Topband
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Topband: Shunt Fed Tower Info

To: <topband@contesting.com>
Subject: Topband: Shunt Fed Tower Info
From: gmguerin at voyager.net (George & Marijke Guerin)
Date: Tue Aug 5 15:06:20 2003
Hi Riki, et. al.,

By grounding the shield on the coaxial feed at the balun and grounding the
reflector and director you probably eliminated the concerns with floating
elements.
Other feed systems with a floating driven element and a low impedance
matching network are more easily overheated by the 160 meter signal.  I seem
to remember one of the G's had to put a choke in series with his matching
network to avoid SWR changes as the network heated up when running full
power.

73,    George    K8GG

----- Original Message -----
From: "R. Kline" <rikik@inter.net.il>
To: "Tom Rauch" <w8ji@contesting.com>; <Cqtestk4xs@aol.com>;
<topband@contesting.com>
Sent: Tuesday, August 05, 2003 12:52 AM
Subject: Re: Topband: Shunt Fed Tower Info


> I used to have  a 3 element KLM 40M beam, and I grounded the elements
> directly to the boom by adding  small straps that were connected to the
> existing strap (that joins the 2 element halves).  Regarding the driven
> element, this wasn't possible, although I did directly ground the coax
side
> of the matching/balun assembly.  Perhaps what Tom suggests would be
> worthwhile for the driven element (although the high reactance should be
at
> 7 MHz - not 14 MHz).  In that case,  2 networks would likely be needed
(one
> for each half element), or perhaps a balanced network could be
constructed.
> The important thing would be to have a low impedance path to  the boom at
> 1.8MHz for all of the insulated elements.
>
> 73,
> Riki, 4X4NJ
..snip


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