Thread: Carbon microphone revitalization
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Old February 16th 09, 06:54 PM posted to rec.radio.amateur.boatanchors
Fred McKenzie Fred McKenzie is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 317
Default Carbon microphone revitalization
In article ,
(Scott Dorsey) wrote:

They are all pretty much the same other than polarity... you can grab any
cellphone headset or computer headset from the dollar store and use that.

Over the years, I've tried a number of circuits to replace carbon
microphone elements. None had the output voltage of a good carbon
element, but they sound much better if your system has enough
amplification to compensate.

Polarity could be a problem. A carbon microphone is a series DC circuit
where polarity does not matter. If your equivalent circuit requires
proper polarity, simply use a full wave bridge made of 4 diodes. Two of
the diodes will always be forward biased. The DC source voltage will be
reduced by about 1.4 volts, but that should make little difference.

Fred
K4DII
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