Let me ask you TB5EM guys a question.
I have had one for years and use it every year for Field Day on our RTTY
station. We pressed it into service when someone said, "Anyone have a
tribander we can use?" and I had it here in storage. Quickie-style, we just
attached center conductor and braid, each, to each side of the split driven
element with stainless steel hose clamps, didn't use the stainless steel
screws that go through the tubular Cycolac (or whatever it is) insulator at
the center. It worked great, 1:1 SWR, the appropriate SWR curve, good gain
and directionality. We have never seen any reason to change it. I've put
it up on a portable tower at home and have been using it and it's been very
effective here too. I came across a second TB5EM and plan to feed it the
same way and have them up in a stack.
So, getting to the question: What degradation in performance should I be
expecting to see by virtue of not having the balun or hairpin?
73 - Rich, KE3Q
----- Original Message -----
From: "Don Havlicek" <n8de@thepoint.net>
To: <N4CW@aol.com>
Cc: <towertalk@contesting.com>
Sent: Thursday, September 30, 2004 10:32 AM
Subject: Re: [TowerTalk] hairpin
> Just measured mine.
>
> The 'loop' is 25.5 inches either side of the boom attachment point, thus
> is 51 inches overall.
>
> The shape is almost a continuous curve from driven element attachment
> point to boom attachment point EXCEPT the first 3 inches [nearest the
> driven element] at quite 'straight' with a bend at the 3 inch point.
>
> Don
> N8DE
>
> N4CW@aol.com wrote:
> > No dimensions are given in the "Assembly Instructions" sheet that I
> > have.
> > Direct measurements will have to be made.
> > Telrex wasn't long on details...,"If you have followed simplified
> > assembly
> > sheet carefully, you are ready to connect your 52 Ohm co-axial to the
> > 'Balun'
> > provided. Mount the antenna in the clear, 34 fet or higher." Also, "Do
> > not
> > force, alter, modify, or try any inventions! Telrex has precision-tuned
> > and matched
> > this antenna to provide optimum 10, 15, and 20 meter gain, F/B ratio,
> > and
> > 'balanced-pattern'."
> > No dimensions, other than hardware sizes, are given.
> > 73,
> > Bert, N4CW/1
> > _______________________________________________
> >
> > See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> > Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> > any questions and ask for Sherman, W2FLA.
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|