I've made some good progress today.
1. Make the assumption that you can use pretty much any aviation headset in pretty much any GA aircraft with pretty much any aircraft radio that might be installed. Again assume that therefore most aviation headsets operate within a fairly standard set of parameters.
2. David Clark publishes a schematic of their headsets - see http://www.DavidClark.com/schematic/h10-30el.htm
. This diagram shows headphone impedances, two 300-ohm units in series. From this assertion, draw the conclusion that most aviation headsets offer somewhere around 600-ohm impedance on the 'phones.
3. The manufacturer of my headset, Pilot Avionics, offers several microphone choices, detailed on this page: http://www1.drive.net/_pilot-av/pages/microphn.htm
. This page offers three choices, electrically.
- a "Low impedance" electret,
- a dynamic that's listed at "150 ohms + 15 ohms"
- a set of electrets, including mine, the PA-5, which offer 50 ohms at 16 v DC.
So now the problem becomes pretty simple. If you can't find specs on your headset, assume that yours falls close enough to the above specs that it'll work in an aircraft which accepts the above. Check your rig's specs for audio out and mic in. Match impedances with transformers as necessary, match levels with pots as necessary, provide a PTT or VOX, and ham away!
DISCLAIMER: Electronics is not my strong suit. I may very well be missing something important, and I welcome correction. I encourage all readers to check my references and my logic, and use at their own risk.