On the desk today:
Connex 3400-300
Reason for coming in:
Squeals on transmit,
Gets hot,
Talkback removed,
Upon evaluation:
Talkback module messed up.
AMC transistor outer legs jumped with a carbon film resistor.
AMC center leg and emitter was touching.
R249 clipped.
Bias off.
Frequency off.
Fixed:
Removed talkback module,
Replaced AMC transistor due to being shorted (Bad).
Straightened out solder botch around AMC transistor.
Replaced R249
Reset bias to specs.
Realigned radio completely.
Finished:
No more squeal on xmit. The squeal was coming from that messed up talkback module and the AMC transistor being shot due to being shorted.
Completely realigned.
Out the door she goes...
Connex 3400-300
Reason for coming in:
Squeals on transmit,
Gets hot,
Talkback removed,
Upon evaluation:
Talkback module messed up.
AMC transistor outer legs jumped with a carbon film resistor.
AMC center leg and emitter was touching.
R249 clipped.
Bias off.
Frequency off.
Fixed:
Removed talkback module,
Replaced AMC transistor due to being shorted (Bad).
Straightened out solder botch around AMC transistor.
Replaced R249
Reset bias to specs.
Realigned radio completely.
Finished:
No more squeal on xmit. The squeal was coming from that messed up talkback module and the AMC transistor being shot due to being shorted.
Completely realigned.
Out the door she goes...