I'm betting the single pin connector on the headset is a motorola pin. I can plug my single pin motorola headsets into my cobra radios and hear, just not transmit. it has to do with the pin size.
You'll either need to get a motorola radio, or a cobra ptt.. i'm thinking the radio will be easier to find.
The Tier One Tactical Operator
Tippmann Arms M4A1
KWA USP .45, KJW P226, KJW hi-cappa