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Old 07-10-2023, 02:24 PM
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dtvmcdonald dtvmcdonald is offline
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Quote:
Originally Posted by Chris K View Post
I just watched the latest installment. Great stuff and very well instructed. I have a GE 805 "Locomotive" TV that I'm trying to align. Unfortunately, the instructions in the service data does not detail DC peaking with a VTVM and a signal generator. They show the sweep patterns to peak each slug to the correct shape of different traces they show. Can I use the method with the VTVM and just peak the coils or do I need to do it with the scope the way they instruct in the procedure and make little hills and valleys the right shape?

Thanks all.
Chris
Sure you can just use a voltmeter and a calibrated signal generator.
But no matter which version of the set you have, you need a bias
box (a 9v battery with a 5 or 10K pot across it) to set the bias voltage
at the junction of R241 and R243 to -4 volts. This is because the DC from the output otherwise backs up to there ... this does not matter at 60 Hz.

Use an analog meter between pins 2 and 3 of V8A.

Then you just sweep the generator slowly by hand to get the patterns shown. Tedious but it works.
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