[RFI] Subwoofer resolution

Craig Thompson craig at thompsonet.com
Sun Aug 19 12:40:37 EDT 2007

Thanks for the emails and ideas. I did resolve the RFI problem yesterday.
The only remaining issue was keeping the RF from entering through the
input cable. I tried various combinations for ferrite and multiturns and
was able to "fix" the problem. Of course, the real problem was the
rectification of RF in the output stage. That problem remains. However,
stopping the RF from getting to that stage solved the problem adequately.

I tested the Sub Woofer/ "science experiment" by lowering my 2m EME array
to 24 feet (21 DB gain) and aiming it right at the box in my driveway and
putting 15002 to the antenna running FSK441, not a peep!! I took it to my
neighbors and demonstrated it to them and they are now very happy.

I suggested that when purchasing any consumer electronic product that they
ask the salesperson about bringing it back if it is subject to RFI. This
should be a prememptive strike so that they are not looking for the
cheapest Radio Shack Subwoofer that you can buy.

73, Craig

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