[ICOM] IC-2720 Headset?

[Carl Vangsness]

I just spent a frustrating afternoon trying to duplicate Geoff Haines 
N1GY's clever circuit for using a computer headset with his IC-706. I 
have a 2720, connections looked the same. NOPE. Per the HM-133 
schematic, the PTT switch is not connected directly to the leads going 
to the radio. Instead it is one of several switches, each with their own 
function, that pull various leads of an IC to ground to send different 
data to the radio.

SOO, I have my doubts about the "standard" adapter cables from Heil 
working with the Traveler headsets he sells. Question: has anyone found 
a headset that does work with the 2720? I get tired of dropping the 
microphone in the car.

Tnx es 73, Carl WC0V