Hey everyone! I'm looking for some help on a super galaxy mobile. I'll try to provide as much detail as possible.
The PCB number is worn off but I believe it is a EPT3600-xxx
When the radio is first turned on and you key the mic, it will transmit at full transmit power for a split second then lose transmit power but the radio stays in transmit. Then, once you key the radio again, it will switch into transmit but there is no transmit power in any mode no matter how many times I try to key it. I have to turn off and unplug the radio and wait over an hour to try it again, then rinse and repeat to try and find the problem.
So far I have replaced all the electrolytic capacitors.
I replaced the driver transistor "TR44" and both finals "TR43 and TR56" with a NOS Mitsubishi 2SC2166 and two 2SC2312's.
I have the service manual and have checked voltages through out the radio and everything seems to be correct except for a few things.
Final TR43, Driver TR44, AM Mod Amp TR49, AM Mod Amp TR50, AM Mod Amp TR51, and Final TR56, all have the correct voltages when the radio is working correctly but when I lose transmit power I also lose these voltages.
Also with the TX Mixer IC9 everything is correct when the radio is working correctly, but when I lose transmit power I lose the voltage on Pin 1.
Just some additional info - I always have receive, if I switch to PA mode I always have modulation, and sometimes it will stay keyed up with power and modulation for as long as I keep it keyed then it goes right back to only working for a split second. It also doesn't matter what mode I'm in its all the same.
I'm just wondering if anyone has run into a problem like this before or has any ideas. If you need more information or would like me to upload pictures please ask. Thanks in advance everyone.
The PCB number is worn off but I believe it is a EPT3600-xxx
When the radio is first turned on and you key the mic, it will transmit at full transmit power for a split second then lose transmit power but the radio stays in transmit. Then, once you key the radio again, it will switch into transmit but there is no transmit power in any mode no matter how many times I try to key it. I have to turn off and unplug the radio and wait over an hour to try it again, then rinse and repeat to try and find the problem.
So far I have replaced all the electrolytic capacitors.
I replaced the driver transistor "TR44" and both finals "TR43 and TR56" with a NOS Mitsubishi 2SC2166 and two 2SC2312's.
I have the service manual and have checked voltages through out the radio and everything seems to be correct except for a few things.
Final TR43, Driver TR44, AM Mod Amp TR49, AM Mod Amp TR50, AM Mod Amp TR51, and Final TR56, all have the correct voltages when the radio is working correctly but when I lose transmit power I also lose these voltages.
Also with the TX Mixer IC9 everything is correct when the radio is working correctly, but when I lose transmit power I lose the voltage on Pin 1.
Just some additional info - I always have receive, if I switch to PA mode I always have modulation, and sometimes it will stay keyed up with power and modulation for as long as I keep it keyed then it goes right back to only working for a split second. It also doesn't matter what mode I'm in its all the same.
I'm just wondering if anyone has run into a problem like this before or has any ideas. If you need more information or would like me to upload pictures please ask. Thanks in advance everyone.