[Elecraft] K3/0-Mini Microphone Audio Noise

[jmaass at k8nd.com]

I use a K3/0-Mini with RRC boxes to connect to a remote station. 

I connect my dynamic microphone to the K3/0-Mini front panel. The transmitted audio has a loud hash that overwhelms my voice audio. The noise is present even if the microphone is disconnected, driving the amplifier to several hundred watts!

Is this a known problem? Is there a known solution?

Google found a few similar reports, but no solution. I searched the archives back four years, and nothing.

73,  Jeff  K8ND  PJ2ND