Just came back from my neighbors house after trying to fix his
subwoofers.
They seem to like to receive my 80 meter cw signal. 40, 20, 15 and 10 are
clean. I use a vertical on 40 with a matching network at the base that
switches in a loading coil for 80m. If I use the matching network, the
interference is louder then when I use the vertical without the matching
network and tune it with the internal antenna tuner of my xcvr. Interesting.
He has 2 subwoofers. The first one does not react when the speaker
cables
are disconnected and just the power cord is connected. The second one reacts
with only power applied. The level of interference does not change with
volume level. I tried clip on ferrite beads on each speaker cable, with no
effect. Of course I do not know what core material these beads are.
My next step, I suppose, would be to use a power line filter on the
second
sub woofer. The first one I probably need to disconnect everything from the
system and connect one at a time to find the offender. Does this sound like
a reasonable approach? I don't want to pop in every other day with a
different idea so I want to gather as much info as possible and make one
assault.
Does anyone have experience with this type of problem?
TNX,
Tom W3TA
PS TX power is 100W and the antenna is about 100 feet from his house.
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