[Elecraft] K3S Microphone

[Don Wilhelm]

Jim,

A Yaesu microphone will not work with the K3/K3S unless you construct an 
adapter to change the microphone pinout.  There are no menu settings to 
accomplish that feat, you must build an adapter to route the AF and PTT 
and their Return paths to the appropriate pins on the K3/K3S microphone 
jack.

The CM500 has a stereo mic plug, but the tip and ring are connected 
together.  That is no "never mind" for the K3, but for the KX3, it does 
cause a problem.  Without building an adapter, you can turn off bias and 
turn MIC BTN off, and it will work.  The bias is supplied from the 
residual voltage of the digital voltage designed for the MIC BTN.  If 
you find that digital voltage produces digital noise in your signal, the 
only cure is to build an adapter to isolate the ring from that digital 
voltage and if you do that, you will have to turn BIAS on for the CM500 
to operate.

73,
Don W3FPR

On 2/12/2016 5:55 PM, grif80128 at comcast.net wrote:
> Thanks for all the responses. I find them very interesting. The only thing that I'm missing is comments on the Elecraft MH2 Handset. I noticed that the CM500 has two stereo plugs and the mike inputs are mono. I have a Yaesu desk mike but can't figure out the menu settings to use it's PTT switching. In the meantime, I'm having fun with the Heil K2 headset that I bought for use with my KX3. Having great fun with the new K3S! Jim KC0TRK
>