The '735 cable will work on the '706 just fine. The difference is that '735 and other early ICOMs included two wires in the power cable so the on/off switch on the radio would also on/off switch the power supply. That's no longer the case, and I'm not certain which models first included that change. It was certainly handy using the IC735/PS55/AT150. What a sweet setup! 73 Gene N7YW