[Elecraft] K3: R-MH2 mic problems

[Don Ehrlich]

Sure sounds like RF getting into the mic circuit but to prove it check to 
see if the 'feedback' distortion occurs on 160 meters where, normally, RF is 
far less intrusive  and/or with reduced power output.  I use my MH2 with my 
K3 with Mic Sel set to '  FP.L  bias  ' because I found that the FP.H 
setting was providing too much gain in the mic amplifier which caused 
distortion but that was detectable in the monitor with no RF output.

BE SURE TO CHECK TO BE SURE THE SHELL OF THE MIC CONNECTOR is actually 
grounded.  There was a thread recently where some folks were getting RF 
problems due to excessive paint in the hole which mounted the mic connector 
which caused an open ground to the shell of the connector.  Now that I think 
about it that sounds like the likliest cause.

Don K7FJ


>
> The clincher is that if I transmit into a dummy load, the MH2 works fine. 
> Got to be RF feedback, right?  Why would it effect the MH2 and not my 
> Kenwood mic?
>
> Any suggestions?
>
>