[Elecraft] Microphone for K2

[Mike McCoy]

Since I can't seem to find any spec's on microphone requirements for the K2
so I thought I'd ask here:

What impedence (high? low?) and what sort of element works best (electret?
ceramic? etc.).

I see lots of mobile mic's on eBay. Which of the 'big 3' vendors (e.g.
Kensucom) have most had the best success with regard to audio quality, size,
ruggedness, etc. Any particular manufacturer and/or models from the 'Big 3'
anyone might recommend?

Finally, my reason for having a K2 in the first place is for
backpacking/portable ops. I'm considering the Heil BM-10 headset (w/ mic).
Anyone have any experience with a BM-10 + K2 setup?

thanks & 73
Mike - AD5IU