Hi all, I'm experiencing the dreaded PC Speaker hum every time my K2 transmits, even when power is dropped to about 2 W.
The speakers are Harmon Kardon amplified speakers and they do not hum when turned off. Per other threads, I plugged the speakers' wall wart into the same outlet as the K2 and this did improve the situation (hum dropped by about half) but did not completely eliminate it. The computer chassis and K2 are grounded together with a ground strap. I'm going to try some ferrite on the AC power cord, the speaker cable to the computer, and the speaker wire connecting the left and right speakers. In an email to Fair-rite, they suggested their #31 material snap on cores. My thought is that these would be limited in the number of turns of wire to perhaps one, maybe two turns at the most. Would there be additional benefit from getting their toroid cores instead and wrapping several turns of wire versus using their snap on core? Also, would it be better to use a HF low pass filter such as I.C.E.'s 420 to clean up my signal versus trying to fix my speakers? Thanks for any suggestions! 73 N5BCN - Brian ----- K2 #6800 KSB2 KAT2 KIO2 KNB2 -- View this message in context: http://elecraft.365791.n2.nabble.com/RFI-PC-Speaker-Hum-tp5116897p5116897.html Sent from the [HAM] mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
