This is not easy to explain. Here is what i have. The power output of the transceiver cannot be controlled. The power amp works fine when I test it on the bench and drive it with a signal from a signal generator. The output is clean on all bands when observed on a spectrum analyzer. The signal from the transceiver exciter is clean and can be controlled (reduced) with the drive control. When I connect the power amp to the exciter I get full power output with spurs across the entire HF spectrum and cannot reduce the output power. The power supply shuts down due to excessive current. Has anyone run into this problem and what did u do to fix it. i am posting this for the person that is working on my TR-7. any help would be greatly appreciated.