Topband: Shunt Fed Tower Info

[George & Marijke Guerin]

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 at inter.net.il>
To: "Tom Rauch" <w8ji at contesting.com>; <Cqtestk4xs at aol.com>;
<topband at 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