RE: Is my transmitter dead?
I think you did a good job of diagnosing your problem. Since the battery was still well into the usable range it should not be the problem. One thing you might check is that there is a good connection inside the transmitter chassis between the antenna base and the circuit board and check the solder connections between the board and the base of the antenna. You are most probably correct in that some component is being effected by the heat. If the transmitter has been used a lot with power on and the antenna collapsed, the output transitor could be damaged. If you can get a can of coolant (you can get an aerosol can in the USA at radio shack that cools whatever you spray it on) and spray the output stage while in use and it starts working okay again, you know you have found the problem.