[FADCA] KPC 3 Noise

[Doug Christ]

At a recent hurricane seminar, I set up a portable APRS station which did
not work. The KPC3 tnc was generating so much rf hash that it wiped out the
receiver on the HT. Heck, it even interfered with radios not even interfaced
into the APRS setup. The signal is full scale on the HT and the signal
completely disappears when I power down the tnc. I even powered down the
laptop and the tnc would be the only thing on. BTW, I was running it off of
a 9 volt battery, not a AC adaptor. I had noticed that I was having problems
in the past using this unit but usually I am at a FPAC switch working on it
so it really did not take much of a signal to make the tnc work.  I broke a
out a spare KPC3 only to discover the same problem. Someone ran home and
grabbed their own KPC3 which worked better but still had the same problems.

Anyone have any ideas as to where this noise is coming from and what I can
do to stop it? I used the same laptop, tnc and radio before for field day
operations and it worked fine.

Doug/KN4YT