In message <[e-mail]> Doug Person wrote:

> I have made a 20 meter dipole that is 22 ft instead of the usual 33 ft to
> fit between two conveniently located trees.  This gives me a second antenna
> for 20, 90 degrees from the original favoring north/south signals.  I used s
ome
> pvc pipe and about 8 ft of #14 insulated stranded wire close wound to make a
> loading coil for each leg - mounted more or less in the legs center.  With 1
00
> watts it works great.  SWR on the full size 20 is under 2:1 edge to edge. On
 the
> loaded 20 I loose about 100 khz of bandwidth and otherwise find it comparabl
e.

Hi Doug

Before you get too entangled in dissipating the highest current
contributions from your antenna in loading coils, try a very simple
approach. An antenna shorter than resonance will still deliver
radiation energy, but will appear capacitive at the feedpoint. To
match a feed to it you need to add inductance to tune out the
capacitive component leaving you with something like a unity power
factor. This "matcher" is your loading coil.

My instinct would be to duck the need for such lossy narrow band
things. I would leave the full 33ft of wire in the dipole, but
arrange the middle 22ft to be horizontal, and let 5.5 feet dangle
down vertically at each end. If this be inconvenient, then fold
back the 5.5 foot dangly into a loop back to the support insulator.
Do not let the high voltage end connect back to support point.

The idea is to force the current to go the distance down the wire
the full 33ft. The folded back bit is the beginnings of an *end*
loading coil, and will affect the resonant length a bit, but we
resist madly making it any more of a loading coil than we absolutely
have to. This way, you only mourn the loss of the very little
contributions from the ends. If they dangle down, they provide a
little vertical component. If you fold them back, the folded part
cancels some in the descending part anyway.

In practice you will probably find you can fold up the ends of a
resonant dipole with very little effect on the tuning, but do it as
you would any new dipole - start with a bit extra splaying off the
ends, and tune it to resonance by cutting off some inches each side
and checking the resonance with a dip meter/noise bridge or somesuch.

73's G4WNT

--
Graham Seale


From [e-mail] Sun May 19 13:44:37 1996
From: [e-mail](David M. Arruzza)
Newsgroups: rec.radio.amateur.antenna
Subject: WB3U/W7EL/W7XC & OTHERS
Date: 18 May 1996 15:36:06 GMT
Message-ID: <4nkqp6$[e-mail]>

need your input:
due to rearrangement of shack i cannot feed my center fed hertz
antennas  directly at the link coupled tuners. I may have to go to a
remote balun and an spc,L or T net coupler. Operating position is 20
feet from access point.

Antennas to be used: 270' center fed with 450 ohm line 160/80/40
                      88' center fed with 600 ohm line  40/30/20/17
                     130' center fed with 450 ohm line  80-20
                      70' center fed with 450 ohm line  40-10

feedline lengths are 85'


power output 110 watts 830S

Gentlemen your comments and suggestions

73 Dave WA1UUD


I am not crazy about the remote balun/coax/tuner combo but i need some
more options.

I have tried bringing the feedline all the way to the tuners but i have
had reports of RF on the signal and rf floating around the shack.

Operating power is 110 watts output with an 830S


From [e-mail] Wed May 22 18:46:12 1996
From: [e-mail] (ELITECON)
Newsgroups: rec.radio.amateur.antenna
Subject: pro-2037(radio shack)
Date: 20 May 1996 09:37:34 GMT
Distribution: 99
Message-ID: <4npegu$[e-mail]>
Summary: for cellular receptions
Keywords: whats the best transportable antenna

please help


From [e-mail] Wed May 22 18:46:13 1996
From: @wtp.net (MSBF)
Newsgroups: rec.radio.amateur.antenna
Subject: MFJ Hi-Q Loop antenna
Date: 20 May 1996 03:43:50 GMT
Message-ID: <4noppm$[e-mail]>

Has anyone used this antenna and if so, what do you think of it?
WT5C Jim Edlin



From [e-mail] Wed May 22 18:46:14 1996
From: jyfourri@simplet_3.univ-lr.fr (FOURRIER Jean-Yves)
Newsgroups: rec.radio.amateur.antenna
Subject: plot a nec calculation
Date: 17 May 1996 17:10:21 GMT
Message-ID: <4nibtt$[e-mail]>

Hello , i am looking for a prog to plot the nec calculation
(bandwith,elevation and azimut pattern) , i you know a freeware with this
possibility , please send me a E-mail thanks
Dominique F1DOQ


From [e-mail] Wed May 22 18:46:15 1996
From: [e-mail] (EIRINGO)
Newsgroups: rec.radio.amateur.antenna
Subject: Stereo radio antenna quiry
Date: 17 May 1996 16:02:47 -0400
Message-ID: <4nim17$[e-mail]>
Reply-To: [e-mail] (EIRINGO)

I have a SWR and scanner fed thru an AlfaDelt antenna switch and grounded
50 ohm coax. No problems. Question, how to connect a stereo receiver with
holes for 75 and 300 ohms? Why does connecting both ends of a FM dipole
decrease
sensitivity? Any help appreciated. Cody


From [e-mail] Wed May 22 18:46:15 1996
From: [e-mail] (DRW1)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 80mtr loop (cloud warmer)
Date: 19 May 1996 10:54:30 -0400
Message-ID: <4nncn6$[e-mail]>
References: <4ngmqn$[e-mail]>
Reply-To: [e-mail] (DRW1)

I installed a full wave 80 mtr loop about 2 months ago.  It loads well
(with a tuner) form 80 - 10.  If it ever goes down I will replace it with
on cut to 40 mtr., it takes up a little less space, but, as it stands now,
I wish I would have discovered this thing a long time ago.

Don


From [e-mail] Wed May 22 18:46:16 1996
From: David Rice <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Fomula to get SWR from foward and reflected power
Date: Mon, 20 May 1996 17:08:19 -0700
Message-ID: <[e-mail]>
Reply-To: [e-mail]

I have a watt meter that reads foward and reflected power.
The meter does not measure SWR nor does the manual offer any
way to calculate SWR.

Is there a formula that given foward and reflected power would
give me SWR.


From [e-mail] Wed May 22 18:46:17 1996
From: Edward Lawrence <eal>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR antenna - reference: RE flagpole antennas
Date: 20 May 1996 16:08:16 GMT
Message-ID: <4nq5dg$[e-mail]>
References: <4nfi1d$[e-mail]> <4nii04$[e-mail]>

Last I knew, DDRR stood for 'Dual Discontinuity Ring Radiator'.  The basic
antenna was a DRR, or Discontinuity Ring radiator, which is what Jim is
describing.  The theory is idiotic!  However, this antenna does work, which
just shows that you can get practical results even with a faulty theory.
        This antenna is really a variation of a slot antenna, bent into a
circle.



From [e-mail] Wed May 22 18:46:18 1996
From: [e-mail] (Phil Brown)
Newsgroups: rec.radio.amateur.antenna
Subject: Using 2m Colinear for Base Antenna?
Date: Fri, 17 May 1996 21:49:10 GMT
Message-ID: <4nil7v$[e-mail]>
Reply-To: [e-mail]

After several inactive years, I am getting back into hamming. I have
forgotten most of what I knew about antennas, it seems. I have an
unused 2 meter Hustler coaxial colinear antenna, formerly used mobile.
Has anyone had any success using this antenna as a vertical base
antenna? How did you mount it, and did you use any counterpoise?

Thanks.  -Phil N4COD



From [e-mail] Wed May 22 18:46:19 1996
From: [e-mail](Anthony Severdia)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need plans for SHORT 40 meter antenna
Date: 21 May 1996 08:39:08 GMT
Message-ID: <4nrvfc$[e-mail]>
References: <4nrel3$[e-mail]>

In <4nrel3$[e-mail]> [e-mail] (Mark Lebbin) writes:
>
>I am moving into a duplex and I need a very short antenna so I can
stay
>on the ham bands.  Any suggestions?
>
    Yah ...looking for a Magic Answer?   ...with no criteria?
Ya better pound the the books a bit! ...to see what fits.


From [e-mail] Wed May 22 18:46:20 1996
From: [e-mail] (Gerald Phillips)
Newsgroups: rec.radio.amateur.antenna
Subject: Plans wanted for an inexpensive 2m antenna to go outside.
Date: Tue, 21 May 1996 22:47:29 GMT
Message-ID: <4nth5q$[e-mail]>

I am looking for plans/information for an inexpensive 2m antenna that
can be mounted outside.  Please email me if you have anything.
Thanks.

KE4MBD - Travis





From [e-mail] Wed May 22 18:46:20 1996
From: [e-mail] (DaddyDavid)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 80mtr loop (cloud warmer)
Date: 22 May 1996 08:54:19 -0400
Message-ID: <4nv2pr$[e-mail]>
References: <4ngmqn$[e-mail]>
Reply-To: [e-mail] (DaddyDavid)

There is a good practical discussion in W1FB Antenna NB. I've built
several. Simply. PVC insulated wire allows one to reduce the size by .66.
Full size is better. Very forgiving. Symmetry is impt.
Use a Johnson Match Box for best multibad performance.

Give it a try!

de N9PVF


From [e-mail] Wed May 22 18:46:21 1996
From: [e-mail] (Ed  Buchanan)
Newsgroups: rec.radio.amateur.antenna
Subject: 6 M Antenna Tested
Date: Sun, 19 May 1996 20:19:07
Message-ID: <4nop5l$[e-mail]>

Saturday 5-18-96 Cubex Co. tested their new 4 element 6 meter quad
which is designed to be a sideband antenna. This antenna has over
12 dbd gain, this is due to the relatively narrow bandwidth
(50.0-51.0 Mhz.) vswr less than 1.7-1 and resonant at 50.3 the
resonant point can be changed slightly (.5 Mhz) with the unique
Cubex adjustable feed point. Front to back was 15-18 db with a
clean pattern and no strange lobes. This antenna will be available
by the first of June, 1996.
"73" Ed KN6CL



From [e-mail] Wed May 22 18:46:22 1996
From: "Andrew D. Lawlor" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Info wanted on On-Glass Dual Band Ants.  (Larson, Radio Shack, etc.)
Date: Fri, 17 May 1996 16:13:46 -0500
Message-ID: <[e-mail]>
References: <4nhhn2$[e-mail]>
Reply-To: [e-mail]
To: Cobra295 <[e-mail]>

Regarding the Radio Shack "dual band" glass mount 2M/70cm antenna:
It isn't.  Well, okay, it is, sort of.  You can only use it for
one band or the other, not both.  If you want to switch from 2m
to 440 you have to add a radial & re-tune the antenna.  I bought
it and installed it before I realized that it wouldn't work on
both bands without a modification each time.  So, for 40 bucks
you get one or the other.  (And, as a side note, on 2M you lose
an incredible amount of gain when compared to a 5/8 wave 2m
mag-mount).  I would give it two thumbs down. Spend the extra
money and get a true dual band antenna.  73  KC6NMD Andy


From [e-mail] Wed May 22 18:46:23 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Jens Goerke)
Subject: Re: Foil Shield Coax
Message-ID: <[e-mail]>
References: <[e-mail]>
Date: Sat, 18 May 1996 14:59:32 GMT

Cougercat ([e-mail]) wrote:
> Does anybody know where one can pick up coax that has a foil shield as well
> as a copper braided shield?  Something simular to Larsen Anttenna Co.
> "Digi-Shield" coax but NOT from Larsen?  I need it in RG-58 and RG-8 size.

I've seen the RG-58 variety used for high-quality 10-base-2 EtherNet
installations, so you might give it a try. It's kind of stiff, though.

Hope that helps,
        Jens, DB9LL
--
Do _YOU_ know where your towel is?


From [e-mail] Wed May 22 18:46:24 1996
From: Ed Sikorski <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: WTB: Fiber Glass Pole for Boom
Date: Wed, 22 May 1996 11:15:50 -0400
Message-ID: <[e-mail]>

Thanks for taking the time to read this.

I am looking for a fiber glass pole 1.5" or 2" in diameter and 32' - 35' long
to be used as a
boom.  I want to build an 2 element 80m dipole paristic array that is describe
d in the Low
Band DXing book by ON4UN.  If you know were I can purchase such an item please
 let me know via
email at [e-mail].

If you have any options on boom material please let me know via email.

73

ed AA8PA


From [e-mail] Wed May 22 18:46:25 1996
From: [e-mail] (EIRINGO)
Newsgroups: rec.radio.amateur.antenna
Subject: Stereo Antenna
Date: 20 May 1996 12:03:06 -0400
Message-ID: <4nq53q$[e-mail]>
Reply-To: [e-mail] (EIRINGO)

By SWR I mean a short wave receiver (HF150). Connecting both ends of a300
ohm line FM dipole into a stereo's 300 ohm holes wipes out all but the
strongest signals. Such radios have holes also for 75 ohms also, but no
jacks. I wired a 239
jack and have tried straight to the 300 ohm leads inside the radio, as
well as thru
a standard 75/300 converter. In both cases no sound from the lead, only
from a
small AM loop, also commonly supplied with these stereo radios. Maybe such
radios are easily overloaded? The mono FM on my RS2006 is very good, using
the outside antenna setup. Cody




From [e-mail] Wed May 22 18:46:26 1996
From: [e-mail] (Eugene Kays)
Newsgroups: rec.radio.amateur.antenna
Subject: Mounting Advice
Date: 17 May 1996 17:20:31 GMT
Message-ID: <4nicgv$[e-mail]>

I am recently purchased a new Dodge RAM pickup.  I need ideas on how to
get a mobile antenna mounted.  The antenna I have and had planned to
reuse is a Diamond 7900.  I lillte taller than a 5/8 2M.  I have a camper top
on it and this means no edge area of the bed is available.  I don't want to
use a glass mount installation.  My main operation in the mobile is on
simplex and I do not want to give up on the range obtained by the Diamond.

Any ideas would be welcome.

Thanks es 73, Gene
[e-mail]
KA5ALN



From [e-mail] Wed May 22 18:46:26 1996
From: [e-mail] (Cecil A. Moore~)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Testing a balun with a noise bridge question
Date: 21 May 1996 15:44:52 GMT
Distribution: world
Message-ID: <4nsodk$[e-mail]>
References: <4noats$[e-mail]> <4np283$[e-mail]>

In article <4np283$[e-mail]>,
Cecil Moore  <[e-mail]> wrote:

>Your measurements look
>reasonable and the balun will work just fine assuming a load
>close to 50 ohms.

Forgot to add that a balun has a lower frequency limit and an
upper frequency limit. A balun designed for 30m may not have
enough inductance on 80m and may have too much capacitance
on 10m. A flat response from 3 to 30 MHz is extremely difficult
to achieve (impossible for me :-)

73, Cecil, KG7BK, OOTC  (not speaking for my employer)


From [e-mail] Wed May 22 18:46:27 1996
From: [e-mail] (Guy Teague)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Miracle Baby by Comet
Date: 21 May 1996 04:02:45 -0400
Message-ID: <4nrtb5$[e-mail]>
References: <[e-mail]>

Andrew Lin ([e-mail]) wrote:
: I have a Kenwood TH-79AD HT and I am looking for a smaller antenna to
: replace the original one.  I have the Miracle Baby by Comet in mind.
: Any suggestions or comments would by appreciated.

: Thanks in advance.

: Andrew
--------

Well ... it's small.
--
Cheers  73 de  [e-mail]  "They're out there"              K Kesey
Guy     KG5VT  [e-mail]  "Hey don't eat that yellow snow" F Zappa


From [e-mail] Wed May 22 18:46:28 1996
From: Jake Brodsky <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: DDRR antenna
Date: Mon, 20 May 1996 16:16:24 -0700
Message-ID: <[e-mail]>
References: <4nfi1d$[e-mail]>

I have seen the DDRR antenna in ARRL literature for years.  I've read
a lot about WHAT the DDRR is.  I haven't seen anything about HOW it
works or WHY it is built the way it is.  Does anyone have
performance data on this beast?  What trade-offs does it have?  Can
one make concentric DDRR antennas for more than one band?  If someone
doesn't reply soon, my curiousity may get the better of me and I might
just have to build one...

73,

Jake Brodsky, AB3A
<[e-mail]>
Cessna Cardinal N30946
PP-ASEL-IA
"Beware of the massive impossible!"


From [e-mail] Wed May 22 18:46:29 1996
From: [e-mail] (Mak Wai Han Maria)
Newsgroups: rec.radio.amateur.antenna
Subject: yagi antenna question
Date: 21 May 1996 13:51:37 GMT
Message-ID: <4nshp9$[e-mail]>

hello eveyone,
    recently i bought a yagi 5 element 50w 144-146mhz antenna
    it works fine
    unforturnately, one of the director(the one closest to the emitter)
    is broken into 2 pieces.
    i wonder whether it is possible i just use some super glue
    to glue them together?
    is the director need to be conducted?('coz if i use glue
    it will not conduct)
    if anyone knows it , please email me!!

    Thanks!

VR2ZPM
5/21/96


From [e-mail] Wed May 22 18:46:30 1996
Newsgroups: rec.radio.amateur.antenna
From: Monty Wilson <[e-mail]>
Subject: Re: 80mtr loop (cloud warmer)
Message-ID: <[e-mail]>
Date: Wed, 22 May 1996 13:53:05 GMT
References: <4ngmqn$[e-mail]> <[e-mail]>

Siegfried Rambaum <[e-mail]> wrote:
>On 17 May 1996 [e-mail] wrote:
>
>> Looking to build a 80mtr loop about 20' off the ground...
>
>*thinking* ... I just cannot imagine how you would get a sensible loop
>for eighty with just 6 meters above the ground....

I can't explain it myself, but my loop is about 20' up on one end and
about 30' up on the other side, and I'm getting great reports on 75m
from all around Texas.  Best of luck with your loop.  And by the way,
you might consider trying it with just a balun before you hook up your
tuner.  You might be surprised what it can do without tuning.

--
.........Monty.
[e-mail]




From [e-mail] Wed May 22 18:46:31 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: WB3U/W7EL/W7XC & OTHERS
Date: 21 May 1996 16:21:03 GMT
Message-ID: <4nsqhf$[e-mail]>
References: <4nkqp6$[e-mail]> <4nqu4m$[e-mail]>

Cecil Moore <[e-mail]> wrote:
>I have a Ladder-Line Length Selector
>remotely switched with 6 4PDT relays that gives me 0-63 ft variable
>lengths in increments of one foot.

For anyone looking for cheap relays for ladder-line switching, there's
a good one in the latest All Electronics catalog (1-800-826-5432).

Omron LY2-0-DC24 are DPDT rated at 12 amps at 240vac. Their dielectric
strength is rated at 2000vac. They are priced at $2 each Cat# RLY-145.
Using 12 of these relays, one can build a 0-63 ft. Ladder-Line Length
Selector for $24 (plus ladder-line and 6 remote toggle switches).

IMO, these relays will handle 150 watts with no problem. I'm going
to try them at 600 watts. Anyone interested in details, email me at
[e-mail]

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Wed May 22 18:46:32 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Coax cable shielding - Help please
Date: 20 May 1996 12:29:53 -0400
Message-ID: <4nq6m1$[e-mail]>
References: <[e-mail]>

There is magnetic (and electric) field coupling between the shield and the
center conductors. It causes the center conductor (if the center is
floating without a return path from end to end) have equal in phase
voltages with the shield area next to each area of the center conductor.
The result is there is no potential difference between the center and the
shield, Faraday is happy with that mode.

Imagine we are flea sized people crawing in the cable with a RF voltmeter.
We could NEVER measure any potential difference with our meter IF the
center conductor is unterminated at both ends and we confine our
measurements to things INSIDE the cable.

We can't measure current or voltage INSIDE the cable with our little
meter.

If we crawl back on the outside, we will measure exactly the same voltage
end to end on the center as on the shield. The coax (twisted or coiled,
straight or bent) is indeed a transformer.

How the cable behaves depends more on what we do with our outside world
connections than how many "shields" we have.

73 Tom


From [e-mail] Wed May 22 18:46:33 1996
Newsgroups: rec.radio.amateur.antenna
From: Monty Wilson <[e-mail]>
Subject: Re: 11 meter antenna for 10 meters
Message-ID: <[e-mail]>
Date: Tue, 21 May 1996 20:32:29 GMT
References: <4nsr4t$[e-mail]>

[e-mail] (Phil Brown) wrote:
>Getting back into hamming after several years lapse. Got an old 1/4
>wave CB mobile fiberglass antenna left by my father in law. Anyone
>ever use one of these for 10 meters?

Lots of folks will tell you that there's no point in making a ground
plane for 10m unless it's 5/8 wave.  I caution against such a blanket
statement.  I picked up a CB ground plane cheap when I first got
back into radio several years ago.  I shortened the radial
elements, and removed the loading coil from the driven element and
shortened that also.  Yes I think it works much better if you have
all the radial elements at 1/4 wave.  I worked several countries
on it, and had loads of fun until I got the Butternut and didn't
need the ground plane anymore.  I ended up getting the same $20
back out of it that I had originally paid.

Back when I was converting CB rigs for 10m and 12m use, I did make
some 10m mobile antennas by shortening CB antennas, but always the
whip types, never fiberglass.

--
.........Monty.
[e-mail]




From [e-mail] Wed May 22 18:46:34 1996
From: [e-mail] (Mike Obermeier)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Foxhunt antenna?
Date: Wed, 22 May 1996 05:58:39 GMT
Message-ID: <4nua7n$[e-mail]>
References: <4nfm8j$[e-mail]>

[e-mail] (David Black) wrote:

>I'm looking for information on how to build foxhunt/T-hunt
>handheld antennas for 2m, 440 and 1.2. We have some creative
>people here in the Bay Area who've sent along some idears,
>and I'm told there is a book by the ARRL available too.

>I'd like to build something that's small enough to use while driving
>around in a car, while attached to an HT.

>Cheers,

>Dave KE6AJC

If hunting while mobile is your goal you'll get great results with any
version of the build it yourself quad.  Rig yourself a window mounted
mast with the quad on top.  Put an attenuator inline to knock down the
signal as you get closer to the fox.  You could even build multi-band
quad ( tuned elements for each band mounted on the same mast).  This
arrangement could be stored in the trunk when your not using it.  If
you plan to hunt with your HT prepare yourself for lots if intermod, a
helical filter may be in order.  "Transmitter Hunting- Radio Direction
Simplified" by K0OV/WB6UZZ is a very good reference and has some
simple & easy to build antenna projects. Happy Hunting!

73 de KD6SNE  Mike Obermeier , ARRL  O.O.



From [e-mail] Wed May 22 18:46:35 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: J-pole vs. half wave dipole.
Date: 17 May 1996 18:10:08 GMT
Message-ID: <4nife0$[e-mail]>
References: <4ng8j6$[e-mail]>

Gary V. Deutschmann, Sr. ([e-mail]) wrote:

(re: feeding a half-wave vertical against a counterpoise
instead of using a J-pole)

: Not everyone has room for a counterpoise!

It doesn't take much.  I did some modeling of feeding a
halfwave against minimal radial systems, and found as I
recall that even feeding against two, three or four
1/8 wave radials yielded slightly higher gain than
a J-pole.  Each assumes perfect decoupling from the
feedline; the halfwave-over-radials system also assumes
lossless impedance matching.

One of the most attractive things about the J-pole design
is that there are no insulators under tension; the
end-fed halfwave-over-radials looks like it's going to
need an insulator for the radiator, unless it's
perhaps the extension of the center conductor of
a quarter wave coaxial stub which is below the radials...
that might not be a bad mechanical design to duplicate
in a ham's workshop.

--
Cheers,
Tom
[e-mail]


From [e-mail] Wed May 22 18:46:36 1996
From: [e-mail] (Koellner, Guenter)
Newsgroups: rec.radio.amateur.antenna
Subject: ? Inductance for 5/8 lambda
Date: 15 May 96 19:21:00 GMT
Message-ID: <[e-mail]>


Hello all,

I want to build a 5/8 wavelength vertical for 29.250MHz and 14.200MHz as
I got a flexible length military antenna.

freq    wavelength  5/8
29.250  10.256m     6.4m
14.200  21.127m    13.2m

Now a question: what is the value of the coil to be added on the base for
each system to match it to a 50ohm cable?

What is the inductance that is needed to use the 6.4m long antenna on
14.200MHz? That if I do not want to change the length of the antenne while
QSY?

All would lead to an coil with two taps:

 - full coil for using the 6.4m long antenna on 20m
 - next tap to use the 13.2m long antenna as 5/8 on 20m
 - shortest tap to use the 6.4m long antenna on 10m

Do you agree? Can anyone tell me the inductance needed for that?

Would you please send a copy of your answer to my personl email?

vy 73, Guenter, DL4MEA@DB0KCP.#BAY.DEU.EU   (AX.25)
                [e-mail]            (Internet)
                http://www.scn.de/~koellner (WWW)


From [e-mail] Wed May 22 18:46:39 1996
From: [e-mail] (Zacharias Liangas)
Newsgroups: rec.radio.amateur.antenna
Subject: questions on loop antenna
Date: Tue, 21 May 1996 10:21:49 GMT
Distribution: world
Message-ID: <4ns4v4$[e-mail]>
Reply-To: [e-mail]

Friends

These last days I have made some experiments with my new loop antenna.

It is made in a woodenbut relatively sensitive  frame as two points of
it have crashed due to use of very long (9 cm) nails ( and of
thickness 1.4 mm )
These  rods are of 1.5 m X type in which  the wire forms a square area
rather than the 'classical' rhombic.
After this i have put a wire of 1.0 mm hard type for 11 windings on
the wooden fame (non standed) which  not 100 % formed a coil as some
wounds had a tolerance from the exact square of max .6 cm
Finally after building it I tested  it with and without capacitor for
its main use in MW
To my surprise the antenna did not show resonace  with capacitor  but
inly without capacitor  and at the first 2-3 wounds !
Its results were s not so satisfactory for me as the LOwe HF150  in
its ATT position, together with 8 m of RG 59 and clips to the
antenna's zero and 2 nd  wound showed lower signals than of mine AIWA
J150
The nice of the antenna is that it showed good results with its nulls.
IN less than 5 degrees the antenna could null out many signals except
of the two local stations of 50 kW
I do not know why the antenna  does  not  work properly ( ie with the
capacitor in paralell )
What do you think I need? To change the  wire with a flexible so that
geometry can be 99.5% accurate ? Or I need anything other ?

I have tried the same project two years ago with a rhombic frame in
which  the antenna worked properly with the variable capacitor


Zakaria Liang!
(namanya untuk kawan sahaja!)



From [e-mail] Wed May 22 18:46:40 1996
From: [e-mail] (Bob Boardman)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR antenna - reference: RE flagpole antennas
Date: 17 May 1996 18:53:56 GMT
Message-ID: <4nii04$[e-mail]>
References: <4nfi1d$[e-mail]>
Reply-To: [e-mail]

In article <4nfi1d$[e-mail]>, [e-mail]
 (Jim Flanders) writes:
>
>When I answered the article - flagpole antenna - many people emailed
>me with a question on what is a DDRR antenna. See ARRL Antenna manual
>page 6-9.DDRR is short for Directional Discontinuity Ring Radiator.
>First described in Electronics, Jan 1993.  Later research described in
>July 1972 by W2WAM.  Imagine the antenna as a small ring insulated just
>above a ground plane.  Distance above the ground plane is 0.0069 wave
>length.  Ring diameter is 0.078 wavelength. The coax feedpoint is 0.25
>of distance above ground plane.  The far end from the feed is tuned
>with a capacitor to ground. The diameter of the conductor is large; i.e
>40 meters is 2 inches.  I recently built one for 40 meters, and it is
>mounted to look like a car carrier on top of my VAN.  I had a muffler
>shop bend and weld the 2" pipe. It is first mounted on a plywood frame
>that is covered with copper screen. A motor (from tanner electronics)
>tunes the capacitor. The whole thing is topped with a fibreglass cover,
>and the unit is demountable from the van, and can be operated while
>placed on my outshed. Size of the plywood is 5' X 11'.
>Jim W0oog/5 in Plano on 147.180
>
    OK, let me work this out.  40m * .078 = 10 ft 3 in diameter, and
  40m * .0069 = 10.87 inches.  The 10' 3" diameter would make it kind of
  wide for most vehicles.  But the circumference would be 10'3" * 3.14159...,
  about 32 ft., and you say you used a 5' x 11' plywood base, which would
  have a "circumference" of 11+11+5+5= 32 ft., so I guess your "ring" is
  actually a 5' by 11' rectangle, mounted 10.87" above the ground plane?
  And you say the correct pipe diameter is 2" for 40m - is this calculated
  as 2"/40m = .0013 wavelength, for other wavelengths?

    But the big question is, How well does it work compared to other
  mobil 40m antennas?

  73,

  -Bob

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
=
| Bob Boardman, Albuquerque, New Mexico - KC5SFW - ARRL, Upper Rio FM Society
|
|         <[e-mail]>     PGP 2.6.2 public key available
|
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
=


From [e-mail] Wed May 22 18:46:41 1996
From: [e-mail] (Dale Chidester)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Plans wanted for an inexpensive 2m antenna
Date: 22 May 1996 12:49:20 GMT
Message-ID: <4nv2gg$[e-mail]>
References: <4nth5q$[e-mail]>
Reply-To: [e-mail]

They don't come much cheaper than this one!

73,
        Dale


        Plumber's Special 2 meter Vertical Dipole

A number of years ago, I built a 2 meter vertical dipole antenna out of plumbi
ng
parts.  This antenna has been mounted on the chimney ever since and withstood
all onslaughts from the weather, including 70+ mph winds, record snowfalls, su
b
zero temperatures, etc.  The following shows the basics, although certainly no
t
to scale:


       10' 1" OD PVC Pipe         ________   20" Cu Pipe  _________  20" Cu Pi
pe  __
       __________________________|        |______________|         |__________
___|  |
     ______________________________________________________
      |
COAX ______________________________________________________--------\
      |
       ___________________________        _______________/         _\_________
___   |
                                 |________|              |___   ___|
   |__|
                                                            |   |
                                                            |   |
                                                           _|   |_
                                                           |     |
                                                           |_____|

                                 PVC Coupling            PVC Tee w/ stub
  End Cap
                                                          and end cap

Two 20" pieces of 1" OD Cu (copper) pipe are cut for the dipole part of the an
tenna.  I
soldered the center conductor of the coax (52 ohm) to the upper piece and the
shield
to the lower piece.  Pay attention to how things are strung together!  I used
a PVC
Tee for the center insulator so I could inspect the coax while assembling and
then
sealed it with a short stub and end cap.  A plain coupling could be used for t
he center
insulator.  End caps, Tee and joints between the Cu pipe and PVC parts were ep
oxied
for mechanical strength and weather sealing.  Two holes were drilled at the bo
ttom of
the 10' section of PVC pipe and a wire tie used to secure the coax to the pipe
 for
strain relief.  The 10' PVC pipe is mounted to the chimney and the coax lays o
n the
roof.  SWR is < 1.3:1 from 144 to 148 MHz.  Overall appearance is not too bad,
 either.




From [e-mail] Wed May 22 18:46:43 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: RE: Coaxial Cable Shielding
Date: 15 May 96 01:12:41 GMT
Message-ID: <[e-mail]>

Adding some comments to the msg posted by...
[e-mail] (Graham Seale)....

Last year we did a small research concerning some different coaxial
cables brands and some different connectors/manufacturers.

This rehearse was done using CATV items, so the impedances was 75 ohm. The
set-up used was not too much controlled and scientific but for our
purpouses was enough.
At the CATV industry, as every operator intend to use it's plants at both
ways, one concern is the called "ingress" and, at the other side, the law
is worried about the "leakeage".
The return path at most of the CATV plants falls between 5MHz and 30MHz.
This part of the spectrum don't need too much expanation about.

The CATV coaxial cable providors have several models and sizes with
different braid amount: so we find standard shielding (67% braid
coverage), dual shield (claimed 90% or so), tri-shield, quad-shield and
hard-line.

So we pick 4 samples, different braid amounts, RG59 cables. We used the
same "F" connector (same apparent lay-out), one type for each cable
diameter. All cables were terminated by a standard 75 ohm load.
This cables were placed at one small tower, vertically, lenght abt 25'.

The detector was a Tektronix 2714 spectrum analyzer with a built-in
pre-amp(20dB gain). The results:

The 67% braid cable allow an "ingress" of some locals broadcasts (FM band)
that are about 3 to 5 kilometer apart. I don't know the field strenght
so...
The absolute measured level, worst case, was something about -52dBmV.
Some "clinic eye" can realize about an interference at this level, since
the minimun signal we use at the TV set (here, at least) is 0dBmV.
The other cables didn't allow any measurable signal, even setting the
spectrum analyzer to the "worst case" FM signal and trimming the span/div
and IF resolution/video filter to an optimal set-up.


BUT: when we lose the spectrum side "F" connector abt 1/4 turn, all exist
ing signal at the 67% braid cable increase 20...30dB!
At the other cables, this signal appear from the noise floor at the same
set-up (loose connector). The amount was the same:20 to 30dB.

Nothing scientific but we realize that in a practical situation, the
connector we were using was not the guilty. The cable, in certain areas.
But the assembly care...this item had the heaviest influence.

Times-Fiber, Trylogy, Comm-Scope, Belden and other brands normally have
some papers concerning the ingress/leak at those cables, normally
considering the age and the "number of times that some piece of cable was
bent", due to temperature changes. Most of them claim that a 90% braid
covereage cable still having a -100...-115dB EMI.

Note: at this set-up, the commom mode problem was avoided(we tried) using
some ferrite blocks, close to the spectrum analyzer).
We still using the same 67% braid covereage cable and only when a
specific path become interfered we search the source/spans affected and c
change it by a dual shield span.

Best regards. Marcus. [e-mail] - S.aulo - Brasil.


From [e-mail] Wed May 22 18:46:45 1996
From: [e-mail] (Doug Reed)
Newsgroups: rec.radio.amateur.antenna
Subject: 2.4 Ghz antennas
Message-ID: <[e-mail]>
Date: Mon, 20 May 1996 07:21:39 -0100

TG>In article <4mtfa8$[e-mail]>
TG>           [e-mail] "WB3U" writes:
TG>> Not at all.  These antennas are available in omnidirectional
TG>> patterns ranging from 11.5 dBi (8-bay) through 16.0 dBi (24-bay).
TG>> Physically, they resemble a vertical pipe 5" diameter with a
TG>> length ranging from about 3' to 10'.  When they are top-mounted on
TG>> a tower, visualization of the pattern would produce something akin
TG>> to a pancake on a stick.

TG>Perhaps you live in a two-dimentional world.  The array you described
TG>sounds very far from omni-directional to me.
TG>Regards,
TG>   Tony - G3SKR / AA2PM                  email: [e-mail]

Hi Tony.
It sounds to me like Jack is describing a stacked set of Alford Slot
antennas.  These are one of the most common forms of omni-directional
horizontally polarized antennas made.  I'd go so far as to say that most
TV stations use this form of antenna, although much larger because of
the lower frequency.  The Alford Slot antenna doesn't get much press in
the common ham handbooks.  You will find references to them in the ham
TV publications and it was mentioned in the ARRL UHF projects manual as
an easy antenna for a UHF beacon system.  Of course most ham antennas
wouldn't be 16 bays long either.

If you want to visualize the Alford slot, think of a section of 4"
aluminum vent pipe.  This stuff comes from the hardware store with a
seam down the side and you clip the edges together to make the pipe.
To make an Alford slot you would add metal braces at the top and bottom
to hold the seam edges apart about 1/2 inch.  The total length of the
slot would be 1/2 wave length from short to short.  You then feed it in
the middle with a 200 ohm (?) balanced feed.  The other critical length
is the circumference of the tube since it has to be about 1 wavelength
at the frequency of operation.  If you think of it as a 1 wavelength
wire loop stretched to make a 1/2 wave cylinder, you will not be too
wrong. For antenna theory, I think the Alford slot was a derivation of
the plain old slot antenna where the plane surface was changed to a
cylinder.

As I said, these antennas are very common in TV applications because the
TV station wants a very uniform horizontal pattern.  Ham TV repeaters
want similar patterns and simple Alford slots made from 1/2" galvanized
hardware cloth have been described in ATVQ magazine.  The problem with
building the antenna is making a good low loss balun.  Particularly if
you want to stack them for more gain.  Another common antenna for ham TV
and VHF SSB is the Big Wheel or Little Wheel antennas.  They were
developed in the early 60's and have almost disappeared from the current
ham handbooks.  But they had good omni directional patterns and a little
gain over a dipole.  Fairly easy to build but also pretty large.  They
consist of three 1 wavelength loops formed into three petals like
clover.  The three loops are paralleled and matched to coax with a
simple stub.  Take a look in a 1968 VHF Antenna book.  It might be
listed in the new ARRL antenna handbook but I don't have one so I don't
know.  Olde Antenna Labs makes and sells Little Wheels for 432 and up.

Hope this helps. 73's.

Doug Reed, N0NAS                email: [e-mail]

 * SLMR 2.1a * Hello, I am part number |||||||>||||||||




From [e-mail] Wed May 29 23:38:52 1996
From: [e-mail] (Phil Brown)
Newsgroups: rec.radio.amateur.antenna
Subject: 11 meter antenna for 10 meters
Date: Tue, 21 May 1996 18:31:25 GMT
Message-ID: <4nsr4t$[e-mail]>
Reply-To: [e-mail]

Getting back into hamming after several years lapse. Got an old 1/4
wave CB mobile fiberglass antenna left by my father in law. Anyone
ever use one of these for 10 meters? Do I have to have 1/4 wave
radials to get it to load up. Thought I would just cut it to length
and mount it on a pole on the roof. Thoughts?
Thanks.
Video Production by MEDIASSOCIATES
Like Flowers? Check out our home page at www.tigerweb.com



From [e-mail] Wed May 29 23:38:53 1996
From: "Anthony R. Gold" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: Fri, 24 May 96 14:00:04 GMT
Message-ID: <[e-mail]>
References: <4mq4ka$[e-mail]> <4nc11f$[e-mail]> <4ncnfu$[e-mail]> <4nd6gd$[e-mail]> <4ne64l$[e-mail]> <4non4l$[e-mail]> <[e-mail]>
Reply-To: [e-mail]

In article <[e-mail]>
           [e-mail] "Steve Richards" writes:

>   We have two antennas to choose from; a 12.5dbi and a 16dbi. Both have a ve
ry
> flat much like a "pancake" pattern but they do give the wide coverage. In th
is
> way the WaveLAN transceivers from a number of buildings can interconnect
> providing a radio WAN. Also, these antennas only cost about $A700. Maybe I
> should suggest to our supplier to raise his price; US$10000 is unbelievable.

Well we now know what to use and a propective user for it in Russia.  I'll
send him your comments and see what he wants to do.  Maybe you could find
someone willing to ship one there, if that's the way he wants to go.

BTW, I think that the $10,000 rig mentioned before was probably rated at
well over 10kW and also perhaps designed to survive 70MPH winds on top of
a 75m high tower :-)

Regards,
--
   Tony - G3SKR / AA2PM                  email: [e-mail]
                                                [e-mail]
                                        packet: g3skr@n0ary.#nocal.ca.usa.na


From [e-mail] Wed May 29 23:38:54 1996
From: Steve Richards <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: Fri, 24 May 1996 21:56:03 +1030
Message-ID: <[e-mail]>
References: <4mq4ka$[e-mail]> <4nc11f$[e-mail]> <4ncnfu$[e-mail]> <4nd6gd$[e-mail]> <4ne64l$[e-mail]> <4non4l$[e-mail]>

Anthony Gold wrote:
>
> Jerry B. Altzman ([e-mail]) wrote:
>
> : Indeed, omnidirectional (as I understand it) means omnidirectional on the
> : horizon. Jack's respondent is confusing it with >isotropic<.
>
> Jack's respondent was confusing everyone by answering the question posed
> by the first post in this thread.  I understand that this was a mistake
> and apologise.
>
> The start of this thread in <4mq4ka$[e-mail]> was the question
> of "where can I buy an `omnidirectional' [poster's choice of words]
> antenna to add to a 2.4 GHz WaveLAN tranceiver in order to boost it's
> performance by over 11dB."  I said no-way, you'll need amplifiers.  But
> Jack, who also followed-up that same original posting, gave a quite
> different reply.
>
> Perhaps Jack would email his proposals to the original poster, who is
> Shabanov Sergey <[e-mail]> and give him the good news.
>
> Regards,
>
> --
>    Tony - G3SKR / AA2PM                  email: [e-mail]
>                                                 [e-mail]
>                                         packet: g3skr@n0ary.#nocal.ca.usa.na

  This discussion is all very interesting and to some degree shows a knowledge

challenge for this area.  I've been working with the WaveLAN 2.4GHz product in

Australia for the last 3 years, and we have had to develop an antenna that had

a wide coverage area (hence not omnidirectional in all planes). This, I think,

was what the original posting was all about.
  We have two antennas to choose from; a 12.5dbi and a 16dbi. Both have a very

flat much like a "pancake" pattern but they do give the wide coverage. In this

way the WaveLAN transceivers from a number of buildings can interconnect
providing a radio WAN. Also, these antennas only cost about $A700. Maybe I
should suggest to our supplier to raise his price; US$10000 is unbelievable.
        Anyway, I hope that I haven't upset the apple cart on this subject,
and would gladly welcome what else is said

Regards
Steve Richards



From [e-mail] Wed May 29 23:38:55 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: Fri, 24 May 96 21:53:09 GMT
Message-ID: <4o5faj$[e-mail]>
References: <4mq4ka$[e-mail]> <4nc11f$[e-mail]> <4ncnfu$[e-mail]> <4nd6gd$[e-mail]> <4ne64l$[e-mail]> <4non4l$[e-mail]> <[e-mail]> <[e-mail]>

   "Anthony R. Gold" <[e-mail]> wrote:

>BTW, I think that the $10,000 rig mentioned before was probably
>rated at well over 10kW and also perhaps designed to survive 70MPH
>winds on top of a 75m high tower :-)

The power rating is approximately 500 watts, with somewhat higher
ratings available on special order at additional cost.  You're
pretty close on the wind survival; many of these are top-mounted
on towers at heights of 500-750'.  They are used primarily for
multi-channel video transmission, often 30 adjacent channels
split between two antennas.  The power rating is appropriate for
this use, even at 100 watts peak output per channel, due to typical
losses in the combiners, jumpers and flexible waveguide.

The patterns generated by these antennas are exceptionally precise,
with a certain amount of null fill and electrical beamtilt being
standard features.  The latter are required in order to provide
coverage to close-in receive sites.

I'm very curious about antenna designs claiming similar performance
at significantly reduced cost.

73,
Jack  WB3U


From [e-mail] Wed May 29 23:38:55 1996
From: [e-mail] (Ed  Buchanan)
Newsgroups: rec.radio.amateur.antenna
Subject: 6 M antenna revised
Date: Sun, 26 May 1996 22:42:24
Message-ID: <4o8uth$[e-mail]>

Cubex Co has re-tested and re-tuned their 4 element 6 meter antenna.
We have re-tuned this antenna to provide 22 db front to back while
still retaining over 10 dbd gain, this also impvoved the pattern
slightly and makes the antenna shorter (8'X 1-1/2") boom.  This is
an additional benefit for shipping purposes.
"73" Ed KN6CL



From [e-mail] Wed May 29 23:38:56 1996
From: aor <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 6 M Antenna Tested - really????
Date: Wed, 22 May 1996 15:03:18 -0400
Message-ID: <[e-mail]>
References: <4nop5l$[e-mail]>

With all due respect, this sounds a little larger than life.
Boom length has the greatest effect on gain for antennas with
proper boom illumination (number of elements for a given boom
length).  Even on short booms, where quads really shine over
yagis, a 12dbd (14.1dbi) would require a 1.25-1.50 wavelength
boom, about 21-27 feet, and require 5-6 elements. The added
gain in a quad comes from the narrowing of the E plane due
to self-stacking effects.  Without even looking, I suspect
that the boom length is only 120" long (40" between spreaders).
The gain for this antenna is the same for 6 meters, 2 meters,
or 440.  About 9dbi or 7dbd for full-size quad elements with
.15-.20 wavelength spacings.  You would have to double the
boom length to get a 3db improvement, taking you back to
the 21 foot mark (stated above).

What method did they use to measure gain?  Two antennas
pointed at each other, pattern integration, or E and H
plane -3db values?

This just reminds me of the 1975 CB radio days, where 4
element antennas had 14dbd gain, and were less than 1/2
wavelength long.  It just does not happen.  Thanks for
the note just the same.

Al, NW2M


>Ed Buchanan wrote:
>
> Saturday 5-18-96 Cubex Co. tested their new 4 element 6 meter quad
> which is designed to be a sideband antenna. This antenna has over
> 12 dbd gain, this is due to the relatively narrow bandwidth
> (50.0-51.0 Mhz.) vswr less than 1.7-1 and resonant at 50.3 the
> resonant point can be changed slightly (.5 Mhz) with the unique
> Cubex adjustable feed point. Front to back was 15-18 db with a
> clean pattern and no strange lobes. This antenna will be available
> by the first of June, 1996.
> "73" Ed KN6CL


From [e-mail] Wed May 29 23:38:58 1996
From: [e-mail] (Dean Denter)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 6 Meter Antenna Recommendation/Question ???
Date: 28 May 1996 13:59:30 GMT
Message-ID: <4of0s2$[e-mail]>
References: <[e-mail]> <[e-mail]>
Reply-To: [e-mail]

In article <[e-mail]>,
        Bob Lewis <[e-mail]> writes:
>Richard G. Jean Jr. wrote:
>>
>> Hello Everyone,
>>
>> I'm looking for recommendations for 6 meter antennas (homebrew) both
>> omni directional and directional varieties.. Also, what polarization
>> is being used for FM work on 6 meters; I would guess vertical.
>>
>Vertical polarization for FM and Horizontal for SSB is the standard.
>When you get a rig be sure to get SSB too, I think that's the most fun.
>A "halo" antenna makes a good horizontal, omni-directional, zero gain
>antenna.
>

haven't seen a 'halo' before, are there plans around for it somewhere?

regards,
Dean.
--
Dean Denter               work -> [e-mail]
VA3CDD                    play -> [e-mail]
[[[[[[[[[[[[[[I speak only for myself]]]]]]]]]]]]]]



From [e-mail] Wed May 29 23:38:58 1996
From: [e-mail] (Richard G. Jean Jr.)
Newsgroups: rec.radio.amateur.antenna
Subject: 6 Meter Antenna Recommendation/Question ???
Date: 23 May 96 18:32:47 GMT
Message-ID: <[e-mail]>

Hello Everyone,

I'm looking for recommendations for 6 meter antennas (homebrew) both
omni directional and directional varieties.. Also, what polarization
is being used for FM work on 6 meters; I would guess vertical.

I'm going to pick up a 6 meter rig "real" soon (soon as I can find one)
and start experiencing some 6 meter activity...... Might try my luck at
the Ten Tec 6 meter transverter kit for 2 meters, that way I could mess
with it in the mobile without to much fuss.

Thanx In Advance !!!

Rich - N8PFK


From [e-mail] Wed May 29 23:39:00 1996
From: [e-mail](Ted Viens )
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Adcock antenna
Date: 25 May 1996 04:22:17 GMT
Message-ID: <4o61tp$[e-mail]>
References: <[e-mail]>

In <[e-mail]> [e-mail]
(Stan Scalsky) writes:
>
>Has anyone studied Adcock or Wullenweber antennas? In all the papers
I've
>managed to find they all mention goniometers but dont really go into
much
>detail concerning their construction? Are they still made or have they

>been replaced by an electronic equivalent? Any pointers?
>
>-= stan
>
What a strange bit of serendipity...  Monitoring Times had a small
article on the WullenWeber a couple of months ago and the June issue
had a blurb in the letters section answering these questions.
Wullenwebers are massive circular arrays of dipoles.  The goniometer is
an originally mechanical complex rotary switch which allows you to
sweep around the circle of the array.  These have by now been replaced
by an electronic equivalent.  The letter gives the document numbers of
several Naval manuals which are claimed to be the best source of info
on the Wullenweber...
--
Bye...  Ted..
Deep in the Heart of the Armpits of Houston, Texas...


From [e-mail] Wed May 29 23:39:01 1996
From: Lennart Nilsson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Adding 7 MHz to yagi beam
Date: 24 May 1996 12:29:18 GMT
Message-ID: <4o4a2u$[e-mail]>

I have a Fritzel FBDX-506 six-band yagi covering 10-28 MHz at a
60 ft tower and I want to extend operation to 7 MHz without
losing performance on the original bands. What I have in mind is
adding lightweight traps at the end of the already trapped 10
MHz-elements (34 ft long) and let stiff copper wires hang down
some 10 ft or so from each end. The traps for 10 MHz would have
to be made with a high L/C ratio to provide enough loading with
such short extensions. The spacing between the 10 MHz dipole and
reflector is 13 ft.

Has anybody tried a similar idea and what was the result? I am
afraid the spacing will be too short to make a decent match to 50
ohms, so the question is whether I shall be content with just
modifying the driven element. If so, will it perform better than
the quarterwave sloping guywire I am using now? Good advice is
welcome.
73 de Lennart, SM5DFF



From [e-mail] Wed May 29 23:39:02 1996
From: [e-mail] (Brian Williams)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Aluminiun Foil for Apartment Ground Plane?
Date: 22 May 1996 00:49:23 GMT
Message-ID: <4ntoaj$[e-mail]>
References: <4nhnm1$[e-mail]>

In article <4nhnm1$[e-mail]>, eal says...

>Ok, This may indeed be a 'wild hair'.  Has anyone tried putting
>Aluminum foil UNDER the carpet in an upper story apartment to  act as a
>local HF ground plane?  It looks like I am going to be stuck in apartments
>for a few years, and I would like to get a decent antenna in an apartment.
>Can anyone recommend a good book on apartment antennas?   WA5SWD

Be careful to make sure that ANY places that you might have two different
sheets of foil touching each other, you must make sure that they are
joined solidly.  Any movement will cause noise and possible arcing.  If
you decide to lay some under a carpet, make sure it's under any padding
as well.  It's not easy to solidly connect foil pieces together.

Brian - N6ZAU



From [e-mail] Wed May 29 23:39:05 1996
From: "Anthony R. Gold" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Re: Antenna Analysers
Date: Thu, 23 May 96 11:06:14 GMT
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]>
Reply-To: [e-mail]

In article <[e-mail]> [e-mail] "Ken Neal" writ
es:

> My question is a little different-- I have the MFJ-208 for VHF and
> the MFJ-247 for HF.  Would I be gaining anything (other than a
> single unit) by selling these two and buying the MFJ-259?

I don't see the 247 in the current catalogue so I can't comment on that,
but I note that the 208 shows VSWR but not an antenna's resistance at
resonance.  If you fancy knowing this, and it may be useful when say
fiddling with gamma matches for instance, then the 259 will add that one
feature.  Unless you can get most of your money back from selling the
older instruments or you do this for a living, it may not be worthwhile.
Of course, if you've not been naughty, you might try asking Santa :-)

Regards,
--
   Tony - G3SKR / AA2PM                  email: [e-mail]
                                                [e-mail]
                                        packet: g3skr@n0ary.#nocal.ca.usa.na


From [e-mail] Wed May 29 23:39:06 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antennas
Date: 24 May 1996 06:22:01 -0700
Message-ID: <4o4d5p$[e-mail]>
References: <[e-mail]>

Peter Mackowiak <[e-mail]> wrote:
: What are the basics of antenna design?

Hi Peter, IMO one can learn the most about antennas
in the shortest time by using an antenna modeling
program like EZNEC. It is amazing to be able to
perform cut-and-try experiments without leaving the
chair at the computer.

73, Cecil, KG7BK (W6RCA soon), OOTC



From [e-mail] Wed May 29 23:39:07 1996
From: [e-mail] (Jim Overstreet)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Anybody tried GAP Eagle DX vertical?
Date: Mon, 27 May 1996 22:20:37 GMT
Message-ID: <4od9td$[e-mail]>
References: <4o2oob$[e-mail]> <4o4q0d$[e-mail]>

[e-mail] () wrote:

>>.... and know very little about verticals.  Anybody have
>>any first hand data on this antenna?  Thanks. . . .

>Gap antennas come with completely false and exaggerated advertizement
>claims. They are easily beat by simple wire antennas. (there are test
>reports.) It is true that the verticals take up less space though.

>73, Moritz DL5UH

I second that.  I have a friend that bought a Titan, and it is a LOUSY
performer, I think his window screen would work better.






From [e-mail] Wed May 29 23:39:07 1996
From: Martin Davies <[e-mail]>
Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.antenna
Subject: Anyone know how to contact K9AY?
Date: Tue, 28 May 96 21:37:13 GMT
Message-ID: <[e-mail]>
Reply-To: [e-mail]

Hi, I'm trying to find a way to contact K9AY, Gary A. Breed, who
is (or was in 1994) the Editor and Associate Publisher of the
journal "RF Design", the address for which is 6300 S Syracuse
Way, Suite 650, Englewood, CO 80111.

I'm very interested in Gary's patent-pending design for
closely-coupled-resonator antennas which was published in the
Nov 1994 issue of the journal and would like to discuss several
points with him; however so far I've been unable to find any
email or packet radio addresses for him.  Does anyone know how
to get in touch with him (apart from snail-mail)?

By the by, has anyone else tried the c-c-r type of antenna?  I
would be interested in hearing from anyone who has.

73 es TIA,
--
Martin Davies, G0HDB
BBS @ GB7GLO.#46.GBR.EU
DXCluster > GB7DXC


From [e-mail] Wed May 29 23:39:08 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.antenna
Subject: Re: Anyone know how to contact K9AY?
Date: Wed, 29 May 96 18:00:45 GMT
Message-ID: <4oi3as$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>,
   Martin Davies <[e-mail]> wrote:
>Hi, I'm trying to find a way to contact K9AY, Gary A. Breed, who
>is (or was in 1994) the Editor and Associate Publisher of the
>journal "RF Design" . . .

Gary's no longer with RF Design. He's now with Noble Publishing. You might
try their office in Georgia, telephone [phone], fax [phone].

Roy Lewallen, W7EL



From [e-mail] Wed May 29 23:39:09 1996
From: [e-mail] (James J Martin)
Newsgroups: rec.radio.amateur.antenna
Subject: Anyone using a TET antenna?
Date: Fri, 24 May 1996 12:49:15 GMT
Message-ID: <4o4b8i$[e-mail]>

I have a model HB33sp (3 ele tri-bander) and over the years the minium
SWR point has moved from the middle of the bands to just below the low
end.  I tried shorting up the elements which worked on 20 meters not
on 15 or 10.  I would like to hear from anyone also using TET.

Jim W8AC




From [e-mail] Wed May 29 23:39:10 1996
From: [e-mail] (Dale Chidester)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Balun for 2M mobile dipole?
Date: 22 May 1996 12:47:21 GMT
Message-ID: <4nv2cp$[e-mail]>
References: <4nsnln$[e-mail]>
Reply-To: [e-mail]

The following describes the antenna I use.  No balun is required and material
costs are a minimum.

        73,
                Dale



        Plumber's Special 2 meter Vertical Dipole

A number of years ago, I built a 2 meter vertical dipole antenna out of plumbi
ng
parts.  This antenna has been mounted on the chimney ever since and withstood
all onslaughts from the weather, including 70+ mph winds, record snowfalls, su
b
zero temperatures, etc.  The following shows the basics, although certainly no
t
to scale:


       10' 1" OD PVC Pipe         ________   20" Cu Pipe  _________  20" Cu Pi
pe  __
       __________________________|        |______________|         |__________
___|  |
     ______________________________________________________
      |
COAX ______________________________________________________--------\
      |
       ___________________________        _______________/         _\_________
___   |
                                 |________|              |___   ___|
   |__|
                                                            |   |
                                                            |   |
                                                           _|   |_
                                                           |     |
                                                           |_____|

                                 PVC Coupling            PVC Tee w/ stub
  End Cap
                                                          and end cap

Two 20" pieces of 1" OD Cu (copper) pipe are cut for the dipole part of the an
tenna.  I
soldered the center conductor of the coax (52 ohm) to the upper piece and the
shield
to the lower piece.  Pay attention to how things are strung together!  I used
a PVC
Tee for the center insulator so I could inspect the coax while assembling and
then
sealed it with a short stub and end cap.  A plain coupling could be used for t
he center
insulator.  End caps, Tee and joints between the Cu pipe and PVC parts were ep
oxied
for mechanical strength and weather sealing.  Two holes were drilled at the bo
ttom of
the 10' section of PVC pipe and a wire tie used to secure the coax to the pipe
 for
strain relief.  The 10' PVC pipe is mounted to the chimney and the coax lays o
n the
roof.  SWR is < 1.3:1 from 144 to 148 MHz.  Overall appearance is not too bad,
 either.




From [e-mail] Wed May 29 23:39:11 1996
From: [e-mail] (Craig D. Kollai)
Newsgroups: rec.radio.amateur.antenna
Subject: Balun for 2M mobile dipole?
Date: Tue, 21 May 1996 17:53:39 GMT
Message-ID: <4nsnln$[e-mail]>
Reply-To: [e-mail]

        I am planning to buy a 2M mobile transceiver soon as my first rig, and
I am thinking about building my own verticly polorized 1/2 wave (or
possably full wave) dipole antenna.  Once I build it, I intend to
connect to my SWR meter and then to my mobile by coax using an so-239
at my antenna and pl-259 connectors on both ends of the coax.  My SWR
has so-239 on in and out, and I assume my mobile transceiver will as
well.  I believe I shyould use 50-ohm impedance connections for
everything, and plan to design my antenna as such.

        My question is, am I correct in my assumption that I'll need a balun
between teh SWR and Antenna?  If so, can anyone recommend a type,
where to purchase it, and give me a good guess as to how much it will
cost?  I want to add a power booster eventqaully, but I'll probably
keep this first setup under 200 watts, and would like a balun that can
handle such, if I do indeed need one.

        Lastly, I'm taking my no-code technicain licenseon Saturday morning
the 25th, so shortly I'll be adding my call sign to my sig file!


          -Craig D. Kollai          E-mail: [e-mail]
             Visit my web page at::
               http://www.cybergate.com/~ckollai/homepg1.htm




From [e-mail] Wed May 29 23:39:12 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Can I build my own ISOTRON Type Antenna?
Date: Wed, 29 May 96 18:18:52 GMT
Message-ID: <4oi4cr$[e-mail]>
References: <[e-mail]> <4oha1l$[e-mail]>

In article <4oha1l$[e-mail]>,
   [e-mail](Thomas R Mahanna) wrote:
>
>Hi:
>    I like the ISOTRON Antenna, but it is rather expensive. I would
>like to build something similar for my tiny apartment. Where could I
>find info on using large area 'plates' for a transmitting antenna. What
>would the area of a single plate have to be for, say, 80 meters?

To be efficient, a sizeable fraction of a wavelength on a side. You can
make the plates smaller and smaller by putting in more and more loading
inductance as a coil. This makes the antenna less and less efficient due to
unavoidable losses in the coil. By the time you're at the size of the
Isotron, the efficiency is very, very low. But you might get a percent or
so of efficiency with a reasonable size, and lots of stations can be worked
with a watt of radiated power.

Roy Lewallen, W7EL


From [e-mail] Wed May 29 23:39:13 1996
From: [e-mail] (John Chapman)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR antenna
Date: 21 May 1996 21:06:58 GMT
Message-ID: <4ntb9i$[e-mail]>
References: <[e-mail]> <4nrnj7$[e-mail]>

 Sounds similar to M2 SQloop which has horz polarization.

John, N0KIC




From [e-mail] Wed May 29 23:39:15 1996
From: [e-mail] (Graham Seale)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR antenna
Date: Thu, 23 May 1996 21:20:16 GMT
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]> <4nrnj7$[e-mail]> <4ntb9i$[e-mail]>
Reply-To: [e-mail]

In message <4ntb9i$[e-mail]> John Chapman wrote:

>  Sounds similar to M2 SQloop which has horz polarization.
>
> John, N0KIC
>
>

The DDRR has featured in past issues of the ARRL Handbook, and
was also described by W.E. English on pages 28-31 of the December
1971 issue of QST.

Peter Dodd G3LDO published a study of the DDRR in "The Antenna
Experimenter's Guide. The study was by Robert B. Dome who held
115 patents in the fields of transmitters, receivers and antennas
at the time.

The main conclusion was that simply by increasing the height of the
vertical part of the DDRR structure to 3.5 ft (from 1 ft.) allows
a spectacular improvement in efficiency. It changes the radiation
resistance from 0.095 ohm to about 1.16 ohms which increases the
efficiency from 2.75 percent to 25.8 percent (9.8dB increase in
signal strength!).

If you do try it, make it taller, reduce the size of the circular
part to keep the thing tuneable on the band you want, and use
*fat* tubing. Currents get to tens of amps and voltages at the end
across the capacitor measure in kilovolts.

I hope this helps..

73's G4WNT

--
Graham Seale


From [e-mail] Wed May 29 23:39:16 1996
From: [e-mail] (Peter Markham)
Newsgroups: rec.radio.amateur.antenna
Subject: design for 1/4 wave z xfmrs for 1/2" catv hardline?
Date: 27 May 96 19:04:43 GMT
Message-ID: <[e-mail]>


  Looking for a real world design/ideas  for 1/4 wave coaxial linetransformers

to be able to use catv 1/2" al catv  hardline for 144 and 440 mhz, from
a 52ohm source to a 52ohm load. So far a friend's attempts have been
less than favorable, and I am out of ideas for using the hardware on
hand to make the project fly.

                                                      TIA,
                                                             Pete/wa4hei .


From [e-mail] Wed May 29 23:39:17 1996
From: Dave Hand <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: design for 1/4 wave z xfmrs for 1/2" catv hardline?
Date: Tue, 28 May 1996 13:07:18 -0400
Message-ID: <[e-mail]>
References: <[e-mail]> <4oevht$[e-mail]>

Cecil Moore wrote:
>
> Peter Markham <[e-mail]> wrote:
>
> :   Looking for a real world design/ideas  for 1/4 wave coaxial linetransfor
mers
> : to be able to use catv 1/2" al catv  hardline for 144 and 440 mhz, from
> : a 52ohm source to a 52ohm load. So far a friend's attempts have been
> : less than favorable, and I am out of ideas for using the hardware on
> : hand to make the project fly.
>
> Hi Peter, IMO save your effort. Catv cable is 75 ohms. A 52 ohm
> load causes an SWR of 1.44, not enough to worry about on vhf
> unless your run is super long in which case you should be using
> twin lead. In addition, your load is probably not exactly 52 ohms.
>
> If you are really determined to achieve an SWR of 1:1, try
> variable capacitive impedance dividers at both ends.
>
> 73, Cecil, KG7BK (W6RCA soon), OOTC


Easier yet, just prune the cable length to a multiple of 1/2 wave

On 2m the max you would have to cut off is less than 2.6 ft.

Dave Wb4hyp


From [e-mail] Wed May 29 23:39:18 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: design for 1/4 wave z xfmrs for 1/2" catv hardline?
Date: 29 May 1996 13:49:22 GMT
Message-ID: <4ohkl2$[e-mail]>
References: [e-mail]



On 27 May 96 pmarkham said:
 pm>Looking for a real world design/ideas  for 1/4 wave coaxial
 pm>linetransformers to be able to use catv 1/2" al catv  hardline for
 pm>144 and 440 mhz, from a 52ohm source to a 52ohm load. So far a


Why not adjust the load to match the 75ohm hardline.
Then try it without any xformer to see what happens. a 1.5:1 SWR
is not that bad and you might be suprised at how well it works.

Then compare with and matching networks you come up with.

have fun



Mike Neverdosky N6CHV   [e-mail]

`[1;33;41mNet-Tamer V 1.03 - Test Drive



From [e-mail] Wed May 29 23:39:19 1996
From: [e-mail](Anthony Severdia)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Do I need to ground attic antennas?
Date: 24 May 1996 23:51:24 GMT
Message-ID: <4o5i1s$[e-mail]>
References: <4o5chc$[e-mail]>

In <4o5chc$[e-mail]> [e-mail] (John Marx)
writes:
>
>I'm building a home on a rural hilltop.  The location alone will make
it
>lightning prone.  Antennas (mine are receive only for FM, TV and
Public
>Safety bands) will be generally restricted to the attic.  Will their
>location in the attic reduce their tendency to build a charge and
attract
>lightning?  How important is it to ground them?  If it is important,
>should I just tap the coax or is a separate grounding wire needed?
>
>Thanks for any advice.


    If the location itself is "prone to lightning" as you say, you'd
best install an external (separate) lightning accumulator at a high
point and well grounded.  The antennas in an attic would be least of
the problems!

    -=Tony=-


From [e-mail] Wed May 29 23:39:20 1996
From: [e-mail] (John Marx)
Newsgroups: rec.radio.amateur.antenna
Subject: Do I need to ground attic antennas?
Date: 24 May 1996 22:17:16 GMT
Message-ID: <4o5chc$[e-mail]>

I'm building a home on a rural hilltop.  The location alone will make it
lightning prone.  Antennas (mine are receive only for FM, TV and Public
Safety bands) will be generally restricted to the attic.  Will their
location in the attic reduce their tendency to build a charge and attract
lightning?  How important is it to ground them?  If it is important,
should I just tap the coax or is a separate grounding wire needed?

Thanks for any advice.


From [e-mail] Wed May 29 23:39:21 1996
From: Jonathan Helis <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Do I need to ground attic antennas?
Date: 25 May 1996 21:13:58 GMT
Message-ID: <4o7t6m$[e-mail]>
References: <4o5chc$[e-mail]> <4o6145$[e-mail]>
To: [e-mail]

[e-mail] wrote:
>In <4o5chc$[e-mail]>, [e-mail] (John Marx) writes:
>>I'm building a home on a rural hilltop.  The location alone will make it
>>lightning prone.  Antennas (mine are receive only for FM, TV and Public
>>Safety bands) will be generally restricted to the attic.  Will their
>>location in the attic reduce their tendency to build a charge and attract
>>lightning?  How important is it to ground them?  If it is important,
>>should I just tap the coax or is a separate grounding wire needed?
>>
>>Thanks for any advice.
>
>If you are the natural target at a hilltop and are worried about this, put in

>a formal lightning arrestor spike setup on the house.  Phooyee on worrying
>about the indoor receiving antennae.  You have a LOT more to worry about
>than that!
>
>Mike W5WQN as a guest at leviathan.tamu.edu (no mail address there)
>

When I was in school, I had an attic antenna for SWLing for nearly 5
years, and never had a problem.  In another house I lived in for about
the same amount of time, I had another attic antenna, and again, no
problems there.  The antenna was just a long wire that was connected to a
reciever, and when I got my ham ticket, to a tuner, and I never had a
lightening problem inside the house.

The only problem I had was when the roof was wet, such as after a rain,
the antenna wouldn't always load up on some bands like it normally did.
I attributed this to the water making the roof conductive.  I don't know
if this is accurate, but it's as good a guess as any.

Also to be noted is that some roofing materials are conductive, and will
interfere with incoming and outgoing signals.  In my experience,
listening in the rain was difficult anyway, mainly due to electrical
interference from lightening, and it's safter to unplug such appliances
in electrical storms anyway.

These are just my experiences, I didn't live on top of a hill at either
house(we don't have many hills in Southern Louisiana), so my advice may
not apply.  Good luck!

73,

Jon Helis, KB5IAV



From [e-mail] Wed May 29 23:39:22 1996
From: [e-mail] (Graham Seale)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Do I need to ground attic antennas?
Date: Sat, 25 May 1996 11:17:30 GMT
Distribution: world
Message-ID: <[e-mail]>
References: <4o5chc$[e-mail]>
Reply-To: [e-mail]

In message <4o5chc$[e-mail]> John Marx wrote:

> I'm building a home on a rural hilltop.  The location alone will make it
> lightning prone.  Antennas (mine are receive only for FM, TV and Public
> Safety bands) will be generally restricted to the attic.  Will their
> location in the attic reduce their tendency to build a charge and attract
> lightning?  How important is it to ground them?  If it is important,
> should I just tap the coax or is a separate grounding wire needed?
>

Hello John

Structures inside an attic will not "attract" lightning. Every single
lightning arrestor scheme I have ever seen involved *very* sharp points
mounted high outside, connected to a grounded strap, designed to cause a
local corona discharge to reduce the potential of the whole structure.

Presumably if a strike is imminent, it will go somewhere else. As
explained to me, if a strike should happen it will do its damage tracking
down the copper strap, lessening the risk of shock and fire in other parts
of the building.

Although (with cause!) I have had this lifelong lightning paranoia, and I
soak up all that is ever discovered about it, I have yet to find really
authoritative explanations and advice. The whole recipe for strike
avoidance schemes seems to add up to  "lightning attractors". A sailing
friend once said to me..

"Plant a real *sharp* pole, then stay away from it, and you will be OK;
but plant a real *blunt* pole and lean up against it while under an
umbrella, then you are temptimg fate!" He also had a low opinion of those
who would continue to play golf despite smelling ozone around the little
flagpoles.

Perhaps this thread will produce some nice credible stuff about lightning.

73's G4WNT



--  Graham Seale


From [e-mail] Wed May 29 23:39:23 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (xx)
Subject: Dual Band Loop Antenna
Reply-To: [e-mail]
Message-ID: <[e-mail]>
Date: Sat, 25 May 1996 17:20:49 GMT

I'm looking for information (plans, manufacturer's name, reference
book, etc.) about the dual-band, portable, one-wavelength loop antenna
shown on the bottom of page 23 in the May, 1996, Nuts & Volts
magazine.

Please post  your replies here.  Thanks.



From [e-mail] Wed May 29 23:39:24 1996
From: [e-mail] (Joe Ciarcia)
Newsgroups: rec.radio.amateur.antenna
Subject: Eggbeater Plans
Date: Fri, 24 May 1996 16:03:43 -0500
Message-ID: <[e-mail]>

Has anyone ever seen plans to homebrew an antenna
similiar to the M2 Eggbeater? Thanks in advance for info.

73,  Joe   k1jc@empire,net


From [e-mail] Wed May 29 23:39:25 1996
From: [e-mail] (KC8CGX)
Newsgroups: rec.radio.amateur.antenna
Subject: EZNEC Software?
Date: Fri, 24 May 1996 20:10:54 GMT
Message-ID: <4o4qbm$[e-mail]>
Reply-To: [e-mail]

Where could I purchase this antenna modeling software;
approximate price?

Thanks,

Doug
KC8CGX
_____________________________________________
North Central Ohio Skywarn Info
http://www.amnorth.com/redbone/skywarn.html
http://www.amnorth.com/redbone/ham-page.html
http://lrbcg.com/dougd



From [e-mail] Wed May 29 23:39:26 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Fomula to get SWR from foward and reflected power
Date: Thu, 23 May 96 02:15:30 -0500
Message-ID: <[e-mail]>
References: <[e-mail]> <4nrg87$[e-mail]>

Cecil A. Moore~ <[e-mail]> writes:

>Hi David, I'm surprised you have a wattmeter but not an ARRL
>Handbook.

.
From the IEEE Standard Dictionary: a metal radiating strusture that supports
a line current distribution similar to that of a thin straight wire, a half
wavelength long, so energized that the current has two nodes, one at each of
the far ends."
Cheers.


From [e-mail] Wed May 29 23:39:26 1996
From: "Anthony R. Gold" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Fomula to get SWR from foward and reflected power
Date: Thu, 23 May 96 12:46:50 GMT
Message-ID: <[e-mail]>
References: <[e-mail]> <4nrg87$[e-mail]> <[e-mail]>
Reply-To: [e-mail]

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

> From the IEEE Standard Dictionary: a metal radiating strusture that supports
> a line current distribution similar to that of a thin straight wire, a half
> wavelength long, so energized that the current has two nodes, one at each of
> the far ends."

Then the IEEE have a sloppy definition.  Is there any way to energise a
metal structure (and of whatever length) such that, if it has only two
current nodes, they in any other place than at its [far] ends?

Regards,
--
   Tony - G3SKR / AA2PM                  email: [e-mail]
                                                [e-mail]
                                        packet: g3skr@n0ary.#nocal.ca.usa.na


From [e-mail] Wed May 29 23:39:27 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Fomula to get SWR from foward and reflected power
Date: Fri, 24 May 96 04:52:03 GMT
Message-ID: <4o3jfq$[e-mail]>
References: <[e-mail]> <4nrg87$[e-mail]> <[e-mail]>

   Gary Watts <[e-mail]> wrote:

>I'm surprised that it is not a requirement to have one of those
>books. -;
>
>It really dose not matter what year since IMHO it seems that the
>information had been copied for year to year to year

Ditto for the MISinformation.  ;)

73,
Jack  WB3U


From [e-mail] Wed May 29 23:39:28 1996
From: [e-mail] (Ariel Maiselman)
Subject: RE: FS EQUIPOS DE MI ESTACION
Date: 27 May 96 22:35:52 -0700
References: <[e-mail]>
Message-ID: <[e-mail]>
Newsgroups: rec.radio.amateur.antenna

Estoy interesado en la anttena, pero no se cuanto es la pts. por
Dollar, mas o menos dame la idea cuanto en Dollar.

Mandar su respuesta [e-mail]
N3OYK, Gracias


From [e-mail] Wed May 29 23:39:29 1996
From: Luis <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: FS EQUIPOS DE MI ESTACION
Date: Tue, 28 May 1996 09:41:35 -0700
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]>

Ariel Maiselman wrote:
>
> Estoy interesado en la anttena, pero no se cuanto es la pts. por
> Dollar, mas o menos dame la idea cuanto en Dollar.
>
> Mandar su respuesta [e-mail]
> N3OYK, Gracias.. Aproximadamente 1$ USA = 128 Pts.

EB1AKI&EC1ACJ, 73'


From [e-mail] Wed May 29 23:39:29 1996
From: [e-mail] (John cleland)
Newsgroups: rec.radio.amateur.antenna
Subject: Ground or not grounded
Date: 23 May 1996 15:56:12 GMT
Distribution: world
Message-ID: <4o21qs$[e-mail]>
Reply-To: [e-mail]

I will soon be finishing the installation of a full wave loop in the trees on
some undeveloped land which is visited occasionally for camping and hamming.
I have elected to not ground the antenna when not operating.  It seems that
grounding the antenna would encourage a lightning strike and there isn't a
structure to protect.  The trees get hit occasionally anyway.  Anybody have an
y
thoughts on this?

tnx es 73
John, KC5RYQ





From [e-mail] Wed May 29 23:39:30 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Steve Ellington)
Subject: Re: Ground or not grounded
Message-ID: <[e-mail]>
References: <4o21qs$[e-mail]> <4o4pcg$[e-mail]>
Date: Sat, 25 May 1996 11:05:03 GMT

The antenna should be kept grounded at all times. This keeps static
voltage from building up near the area of the antenna which is a prelude
to lightning striking thus providing excellent protection to your
property. If you don't ground it, lighting will be attracted to it and the
huge current will find a path to ground through your feed line then
through your rig. I recommend a resonant loop fed with a 4:1 balun,
current balun preferred, coax to the shack and a good ground on the coax's
shield before it enters the shack.



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


From [e-mail] Wed May 29 23:39:31 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Ham-Ant Digest V96 #301
Date: 28 May 96 05:22:29 GMT
Message-ID: <[e-mail]>
References: <199605271130.EAA01087@.mail.ucsd.edu>

Hi folks! I am looking for info on the MFJ 1796 halfwave
multiband antenna. Is it any good or is it a very long dummy load?
What about quality and performance? Has anyone compared it to
other verticals like the r7?
Many tnx and 73 de ve2rre@va3tcp.#eon.on.ca.noam Pierre Beaudin


From [e-mail] Wed May 29 23:39:32 1996
From: [e-mail] (Steve Peters)
Newsgroups: rec.radio.amateur.antenna
Subject: Help homebrewing a mobile GPS antenna (quadrifilar?)
Date: 28 May 1996 03:12:25 GMT
Message-ID: <[e-mail]>

Thanks for taking a few moments to read this, and maybe to respond...

I am looking to build a homebrew antenna that will function in the band
used to receive GPS signals.  Basically, I have an inexpensive GPS
receiver that I occasionally use in my vehicle.  The vehicle roof and all
the other metal provides a darn good shield, so no signals are rx.

Commercial units are available (for $150!) that purport to receive these
frequencies.  I've seen one , and they're small round, and since I didn't
own it, I couldn't crack it open to take a look see.

So if you have any advice, hints, directions, or references I could look
up, I'd be most appreciative.  You can either post here, or email direct
to [e-mail].

If I get a good response, I'll compile the information neatly, and repost
here, and place it on the WWW.

Thanks and 73s

Steve Peters
N1TYE
Lebanon, NH


From [e-mail] Wed May 29 23:39:33 1996
From: "Vincent D'Elia, Jr" <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: HF antenna for apartment
Date: Tue, 28 May 1996 13:50:45 -0400
Message-ID: <[e-mail]>

I'm thinking of putting my hf on the air and was wondering I should use
as a antenna.
I'm using aYeasu FT-901 and a MFJ tuner
Any suggestions?

Vince
KC6ISS
--
In God we trust, everyone else must show I.D.


From [e-mail] Wed May 29 23:39:34 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF Mobile Antenna type/placement
Date: 24 May 1996 12:51:56 -0400
Message-ID: <4o4pfc$[e-mail]>
References: <4nvemj$[e-mail]>

Subject:        VISALIA MOBILE ANTENNA TRIALS
From:   Jesse Touhey <[e-mail]>
Date:   30 Apr 1996 12:38:13 GMT

                         CONVENTIONAL

CALL        FS/DB        COMMENTS

WA6JPR      62.6         Cntr loaded "Bugcatcher",4"coil, 13.5'
K6UMB*      62.6         Cntr Loaded "VE7BOC" coil, 13.5'
K6IXL       62.3         Cntr Loaded "VE7BOC" coil  13.3'
VE7BOC*     62.2         Cntr Loaded "VE7BOC" coil  13.4'
K7POF       61.5         Cntr Loaded "Homebrew" coil, 13.5'
WB6RVR      61.3         Cntr Loaded "Bugcatcher" coil, 13.4'
W6MMA       60.8         BB3 (screwdriver) 64"whip, 12.9'
WA6QJX*     60.1         Base Loaded "Homebrew" coil 13.4'
WA6SNF      60.1         DK3 (screwdriver) 66"whip, 13'
WB6HQK      59.2         Base Loaded 102" CB whip, 13'
KA6TAY*     57.7         "High Sierra" (screwdriver) 102"whip, 14'
VE7BOC*     57.1         "Hustler High Power system"
KA6TAY*     55.3         "High Sierra" 67"whip instead of 102"whip

                         UnConventional

WA6QJX*     66.1         4'cap hat+two 8'horiz wires on Van
K7POF*      64.4         Large Cap hat, 6"dia coil#10 wire, 13.6'
K6ATP       64.1         Large Cap hat, 3"dia coil, 13.6'
VE7BOC*     64.1         Cap hat, VE7BOC coil, 13.4'
K6SDQ       63.5         Cap hat, Cntr Loaded, 12'11"
KG7BK       59.8         Bent over 108"whip on 40m Hamstick

* Tested more than one antenna type

Conventional: No cap hats,bent over wires etc.

Non Conventional: Cap hats, bent over wires, any config other than
"conventional".

The above trials were held 4/20/96 on 3995kc at the U.S. Towers field
range. Distance from equipment was 0.3 miles. Readings is db above zero
signal thermal noise of the metering system....73s  Jesse (W6KKT)











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From: Jesse Touhey <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: VISALIA MOBILE ANTENNA TRIALS
Date: 30 Apr 1996 12:38:13 GMT
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From [e-mail] Wed May 29 23:39:35 1996
Newsgroups: rec.radio.amateur.antenna
From: Bob Lewis <[e-mail]>
Subject: Re: HF Mobile Antenna type/placement
Message-ID: <[e-mail]>
Date: Tue, 28 May 1996 07:42:34 -0400
References: <4nvemj$[e-mail]> <4o4pfc$[e-mail]>

W8JI Tom wrote:
>
> Subject:        VISALIA MOBILE ANTENNA TRIALS
> From:   Jesse Touhey <[e-mail]>
> Date:   30 Apr 1996 12:38:13 GMT
>
>                          CONVENTIONAL
>
> CALL        FS/DB        COMMENTS
>
> WA6JPR      62.6         Cntr loaded "Bugcatcher",4"coil, 13.5'
> K6UMB*      62.6         Cntr Loaded "VE7BOC" coil, 13.5'
> K6IXL       62.3         Cntr Loaded "VE7BOC" coil  13.3'
> VE7BOC*     62.2         Cntr Loaded "VE7BOC" coil  13.4'
> K7POF       61.5         Cntr Loaded "Homebrew" coil, 13.5'
> WB6RVR      61.3         Cntr Loaded "Bugcatcher" coil, 13.4'
> W6MMA       60.8         BB3 (screwdriver) 64"whip, 12.9'
> WA6QJX*     60.1         Base Loaded "Homebrew" coil 13.4'
> WA6SNF      60.1         DK3 (screwdriver) 66"whip, 13'
> WB6HQK      59.2         Base Loaded 102" CB whip, 13'
> KA6TAY*     57.7         "High Sierra" (screwdriver) 102"whip, 14'
> VE7BOC*     57.1         "Hustler High Power system"
> KA6TAY*     55.3         "High Sierra" 67"whip instead of 102"whip
>
>                          UnConventional
>
> WA6QJX*     66.1         4'cap hat+two 8'horiz wires on Van
> K7POF*      64.4         Large Cap hat, 6"dia coil#10 wire, 13.6'
> K6ATP       64.1         Large Cap hat, 3"dia coil, 13.6'
> VE7BOC*     64.1         Cap hat, VE7BOC coil, 13.4'
> K6SDQ       63.5         Cap hat, Cntr Loaded, 12'11"
> KG7BK       59.8         Bent over 108"whip on 40m Hamstick
>
> * Tested more than one antenna type
>
> Conventional: No cap hats,bent over wires etc.
>
> Non Conventional: Cap hats, bent over wires, any config other than
> "conventional".
>
> The above trials were held 4/20/96 on 3995kc at the U.S. Towers field
> range. Distance from equipment was 0.3 miles. Readings is db above zero
> signal thermal noise of the metering system....73s  Jesse (W6KKT)
>
>
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> Newsgroups: rec.radio.amateur.antenna
> Subject: VISALIA MOBILE ANTENNA TRIALS
> Date: 30 Apr 1996 12:38:13 GMT
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The "shoot-out" tests are true for 75 meters but I would suspect less of
a difference in antennas as you go higher in frequency (i.e. 40 and 20
meters).  I'd like to see similar tests on other bands.



From [e-mail] Wed May 29 23:39:36 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: High SWR problems
Date: 23 May 1996 19:56:01 -0700
Message-ID: <4o38g1$[e-mail]>
References: <4o3353$[e-mail]>

Bob Fetter <[e-mail]> wrote:
: I don't have any idea what else to do. Does anyone have any ideas as to
: what is wrong?

Bob, do you have a ground plane? Without one, you have only
half an antenna. Try three or four radials at the base of
the antenna. You've probably seen fixed CB ground plane
antennas - make it look like that.

73, Cecil, KG7BK (W6RCA soon), OOTC


From [e-mail] Wed May 29 23:39:38 1996
From: [e-mail] (Bill Nelson)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: High SWR problems
Date: 24 May 1996 04:52:30 GMT
Message-ID: <4o3fae$[e-mail]>
References: <4o3353$[e-mail]>

Bob Fetter ([e-mail]) wrote:
: This will most likely be a simple one for most of you hams out there, but it

: has me stumpted. I am using a CB radio for a base station to keep in
: touch with our mobil neighborhood watch patrollers. I've got a 102" whip
: antenna mounted on the edge of my roof. I'm using RG-58/U coaxial cable,
: and I've tried to keep the length of the coax to multiples of 11'10" as best
 I
: could. I've done all this and still I have almost 25% reflected power
: showing on my SWR tester. I've tried to tune it by clipping off about 1 - 2"

: pieces of the RG-58 at a time and testing it again, but this hasn't helped
: any.
: I don't have any idea what else to do. Does anyone have any ideas as to
: what is wrong?

The problem is that you are trying to solve your problem the wrong way.
Changing the coax length will NOT affect the VSWR, although it may change
the meter reading you get.

The only way to actually affect the VSWR is by changing the impedance of
the antenna.  This is usually done by adjusting the length of the antenna.
In your case, the problem is probably due to your using a mobile antenna
as a fixed station antenna. Such antennas are NOT designed to operate
without a groundplane. You can probably improve the match by providing
some ground radials. A better solution would be to get an antenna designed
for base use.

Bill





From [e-mail] Wed May 29 23:39:39 1996
From: [e-mail] (John Marx)
Newsgroups: rec.radio.amateur.antenna
Subject: How much does FM polarity shift over 75 miles?
Date: 24 May 1996 22:25:44 GMT
Message-ID: <4o5d18$[e-mail]>

I'm interested in improving reception of a distant FM station (about 75
miles away).  The station transmits a vertical and horizontal signal of
about 15kw.  The terrain is generally low rolling hills.  I have a six
foot FM band antenna and a good receiver with narrow filters (150khz).
My questions are: how much does the polarity shift over that distance?
If the signal is arriving at an angle, does it result in a significant
loss of gain?  And, of course, is there anything I can do about it?

Any advice appreciated.


From [e-mail] Wed May 29 23:39:40 1996
From: [e-mail] (CHARLES J. MICHAELS)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: How to connect coax to a quad antenna ???
Date: 22 May 1996 03:38:15 GMT
Message-ID: <4nu277$[e-mail]>


Robert G. Strickland
[e-mail]
        said, in response to a queastion about connecting a common
feed line to the several driven elemtns of a quad -

I have done some modeling of common feed quads using EZNEC, and the
general picture is that on 10m, the pattern is semi-useless. Also, for
a five band quad, all feeds tied together with one 2:1 balun, there
are significant drive impedance mismatches. My conclusion is that each
band is best driven separately, with matching adjusted for each band.


Robert,
        Wouldn't this modeling in EZNEC be subject to the requirements
shown in the *Crossed dipole* model shown on page 29 of the EZNEC
manual?
        The required minimum length of .02 wavelengths for the wire
containing the source would seem to distort the quad from its real
length and shape.
        I have run into this problem before trying to model some
of the multiband verticals etx.../

charlie, W7XC
--


From [e-mail] Wed May 29 23:39:41 1996
From: Louis Bertrand <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Larsen glass mount antennas
Date: Wed, 22 May 1996 12:59:40 -0400
Message-ID: <[e-mail]>
References: <[e-mail]> <4nqe7c$[e-mail]> <4nqts7$[e-mail]>

[e-mail] wrote:
>
<SNIP>
>
> I suppose that the 242 may not be as sensitive, and it may also have to do w
ith
> the fact that he side-mounted the antenna, in other words didn't want to put
> it on the center of windshield or back window (due to defroster lines), so h
e put it
> on a side window on the back of his mini-van...
>

I was concerned about the effectiveness of glass mount antennas through
the shading pattern
on my 92 Chev Corsica, so I bought a cheapo Midland glass-mount dual
band and did an
experiement (naw, that's too easy!  It's better to talk it to death...)

I applied the antenna to the side window, then to the back window, both
times using masking
tape to hold everything in place.  I then measured the transmit SWR with
a good Bird meter. I couldn't measure receive signal strength because
I'm using a recycled commercial mobile.

To my surprise, the SWR was slightly better on the back windshield
(1.4:1 vs. 1.5:1 typically).
My conclusions:
1) the shading has no effect;
2) the height of the antenna above the car roof is important (that would
explain the
   performance of the antenna on the side window of your friend's van).
3) alignment of the inside and outside portions is very important.

I'll probably ditch the cheapo Midland when Larsen re-issues their KG
dual-band
antenna later this year.

Ciao!
 --Louis (ve3vhw)

--
The usual disclaimers apply.

Louis Bertrand, Senior Engineer      Motorola Canada LMPS
Toronto Design Centre                3900 Victoria Park Avenue
SMTP:  [e-mail]           North York, Ontario, Canada


From [e-mail] Wed May 29 23:39:42 1996
From: [e-mail] (Anthony O. Cardenas ~ WA6IGJ)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Re: Larsen glass mount antennas
Date: Sat, 18 May 1996 00:46:28 GMT
Message-ID: <[e-mail]>
References: <5e7cc$11271c.2ce@NEWS> <4nd2v8$[e-mail]>

Truth is...

The 'thru-the-glass' antenna(s) uses two plates as capacity-coupling
between the coax and antenna.  It will never equal the efficiency of a
direct connection to the active element (period).

Tony
WA6IGJ


From [e-mail] Wed May 29 23:39:43 1996
From: Barry Williams <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: re:Log Periodic Antennas
Date: Wed, 22 May 1996 19:52:55 -0500
Message-ID: <[e-mail]>

I have been using the KLM 10 to 30 Mhz. 7 element LPDA for a couple of
years.  I had a problem initially with the insulator on the longest
element.  KLM says that they have changed the materials and that the new
insulators are much stronger.  I made an aluminum plate to support mine,
and it has been O.K.  I did notice the reduced front to back ratio when
comparing to the TB6EM I had been using.  I also noticed that this
antenna is very sensitive to metallic objects in the near field.  It is
on a 67' Rohn 45G fold over.  It is guyed at 43', about 30 feet below
the antenna.  When rotating the antenna the SWR goes up and down.  I am
checking with the MFJ analyser through 50' of RG213 and about 80' of
9913.  I planned to put a vee on this tower but decided to move it to
another tower after seeing the SWR variations.

73
Barry


From [e-mail] Wed May 29 23:39:44 1996
From: sarosiw (sarosiw)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Log Periodic Antennas
Date: 24 May 1996 19:11:06 GMT
Message-ID: <4o51ka$[e-mail]>
References: <199605200336.UAA06267@.mail.ucsd.edu> <[e-mail]>

In article <[e-mail]>,
[e-mail] says...
>
>Has anyone ay experience with log antennas for HF -- especially the
>Cushcraft Log periodic.
>--
>. . . 73 and type to you later
>     ____.      .__
>    |    | ____ |  |__   ____
>    |    |/  _ \|  |  \ /    \
>/\__|    (  <_> )   Y  \   |  \
>\________|\____/|___|  /___|  /
>                     \/     \/
> ______________________________________________________________
>| John L. Gianotti KF9GW     [e-mail]  |
>| Dir Computer Services       VOICE:     [phone]  x260  |
>| Lake Central School Corp.     FAX:     [phone]        |
>|______________________________________________________________|
>
Hi John,

I built a ten element LPDA, 22 feet long, with ten elements. Best
antenna I every had and built. It covers 13.5 to 30 MHz. I used
it extensively during the Desert Storm (USAF/MARS).


-WS KB4YLY




From [e-mail] Wed May 29 23:39:45 1996
From: Richard Kiefer <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Log Periodic Antennas
Date: Sat, 25 May 1996 11:17:04 -0700
Message-ID: <[e-mail]>
References: <199605200336.UAA06267@.mail.ucsd.edu> <[e-mail]>

John L. Gianotti wrote:
>
> Has anyone ay experience with log antennas for HF -- especially the
> Cushcraft Log periodic.
> --
> . . . 73 and type to you later
>      ____.      .__
>     |    | ____ |  |__   ____
>     |    |/  _ \|  |  \ /    \
> /\__|    (  <_> )   Y  \   |  \
> \________|\____/|___|  /___|  /
>                      \/     \/
>  ______________________________________________________________
> | John L. Gianotti KF9GW     [e-mail]  |
> | Dir Computer Services       VOICE:     [phone]  x260  |
> | Lake Central School Corp.     FAX:     [phone]        |
> |______________________________________________________________|


Hi John,  Yes I have used a 10 element Tennadyne LPDA extensively on
14-30 Mhz.  It worked fine for what it is.  For example, it is not a high
gain antenna, maybe 2-4 dbd depending on band.  Only a couple of elements
are active on any one band.  As best I could tell F/B ratio was about
14-18 db, not to bad.  I was ver light weight for a 5 band antenna, about
55 lbs, and very easy to put up.  I used a bead balun of about 15 bead
sliped over the coax at the feed point, Fairite # 43 material.

The only real advantage to a LPDA is wide bandwidth.  If you want gain
use something else like a quad or yagi.  Do not know anything about the
Cuchcraft unit but most anything should work ok since the basic concept
is very non critical.  The main concern is mechanical durability.

Good luck.  If you put up the Cushcraft let me know the results.

Dick, K0DK


From [e-mail] Wed May 29 23:39:47 1996
From: [e-mail] (Brian Williams)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Miracle Baby by Comet
Date: 22 May 1996 01:05:46 GMT
Message-ID: <4ntp9a$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] says...
>I have a Kenwood TH-79AD HT and I am looking for a smaller antenna to
>replace the original one.  I have the Miracle Baby by Comet in mind.
>Any suggestions or comments would by appreciated.
>Thanks in advance.
>Andrew

As long as you don't mind performance that seems to be only half that
of a regular rubber duck, the Miracle Baby is great.  Other than it's
small size, there is no advantage of using it.  Soooo, if you are so
close to the repeaters that you want to use, or are so close you can
easily work simplex, it's best stick with as high a gain (actually as
low a loss) portable antenna as you can find.

Brian N6ZAU



From [e-mail] Wed May 29 23:39:47 1996
From: [e-mail] (Rod Landers)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Miracle Baby by Comet
Date: Wed, 22 May 1996 13:38:54 GMT
Message-ID: <4nv58o$[e-mail]>
References: <[e-mail]>

Andrew Lin <[e-mail]> wrote:

>I have a Kenwood TH-79AD HT and I am looking for a smaller antenna to
>replace the original one.  I have the Miracle Baby by Comet in mind.
>Any suggestions or comments would by appreciated.
>Thanks in advance.
>Andrew

I heard someone say that if that antenna worked it was a Miracle baby

73, Rod WI0T



From [e-mail] Wed May 29 23:39:48 1996
From: Harv Shore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Mobile Antenna  -  Screwdriver vs Tuner and Non resonant antennas
Date: 22 May 1996 00:34:22 GMT
Message-ID: <4ntnee$[e-mail]>

The vehicle is a Dodge Conversion Van with an extended top made
of fiberglass.  The radio will probably be the ICOM 706.

Now for the antenna

considering the "screwdiver" class   --  brand TBD  any ideas?
also using an automatic tuner with a fixed length radiator.

One friend suggested the antenna could be horizontal and
hinged so it could be vertical when we are at the camping grounds.

Your opinion
Your experience

Harv
K6EXO


From [e-mail] Wed May 29 23:39:49 1996
From: Jack Cronn <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Mobile Antenna  -  Screwdriver vs Tuner and Non resonant antennas
Date: 23 May 1996 23:58:23 GMT
Message-ID: <4o2u2v$[e-mail]>
References: <4ntnee$[e-mail]>
To: [e-mail]

I use a 'screwdriver' type antenna and can report nothing but good luck.
I do almost 100% of my operating mobile and have received many fine
reports. I use a TS50. I've never used any other type, but cannot imagine
having any other type, since this has so much convenience. Good luck and
hope to meet you on the Air.    73's     Jack/N9VLO



From [e-mail] Wed May 29 23:39:50 1996
From: [e-mail] (Sean McCarthy)
Newsgroups: rec.radio.amateur.antenna
Subject: Multi-banding a bug catcher?
Date: Tue, 28 May 96 05:48:59 GMT
Message-ID: <4oe427$[e-mail]>


Has anyone ever multi banded a bug catcher by shunting out a portion
of the coil? Seems like a good idea for easy band change mobiling.

Comments?

Sean


From [e-mail] Wed May 29 23:39:52 1996
From: Jonathan Helis <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need plans for SHORT 40 meter antenna
Date: 22 May 1996 01:49:08 GMT
Message-ID: <4ntrqk$[e-mail]>
References: <4nrel3$[e-mail]>
To: [e-mail]

If your thinking of a commerical antenna, I have used the MFJ-1621 with
some success.  This is a 54 inch whip that works 40-10 meters.  It won't
work as well as a full size antenna, but it will radiate.  It's only
around $80 new, although I've seen them for $50 used at hamfests.

You may want to get a copy of the W1FB Antenna Book from the ARRL or
another ham books dealer.  It has some good ideas for shortened antennas
you may want to try.

For the ultimate in simplicity(or stupidity, depending on your point of
view), you may want to do what I did in my first apartment:  I put a
square loop on the balcony, set it up so that it could be operated as
either a closed or open loop, fed it with twinlead to a homebrew antenna
tuner, and tried loading up anywhere I could.  This antenna's resonant
frequency was around 22 mhz(it will vary depending on the size of the
balcony.  I have a larger one now, and plan to put one of thes up again
soon), and was able to load it up on 40-10.  It even loaded up on 80, but
I didn't try it there.  I did have some luck on 40 CW in the daytime,
working nearby states with a fairly good signal.  One Friday night, I
loaded it up on 20 CW, heard a DL calling CQ, and decided to call him
just to see what would happen.  He came back to me!  I was very
surprised.  This just goes to show that you can still work HF in a
limited area, with a little skill, creativity, and willingness to try
anything.

Good Luck!

73,

Jon Helis, KB5IAV



From [e-mail] Wed May 29 23:39:53 1996
From: [e-mail] (Cecil A. Moore~)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Off-centre fed dipole theory question.
Date: 25 May 1996 13:52:57 GMT
Distribution: world
Message-ID: <4o73bp$[e-mail]>
References: <4nv5sv$[e-mail]> <4nvbbr$[e-mail]> <4o5g50$[e-mail]>

In article <4o5g50$[e-mail]>,
WB3U <[e-mail]> wrote:

>I'm very curious about this phenomenon.  Why would the feed
>location change anything besides the feed impedance?

Hi Jack, just a guess. What would happen with a quarter
wave vertical with one radial if you lengthened the
radiating element and shortened the radial to keep
the overall total length constant? My guess is the
resonant frequency would change.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)


From [e-mail] Wed May 29 23:39:53 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: phased array antenna - ComTek
Date: 26 May 1996 02:06:13 GMT
Message-ID: <4o8eal$[e-mail]>
References: <[e-mail]> <4o744b$[e-mail]>
Reply-To: [e-mail]

In <4o744b$[e-mail]>, Karl Oyster <[e-mail]> writes:
>Paul,
>
>If you get responses, please post a summary to the list.
>I'm close to being "in the market" for an 80M system like
>this, but don't know the first thing about how to get it
>done.
>
>Thanks.....
>
>
>Karl, NQ1W
>
>

With four plugs of concrete at more than a cubic yard each and four stalks
of Rohn 25G at some 66 feet each, plus the DX Engineering phase box,
the phase lines, the control line and feed line to the shack, as well as the
radials that both sink the lightning and provide the RF return.......

     I can tell you it is a LOT of work.......

         :)


Mike W5WQN as a guest at leviathan.tamu.edu (No mail address there)



From [e-mail] Wed May 29 23:39:54 1996
From: Jeff Hutchinson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Phased B-nut Antennas
Date: Sun, 26 May 1996 12:46:15 -0400
Message-ID: <[e-mail]>

Does anyone have experience with phasing Butternut vertical antennas? I
have two antennas up, spaced 1/4 wave at 14mHz, fed in series with a 3/4
wavelength phasing oine between them.  Any suggestions?
73, Jeff W4PBC


From [e-mail] Wed May 29 23:39:56 1996
From: [e-mail] (Jim Flanders)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Phased B-nut Antennas
Date: 28 May 1996 20:09:46 GMT
Message-ID: <4ofmia$[e-mail]>
References: <[e-mail]>

Jeff:
  If I read you right.  You are feeding the 1/4 wave Verts. with 3/4
wave between them. This = 270 degrees which is effectively -90 degrees.
             |      |   A -90 degree phase difference with 1/4 wave
   feed------|      |   spacing results in a theoretical 3.1 db gain
              \    /    in one direction, and a null in the oposite dir
               \  /
                \/<--3/4 wave     You may want to switch the
directivity.  This can be achieved by feeding in the center with 1/4
wave coax running to the switchbox.  Then switch in the 90 degrees to
either side for +/- 90 degrees.
           |<-vert                        |<-vert
           |                              |
            \                            /
             \         /\<-1/4wave coax /<-1/4 wave coax
              \       \  \             /
               \       \ /            /
                -----------------------
     feed-------| switch box           |  One thing I read about, but
                ------------------------
did not hit home til I did it, is the antennas have to be as identical
as possible, otherwise the expected pattern is not achieved.
Jim W0oog/5
In article <[e-mail]>, [e-mail] says...
>
>Does anyone have experience with phasing Butternut vertical antennas?
I
>have two antennas up, spaced 1/4 wave at 14mHz, fed in series with a
3/4
>wavelength phasing oine between them.  Any suggestions?
>73, Jeff W4PBC



From [e-mail] Wed May 29 23:39:57 1996
From: Jeff Hutchinson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Phased B-nut Verticals
Date: Sat, 25 May 1996 23:17:01 -0400
Message-ID: <[e-mail]>

I have erected two Butternut vertical antennas, spaced 16.5 feet apart
(1/4 wave at 20m), and am feeding them in series, with a 3/4 wavelength
phasing line between them.  Does anyone out there have any experience
with using arrays of Butternut antennas?  I have some questions.
73
Jeff W4PBC


From [e-mail] Wed May 29 23:39:58 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PLANS FOR DUALBAND JPOLE (Binary file, Graphics)
Date: Mon, 27 May 96 16:49:43 GMT
Message-ID: <4ocqmf$[e-mail]>
References: <4nth5q$[e-mail]> <4o5365$[e-mail]> <4ob4u4$[e-mail]> <[e-mail]>

 [e-mail] (xx) wrote:
>[e-mail] (Cecil A. Moore~) wrote:

>>Hi Randy, are you ignoring the rec.radio.amateur.* guidelines
>>or haven't you read them? Binaries are against the guidelines.

>Stick it, Cecil, the rest of us appreciated the post---and tell
>your Dad to use some of his hard-earned social security
>money to buy a 28.8 modem.

No, the rest of us did not appreciate the post.  This is a
discussion group, not a binary group, and you should learn the
difference.  Besides, with a name like "xx", your opinion isn't
worth much.

73,
Jack  WB3U


From [e-mail] Wed May 29 23:39:59 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Rooster)
Subject: Re: Plans wanted for an i
Message-ID: <[e-mail]>
Date: Sun, 26 May 1996 18:11:21 GMT

page 18-37, ARRL antenna book, 15th ed.  "groundplane antennas for 144,
220, and 440 MHz".  these are made from a so-239 connector, brass rod,
just your basic inexpensive stuff.  Four radials bent down as 45 deg, a
vertical 1/4 wave.

similar design pg. 20.59, 1995 ARRL handbook for radio amateurs.
---
 ■ OLX 2.1 TD ■ The Large Print Givith, and the Small Print Taketh Away

--
rooster



From [e-mail] Wed May 29 23:39:59 1996
From: Jeff Hutchinson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Plans wanted for an inexpensive 2m antenna to go outside.
Date: Sat, 25 May 1996 23:10:18 -0400
Message-ID: <[e-mail]>
References: <4nth5q$[e-mail]>

Gerald Phillips wrote:
>
> I am looking for plans/information for an inexpensive 2m antenna that
> can be mounted outside.  Please email me if you have anything.
> Thanks.
>
> KE4MBD - Travis
I am using the rubber ducky that came with my HT.  I made up a little
extension cable that allows me to put the antenna up a few feet in the
room.  It's sufficient to hit any of the local repeaters, which is all I
wanted to do.  Maybe it would work for you, too.
73
Jeff Hutchinson W4PBC


From [e-mail] Wed May 29 23:40:00 1996
From: Mark Saunders <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: R7000?
Date: Tue, 21 May 1996 23:22:41 -0700
Message-ID: <[e-mail]>
References: <4nhqhe$[e-mail]>

Roger J. Buffington; AB6WR wrote:
>
> Has anyone used the new Cushcraft R7000?  I'm curious as to how it
> performs.  I'm also interested in knowing how it handles high power at a
> near 100% duty cycle, as for SSTV or digital operations (Amtor/Pactor/RTTY).
>
> The R-7 was notorious for blowing traps at even modest power levels. (The
> R5 does not suffer from this problem, in my experience.)  Did the R7000
> cure this problem?

Roger,

I'm going to buy one with the R80 80m add-on kit next month.  My old Hy-Gain
AVT18 5 band vertical is 25 years old and in bad condition.  I'll fix it up an
d
use it for Field Day and camping expeditions.

I contacted Cushcraft via their home page  http://www.cushcraft.com.  Send the
n
an e-mail message from their page, and they will respond to you.  I'm impresse
d
with the rapid responses I received.

Regards,

Mark Saunders - KJ7BS
Glendale, AZ
PACKET:   [e-mail]
INTERNET: [e-mail]


From [e-mail] Wed May 29 23:40:01 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Pete Soper)
Subject: Re: Radio Shack Tandy Coax any good?
Date: Tue, 28 May 1996 13:56:35 GMT
Message-ID: <[e-mail]>
References: <[e-mail]> <4oaubn$[e-mail]>

[e-mail] (Red5or7) writes:

>DOG LEASH!  But, some time ago, they started improving their braid
>coverage.  Now, I think it's right up there with the other brands.  Say,

By coincidence last night I made a stub filter out of a piece of junk box
RS RG8 that I bought around 2/95. The braid coverage looked fine to my eye.
It's their prices that drove me to mail order suppliers long ago.

Regards,
Pete
KS4XG


From [e-mail] Wed May 29 23:40:02 1996
From: John O'Brien <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Request comments - Larson mag-mounts
Date: Mon, 27 May 1996 03:23:20 -0400
Message-ID: <[e-mail]>
References: <4ndrjl$[e-mail]> <4nfg6b$[e-mail]> <Pine.SUN.3.90.960523225041.6860B-100000@zippy>

Ken Harrison wrote:
>
> On 16 May 1996, Brian D. Stevens wrote:
>
> > : I am requesting comments about Larson Antenna mag-mounts.  I have
> > : experienced with two different NMO-MM mag-mounts that corroded inside an
d
> > : became disconnected (electrically) from the capacitive coupling surface
> > : on the base - resulting in high SWR.  Anyone else experience this?
> >
> > Mine kept falling off at highway speeds and were destroyed before
> > they had time to corrode.
> >
> > B
>
> I've got a LM-MM and have NEVER had it fall off.  It has sustained
> continuous speeds of 85 MPH, also.  You must be doing something wrong.
>
> Oh, oh...  I know!  Is your vehicle steel?   <snicker... couldn't resist.>


greetings!
i have a larson mag mount antenna,
i've used it for about the last 4 years and have had no problems with it <knoc
k on
wood>
it hasn't fallen off yet, and i tend to travel a bit _too_ fast on the highway
s ;)
do you leave the antenna on the car at all times?
when it's not in use it sits in the trunk,
my dad has the same antenna <2m mag mount> and he never takes it off his truck
,
he's only had one problem with it so far and that was because the coax had sho
rted at
the feedpoint, i had a similar problem and replaced the coax <after some delic
ate
surgury>

comments?
i think it is a very good antenna, my section of town is a major "hole" and th
at lil
antenna gets me out <along with my old kenwood mobile rig......#'s? what are t
hose ;)
>

73's

John
N1NJI

ps..
i homebrew all my other antennas,
i have a j-pole made out of copper pipe
and a 1/4 groundplane made out of coat hangers <the old wire ones, the plastic
 ones are
tough to solder ;) >
antone know of any good, and cheap programs for the ibm/pc platform...
design, testing, etc...
tnx!
------------------------------------------------------------------------------

Radioactive cats have 18 half-lives.


From [e-mail] Wed May 29 23:40:03 1996
From: Bert - ns4w <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Rohn 25 limits
Date: Tue, 28 May 1996 17:32:38 -0700
Message-ID: <[e-mail]>
Reply-To: [e-mail]

Hi All,

Assume a Rohn 25G tower, concreted base section, 3'X4'X3' hole.  What
windload ratings at 20' & at 30' ?



Thanks, Bert - NS4W
[e-mail]


From [e-mail] Wed May 29 23:40:04 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Daniel Senie)
Subject: Re: RS telescoping masts?
Message-ID: <4ob995$[e-mail]>
References: <4n54i5$[e-mail]> <4nv32g$[e-mail]> <4o1loa$[e-mail]> <[e-mail]>
Date: Mon, 27 May 1996 03:58:29 GMT

In article <[e-mail]>,
Bruce Burke  <[e-mail]> wrote:
>[e-mail] wrote:
>>
>>         The Home Depot product is basically the same thing as the RS. Same
>> cautions apply. Be sure to guy properly, don't walk it up, don't put much u
p there.
>>
>> Jim N7TCF
>>
>> In <4nv32g$[e-mail]>, [e-mail] (DaddyDavid) writ
es:
>> >They look good , but I've not used them. A cheaper alternative at Home
>> >Depot is a three section 15' tublar steel telescoping bird feeder pole.
>> >I've had one up in 40+ winds with 7 lbs of wooden  bird house at the top.
>> >Very easy to Telescope.
>> >de N9PVF
>
>Fifteen feet is a little much to transport. Most vans and Chevy Blazer style
>vehicles will handle 10 feet.

That's what roof racks were invented for! We regularly have 18 foot long
kayaks on the roofs of our vehicles. (Yeah, it does look a little odd).

Dan N1JEB



From [e-mail] Wed May 29 23:40:05 1996
From: [e-mail] (Cliff Davies)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: T2FD Dimensions??
Date: Mon, 27 May 1996 12:07:11 +0100
Message-ID: <4oc69m$[e-mail]>
References: <4obete$[e-mail]>

In message <4obete$[e-mail]>
        [e-mail] (Eric Skaggs) writes:

> Anybody out their have dimensions for a 80-10 mtr. T2FD antenna
> utilizing 50 ohm terminating resistor????

> Eric KI6EO

Hi Eric,
  For 3.6 and up it's 91' 1" (27.76m) and a spacing of 2' 8"ins,
Thats each side AND includes the spacing, I've only ever seen
reference to using anything between a 300-600 ohm terminating
resistor,... but I could be wrong:)  Email me if you need more info.

Cliff
GI3HNM






From [e-mail] Wed May 29 23:40:06 1996
From: [e-mail] (JAMES MCEWEN)
Newsgroups: rec.radio.amateur.antenna
Subject: test,do not bother to read
Date: 23 May 96 16:38:05 GMT
Message-ID: <[e-mail]>

     told U so!

     KA6TPR



From [e-mail] Wed May 29 23:40:08 1996
From: [e-mail] (Alex Evonosky)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Tribanders?? Which to Buy???
Date: Wed, 22 May 1996 22:58:24 GMT
Message-ID: <4o079r$[e-mail]>
References: <4nne5t$[e-mail]> <[e-mail]>

BJR <[e-mail]> wrote:

>Peter Bealo wrote:
>>
>> Hi, I'm interested in a new tribander in the <=$600 range. Any opinions
>> out there about which to consider??
>>
>> I am replacing an old Telrex that did a great job for me, but alas is no
>> more (didn't survive the last move we made).
>>
>> The new antenna will be up ~30 feet.
>>
>> How about the Mosley stuff?? Some friends like Cushcraft. WHat do you
>> think?
>>
>> The antenna must be able to withstand tough New Hampshire winters.
>>
>> Peter  WB2MJG  Plaistow NH

>Peter,

>Take a look at Force 12, most notably the C3. I put one together
>yesterday in about 2 hours. No hose clamps - antenna elements are
>riveted together. You can actually put the thing together without a tape
>measure as all element holes are pre-aligned at the factory. Like the
>KLMs no traps either. As to performance, my C3 is still on the ground but
>I have used others in the past and they work as advertised.

>You can e-mail me if you would like to discuss in more detail, however
>my Prodigy E-mail connection is intermittent so don't know if I can
>receive any mail or not.

>Bob R. (VE6KRR)

You can try the KLM KT-34XA...Excellent performer and can be found
priced around the 600 mark..  Excellent results and windload is abt
9sq ft.
Alex-kb4lbx




From [e-mail] Mon Jun 03 17:22:57 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PLANS FOR DUALBAND JPOLE (Binary file, Graphics)
Date: 27 May 1996 14:27:01 -0700
Message-ID: <4od6n5$[e-mail]>
References: <4nth5q$[e-mail]> <4o5365$[e-mail]> <4ob4u4$[e-mail]> <[e-mail]>


xx <[e-mail]> wrote:

: Stick it, Cecil, the rest of us appreciated the post---and tell
: your Dad to use some of his hard-earned social security
: money to buy a 28.8 modem.

Too yeller-livered cowardly to post under your name, eh?
Are you advocating violation of the r.r.a.* guidelines?
If you're a ham, your're one of the rotten apples of
amateur radio. Did you pass the Morse code test? :-)

I gave my dad a 14.4 modem. The telephone lines in Madisonville,
TX are so bad that the modem always reverts to 1200 baud.

You can appreciate a binary posting just as well if it is
posted where it belongs - on a binary group. And thousands
of dollars of r.r.a.* bandwidth need not be wasted by
posting it here against the guidelines.

Can't bring myself to say 73 - doubt if you know the
meaning anyway.

Cecil, KG7BK



From [e-mail] Mon Jun 03 17:22:58 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (xx)
Subject: Re: PLANS FOR DUALBAND JPOLE (Binary file, Graphics)
Reply-To: [e-mail]
Message-ID: <[e-mail]>
References: <4nth5q$[e-mail]> <4o5365$[e-mail]> <4ob4u4$[e-mail]>
Date: Mon, 27 May 1996 15:17:28 GMT

[e-mail] (Cecil A. Moore~) wrote:

>In article <4o5365$[e-mail]>,
>Randy Seacat <[e-mail]> wrote:
>>
>>Here are the plans for a dualband copper catus (Jpole) that I put together
>>in a graphical format. Wish we had a rec.radio.amateur.binaries or
>>something.

>Hi Randy, are you ignoring the rec.radio.amateur.* guidelines
>or haven't you read them? Binaries are against the guidelines.
>Simply post the binary to a binary group and do a descriptive
>posting here telling everyone where you put it.

>My dad doesn't appreciate having to spend his social security
>to download your binary files at 1200 baud over long distance.

>73, Cecil, KG7BK, OOTC  (not speaking for my employer)


Stick it, Cecil, the rest of us appreciated the post---and tell
your Dad to use some of his hard-earned social security
money to buy a 28.8 modem.



From [e-mail] Mon Jun 03 17:22:59 1996
From: [e-mail] (Mark Walker (N9HCI))
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 80mtr loop (cloud warmer)
Date: Mon, 27 May 1996 17:13:31 GMT
Message-ID: <4ocnhl$[e-mail]>
References: <4nnmnv$[e-mail]>

Hello, all!  You may have seen my earlier posts here, where I related
my amazing DX success with a low horizontal loop.  It's a killer
antenna and if you want to know just why it's so great on 20-10, check
out May 1990 QST on page 28.  Complete with E and H-plane diagrams.
I have been collecting info from other loop owners for several years,
and at this point, I would have no other antenna connected to my
shack.  The debates on this subject, like any other in ham radio,
could go on forever.  All I can humbly suggest is that anyone with a
little space try it out.  There aren't many tricks involved, but I've
already helped several guys with some info from earlier postings here
and am glad to help again.  Of course, I'd rather have monbanders at
90 feet, but short of that, I'll never own any other antenna.
By the way, I rarely use it on 75 or 160, but the big bonus there is
that its an extremely quiet antenna.
73, good DX to everyone, Mark N9HCI   [e-mail]



From [e-mail] Mon Jun 03 17:23:00 1996
From: Jake Brodsky <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR antenna
Date: Tue, 28 May 1996 12:32:17 -0700
Message-ID: <[e-mail]>
References: <[e-mail]> <4nrnj7$[e-mail]>

So in summary, a DDRR would be a very short vertical antenna with
one heck of a capacity hat *real* close to the ground.  Or is it
something more like a loaded loop running real close to the ground?

I'm also a bit curious as to why the emphasis on large pipe?  Is it
skin effect and high currents they need to overcome?

73,
Jake Brodsky, AB3A
"Beware of the massive impossible!"


From [e-mail] Mon Jun 03 17:23:01 1996
From: [e-mail] (CooperJim)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Need plans for SHORT 40 meter antenna
Date: 28 May 1996 12:34:55 -0400
Message-ID: <4of9vf$[e-mail]>
References: <4odo7p$[e-mail]>
Reply-To: [e-mail] (CooperJim)

The ARRL Antennea Book has designs for small transmitting loop antenneas
that cover 40 meters.  These work well but have narrow bandwidth.


From [e-mail] Mon Jun 03 17:23:01 1996
From: [e-mail] (Gyro)
Newsgroups: rec.radio.amateur.antenna
Subject: Butternut HF6v  High noise
Date: 28 May 1996 20:51:32 GMT
Message-ID: <4ofp0k$[e-mail]>

I was given(so I thought) a hf6v 80 - 10 with the 160 coil added on it.
Now I have been asked to buy it. It is about 3 years old and seems to work ok.
Anyone know what this should be worth?
Also...I have about 7-9 s units of noise most of the time. The antenna is up
30 ft. which is about 6 ft(base) above the roof. The mast goes down to a 200
ft long chainlink fence post and is attached there . What can I do about this.
The noise is not much affected by band. I am in a commercial complex. Could
the power be filtered differently?
thanks in advance. 73..............KE6OTT



From [e-mail] Mon Jun 03 17:23:02 1996
From: [e-mail] (Nick J Chiarchiaro, AET / N2QXF)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: HF antenna opinion
Date: Tue, 28 May 1996 22:36:05 GMT
Message-ID: <4ofvhu$[e-mail]>
References: <4ocnq6$[e-mail]> <4oe8ni$[e-mail]>

[e-mail] (WB3U) wrote:

>   [e-mail] (Nick J Chiarchiaro, AET / N2QXF) wrote:

>>I have  aquestion to the group.  I have recently 'liberated' a
>>point on my roof for another antenna.
>>
>>I am trying to decide which avenue to pursue.  A vertical or
>>rotatable dipole.
>>
>>Currently I am using a set of paralell dipole 80-10 at 35'.  Reults
>>are not bad and I realize at 80-40 it is relatively omnidirectional.
>>
>>The mounting location is at 50' above ground on a rather sturdy
>>mount. (it held a 13b2 2m beam and 2 phased 4 el 2m beams)
>>
>>I was thinking of getting the 40/20/15/10 world ranger dipole from
>>cushcraft.  While it would have 0db gain it would still have some
>>directivity on the upper bands.  However, the radiation angle I
>>think would be rather high.
>>
>>Then I started thinking of a 80-10 vertical.  The radiation angels
>>all seem to be around 16dg.  Being the height is kinda high I could
>>probably get away with no to many radials or if I get a model that
>>doesn't 'reuire' any.

>Efficiency of multi-band verticals is usually much less than
>full-size dipoles on 80 & 40 meters, due in part to the shortened
>elements and losses in the multiband feed system.  Also, verticals
>are noisier than horizontal wires, so the choice may depend on
>where you live.  The problem of noise will obviously be worse in a
>metropolitan area.

>The difference in radiation angle that you mentioned is also a
>factor. Generally speaking, the dipole will be superior at
>distances of 1,000 miles and less, while the vertical will often
>provide improved DX performance.

>Despite it's somewhat reduced efficiency, I would probably add
>the vertical.  That way, you could switch in whichever type of
>antenna is most effective for the prevailing conditions.  I
>wouldn't spend additional money for a vertical capable of 80M
>operation though.  The efficiency is likely to be very poor on
>that band and it may not even perform as well as the dipole
>you're already using.

>73,
>Jack  WB3U
Tnx jack,

Most who have responded kinda like full size dipoles the best, as long
as there is room for them. <g>

So with that in mind i would probably stay with the dipoles, and
'save' the money

Nick




From [e-mail] Mon Jun 03 17:23:04 1996
From: [e-mail](Anthony Severdia)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: need help with wire dipole
Date: 29 May 1996 00:58:36 GMT
Message-ID: <4og7fs$[e-mail]>
References: <[e-mail]>

In <[e-mail]>
[e-mail] (Charlie Fortner) writes:
>
>I'm planning to put up a 250 ft (approx. full wave 80m) wire dipole
and
>feed it with ladder line for use as a multiband antenna.  If the legs
are
>more than 90 degrees apart in the horizontal and veritical planes,
will
>the radiation pattern be substantially different that if it was 180
>degrees in each plane?  Any other suggestions appreciated.  Thanks.
>
>73 de KF4GJQ (Charlie Fortner)

    Charlie, you don't say how high at the apex!  This makes a
considerable difference too.  Yes, the radiation pattern will be
different at the fundamental freq and very different at the harmonics
but if you put up such "long one" don't worry about it ...just use it
and make your observations!  Good luck

    -=Tony=-



From [e-mail] Mon Jun 03 17:23:05 1996
From: John O'Brien <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Plans Needed for 2-Meter J-Pole (Plumbers Delight)
Date: Wed, 29 May 1996 01:33:33 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>

[e-mail] wrote:
>
> Does anyone know where, _on the Net,_ I can find plans for a "Plumbers Delig
ht" 2-meter
> J-Pole? (The type I'm thinking about is made from 1/2" copper pipe.)
>
> [This is for a beginner---he's in a geographic location/situation that makes
 textbook
> access difficult.  It would be my intent to zip it up and e-mail it to him..
.he has
> plenty of 1/2 copper pipe, tho!]
>
> 73
>
> KJ6EF

check out:
ftp://ftp.funet.fi/pub/dx/txt/antennas/jpole.txt

it has the plans for the "plumber's dream"
i did a search using lycos, http://www.lycos.com/ searched for jpole and
the first entry i found was this text file, there is another file in
that directory for a jpole made out of 300ohm<?> tv wire.....
i use the copper pipe jpole, and my radio club <the bristol county
repeater association
http://www.ici.net/cust_pages/roland-d/roland-d.html >
has had some discussion over plans for the antenna, we've got two sets
of plans, each one sugesting a different feed point, i have mine fed at
one point, a friend of mine has his fed the opposite way, and both work
fine as far as we can tell, i get a good match all across the 2m
band....it's a big step up from the 1/4 wave groundplane i built out of
coathangers :)

-john...
N1NJI
<tech-lite, tastes great, less code>
---------------------------------------------------------------
disclaimer:
signature file brought to you by the makers of prep-h "cause one asshole
just isn't enough"
-loading signature file-

you've just been violated by:
John W. O'Brien III
poet, actor, lover,electrical engineering student, computer god, and all
around
genius.

has been quoted as saying:
-> "Quos amor verus tenuit tenebit"
->"Radioactive cats have 18 half-lives."
->"love is like dogshit, you don't 'fall in love'
you step in it."




From [e-mail] Mon Jun 03 17:23:06 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Multi-banding a bug catcher?
Date: 29 May 1996 02:20:44 -0400
Message-ID: <4ogqbs$[e-mail]>
References: <4ofres$[e-mail]>

In article <4ofres$[e-mail]>, [e-mail] (Sean
McCarthy) writes:

>Hi Cecil,
>
>I was thinking of a passive approach using parellel capacitance to shunt
a
>portion of the coil. Swan made an antenna like this called a 742 or
370-19.
>
>They used 2 varible and 2 fixed caps to shunt 2 portions of the coil,
giving
>75/40/20 operation. Their coil was 2" diameter, 10 tpi, 85 turns total.
>A fixed 100pf 5kv in series with a 125pf varible was connected from the
>10th turn to the 28th turn, and again from the 33rd to the 44th.
>
>Sean

Hi Sean,

That is a disasterious thing to do to a loading coil. It radically
increases the circulating currents, makes the antenna become
narrow-banded, and lowers the efficiency all in one swoop!

That's one of the reasons a capacitance hat should never be mounted close
to a loading coil.

73 Tom


From [e-mail] Mon Jun 03 17:23:07 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna,rec.radio.homebrew
Subject: Re: Need Source for Aluminum Tubing
Date: Wed, 29 May 1996 03:50:28 GMT
Message-ID: <4oghpq$[e-mail]>
References: <4nqb6l$[e-mail]> <4o7h6s$[e-mail]>

Give Texas Towers a call Gerald can fix you up with all the aluminum
you need.
Tony
[e-mail] (peter J thompson) wrote:

>[e-mail] (Chris Smith, NR3O) wrote:

>>Am looking for local (MD/DC area) or mail order source for aluminum
>>tubing for antenna project.  1/2, 3/8 and 1/4" diameters in 5-6 ft
>>lengths.

>>73 and tnx de Chris

>>Please respond here and to [e-mail]
>Chris,

>       I think you can get Al. Tubing in the sizes you mentioned in most of
>the larger
>hardware stores (Eg.Hechinger here in DE).  I'm pretty sure I saw some
>while I
>was looking
>for some 2in diameter which, so far I have been unable to locate!  I
>need
>about 12 to 15in
>to replace the base of my Cushcraft R5 which got damaged.  Please let
>me know
>if you find
>out about any good sources.

>73, Pete N3EVL







From [e-mail] Mon Jun 03 17:23:08 1996
Newsgroups: rec.radio.amateur.antenna
Subject: Re: hacking a 2M 5/8 magmount installation thru hole in apartment
Message-ID: <[e-mail]>
From: [e-mail] (Mike Morris)
Date: Wed, 29 May 1996 04:29:29 GMT
References: <4nfi1d$[e-mail]> <[e-mail]>

[e-mail] (N4JVP) writes:

>On Mon, 27 May 1996 01:55:46 GMT, [e-mail] (Robert Casey)
>wrote:
>-snip-
>>before.  And the landlord won't see it, and probably wont see the 1/4
>>inch hole in the ceiling after I move out.  A little spackle will
>>take care of it anyway.

>forget the spackle, try a dab of plain old dab of white toothpaste.
>Toothpaste will not shrink either and its a lot cheaper than a small
>can of spackle....

Or stick a Moly bolt in the hole and hang a $9.95 battery oeraated smoke
detector on the Moly.


--
Mike Morris                              [e-mail]
#include <disclaimer.std.h>      I have others, but this works the best.
  Looking for CDA-banned material?  Try the bible: Genesis 19:30-38,
  or Ezeikel 23:20.


From [e-mail] Mon Jun 03 17:23:09 1996
From: [e-mail] (Kevin  AstirCS "1U"   KO0B)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Phased B-nut Antennas
Date: Wed, 29 May 1996 10:20:23 -0700 (PDT)
Message-ID: <4ohted$[e-mail]>
References: <[e-mail]>


>Does anyone have experience with phasing Butternut vertical antennas? I
>have two antennas up, spaced 1/4 wave at 14mHz, fed in series with a 3/4
>wavelength phasing oine between them.  Any suggestions?

I envy the fact that you have the real estate to do such
experimenting!

I had a roof mounted Butternut bander up , 4 radials on 80 & 40, 6 on
20 & 15, and 12 on 10...untill it tangled with tornado associated
winds & neighbors airborn tool shed (no exageration!) and expired.  It
was one excellent radiator in A/B comparison  with dipoles.

One big suggestion:

Beg, buy, borrow or steal a copy of  ARRL Antenna Book, and read
everything on feeding of  phased verticle arrays written by Roy
Lewallen (W7EL).  Then read it again and again untill it all sinks in.

My Antenna book is a couple of years old..hopefully the material on
phased arrays is still in the current book. Roy?

The Readers Digest version:

The Phase and magnitude of the radiation from a verticle is determined
chiefly by the _current_ flowing at it's feedpoint.

Unless it presents a   50ohm resistive load, (or whatever Z0 might be
for the line you use) , then the current supplied to the radiator will
_not_ be phase shifted by the electrical length of the line, and may
be either greater or less than current in other element.

The other radiator in the phased array disturbs the feedpoint
impedance of the antenna, so that even an antenna which is perfectly
matched by  it's lonesome will not be so when used in the array.

So the phase and magnitude of the currents is not determined soly by
the lengths of the feedlines. (though it still matters)
Connecting two identicle verticles with 3/4 wave line between them
will _not_ result in quadrature current flowing in the elements.

Roy Lewallan may not have been the first to figure this out, but he
has done a magnificent job of presenting the material, and has come up
with a very slick, simple way to deal with the problem.  Compared to
radials, mechanical considerations, etc, doing it right doesn't
require a lot more effort, and very little expense.

The data presented by W7EL indicate that this doesn't have much impact
on forward gain, but has a _huge_  effect on F/B.  With two verticles,
you are looking at only ~3dB forward gain anyway, so the real
motivation should be F/B improvement.

W7EL does suggest that you stick to simple 1/4 wave radiators.
Hinting that "shorteners"  (Like the Butternut resonators) may cause
some odd effects when used in an array.

I would still be tempted to try to make it work, however.
As 1/4 wave spacing will only be on one band, you could make up a
"monoband Butternut" (1/2 wave on twenty, or 1/4 wave on 15 for
example) and save the expense of a second  "real" Butternut.  Do the
final tweaking with a test source ~ 1/2 mile off the back, and try to
get a null.

The ~1/4 wave (on 20) 75 Ohm section (I assume Butternut still doing
this) will throw a wrench in W7EL's current forcing method. So it
would be best to eliminate it and find some other way to get SWR down
on 20.

-73-, and If anything I said reduces you willingness to experiment,
then by all means ignore me!

ko0b
I





From [e-mail] Mon Jun 03 17:23:11 1996
From: [e-mail] (Lluis Arasanz i Nonell)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: PLANS FOR DUALBAND JPOLE (Binary file, Graphics)
Date: Wed, 29 May 1996 11:04:17 GMT
Message-ID: <[e-mail]>
References: <4nth5q$[e-mail]> <4o5365$[e-mail]>
Reply-To: [e-mail]

[e-mail] (Randy Seacat) wrote:

+--->[e-mail] (Gerald Phillips) writes:
+--->
+--->>I am looking for plans/information for an inexpensive 2m antenna
that
+--->>can be mounted outside.  Please email me if you have anything.
+--->>Thanks.
+--->
+--->>KE4MBD - Travis
+--->
+--->
+--->
+--->Here are the plans for a dualband copper catus (Jpole) that I put
together
+--->in a graphical format. Wish we had a rec.radio.amateur.binaries
or
+--->something.
+--->


Which bands   2mts / 70 cmts ?

thanks.


From [e-mail] Mon Jun 03 17:23:11 1996
From: [e-mail] (Adam Maurer)
Newsgroups: rec.radio.amateur.antenna
Subject: 6MX eggbeater
Date: 29 May 1996 11:54:11 GMT
Message-ID: <4ohdt3$[e-mail]>

Hi, Adam in Melbourne here.

Has anyone had any experience with eggbeaters, particularly on 6MX?
What's the performance like?
Any there any good articles you could make me aware of?

Please email me and let me know.

73, Adam VK3ALM



From [e-mail] Mon Jun 03 17:23:13 1996
From: [e-mail] (Jim Flanders)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR antenna
Date: 29 May 1996 17:04:33 GMT
Message-ID: <4oi031$[e-mail]>
References: <4of131$[e-mail]> <4ofimj$[e-mail]>

Tom:
  My next question is:  What will give me more signal on 40 from my
Van? Will it be a DDRR mounted on the roof - or will it be a Texas
Bug Catcher?  You don't have to answer the question.  I am going to
try to find someone In the N. TX or S. OK area that will loan me a TBC
for a weekend test after I modify the DDRR for 2 ft spacing.
Jim W0oog/5 in Plano TX on 147.180 & subvets net on 14.243 @ 1130 CST.


In article <4ofimj$[e-mail]>, [e-mail] says...
>
>In article <4of131$[e-mail]>, Edward Lawrence <eal>
writes:
>
>>Since I was the person who posted the "idiotic" comment, I will
expand on
>>the reason I said that.  The first article I ever saw referred to a
CB
>>version,
>>and the 'hula hoop' antenna was described as a DRR, or 'Discontinuity
>Ring
>>Radiator'.  The name came from the originators idea that the thing
>radiated
>>because each little change in direction caused a 'discontinuity" ie:
>>impeadance
>>change, thus leaking RF at this supposed 'discontinuity".  This is
>hogwash!
>>Granted, I did not read the original papers on this antenna, but I
think
>the
>>name says it all.  Thus I say "idiotic" theory!
>
>Many mystical antennas (like the DDRR) are based on incorrect or pie
in
>the sky theories.
>
>Correctly described, the DRR or DDRR is a short top loaded vertical.
EM
>radiation occurs primarily from the short vertical section. There is
no
>"magic" or unique theory involved. The DDRR doesn't behave at all like
a
>slot antenna, it behaves much more like a VERY short vertical section
>inverted L with a folded flat-top.
>
>If you want to see a similar re-invention of the same inefficient
design,
>look at the ARRL Antenna Compendium. There is a "Magnetic Folded Loop"
>that uses the same principle, rolled in with some wild theory about
the
>element being a low loss "magnetic radiator". It goes on to describe
an
>even wilder theory, how the folded element raises the radiation
resistance
>and efficiency.
>
>"Designers" bend the area that doesn't radiate a bit differently, and
>claim a wild new magical high efficiency design.
>
>In reality, all of these antennas are very short low efficiency top
loaded
>verticals (like a **very short** inverted L), or small arrays of the
same
>low efficiency antenna designs.
>
>"Idiotic" may sound a bit harsh, but it is a correct description of
>feebleminded or foolish theories surrounding these antennas. If you
take
>notes and look closely at their behavior, they follow all the rules of
any
>short radiator.
>
>73 Tom



From [e-mail] Mon Jun 03 17:23:13 1996
Newsgroups: rec.radio.amateur.antenna
From: lloyd korb <[e-mail]>
Subject: Dual Band Yagi Design
Message-ID: <[e-mail]>
Date: Wed, 29 May 1996 19:20:21 GMT

Has anyone tried to model any dual band yagi's with YA,YO, AO or
YAGIMAX?  I would like to model a 6 & 2 meter yagi on the same boom.

Lloyd  K8DIO
[e-mail]



From [e-mail] Mon Jun 03 17:23:14 1996
From: [e-mail] (Keith A Monahan)
Newsgroups: rec.radio.amateur.antenna
Subject: Antennas
Date: 29 May 1996 20:19:04 GMT
Message-ID: <4oibfo$[e-mail]>

        I'm still rather new to the radio field, so you'll have to forgive
any questions that many of you will consider basic.

What is an ideal antenna for each band? ie, what is the relationship between
frequency and length of antenna?

Can an antenna be too long or too short?

Whenever someone talks about a 1/4 wave or 5/8 wave antenna what do they mean?
Which is better? And why?

Is there some sort of basic principle that states, antennas will be more
efficient if they are some even multiple of the wavelength?

All size considerations excluded, would the BEST possible antenna be one that
is the same length as the wave of the frequency?

Thanks in advance.
Keith




From [e-mail] Mon Jun 03 17:23:15 1996
From: Darrel Emerson <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: design for 1/4 wave z xfmrs for 1/2" catv hardline?
Date: Wed, 29 May 1996 22:46:17 -0700
Message-ID: <[e-mail]>
References: <[e-mail]>
To: Peter Markham <[e-mail]>

Peter, here is an alternative to the quarter-wave matching section,
to match 75-ohm to 50-ohm coax.
   Since you're matching 75 ohm cable to 50 ohm cable, you probably
have spare lengths of each.  From the 50-ohm cable, connect
one twelth-wavelength (electrically) of 75-ohm cable.  Then
connect a one-twelth-wavelength of 50-ohm cable between the free
end of this section of 75-ohm, and the final 75-ohm cable you're
matching.
   e.g.
          ----------------++++----++++++++++++++++++
              50 ohm       75  50       75 ohm

   This avoids trying to find a length of 61-ohm coax to make
a quarter-wave matching transformer.  The bandwidth of this transformer
is very reasonable (at least comparable to the true quarter-wave
matching transformer.)  The only disadvantage is that there's one more
connection than in a simple quarter-wave transformer.
   If you plot this out on a Smith chart, allowing for the 1:5 SWR
in each component of the matching transformer, it's fairly easy to
see how this transformer works.  (Strictly speaking it's not
EXACTLY one-twelth sections, but it's close enough and easier
to remember.  You can use the Smith chart to show how close it comes.)
     Good luck,
         cheers,
             Darrel Emerson, aa7fv.


From [e-mail] Mon Jun 03 17:23:16 1996
From: [e-mail] (CARRJJ)
Newsgroups: rec.radio.amateur.antenna
Subject: miniNEC software
Date: 30 May 1996 02:02:28 -0400
Message-ID: <4ojdlk$[e-mail]>
Reply-To: [e-mail] (CARRJJ)

Does anyone know where to download the BASIC for miniNEC (not EZNEC and
ELNEC which are proprietary). Reply to [e-mail]


From [e-mail] Mon Jun 03 17:23:17 1996
From: [e-mail] (Lynn Stolz)
Newsgroups: rec.radio.amateur.antenna
Subject: Anybody using Fritzel Windoms?
Date: 30 May 1996 08:35:21 -0400
Message-ID: <4ok4m9$[e-mail]>


I'd like to hear from anyone using the Fritzel OCF antenna(s).
...wondering how well you like or hate it.  do you have it installed
in the suggested inverted-vee configuration or not, etc...

I am thinking of replacing my old separate 40 and 80 meter dipoles with one.

Thanks,

Lynn N8AJ
--
Lynn Stolz  N8AJ [e-mail]


From [e-mail] Mon Jun 03 17:23:18 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: DDRR antenna
Date: 30 May 1996 10:10:59 -0400
Message-ID: <4oka9j$[e-mail]>
References: <4oi031$[e-mail]>

In article <4oi031$[e-mail]>, [e-mail] (Jim Flanders)
writes:

>Tom:
>  My next question is:  What will give me more signal on 40 from my
>Van? Will it be a DDRR mounted on the roof - or will it be a Texas
>Bug Catcher?  You don't have to answer the question.  I am going to
>try to find someone In the N. TX or S. OK area that will loan me a TBC
>for a weekend test after I modify the DDRR for 2 ft spacing.
>Jim W0oog/5 in Plano TX on 147.180 & subvets net on 14.243 @ 1130 CST.
>
>

That's an easy question to answer. It will be a DDRR.

Remember this and you won't go wrong....

Antennas generate the EM (Electromagnetic) radiation effect from
accelerating electrons. Other effects disappear rapidly as distance is
increased. The only way that effect is canceled is when two separate
groups of electrons are accelerated opposite directions.

In the DDRR, the electrons in the short vertical section have no opposing
electrons to cancel their effects. The short vertical section radiates
freely. The horizontal section, being folded and near a groundplane,
induces current in the groundplane that opposes the radiation effect of
the electrons in the ring. That's why the ring area radiates poorly, and
the antenna has little very horizontally polarized radiation.

There is one tiny area where the useful radiation occurs in this antenna,
the vertical conductor. That is why, if you look at the previous post
about radiation resistance and efficiency, you will see the radiation
efficiency increased by the square of the height increase.

I'm afraid there is no magic involved in this antenna (as with any
antenna). In this case, its radiation resistance is virtually the same as
any conductor the same height carrying linear current over it's length. If
you replaced it with short top hat loaded vertical with proper design, the
vertical would win! The vertical would have less distributed loss in the
hat than the DDRR has in the ring.

73 Tom


From [e-mail] Mon Jun 03 17:23:19 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Multi-banding a bug catcher?
Date: 30 May 1996 10:11:47 -0400
Message-ID: <4okab3$[e-mail]>
References: <4oipmv$[e-mail]>

In article <4oipmv$[e-mail]>, [e-mail] (Sean
McCarthy) writes:

>
>Never thought about this. What do you recomend for 75-10 mobile opeation?
>Do you reccomend skipping the cap hat or how far up from the coil would
you
>put it?
>I have a GLA systems bug-catcher, 5' mast, #66 coil (3"x10", 6 T.P.I.)
>Without a hat, I would need 8' of whip to resonate, I have a 12" hat.
>
>Lots-o-questions...
>
>Sean

Hi Sean,

An antenna radiates because of the electrons moving in the element.

Those electrons stop moving (the current terminates) in a capacitance, the
smaller the capacitance the move voltage appears at that point.

If the hat has a lot of capacitance compared to the whip, most of the
current flows into the hat. If the hat is below the top of the whip, the
area of the whip above the hat is just waving in the breeze with no (or
greatly reduced) current. If the hat is large (capacitance wise) you might
as well snip the whip off above the hat and throw it away.

The next time you see a long whip and a huge hat a few feet above the
coil, remember this. Grin and remind yourself the whip must be a status
symbol because it sure isn't radiating.

The position of the hat is probably more important than the position or
size of the coil in most cases. Remember three rules:
The current entering and leaving the coil is essentially equal at both
ends.

The taper of the current above the coil is effected mainly by where the
terminating capacitance is.

The radiation resistance and efficiency are greatly increased when the
current is as large as possible over the maximum length possible. Doubling
the current area is equivilent to reducing losses four times! That's why I
concentrate on linear current over the entire radiator, rather than a huge
coil.

73 Tom


From [e-mail] Mon Jun 03 17:23:20 1996
From: Roland S Geter Sr <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: FS EQUIPOS DE MI ESTACION
Date: 30 May 1996 11:09:49 GMT
Message-ID: <4ojvlt$[e-mail]>
References: <[e-mail]>
To: [e-mail]

Si todavia tienes el KENWOOD TS=450SAT favor de explicar su precio in
dolares U.S.

Gracias
Rolando



From [e-mail] Mon Jun 03 17:23:21 1996
From: Roland S Geter Sr <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: FS EQUIPOS DE MI ESTACION
Date: 30 May 1996 11:11:32 GMT
Message-ID: <4ojvp4$[e-mail]>
References: <[e-mail]>
To: [e-mail]

Si todavia tienes el KENWOOD TS-450SAT favor de explicar el precio en
dolares U.S.

Gracias
Rolando



From [e-mail] Mon Jun 03 17:23:21 1996
From: Roland S Geter Sr <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: FS EQUIPOS DE MI ESTACION
Date: 30 May 1996 11:12:44 GMT
Message-ID: <4ojvrc$[e-mail]>
References: <[e-mail]>
To: [e-mail]

Si todavia tienes el KENWOOD TS-450SAT favor de explicar el precio en
dolares U.S.

Gracias
Rolando



From [e-mail] Mon Jun 03 17:23:22 1996
From: Roland S Geter Sr <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: FS EQUIPOS DE MI ESTACION
Date: 30 May 1996 11:12:46 GMT
Message-ID: <4ojvre$[e-mail]>
References: <[e-mail]>
To: [e-mail]

Si todavia tienes el KENWOOD TS-450SAT favor de explicar el precio en
dolares U.S.

Gracias
Rolando



From [e-mail] Mon Jun 03 17:23:23 1996
From: Roland S Geter Sr <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: FS EQUIPOS DE MI ESTACION
Date: 30 May 1996 11:13:52 GMT
Message-ID: <4ojvtg$[e-mail]>
References: <[e-mail]>
To: [e-mail]

Si todavia tienes el KENWOOD TS-450SAT favor de explicar el precio en
dolares U.S.

Gracias
Rolando



From [e-mail] Mon Jun 03 17:23:24 1996
From: [e-mail] (Peter Reed)
Newsgroups: rec.radio.amateur.antenna
Subject: Reduced size HF QUAD - correction
Date: 30 May 1996 11:58:38 GMT
Message-ID: <4ok2he$[e-mail]>

In my posting the length of the bamboo spreaders
should read 8 feet not 6.
            =          =


Peter G4BVH

[e-mail]


From [e-mail] Mon Jun 03 17:23:25 1996
From: [e-mail] (dick sander)
Newsgroups: rec.radio.amateur.antenna
Subject: 160m added to a 18HT Hytower
Date: 30 May 1996 17:11:02 GMT
Message-ID: <4okkr6$[e-mail]>
Reply-To: [e-mail]

I just picked up a used 40m trap for my Hygain 18HT hytower
to operate 160 meters at a flea market.

I don't have any instructions with it. Before I have to deal
with HyGain, I'd thought I try the newsgroup.

I attached the uncovered end (opposed to the black plastic
cover on the other end) to the very top of my hytower. I
attached 105ft of wire to the covered end and strung it up.

The vswr on 75m stayed about the same. On 40m the vswr dip dropped
down to 6.8 MHz. I tweaked the 105ft wire to 1.85 MHz vswr dip.

I then removed the 90" 40m stinger from the top of the hytower.
The vswr dip on 75m went up to nearly 4 MHz. On 40m the vswr dip
moved up to 6.95 MHz. I retweaked the 105ft wire to 1.88 MHz.

My questions are:

Could I have the 40m trap backwards?
Should I have not needed to remove the 40M stinger?
Should the trap mount slightly below the top the tower?
Could the trap be bad?
Does anyone have anything to add that might help me with
the installation of the trap?

Thanks and 73,
Dick Sander - K5QY









From [e-mail] Mon Jun 03 17:23:26 1996
From: [e-mail] (Your Name)
Newsgroups: rec.radio.amateur.antenna
Subject: 1/2 wave dipole vs. full wave question.
Date: 30 May 1996 18:35:41 GMT
Message-ID: <4okppt$[e-mail]>
Reply-To: [e-mail].

Hello antenna folks:

I have a question. Perhaps someone could share a little insight with me.

The other day I set up my old CB radio (no flames please) which I hadn't playe
d with since my
highschool days - 10 years ago. I consulted my ARRL handbook, (I'm interested
in HAM stuff) got about $3.50 worth of #10
guage copper wire, some RG-8 coax, constructed a 1/2
wave dipole antenna, and tuned it up using a VSWR meter (readings around 1.4:1
).

It seems to work pretty well from my house next to
the ocean - last night I contacted a station in Newfoundland from my place
in Massachusetts (!).

The antenna is strung horizontally from the highest point
on my house (about 28 feet) to a nearby tree. Rope is tied to the copper wire,

and is what is tied to the house and the tree. (I figured that unless it rains
,
it should be a good enough insulator)

Anyway, my question:

All other things being equal, if I constructed
my homebrew antenna version 2.0 as a full wavelength, instead of a 1/2,
would there be any real measurable results? Would the impedence of the
antenna change, necessitating some sort of a matching network? Just
curious. Any guidance would be appreciated.

If you would E-mail me your reply, I'd probably get it sooner.

Thanks a bunch,

and 73's






Chris.


From [e-mail] Mon Jun 03 17:23:27 1996
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Jim Cluett)
Subject: Re: Anybody using Fritzel Windoms?
Message-ID: <[e-mail]>
Date: Thu, 30 May 1996 18:58:43 GMT
References: <4ok4m9$[e-mail]>

In article <4ok4m9$[e-mail]>,
Lynn Stolz <[e-mail]> wrote:
>
>I'd like to hear from anyone using the Fritzel OCF antenna(s).
>...wondering how well you like or hate it.  do you have it installed
>in the suggested inverted-vee configuration or not, etc...
>
>I am thinking of replacing my old separate 40 and 80 meter dipoles with one.
>
>Thanks,
>
>Lynn N8AJ
>--
>Lynn Stolz  N8AJ [e-mail]

I'm using the FD-4. This is a fine antenna. I'm
using it with a yaesu FT-900AT. I use it on all
bands from 80 to 10. Working great DX on all bands,
very good reports. I have no hesitation in recommending
it. Very fine quality hardware. Be careful about
having a good ground. Mine is about 45 feet in the air,
straight across (not inverted V).
hope this helps
N1TOD



From [e-mail] Mon Jun 03 17:23:28 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: phased array antenna - ComTek
Date: Thu, 30 May 96 19:11:16 GMT
Message-ID: <4ol04l$[e-mail]>
References: <[e-mail]> <4o744b$[e-mail]> <4o8eal$[e-mail]> <4o8r48$[e-mail]> <4oe0vi$[e-mail]>

  [e-mail] wrote:

>          There are worse forms of insanity.
>
>          Try a full sized 3 element rotary array on 80 at 195 feet!

I've seen that antenna!  About 50 miles west of Houston, I think. ;)

73,
Jack  WB3U


From [e-mail] Mon Jun 03 17:23:29 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Antenna wire diameter important?
Date: Thu, 30 May 96 19:42:30 GMT
Message-ID: <4oktln$[e-mail]>
References: <4ok0h7$[e-mail]>
Keywords: wire

In article <4ok0h7$[e-mail]>,
   [e-mail] (L. DE BRUIJN) wrote:
>Is the width of the wire used for an antenna important? I'm using 26SWG
>(0.45mm) diameter wire at the moment for a long wire antenna. I can see
how
>it might make a difference at high power (increased temperature
dissipation
>problems) but does it matter for receive? TIA
>
>                       73 de
>                       Laurens

The wire diameter affects the resonant frequency, bandwidth (the range of
frequencies over which a specified maximum SWR is obtained), and loss
(therefore efficiency). None of these is important for receiving at
frequencies below VHF.

Roy Lewallen, W7EL


From [e-mail] Mon Jun 03 17:23:29 1996
From: Chuck Bland <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna
Subject: Just enough to hang my. . .antenna
Date: 30 May 1996 19:54:16 GMT
Message-ID: <4okud8$[e-mail]>

Greetings,

I'm in the process of hanging a dipole antenna, and I will be using ropes
at the ends to suspend it.

What type of rope should I use? I live in Sacramento, CA. Hot, dry
summers, rainy, windy winters. No snow.

73's

Chuck - n6dbt




From [e-mail] Mon Jun 03 17:23:30 1996
From: Steve Kennedy <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment
Subject: Re: Antenna Analysers
Date: 30 May 1996 20:28:56 GMT
Message-ID: <4ol0e8$[e-mail]>
References: <[e-mail]> <[e-mail]>
To: [e-mail]

I bought one of the MFJ 259 units too.  I don't know how I muddled through ant
ennas and
resonant circuits before I got this unit.  It is great!

The peace of mind and surity it brings to my dealings with resonance and imped
ance approaches a
religious experience!

Steve
WB7PSD



From [e-mail] Mon Jun 03 17:23:31 1996
From: [e-mail] (Mika Antero JΣppinen)
Newsgroups: rec.radio.amateur.antenna
Subject: Multiband-ant Help!
Date: 30 May 1996 21:51:42 GMT
Message-ID: <4ol59e$[e-mail]>

Hello,

        I am looking for instructions for multiband antenna for
        receiving purposes from low-vhf to approx 1GHz.
        I have allready familiar with discone but was wondering
        does there exist similar type wide-band coverage antenna?
        Ofcourse there is log-periodig-yagi's but I am looking
        for more likely something omnidirectional GP type.

        Ofcourse it obvious that these multiband-antennas are always
        compromises but if you might have some hints to replace my
        VHF (2m) gp to someting else which is hooked-up to R7100
        let me know!

        Antero Jappinen  Email  [e-mail]
                         Packet [e-mail]




From [e-mail] Mon Jun 03 17:23:32 1996
From: [e-mail](Anthony Severdia)
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna
Subject: Re: Just enough to hang my. . .antenna
Date: 30 May 1996 22:22:04 GMT
Message-ID: <4ol72c$[e-mail]>
References: <4okud8$[e-mail]>

In <4okud8$[e-mail]> Chuck Bland
<[e-mail]> writes:
>
>Greetings,
>
>I'm in the process of hanging a dipole antenna, and I will be using
ropes
>at the ends to suspend it.
>
>What type of rope should I use? I live in Sacramento, CA. Hot, dry
>summers, rainy, windy winters. No snow.
>

    Polypropylene would be best as an insulator but make sure it
is BLACK for UV resistance (common stuff is yellow).  But, why not
use a couple of cheap glass insulators?

    Braided Nylon is NG because it deterioriates pretty fast.
Dacron is much better and stretches less.

    -=Tony=-    W6ANV   San Francisco



From [e-mail] Mon Jun 03 17:23:33 1996
From: [e-mail] (Bill Bennett)
Newsgroups: rec.radio.amateur.antenna
Subject: Copper cactus
Date: Thu, 30 May 1996 23:52:46 GMT
Message-ID: <4olccd$[e-mail]>

Some time back i saw directions and dimentions on building j-poles
is there some one out there that knows the URL to find this?




From [e-mail] Mon Jun 03 17:23:34 1996
From: [e-mail] (Robert Morgenstein)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Code Speed Change:  Help Needed
Date: 31 May 1996 01:23:15 GMT
Distribution: world
Message-ID: <4olhm3$[e-mail]>
References: <[e-mail]> <[e-mail]>

ED WELCH ([e-mail]) wrote:
: -> Rick, You really can NOT eliminate the requirement without turning
: -> the bands into an uncivilized mess (eg,CB).  Perhaps a lowering from
: -> 13 to 10 WPM is about all the concession I'd be willing to accept.
: -> This type of compromise, or
: -> some concession will no doubt have to be made at some point, it's
: -> just a matter
: -> of time, realistically.  The internet, for example has much allure
: -> and is so easy and without any requirements or skills whatever, that
: -> a person thinking of

: Good post.

: I'm studying now for my novice/tech+...nothing less than code.  By the
: time I test I'll *know* at least the basics involving in operating a
: amateur radio station that I will be proud to say is mine.  And because
: I have the *desire* and *determination* I *will* pass the code.  If I
: didn't really care to study and practice then I wouldn't get the added
: frequency priveleges.  Basically, if a person wants the additional
: frequency priveleges then he/she should *study* and *practice*.  If that
: person doesn't want to study and practice....well, he/she must not
: really be serious about about the use of the HF bands.  Come on folks,
: the good ol' USA has been giving out free-rides for way too long, must
: it enter into a long-lived and respected hobby, too?   There's a
: mentality of "give me" prevalent in today's society, what ever happened
: to "what can I give?".

: I'm studying the code, I don't feel like someone's mistreating me by
: "making" me study it.  Rather, I feel humbled that I live in a country
: with the freedom and opportunity to do so.

: [e-mail]
To all;

Just my own experience regarding code. I didnt realize what a valuble
asset I had in knowing code. I recently had throat surgery and could not
hold a conversation of any sustained length. I spent many happy ours "
" talking " in code. Hey, no one is assured of tomorrow, you never know.
Bob; WA2EAW


From [e-mail] Mon Jun 03 17:23:35 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: Re: VanGorden wire antennas?
Date: 31 May 1996 01:56:54 GMT
Message-ID: <4oljl6$[e-mail]>
References: <4nssrr$[e-mail]>
Reply-To: [e-mail]

In <4nssrr$[e-mail]>, [e-mail] (Phil Brown)
writes:
>Anyone using Van Gorden wire antennas? Can't seem to find the time to
>make up a dipole, thought I might try one of the Van Gorden kits for
>either single or multiband. Does the multiband require a tuner? How
>well does the D40 load up on 15 meters?
>
>Thanks
>
>
>Phil Brown N4COD
>[e-mail]
>Video Producer/Instructor
>Like Flowers? Check out our home page at www.tigerweb.com
>
Phil,
 If you get it to work, post how you did it. I know a couple of thousand folks
 that
 would be eager to find out too. Good Luck!
                                                                    Jim


From [e-mail] Mon Jun 03 17:23:36 1996
From: [e-mail] (KC8CGX)
Newsgroups: rec.radio.amateur.antenna
Subject: Just purchased MFJ-1750 5/8 wave
Date: Fri, 31 May 1996 01:58:18 GMT
Message-ID: <4ol8u4$[e-mail]>
Reply-To: [e-mail]

Just received and installed the MFJ-1750 5/8 Groundplane.
Well engineered, easy SWR adjustment (1:1.4) 146MHz
For $19.95 you can't beat it.
(Just don't poke yourself in the eyes with the radials while
assembling).

Doug
KC8CGX


_____________________________________________
North Central Ohio Skywarn Info
http://www.amnorth.com/redbone/skywarn.html
http://www.amnorth.com/redbone/ham-page.html
http://lrbcg.com/dougd



From [e-mail] Mon Jun 03 17:23:37 1996
From: [e-mail] (Gyro)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Code Speed Change:  Help Needed
Date: 31 May 1996 03:24:55 GMT
Distribution: world
Message-ID: <4oloq7$[e-mail]>
References: <[e-mail]> <[e-mail]>

I agree that the Code should stay. I just upgraded to a Gen(with 20
WPM)So....The Extra is hopefully in my future. Anyway, I worked for 1 hour a
night for about 6 months on the Tapes and played on the air with my Tech-Plus
to get to 20! It was hard but if I can do it, Anyone can.
Now.......Should this Thread not be better suited to another group?
It seems like every group I read has tireless postings about eliminating code.
[e-mail]




In article <[e-mail]>, [e-mail] says...
>
Rick, You really can NOT eliminate the requirement without turning
 the bands into an uncivilized mess (eg,CB).  Perhaps a lowering from
 13 to 10 WPM is about all the concession I'd be willing to accept.
 This type of compromise, or
 some concession will no doubt have to be made at some point, it's
 just a matter
 of time, realistically.  The internet, for example has much allure
 and is so easy and without any requirements or skills whatever, that
 a person thinking of

>Good post.

I'm studying now for my novice/tech+...nothing less than code.  By the
time I test I'll *know* at least the basics involving in operating a
amateur radio station that I will be proud to say is mine.  And because
I have the *desire* and *determination* I *will* pass the code.  If I
didn't really care to study and practice then I wouldn't get the added
frequency priveleges.  Basically, if a person wants the additional
frequency priveleges then he/she should *study* and *practice*.  If that
person doesn't want to study and practice....well, he/she must not
really be serious about about the use of the HF bands.  Come on folks,
the good ol' USA has been giving out free-rides for way too long, must
it enter into a long-lived and respected hobby, too?   There's a
mentality of "give me" prevalent in today's society, what ever happened
to "what can I give?".

I'm studying the code, I don't feel like someone's mistreating me by
"making" me study it.  Rather, I feel humbled that I live in a country
with the freedom and opportunity to do so.

[e-mail]



From [e-mail] Mon Jun 03 17:23:38 1996
From: Roger Cox <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 2.4 GHz antennas
Date: 31 May 1996 04:03:57 GMT
Message-ID: <4olr3d$chd$[e-mail]>
References: <[e-mail]>

There is a BIG difference between a $A700 WLAN antenna and a
US$10000 MMDS "Broadcast" antenna.  WLAN is limited here in the
states to 1 watt.  The antenna can have no more than 6 dB gain,
otherwise the transmitter output power must be reduced by the
same amount that the antenna gain is over the 6 dB figure.  Most
of the WLAN companies transmit less than 100 mW anyway.  Typical
range is less than 3 miles, even when using directive antennas.
Some people have gotten around the FCC limitations by using the 6
dB gain antenna only on transmit, and using 20 to 30 dB gain
dishes on receive.

The MMDS antenna is meant for HIGH-POWER broadcasting, and it
costs more because of that.

73, Roger WB0DGF

--
Roger Cox


From [e-mail] Mon Jun 03 17:23:39 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: design for 1/4 wave z xfmrs for 1/2" catv hardline?
Date: Fri, 31 May 96 04:23:04 GMT
Message-ID: <4om0fe$[e-mail]>
References: <[e-mail]> <4oigqk$[e-mail]> <4okjk1$[e-mail]>

   [e-mail] (Jim Garver) wrote:

>What I did was to take a large 75 ohm carbon resistor scrounged
>from a very old radio and solder it onto an 'N' connector with
>very short leads.  I use this with RG-11 or up the tree on the end
>of the hardline to calibrate my SWR meter mounted directly on the
>back of the rig or inside.  I make sure I get 1.5:1 and then I stick
>on the antenna and adjust for 1.5:1 again.

If a 75 ohm load attached to a 75 ohm feedline creates a reading
of 1.5:1, the meter is detecting impedance, not reflected current.
Under these conditions, I wonder if the same reading won't be
created by more than one value of load impedance?  If so, the
only way to be sure the SWR on the line is 1:1 (in other words,
that the antenna is actually 75 ohms), would be to vary the
feedline length as a test.  If varying the length a few feet
causes the meter reading to change, the load isn't 75 ohms. Of
course, in order to be valid, this also requires that the
operator be certain there is no RF on the outside of the cable.

73,
Jack  WB3U


From [e-mail] Mon Jun 03 17:23:40 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Off-centre fed dipole theory question.
Date: Fri, 31 May 96 04:58:42 GMT
Message-ID: <4om2i6$[e-mail]>
References: <4o5g50$[e-mail]> <4ofrr3$[e-mail]> <4ogopq$[e-mail]>

   Cecil Moore <[e-mail]> wrote:

>Hi Tom, just ran it in free space. Resonant frequency seems to
>be the same for center-fed and off-center-fed in free space.

Thanks for the info Cecil.  I guess the difference you saw over
ground is too small to be noticed most of the time.  Just the same,
I'm glad to know about this effect.

73,
Jack  WB3U


From [e-mail] Mon Jun 03 17:23:41 1996
From: Cameron Hughes <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.broadcasting,rec.radio.info,rec.radio
Subject: What's a good AM tuner?
Date: 31 May 1996 07:11:58 GMT
Distribution: world
Message-ID: <4om63u$[e-mail]>



I'm looking for a superior AM tuner, currently in production, for a stereo sys
tem.
 I need to be able to put the Kiwa Air-Core Loop antenna on it so it has to ha
ve a
two-post external antenna terminal.  My main concerns will be sensitivity and
clarity as I want to tape old-time radio programs.

Thanks in advance for any help.

--


     ********************** Cameron Hughes **********************
     **************** [e-mail] ****************
     ********************* Carpe diem, baby *********************
     ************************************************************



From [e-mail] Mon Jun 03 17:23:42 1996
From: Doug Braun <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Tonna Antennas
Date: Fri, 31 May 1996 09:27:24 -0700
Message-ID: <[e-mail]>

Does anybody have an address or phonbe number, in Europe or
anywhere for this company?  Do they make just VHF antennas,
or orther stuff as well?  Is their stuff any good?

Thanks,

Doug Braun
N1OWU


From [e-mail] Mon Jun 03 17:23:43 1996
From: [e-mail] (Greg Kopp (N8JMS))
Newsgroups: rec.radio.shortwave,rec.radio.swap,rec.radio.scanner,rec.ham-radio,rec.radio.amateur,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.dx
Subject: COMPUTER SHOW / HAMFEST - June 16, 1996 (Ohio)
Date: Fri, 31 May 1996 10:35:05 -0400
Message-ID: <[e-mail]>

What:
HAMFEST - COMPUTER SHOW - ELECTRONICS FLEA MARKET

When:
June 16, 1996

Time:
8AM - 1PM

Where:
Nordonia High School, Macedonia, Ohio (Just south of Cleveland)

-------------------

Join the Cuyahoga Amateur Radio Society at its 5th annual Hamfest!

This years Grand Prize:
- An Icom 2350H Dual Band Mobile!

And don't miss out on these door prizes:
- An Icom 2GXAT 2m Handheld!
- A 28.8K External Modem!
- A Handheld Scanner!

-------------------

Tickets are $3.00 in advance. ($4.00 at the door.)

Inside Vendor Spaces are $11.00 each and include one admission ticket.
Additional spaces are available for $8.00. (Inside vendor setup will be on
Saturday night 6pm-9pm and Sunday morning at 6am.)

Outdoor Vendor Spaces are $4.00 each.

For reservations or info, call Rich James, N8FIL at 1-800-404-2282, visit
our WWW site at "http://www.cars.org" or send e-mail to: [e-mail]

73 de N8JMS


From [e-mail] Mon Jun 03 17:23:44 1996
From: [e-mail] (Dale Chidester)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Anodizing/Protecting Copper Antennas?
Date: 31 May 1996 11:48:13 GMT
Message-ID: <4omm9t$[e-mail]>
References: <4okct6$[e-mail]>
Reply-To: [e-mail]

Why bother?  Copper pipe will evenutally age to the greenish patina associated
with the roofs (rooves?) of very old buildings, the Statue of Liberty, etc.
I've have a Cu pipe vertical dipole for 2 meters up for 10 years and it's now
to
the dark brown/black stage... no decrease in performance.

73,
        Dale  N3HAL


In article [e-mail], [e-mail] (Harold G. Peach, Jr.) wri
tes:
>Several years ago (late '80s or early '90s)I recall reading an article
>in QST or possibly CQ Magazine on building an antenna made from copper
>pipe.  In the construction article it described a process of bathing
>and rinsing the copper that first turned it green, then returned it to
>a flat finish that would not corrode in the weather.
>
>I now find myself in need of the process, but unable to locate the
>article.  Does anyone know the process or preferably have a reference
>to the article?
>
>Thanks,
>Harold - N4FLZ
>[e-mail]
>---
>Harold
>[e-mail]
>







From [e-mail] Mon Jun 03 17:23:45 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna
Subject: Re: Just enough to hang my. . .antenna
Date: 31 May 1996 13:27:21 GMT
Message-ID: <4oms3p$[e-mail]>
References: <4okud8$[e-mail]>
Reply-To: [e-mail]

In <4okud8$[e-mail]>, Chuck Bland <BlandRanch@wor
ldnet.att.net> writes:
>Greetings,
>
>I'm in the process of hanging a dipole antenna, and I will be using ropes
>at the ends to suspend it.
>
>What type of rope should I use? I live in Sacramento, CA. Hot, dry
>summers, rainy, windy winters. No snow.
>
>73's
>
>Chuck - n6dbt
>
>
 How long is the dipole? How heavy is the wire you intend to use? How
 long does the rope have to be? Overall, nylon rope works pretty well.
 I have a 160 Meter dipole held up by thick string nylon. You can pick up
a spool at a Builders Square, Lowes, etc for 4-5 bucks. About 230 feet of
this heavy string. I double it, it lasts 3-4 years in very harsh northern Indi
ana
weather. I guess the rule of thumb is to get only what you need. Some of
this 'parachute cord' will outlast you and your QTH, but it's very salty.

                                                                    Jim



From [e-mail] Mon Jun 03 17:23:46 1996
From: [e-mail] (Rob Whitacre)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 6 Meter Antenna Recommendation/Question ???
Date: 31 May 1996 13:43:06 GMT
Message-ID: <4omt1a$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] says...
>
>Hello Everyone,
>
>I'm looking for recommendations for 6 meter antennas (homebrew) both
>omni directional and directional varieties.. Also, what polarization
>is being used for FM work on 6 meters; I would guess vertical.
>
>I'm going to pick up a 6 meter rig "real" soon (soon as I can find one)
>and start experiencing some 6 meter activity...... Might try my luck at
>the Ten Tec 6 meter transverter kit for 2 meters, that way I could mess
>with it in the mobile without to much fuss.
>
>Thanx In Advance !!!
>
>Rich - N8PFK

For FM work (vertical), the cushcraft ringo is a decent way to go for the
house. Also, Diamond and Comet make some tri-band antennas for 6, 2, 440. If
you use a base loaded antenna in the car, put it in the middle of the roof.
Otherwise, use a 1/4 wave and try to keep as much of the antenna above the
car body as possible. For Sporadic-E, the polarization doesn't matter a whole
lot.

Rob WB8WQA



From [e-mail] Mon Jun 03 17:23:47 1996
From: [e-mail] (Rob Whitacre)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.space
Subject: Re: Reference for patch antennas
Date: 31 May 1996 13:50:14 GMT
Message-ID: <4omtem$[e-mail]>
References: <4o55c4$[e-mail]>
Keywords: Tumbler, chain, fob, lock

In article <4o55c4$[e-mail]>, [e-mail] says...
>
>I'm interested in the design of patch antennas to evaluate them as a low
profile
>alternative to crossed yagis, helicals etc for OSCAR work.
>
>I recently talked to an AMSAT rep that talked about testing the 3D birds
>antennas by using them for just that, contacting FO20 or AO13 I think.
>
>I have looked in my references and can only find passing mention to patch
>antennas and would like to know if someone can suggest a reference that goes
>into dome detal such as theory of operation and design parameters.
>
>
>Jim
>KF6AGJ
>

Check out the "Antenna Engineering Handbook" by Jasik and Johnson. One thing
you want to pay attention to with any of these omnidirectional circular
polarized antennas is how the CP holds up versus elevation angle.

Rob WB8WQA




From [e-mail] Mon Jun 03 17:23:48 1996
From: Merv Stump <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Loop Impedance At Frequencies Above the Design Point
Date: 31 May 1996 13:53:38 GMT
Message-ID: <4omtl2$[e-mail]>

At Jack's (WB3U) suggestion I did a quick model of a full-wave loop on 80
meters and then checked its impedance on other bands.  The loop modeled
was a square 66 feet on a side, parallel to the ground and 50 feet high.
The ground was specified as "average" (Dielectric Constant = 13;
Conductivity ms/m=6). The following were the results:

Frequency     Impedance
3.8Mhz         117 -j2
7.2Mhz         280 -j215
14.2Mhz        261 -j711
28.5Mhz        707 -j785

Incidentally, the results vary considerably depending on ground and height
above ground.

Regards, Merv



From [e-mail] Mon Jun 03 17:23:49 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: need help with wire dipole
Date: Fri, 31 May 96 14:25:15 GMT
Message-ID: <4on3oj$[e-mail]>
References: <[e-mail]> <4ogtug$[e-mail]> <4okuue$[e-mail]>

   Chuck Bland <[e-mail]> wrote:

>A link-coupled tuner would do the job quite nicely. Sure, it may
>set technology back about 30 years, but the system would be better
>than a "mere balun".

The unqualified use of baluns is what has set the Amateur community
back thirty years.  Overlooking the advantages and versatility of
link coupling on the basis of its age is akin to replacing the
family sedan with a hovercraft.  ;)

73,
Jack  WB3U


From [e-mail] Mon Jun 03 17:23:50 1996
From: [e-mail] (Christer Jogenborn)
Newsgroups: rec.radio.amateur.antenna
Subject: 3-bnd Vertical OMTA?
Date: 31 May 1996 15:00:28 GMT
Message-ID: <4on1ic$[e-mail]>
References: <4omv2p$[e-mail]>
Reply-To: [e-mail]

OMTA - Vertical, trapless, multi-band.
- just what I need for my small backyard...

Anyone with feedback on the OMTA ? -  as described
in October 1995 QST, article by AL7KK

I am looking for SWR, bandwith, and elevation plot
data on the OMTA 3-bander (40,20,15m)
or - are there better ones out there?

Chris sm0ncl




From [e-mail] Mon Jun 03 17:23:51 1996
From: [e-mail] (Frank Dinger)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: Anybody using Fritzel Windoms?
Date: Fri, 31 May 1996 16:11:08 +0100
Message-ID: <4oq0um$[e-mail]>

In message <[e-mail]>
        [e-mail] (Jim Cluett) writes:

> In article <4ok4m9$[e-mail]>,
> Lynn Stolz <[e-mail]> wrote:
> >
> >I'd like to hear from anyone using the Fritzel OCF antenna(s).
> >...wondering how well you like or hate it.  do you have it installed
> >in the suggested inverted-vee configuration or not, etc...
> >
> >I am thinking of replacing my old separate 40 and 80 meter dipoles with one
.
> >
> >Thanks,
> >
> >Lynn N8AJ
> >--
> >Lynn Stolz  N8AJ [e-mail]

> I'm using the FD-4. This is a fine antenna. I'm
> using it with a yaesu FT-900AT. I use it on all
> bands from 80 to 10. Working great DX on all bands,
> very good reports. I have no hesitation in recommending
> it. Very fine quality hardware. Be careful about
> having a good ground. Mine is about 45 feet in the air,
> straight across (not inverted V).
> hope this helps
> N1TOD

=======================response from GM0CSZ / KN6WH =======================
Indeed the Fritzel FD4 Windom is a good antenna ,I am using it since
1985 , but it definitely does not work on 15m (21.000 - 21.450 MHz)

Frank Dinger , Inver by Tain , Ross-shire IV20 1RX - Scotland UK
e-mail :  [e-mail]
Packet :  GM0CSZ @ GB7NOS.#76.GBR.EU



From [e-mail] Mon Jun 03 17:23:52 1996
From: [e-mail] (Chuck Bland)
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.antenna
Subject: Re: Just enough to hang my. . .antenna
Date: 31 May 1996 16:13:21 GMT
Message-ID: <4on5r1$[e-mail]>
References: <4okud8$[e-mail]> <4ol72c$[e-mail]>

In article <4ol72c$[e-mail]>, [e-mail]
says...
>
>In <4okud8$[e-mail]> Chuck Bland
><[e-mail]> writes:
>>
>>Greetings,
>>
>>I'm in the process of hanging a dipole antenna, and I will be using
>ropes
>>at the ends to suspend it.
>>
>>What type of rope should I use? I live in Sacramento, CA. Hot, dry
>>summers, rainy, windy winters. No snow.
>>
>
>    Polypropylene would be best as an insulator but make sure it
>is BLACK for UV resistance (common stuff is yellow).  But, why not
>use a couple of cheap glass insulators?
>
>    Braided Nylon is NG because it deterioriates pretty fast.
>Dacron is much better and stretches less.
>
>    -=Tony=-    W6ANV   San Francisco
>

Well, there are insulators on the end of the antenna, but I'll need some
rope to tie to the other end of the insulators to suspend the antenna in
the air.

Chuck - n6dbt



From [e-mail] Mon Jun 03 17:23:53 1996
From: [e-mail] (Parf)
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 1/2 wave dipole vs. full wave question.
Date: 31 May 1996 18:34:53 -0400
Message-ID: <4ons6d$[e-mail]>
References: <4okppt$[e-mail]>
Reply-To: [e-mail] (Parf)

Assuming you are still intending on center feeding the antenna:
The feed impedance would be VERY high (somewhat dependent upon conductor
diameter).

From memory, I believe the pattern is cloverleaf- both halves are in
phase.

Look in the Handbook @ extended double Zepps- a little more gain and feed
techniques.

73,  Dale WA2YPY


From [e-mail] Mon Jun 03 17:23:54 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.antenna
Subject: Antenna Engineering Handbook - SOLD OUT
Date: Fri, 31 May 96 18:46:53 GMT
Message-ID: <4onj39$[e-mail]>
References: <[e-mail]> <4ojbij$[e-mail]>

Just received a refund check from Edward R. Hamilton, Bookseller,
with a note that #292338 is sold out. :(

73,
Jack  WB3U


From [e-mail] Mon Jun 03 17:23:55 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.antenna
Subject: Re: 1/2 wave dipole vs. full wave question.
Date: 31 May 1996 20:07:02 -0700
Message-ID: <4ooc4m$[e-mail]>
References: <4okppt$[e-mail]> <4ons6d$[e-mail]>

Parf <[e-mail]> wrote:

: From memory, I believe the pattern is cloverleaf- both halves are in
: phase.

A full-wave is not cloverleaf. A 1.25 WL is maximum broadside
gain and is still not cloverleaf. You have to get above 1.25 WL
for it to be cloverleaf. It is definitely a beautiful cloverleaf
by 1.7 WL.

73, Cecil, KG7BK (W6RCA soon), OOTC