Got another Galaxy Saturn on the desk today. Someone stamped the sale date on the inside heat shield. Sell date was July of 1996.
Issue:
Low transmit power.
Evaluation:
Tested finals, driver, pre-driver, af regulator, Passthrough regulator, solder joints. All check out good, except for the last coil past the final which had come loose from the board. Resoldered and still same low output.
Checked each stage with my oscope.
Mixer shows good signal on output.
Pre-driver shows good signal.
Driver shows good signal.
Each final shows good signal.
Each stage shows amplification from the previous stage. Collector voltages are correct, base Ma is correct. Just low output.
Story is, a local just purchased it out of storage from a couple years, hooked it up and talked on it about a month or so until the power slowly dropped to 7w swing max in any mode.
After thinking it over, I thought about the output caps. I yanked both and tested each.
The 560pf tests as 325pf and not stable, changes each time I check it.
The 820pf tests as 796pf and is stable, doesn't change each time I check it.
Guess the 560pf shot it's wad....
Issue:
Low transmit power.
Evaluation:
Tested finals, driver, pre-driver, af regulator, Passthrough regulator, solder joints. All check out good, except for the last coil past the final which had come loose from the board. Resoldered and still same low output.
Checked each stage with my oscope.
Mixer shows good signal on output.
Pre-driver shows good signal.
Driver shows good signal.
Each final shows good signal.
Each stage shows amplification from the previous stage. Collector voltages are correct, base Ma is correct. Just low output.
Story is, a local just purchased it out of storage from a couple years, hooked it up and talked on it about a month or so until the power slowly dropped to 7w swing max in any mode.
After thinking it over, I thought about the output caps. I yanked both and tested each.
The 560pf tests as 325pf and not stable, changes each time I check it.
The 820pf tests as 796pf and is stable, doesn't change each time I check it.
Guess the 560pf shot it's wad....