Look at the plug end and figure out the colors from there (use a VOM or some other electrical tester to figure out which wire is connected to where). There are three conductors on a microphone plug, starting at the end (tip):

tip - push-to-talk contact
ring - microphone audio signal
sleeve - common for both PTT and microphone audio

PTT is implemented as a switch between tip and sleeve conductors, if the switch is closed, the mic is keyed. PTT on the stick is usually wired in parallel with the jack circuit, however, a microphone may not work unless you use the built-in key, as the microphone key switch often also opens/closes the microphone audio signal, so multiple microphones can be used on the same circuit. But, why would you want to hard wire a microphone at all? I'm installing a boom microphone in our newly acquired Std Cirrus (all such installation work will be inspected and signed off by an A&P, for those who like to kvetch), rather than muck with the existing wiring, I just added a Switchcraft S-230 right-angle plug at the end of the boom mic wiring, left the tip conductor unconnected (PTT switch on stick will still work), and plug it into the existing microphone jack. That way, we can also pull out the boom mic plug and use a handheld mic as a backup.

Marc

On Wednesday, February 4, 2015 at 4:45:06 PM UTC-8, Doug Mueller wrote:
Hello all, I have a dittel FSG-60M Radio in my glider. It has a mic plug
with a telex IR Electric headset. The headset is inconvenient and I got a
Dynamic Mic from Wings and wheels. The glider was hard wired with a
PTT and a separate speaker. I have removed the plug on the end of the
mic and I wish to hard wire the mic. A brown,white wire with a ground
are in the mic line. I do not have a wiring diagram for the mic. I looked
at the FSG-60M installation instructions was trying to figure out if an
amplifier is needed to run the new set up. W&W was not very helpful
and I could use some expertise as I thought it would be rather simple
to replace the mic. The radio is set up for a dynamic mic already. It is
inscribed on the outer case. I do not believe it was ever changed from
the previous owner. Anybody with experience with this set up? Thanks,
Doug