[Elecraft] KX3 PC Headset Stereo mike

[GDanner]

Peter,
Bias is "added" to the tip via menu.

The voltage you read on the 1st ring is the pull-up for the PTT & UP/Down 
buttons.

See the schematic for the MH3 microphone ( 
http://www.elecraft.com/manual/MH3%20Rev%20A.pdf ).
It does show the connections to the mic plug.
I can not find the Mic jack on the KX3 schematics.

I used the MH3 schematic to make an adapter to interface my K3 microphones 
in case I need my KX3 to back-up my K3 & KPA500.

73
George
AI4VZ



-----Original Message----- 
From: Peter Eijlander (PA0PJE)
Hi Dom,

When I measure the mic connection with a standard 3.5 mm. stereo cable
with two RCA plugs at the other end, I end up having no voltage on the
tip of the 3.5 mm plug and 2.4 volts on the middle ring. That is the
situation I'd expect it to be: These mics are usually wired for mic
inputs of soundcards and they carry the bias supply voltage on the
middle ring and the AF output comes from the tip.

. . .