A quick check with a meter for around 6 Volts DC on the collector (metal tab) of the final transistor while transmitting would be a good place to start.
A symptom of "no transmit" is too much like "my car won't start". More than one possible cause. You test the individual parts of the system one by one. You'll usually find more than one part of the system that passes its test. Eventually this process will lead you to the component or connection that's causing the trouble.
Troubleshooting is a technique, applying logic to find the root of a fault. If there is no DC power on the final transistor, that would cause this fault. Like the man said, if you have a zero reading here, Q602 is the next place to look. The emitter leg, the one on the right with the legs down, should have that approx 6 Volts DC on it. If this reading is zero, AND you have voltage on the base leg, the one on the opposite side, then Q602 has failed. An open circuit between the base and emitter on this part is a common way for it to fail.
Not the only possibility, but the process involves identifying all the potential causes that have NOT failed, one by one. Starting at the 'downstream' end of the AM transmitter's block diagram is what I would do.
73
A symptom of "no transmit" is too much like "my car won't start". More than one possible cause. You test the individual parts of the system one by one. You'll usually find more than one part of the system that passes its test. Eventually this process will lead you to the component or connection that's causing the trouble.
Troubleshooting is a technique, applying logic to find the root of a fault. If there is no DC power on the final transistor, that would cause this fault. Like the man said, if you have a zero reading here, Q602 is the next place to look. The emitter leg, the one on the right with the legs down, should have that approx 6 Volts DC on it. If this reading is zero, AND you have voltage on the base leg, the one on the opposite side, then Q602 has failed. An open circuit between the base and emitter on this part is a common way for it to fail.
Not the only possibility, but the process involves identifying all the potential causes that have NOT failed, one by one. Starting at the 'downstream' end of the AM transmitter's block diagram is what I would do.
73
