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Re: Topband: Comparison of Vertical Arrays for Low Band Receiving

To: Jim Brown <jim@audiosystemsgroup.com>, w5znjoel@gmail.com
Subject: Re: Topband: Comparison of Vertical Arrays for Low Band Receiving
From: Mike Waters <mikewate@gmail.com>
Date: Wed, 22 Jan 2025 15:16:27 -0600
List-post: <mailto:topband@contesting.com>
Gentlemen,

I never used preamps at the feedpoints of my Beverages*, and I probably
should have left out "at the feedpoint". I just noticed that Joel's graphs
sometimes showed a very low signal level from the Beverages, and was
curious.

*However, I *did* use a preamp at the station end of the F-6 feedlines to
them. (A series 2k pot there adjusted the level to match the TX antenna;
and on occasion eliminated intermod.) The output of a Beverage is rather
low, and sometimes I would switch between them and the inverted-L, etc.

Having said that, somewhere I read that on occasion, others absolutely
needed them at the feedpoint, when the noise floor was exceptionally low (I
believe just before sunrise). But I guess that's a moot point here.

The longest F-6 feedline here was about 600'.

On Tue, Jan 14, 2025, 3:10 PM Jim Brown <jim@audiosystemsgroup.com> wrote:

> On 1/14/2025 12:13 PM, w5znjoel@gmail.com wrote:
> > Thanks. No, I did not have preamps at the feed point of the Beverages.
>

How about at the station end, Joel? Sorry, I should have been more clear.

Is the sensitivity of a one wavelength Beverage low enough that a preamp
> at the feedpoint is needed? Loss in decent coax is pretty low at 2 MHz, ...
>

As I said, sometimes it is, according to others. Sorry I don't have a
reference. :-)

73 Mike
W0BTU
https://web.archive.org/web/20190827040547/http://w0btu.com/

>
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