[CQ-Contest] Nagging problem

Pete Smith n4zr at contesting.com
Tue Feb 19 17:10:44 EST 2002

At 03:50 PM 2/19/02 -0500, Mike Wetzel wrote:
>I recently experienced some very similar problems, rf wise.  I've been
>fighting my problems for the last 2 months and haven't exactly figured out
>what is wrong.  What I did to fix the problem on CW was to install a bypass
>cap (.001) on the lead from the computer to the keying transistor in the
>keying interface.  Now last weekend in the contest that worked for the first
>24 hours then I had to install a second bypass cap from the base of the
>keying transistor (in between the resistor and the transistor) that got me
>through to the end of the contest.

At various times I've also found that grounding the computer case carefully
to the station bus solved the problem.  It also seems to me that a few
turns on a toroid, even with good shielded cable, will help to handle any
common-mode currents that might be flowing between computer and radio.

73, Pete N4ZR

Sometimes a tower is
just a tower

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