Note the changed subject. Computer speakers are cheaply made, no shielding. If you are lucky won't have issues. In your cases, suggest moving them away from equipment. Don't forget that stray rf loves audio as well. Grounding, antenna location, etc. can all play a role. (I have no hum while transmitting. I did add an isolator between the K3 and amplified PC Speakers.) 73, Bill K9YEQ
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Monday, August 01, 2011 2:14 PM To: [email protected] Subject: Re: [Elecraft] KPA 500 Hum Klaus, Are you sure it is the KPA500? My computer speakers in the shack will hum when using any of my HF amplifiers on CW. 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member On Mon, 1 Aug 2011 07:33:05 +0000, Klaus Koppendorfer <[email protected]> wrote: > >Last week i assembled the kpa500 of oe6rdd when we transmit we hear a >realy loud hum (50hz) in the rythm of the cw signals > >i have compared this with my own kpa-500 and there is no hum i have >tried to loosen the big srew which holds the tranformer with no result > >any ideas ?? > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
