[NLRS] Trip Report

[Clair J. Robinson]

Bob, WØAUS, and I drove down to Ellendale today to see what we could do 
about Matt's, KAØPQW, TVI problem. As it happens we weren't able to do 
very much.

The problem turned out to be direct audio rectification of Matt's 2m 
signal occuring in the offending set at a point following the volume 
control. We did not see any interference to the video. Disconnecting the 
antenna (cable) lead from the set had no effect whatever. We tried 
various coilings and bunchings of the power cord without much effect, 
either, other than that we were sometimes able to make things worse. 
After discovering that where we stood in the room had some effect, we 
taped aluminum foil to the rear of the set, which is the side towards 
Matt's QTH. This helped but did not eliminate the problem.

The neighbors' house is NE of Matt's. We found that there is little or 
no interference unless Matt's beam is aimed to the NE or close. Even 
then, it is probably tolerable when power is reduced to 10 watts. 
Turning the TV audio up pretty well drowns it out, then.

We also tried using FM. As expected, there was no interference. Using CW 
resulted in noticable keying 'thumps' at 150 watts when Matt's beam was 
aimed NE.

Although we tried, we could detect no problem on 6m.

We also looked at Matt's rotator controller and audio position 
indicator. It seems that the pot in the rotator is seriously 
intermittant. When we first checked, it was open between leads 3 and 7, 
the ends of the pot. We rocked the rotator back and forth and it seemed 
to heal itself momentarily. I suspect a bad connecton to the wire at one 
end of the pot. The rotator will need to be replaced or repaired.

73, CJ KØCJ