I have a Pro 106, I wanted a listen only acoustic headset to listen to it in one ear so I picked up one on ebay. When it arrived, I noticed it had a 2.5mm listen only end, so I went to RS and got an adapter to 3.5. Plugged it in, and I does not transmit through the earpiece. Everything connects perfectly. I tried it in other devices and it works fine with the adapter. Any thoughts?