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Re: clamps on M2 436CP30 antenna

I would be interested to hear the "substance" of this claim. In the many
years of using vhf/uhf yagis, I have never seen any claim that placing a
metal mast in the same plane as the polarization would do anything less than
ruin the antenna's performance. My own experiments verified this on 70cm, as
does modelling any high gain uhf yagi with EZNEC.

Further, the designer of the 30CP is very specific regarding the mast,
indicating it would severely compromise the antenna's performance. He even
went to great lengths to minimize the boom to mast bracket to avoid
compromising the circularity. Why would that be necessary if we can slap a
1.25 or 1.5 inch metal mast right in the middle of the array and have no
"bad effects".

Maybe I read the information incorrectly, but if the claim is that you can
put a sizable metal mast through a circular yagi and not cause problems, I'm
moving to Missouri. (The "show me" state.)

So, please, if anyone has a summary of the "conclusions" that are being
referred to and they actually make the claim as described above, I would
LOVE to see them and send them to people who have worked most of their lives
with the problem....only to find out there never was a problem. Gee...think
of all the money we could have saved on fibreglas <g>.

Pardon my skepticism, but if something seems too good to be true, it
probably is.

Nothing would please me more, however, if we were all wrong and had been
wasting our time and money. I anxiously await the proof.


hasan, N0AN

----- Original Message -----
From: "Gary "Joe" Mayfield" <gary_mayfield@hotmail.com>
To: <kd9kc@elp.rr.com>; <amsat-bb@AMSAT.Org>
Sent: Wednesday, August 22, 2001 7:34 AM
Subject: Re: [amsat-bb] clamps on M2 436CP30 antenna

> I believe it was the 11th Symposium held in Arlington, TX.  That would
> it 1993.  I do not know if the proceedings are still available.  Those
> Symposium proceedings are often full of good stuff!
> 73,
> Joe
> ka0yos@amsat.org
> P.S. I will look it up tonight and if I am wrong I will post a correction.
> ----- Original Message -----
> From: "Michael P. Olbrisch" <kd9kc@elp.rr.com>
> To: "'Gary "Joe" Mayfield'" <gary_mayfield@hotmail.com>;
> <amsat-bb@AMSAT.Org>
> Sent: Tuesday, August 21, 2001 8:44 AM
> Subject: RE: [amsat-bb] clamps on M2 436CP30 antenna
> >
> >
> > > -----Original Message-----
> > > From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org]On
> > > Behalf Of Gary "Joe" Mayfield
> > > Sent: Tuesday, August 21, 2001 12:43 PM
> > > To: amsat-bb@AMSAT.Org
> > > Subject: Re: [amsat-bb] clamps on M2 436CP30 antenna
> > >
> > > As Kent Britain showed at a past AMSAT symposium if done
> > > correctly (it's almost hard to do incorrectly) it will not impact
> > > antenna performance, and of course it is much tougher!
> > >
> > > 73,
> > > Joe
> > > ka0yos@amsat.org
> >
> > Is this data available somewhere in written form?  I sure would
> > like to study it.
> >
> >
> > Vy73,  Mike.   KD9KC    MARS: AAV6EV
> >
> > My E-mail address: mailto:kd9kc@elp.rr.com
> > Ham Radio page: http://www.qsl.net/kd9kc/
> > Gun page: http://home.elp.rr.com/elpasochl/
> > Dog page: http://www.geocities.com/heartland/estates/4174
> >
> > Freedom is expensive.  Those who are not willing to
> > pay the price ultimately lose everything.
> >
> >
> >
> >
> ----
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