[Elecraft] Using a PC headset with K3, connections reverse at rear MIC jack?

[David Woolley (E.L)]

I believe the theory behind PC microphone connections is that the same 
connector will work for both dynamic and electret microphones.  Dynamic 
microphones use mono plugs, which short the "bias".  That isn't a 
problem as the bias is not a voltage source - it is actually the 
drain(?) load on the pre-amplifier in the electret microphone - so quite 
a high resistance source.  Any DC blocking is assumed to be in the PC.

Electret microphones connect the "bias" by having ring and tipped 
connected together.

Electret microphones don't need any real bias, as the electret provides 
a permanent electrostatic field.

-- 
David Woolley
Owner K2 06123.


On 29/10/13 15:22, MontyS wrote:
>
> The rear mic jack is a mono, not stereo, jack.  It will short the ring
> and sleeve together.  Audio is on the tip, as is the voltage.  The mic
> should have a blocking capacitor to isolate the audio from the voltage.
>
> This is standard for every radio I have owned.  If a stereo jack is
> used, it would be for PTT, not a separate bias connection.
>