MTS DOES NOT ENDORSE THE ABOVE LINKS, ANGELFIRE ADDED THIS
ICOM 50W VHF Units
The most common symptom is low or no Tx power. This is usually caused by the VHF Power Amp. This is not ICOM's fault so much. The SC1091 is the 45/50 W final Module, and has the generic name of SAV17. The SAV17 has a weak design, the transistor mounting is too close to the ceramic PCB the compontents are mounted to, and as the transisitors heat they push on the ceramic surface, sometimes the pressure is to extreme and the surface cracks breaking the VCC power to the final or driver. This is usually repairable. Not always though. Low power setting is not any better and actually may be worse, the module is biased for 50W operation and low power is very inefficient, so there is still allot of heat release to the heatsink.