George,
If you have a moment a few more details about the feed-point amplifier would be
appreciated. Is this a custom unit or an of-the-shelf commercial unit please?
Thanks for your time.
Patrick, W7TMT
________________________________
From: Topband <topband-bounces+w7tmt=outlook.com@contesting.com> on behalf of
GEORGE WALLNER <aa7jv@atlanticbb.net>
Sent: Wednesday, October 2, 2024 7:55:20 PM
To: ws6x.ars@gmail.com <ws6x.ars@gmail.com>; topband@contesting.com
<topband@contesting.com>
Subject: Re: Topband: E51D Oct 1
Thank you Wes, but it wasn't my "ears" (which are not what they are used to
be) but a new RX antenna and a very low noise pre-amplifier, that we
installed yesterday morning. Your signal was an easy copy with this new
antenna. There was no trace of it on the TX antenna! (You also set your
frequency well: a couple of hundred Hertz away from the other callers but
still withing the RX passband.)
There is a timely thread going on about a "Low Frequency RX Antenna". The
antenna we installed yesterday is a single support variant of this VE3DO
loop, which is essentially a delta loop. This type of antenna is easy to
install and gives you an RDF that is just a few of dB-s shy of a small
Beverage, but at a much lower gain. The key is a low noise amplifier located
at the antenna. This is a must in almost all situations. The amp is remote
not to overcome the coax losses (which it does), but to ensure that
amplification takes place before noise is introduced into the RX system. We
have a single RIB on a small cay with two Honda 22i generators. Like most
temporary installations, grounding is less then perfect and some noise
couples into the RX circuit. A low noise pre-amp at the antenna, turns a -30
dBi RX antenna into a -10 dBi RX antenna with an RDF of 7 dB. That is
sufficient to
overpower the noise that inevitably gets into the receiver.
I will be on TB again tonight.
73,
George,
E51D
PS: You can easily expand this antenna to cover four directions by adding a
second loop on the same support at 90 degrees, and use switchable
transformers to change directions.
On Wed, 2 Oct 2024 11:12:43 -0400 wrote:
>As a tribute to George's incredible ears on E5-N, this morning, at 1107 UTC,
>just before local SR, I worked E51D QRP, using a "nothing special" Inv-L.
>This is from Northwest Rockingham County, VA, FM08. The signal was solid
>copy, averaging around S7. Signal strength was not quite as loud as 2 days
>prior, when peaks reached nearly S9.
>Oddly, yesterday, morning, on FT8, I couldn't work E51D with a kW!
>Thanks, George.
>Jim - WS6X _________________
>Searchable Archives:
>http://www.contesting.com/_topband
> - Topband Reflector
>
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