Very old post I know, but I came across it and there are a couple of errors.
There are 3 main microphone types used on aircraft:
1/ Amplified or "carbon compatible". These are used on the majority of light aircraft and civil aircraft. They are replacements for the earliest carbon microphones and require a DC energising voltage (8-15V in series with about 500 ohms)
Headsets with these typically have two separate plugs. Some newer airliners us multipole "XLR" types. The actual microphone element, may be dynamic or electret depending on the design. As it's amplified the system doesn't care. The output voltage is high, hundreds of millivolts
2/ High impedance dynamic. Used on UK / European military aircraft and some North American military. These are dynamic or moving coil microphones with an impedance of around 200 Ohms. Medium output around 100 millivolts. No DC voltage required. Basically the same as used on land radios. Typically a brass 4 conductor "UK" NATO plug.
3/ Low impedance dynamic. Used on North American military aircraft. Impedance is about 5 Ohms. Low output of around 100 microvolts. Not used much elsewhere.
You can adapt a high impedance dynamic microphone to use on a carbon compatible aircraft using a simple 1 transistor amplifier. This is powered by the system.
You can use a high impedance dynamic on a a low impedance system with a transformer or even a resistive attenuator.
You can adapt a low impedance dynamic to work on a carbon or high impedance using an amplifier (different gains for the two systems. This will need external power (batteries) for low impedance and may need the for cabon.
Summary: Low impedance Dynamic is a right pain to work with.