I just bought a used RV-6a and am having problems with the radio - XCOM-760 VHF. It can pick up close transmissions (tower, airplanes on the ramp), but can't pick up anything distant. I checked the connections, reset the radio to factory settings, tried different headsets, reset squelch. Nothing made a difference. I think I need to get it repaired, but the manufacturer is out of business. Does anyone know where I can get it repaired?