I've got a galaxy dx44v on the bench and I've hit a wall. I'm getting receive audio through the radio but cannot get tx audio through it. I've traced it back to C191 on the board and seem to lose it after that. Another thing I have noticed on the voltage of tr51 the middle leg of the transistor has roughly 14 volts on it. When I key the radio I'm only getting a half watt deadkey with no audio. Typically when this transistor is shorted it key high with no modulation. I've replaced tr51, c191, c129 so far with no luck. Any suggestions I'd be glad to try at this point.
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Galaxy dx44v problem
- Thread starter Derrick Walls
- Start date
That transistor may usually fail in that fashion but that doesn't mean it can't also fail in this fashion. Unsolder the leads from the board and test it using the diode function of your multimeter. My guess is that it will test bad.
Obviously this is just conjecture but the reason for your half watt deadkey could be because all the current you are trying to draw to your driver and final are being shunted to ground by this transistor being shorted. Don't forget to check the to-220 transistor just in front of it and also the I believe 2SC945 TO-92 transistor in that area
LC
Obviously this is just conjecture but the reason for your half watt deadkey could be because all the current you are trying to draw to your driver and final are being shunted to ground by this transistor being shorted. Don't forget to check the to-220 transistor just in front of it and also the I believe 2SC945 TO-92 transistor in that area
LC
Single most important question to ask next is if VR13 will run the carrier power up and down like it should. If it does, TR49,50 and51 are almost certainly working just fine.
Or does the carrier level stay the same no matter where VR13 is set?
If C190 fails open-circuit, this reduces the modulator's audio gain almost, but not quite to zero.
But that won't keep VR13 from setting the carrier power. Only affects audio.
And if VR13 won't adjust, you have a problem in D91, TR49, 50, and/or 51.
Transistors don't always fail as a totally dead short/open circuit.
Just usually.
73
Or does the carrier level stay the same no matter where VR13 is set?
If C190 fails open-circuit, this reduces the modulator's audio gain almost, but not quite to zero.
But that won't keep VR13 from setting the carrier power. Only affects audio.
And if VR13 won't adjust, you have a problem in D91, TR49, 50, and/or 51.
Transistors don't always fail as a totally dead short/open circuit.
Just usually.
73
Rock on!
Congratulations. Gotta love it when a plan comes together.
73
Congratulations. Gotta love it when a plan comes together.
73
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