Just before the holidays we had a new ADT wireless alarm system installed in the house. Because we went away for the holidays, I didn't have much time to play on the HF radio since then until last week. Well one night I decided to kick on the amp and have some fun on 40 meters because there were some interesting conditions. After about 30 minutes of talking on the radio, my wife comes in and tells me that the alarm keeps automatically going into the "alarm on" countdown. It got so bad that as soon as she turned it off, the timer started again while I was transmitting! Well, after I looked at the keypad to understand how it was wired, I decided to try putting a 0.1uF ceramic disc capacitor across the terminals on the wall wart transformer. That did the trick. After testing with her on the low bands with 1+ KW output, the alarm doesn't get triggered anymore.
Just thought I'd pass this along in case anyone else ever comes across a similar issue.
Oh the fun of chasing down RFI...
Just thought I'd pass this along in case anyone else ever comes across a similar issue.
Oh the fun of chasing down RFI...
