This is why I asked 'why he wanted it', the threads growing but not really giving any useful answers (as far as we know?), because we don't know his reasons.
The later large telephone microphones didn't use carbon mikes, they had an electronic mike inside with electronics to duplicate the operation of a carbon mike. They were a common replacement for the older carbon mikes to prevent crackles from the mike - who remembers bashing the handset to try and stop the noises? 8)
I believe he wants it for a Parabolic Mic. I told him that a Small Electric condensor mic is hard to get exactially in the focal point. And Also depending on the PINPOINT accuracy of the parabolic, a lot of signal will completely miss a small mic.
Hi Chemelec,
Have you ever heard a small speaker that is used as a microphone? Its strong resonance is in the middle of an adult male's voice spectrum and sounds bad. At least the very low ouput impedance of an amplifier damps it somewhat, but as a microphone there isn't much damping.