[Elecraft] Fw: homebrew KX3 electret microphone

[lmarion]

From: lmarion 
Sent: Saturday, October 25, 2014 6:52 PM
To: 
Subject: homebrew KX3 electret microphone

I am  trying to make a KX3 microphone, no up/down. Just PTT with MIC bias.  
1)  do I need 4 ring jack, or will a 3 ring work?
2)  which jack ring is used for the MIC bias?

            Thanks, Leroy  AB7CE