[Milsurplus] Mic Adapter M-299

[Mike Morrow]

Roger wrote:

> Anyone have any idea what the M-299 mic adapter was used with?

Robert wrote:

>SCR-522.  A note on one of the later manual revisions says "For Use When 
>British Equipment Is Installed In AAF Aircraft". 

It is used to adapt the USAAF T-17 and other common *carbon* element mics to equipment (like the SCR-522 mentioned) that was designed for *dynamic* (and thus voltage producing) mic elements.   Therefore, some 12 or 24 vdc had to be supplied to the M-299 for carbon mic element excitation.

I think the US military held on to inert carbon mic technology long after other nations had gone on to voltage producing mic elements (dynamic, crystal).

73,
Mike / KK5F