John
A lot of unknows here. You didn't describe how the rig is powered, a
prime source of RF feedback for external supplies. Fundamentally there
is a source of RF interfering, feeding back, to your low power system.
Find it and the problems will disappear. Not the most detailed.
Not using an earth ground is definitely a recipe for trouble no matter
how it may have worked for you in the past. Whatever RF you have
floating around has no benign place to go. The ARRL interference book,
distilled from hundreds if not thousands of solutions, may help you to a
solution. In your second floor situation you'll need more than a big
wire due to the length. Try a few inch wide copper strap from the shack
to a ground rod system to keep the inductance down.
Your shack is on the second floor. I'll hazard a guess. Your ants are on
the 3rd, 4th, or 5th floor height wise just above the shack. That pesky
ole inverse square law that bugs all of us..........
73 and good luck
Art
k6xt at arrl dot net
--------------------------------
Message: 7
Date: Fri, 13 Oct 2006 15:47:45 -0400
From: "John K Gotwals" <john@gotwals.com>
Subject: [TenTec] Orion and rf feedback
To: <tentec@contesting.com>
Message-ID: <002401c6ef00$756883a0$0300a8c0@john>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I have moved to a new QTH and am having a problem with rf feedback on SSB
when I connect my Orion I to an amplifier. At my previous location I had a
similar problem but solved it by (1) not using an earth ground, (2) not
strapping the antenna turner, amplifier, and Orion to a shack ground bus
strap, and (3) by inserting a W2DU choke in series with the coax between the
Orion and the L-4B amplifier. This setup was successful in allowing me to
transmit with the amplifier on 80 through 10 meters. At both QTHs the shack
was/is located on the second floor.
Any comments and suggestions would be gratefully received.
John, N9JG
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