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Member Since: July 31, 2010

Country: United States

  • Actually most old phones used carbon granule microphone capsules. They needed a bias voltage to operate (being more like a variable resistance than anything else) and were inherently a little noisy. Also in prolonged use the carbon granules used to pack down and the microphone would produce less and less signal (the fix for which is to whack the handset hard on something solid to break up the packed granules… needless to say its anti-social to do this during a call!). Given that most people will want the bell and dial aesthetic more than the crappy microphone, I’d replace it with a nice, well behaved dynamic or electret module.
    Great project though. Well done.

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