John,
In addition to the other suggestions let me add there is no guarantee
which cable the RF gets into your computer on. You might have to filter
them all. The split cores are really handy and don't cost $9 a copy. For
sure start with the power cord. If it was me I'd do the offending
keyboard cable at the same time. Since it's 80 it might take more than
one core.
You didn't mention grounding. I found it necessary to include the
computer case in my station grounding setup. Not only did it reduce rfi
into the computer, it also reduced PC noise in the receiver. All chassis
go to a single common ground point, then outside to copperclad steel
rods. Since your shack is on floor2, you'll need a wide strap for a
ground bus to keep the L down.
It's normal to have a whole new experience on each band you have RFI. It
all depends on how friendly the RF path into your gear is.
Best wishes. If it was easy, nobody'd have RFI!
73 Art
tentec-request@contesting.com wrote:
Message: 8
Date: Thu, 26 Oct 2006 09:56:03 -0400
From: "John K Gotwals" <john@gotwals.com>
Subject: [TenTec] RF gets into computer
To: <tentec@contesting.com>
Message-ID: <004001c6f906$7f0a0180$0300a8c0@john>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
When I operate on 75 meter SSB with my Orion, my computer beeps and
disconnects/reconnects my USB connected keyboard. Note that I do not have
this problem on 40 meter SSB. My computer is located on the second floor of
a brick house, and one end of my dipole is about 15 feet from my shack.
From comments made by others on this list, I may have to put RF filters on
the cables and wires connected to my computer. I am contemplating the use of
Amidon FT-240-77 ferrite toroids, which have an I.D. of 1.4 inches and cost
$9 each. If I buy in quantities of 10, is there a cheaper source for this
toroid?
Any comments or suggestions on this problem would be appreciated.
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