Hi, I have an old midland XTR 70-1395A radio and I attached the manual here for convenience. Also, as you can probably tell, I have a signalink that I want to interface with the radio. I have already cracked it open and tried to connect my cable to the correct outputs and inputs. The Problem is that I cannot seem to find a common ground. I used the manual to find headers that may be helpful but when I tried to use them all I get on the signalink is noise. And it's not RF that I'm hearing. On this board I found a ground pad which I soldered the gnd wire to and then the other spkr wire to the speaker output and got the same noise. (the signalink still gets the same noise even when I connect ground and spkr direct to the internal speaker) Has anyone else ventured to make their own interface cable for a radio that does not have direct audio outputs? Am I missing something big here? I'm comfortable probing around the inside and soldering directly to the board if necessary. Any guidance greatly appreciated.