Hi all,
Got another 2980 on the desk. Everything works great on this radio with only 1 issue.
Rf power knob all the way up works great, it's when you roll it counter clockwise that's the issue. It will key 7 watts all the way up, but it will only drop to 5 watts all the way down.
Adjusting the low power VR (801) on the switchboard will only drop to 5 watts (goes up fine). The Hi power vr I have set to 5.45v (7 watts).
I removed TR801 off the switchboard and tested it in the tester. Shows fine with a good hfe. Removed VR801 and tested, it shows 2.93k ohms.
R238 had a 47k ohm (yellow, purple, orange) in its spot. I removed it and installed a 5.6k ohm.
There was also a 1n4148 diode shunted across the center pin of the 2sb754 passthrough regulator to another spot. I removed that diode.
Tr32 was removed. Replaced with another 945.
No other mods that I can see. Everything else looks stock.
What could be causing lo power to not go lower than 5 watts?
Thank you in advance.
Got another 2980 on the desk. Everything works great on this radio with only 1 issue.
Rf power knob all the way up works great, it's when you roll it counter clockwise that's the issue. It will key 7 watts all the way up, but it will only drop to 5 watts all the way down.
Adjusting the low power VR (801) on the switchboard will only drop to 5 watts (goes up fine). The Hi power vr I have set to 5.45v (7 watts).
I removed TR801 off the switchboard and tested it in the tester. Shows fine with a good hfe. Removed VR801 and tested, it shows 2.93k ohms.
R238 had a 47k ohm (yellow, purple, orange) in its spot. I removed it and installed a 5.6k ohm.
There was also a 1n4148 diode shunted across the center pin of the 2sb754 passthrough regulator to another spot. I removed that diode.
Tr32 was removed. Replaced with another 945.
No other mods that I can see. Everything else looks stock.
What could be causing lo power to not go lower than 5 watts?
Thank you in advance.
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