[ARC5] Carbon mic replacements

[Robert Nickels]

I'm surprised it hasn't been mentioned that for many years, Motorola and 
GE (and probably other) two-way FM radios used a controlled reluctance 
mic element with an integral transistor impedance matching stage to make 
it directly usable with a carbon mic input. You can probably noodle 
around the Repeater Builder site and find some model numbers but IIRC 
mics with both metal and plastic housings used this design, and they key 
is they all had the 4-pin connector, not the modular type, similar to 
the one shown opened-up here, although most are the driftwood (beige) 
color scheme:

http://forums.radioreference.com/motorola-forum/262809-help-needed-identifying-vintage-remote-microphone.html

The GE Progress Line was similar although the the electronics was 
packaged differently.  The element inside has characteristics similar to 
the famous Shure 444 and I've modified some of them for use as a regular 
hand mic with the characteristics of the 444. GE:  
http://i.imgur.com/Vke2oJS.jpg

The nice thing is, these mics are usually in the "dollar apiece" boxes 
at hamfests.   Shure, Turner, and others also supplied their standard 
hand mics with carbon elements, and virtually any mic you'd find used 
with either an aircraft comm radio or an AM marine radio will be a 
carbon type.

73, Bob W9RAN