[Elecraft] K3, Microham MK2R+, Rear Phone Jack = Hum

Hello Group, I just installed a Microham MK2R+ SO2R box, I connected the HP Audio input of the MK2R+ to the 'rear' phone jack of the K3. Lot's of hum on the receive audio and distortion on my monitored ssb transmissions. When I unplugged the cable from the rear phone jack on the K3 and

Re: [Elecraft] K3, Microham MK2R+, Rear Phone Jack = Hum

Rich, Check your cables. That sounds like an open shield somewhere in your cabling. Do you have a very early K3? Those had inductors in series with the ground path that should have been bypassed. If you do have those inductors, they could introduce hum. 73, Don W3FPR On 3/14/2014 8:39