I have an older nice and clean DX 667V with Toshiba's and no output, but everything else seemingly "works" as it should otherwise. I followed some of the steps here in this other thread and got as far as I could in a short amount of time;
https://www.worldwidedx.com/threads/repairing-a-texas-star-667.164712/
Observations:
- Receive preamp works without issue, yay!!!! The one thing I don't care about works like a charm lol!!!!
- When radio keyed the relay engages, and bulb behind the meter works
- SSB Delay engages like normal when the button is engaged and when I key up on SSB and talk into the mic it acts like it should.
- SWR and power output with the amp off/bypass is fine (currently 2w deadkey) but when the amp engaged, power output drops to about 1/8 to 1/4 watt with Dial A Watt not engaged, and with it engaged, power is about half, as one would expect the circuit to do, putting out around an 1/8 of a watt, and when I turn the variable with D-A-W engaged and off, it affects the output as expected and with smooth taper, so don't "think" the pot is fried.
- Per the transistor testing in that thread, I have proper B+ on all 5 transistors, but some leakage of 0.21 (less than a 1/4 of a volt) on the front two 2879's and the 2290 driver, but show 0.0 on the back two, so wouldn't consider it true leakage, but since all 3 of the front ones have the same exact leakage amount, I would think its from whatever the issue is more than the transistors being the issue?
- I didn't get to the point of floating the transistors as stated further on since I didn't have the time and not actually sure if I had to if they had proper B+ voltage in the previous step.
- In one of the other steps it advises to to to test the relay by shorting the resistor behind the relay to ground, and all other testing it seems OK, and of course relay engages as it should when I did this step.
Again its super clean inside, nothing obviously burnt or smell. Any suggestions where to go next?
Gut shots attached, thank you for any help you can share, hopefully one day through the help I receive here I can be as helpful as some of you guys, pretty green on this amp stuff!
Thanks, Skiman1
https://www.worldwidedx.com/threads/repairing-a-texas-star-667.164712/
Observations:
- Receive preamp works without issue, yay!!!! The one thing I don't care about works like a charm lol!!!!
- When radio keyed the relay engages, and bulb behind the meter works
- SSB Delay engages like normal when the button is engaged and when I key up on SSB and talk into the mic it acts like it should.
- SWR and power output with the amp off/bypass is fine (currently 2w deadkey) but when the amp engaged, power output drops to about 1/8 to 1/4 watt with Dial A Watt not engaged, and with it engaged, power is about half, as one would expect the circuit to do, putting out around an 1/8 of a watt, and when I turn the variable with D-A-W engaged and off, it affects the output as expected and with smooth taper, so don't "think" the pot is fried.
- Per the transistor testing in that thread, I have proper B+ on all 5 transistors, but some leakage of 0.21 (less than a 1/4 of a volt) on the front two 2879's and the 2290 driver, but show 0.0 on the back two, so wouldn't consider it true leakage, but since all 3 of the front ones have the same exact leakage amount, I would think its from whatever the issue is more than the transistors being the issue?
- I didn't get to the point of floating the transistors as stated further on since I didn't have the time and not actually sure if I had to if they had proper B+ voltage in the previous step.
- In one of the other steps it advises to to to test the relay by shorting the resistor behind the relay to ground, and all other testing it seems OK, and of course relay engages as it should when I did this step.
Again its super clean inside, nothing obviously burnt or smell. Any suggestions where to go next?
Gut shots attached, thank you for any help you can share, hopefully one day through the help I receive here I can be as helpful as some of you guys, pretty green on this amp stuff!
Thanks, Skiman1
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