Questions about Bob A IF Alignment Series on YouTube

[Chris K]

Originally Posted by dtvmcdonald

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.

I might try this if only for the exercise. My B&K 415 has a DC output