If you're looking for something portable for instruction use, I have a couple of comments:
I used a Nady PMC-2 communicator for a few years. They are cheap and work well for a while, but break quickly (typically the thin wires break). I can't remember where I bought it, but following is one place. They can be found for $50.
http://www.shmilysgoods.com/nadpmdrivtop.html
I replaced the Nady with a Chatterbox Tandem Pro that I got from Stable Energies. This place also sells the special "Student Headset" which can be shoved into a helmet like the Nady headset. The standard Chatterbox headset is a 2-piece design which is intended to be placed permanently into a helmet. I bought the Tandem Pro and 2 student headsets, and I may eventually hardwire a 2-piece mic into my helmet.
http://www8.mailordercentral.com/stable ... sp?dept=37
So far I am impressed with the Chatterbox and I would recommend it! Anyone find better prices on it than the Stable Energies place?
_________________
Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1