[Boatanchors] Carbon Microphones

[rbethman]

Carbon microphones require a voltage to be applied.

The audio introduced then causes that voltage to alter.

Carbon mikes are NOT like a "Dynamic" or crystal element that creates 
the signal by the piezoelectric properties of the element.

Hence the ability to simply connect a crystal mike to an O'scope and 
observe the background noise.

Place the leads of an O'scope across a carbon mike.  You will not 
observe a signal from background noise alone.

Bob - N0DGN