military radio microphone bias

[monkeysolder]

Hello -

I have a H-250 military handset and am having problems figuring out how to bias the microphone properly. The sound is very faint coming from the mic. Does anybody know what the proper bias voltage is for microphones in military handsets? Or what mic voltage is provided on military radios on the U-229 connector?

Here is the handset - I believe it has the same plug and mic element as almost all other military handsets.

http://sonetronics.com/content/products/handsets/h250.asp

Thanks,