AC In My B-

[dtvmcdonald]

I have a Pilot TV-37. Its got stray 60 Hz everywhere. I've verified that its there even if there is no B+ or B- because the rectifiers AC feeds are disconnected (but heaters are connected). Thus its heater line pickup. In most cases I verified that its not heater-cathode problems by moving tubes of the same type around.

I've also verified that a lot of the problem is modulation
of the RF in the tuner.

I managed to get OK pictures by careful adjustments. Its vitally important to get
the RF level in a good range: if the gain is too high or low it gets worse.
Thus, I need an external attenuator.

You can't really win. The set was designed for pictures that had a constant
average gray, and a constant contrast, no black or white screens. Give it such
a program, and its much happier!