Jim, I've been on travel so apologize for the delayed reply. All I can say is WOW...I thought I was the only one who had this symptom with the K3! I have a similar setup with a Heil boom-mic going through a DX Doubler SO2R switch box, and had horrible SSB distortion on bands above 14 MHz and power levels above about 12 watts (the point where the PA kicks in). I unplugged and replugged cables and changed orientation; somehow eliminating the distortion, but never really found a "smoking gun" or understood the distortion mechanism. The thing that was killing me was that the K3 simply replaced an IC756ProII in the same spot and I had not previously experienced such transmit distortion. Several calls and emails to K3 support had me check the power supply. However the only conclusion we could come to over time was some kind of a weird ground loop.
Other posts seem to be right on target. RF on the mic "shield" line isn't being taken to true ground...and it's finding it's way into the microphone amplifier. Thanks to you smart guys out there, and for Elecraft, how about a design review? 73 Rick N6CY -- View this message in context: http://n2.nabble.com/K3-RF-Feedback-Problem-tp1442033p1452766.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
