1948 Motorola VX101 brightness changes picture size

[old_tv_nut]

Originally Posted by Resonance1

... all the tubes are tested and good...

Lots of posts here say don't trust a tube tester to tell you if the high power / high voltage tubes are OK. I would try tube substitution first.

[Electronic M]

Originally Posted by old_tv_nut

Lots of posts here say don't trust a tube tester to tell you if the high power / high voltage tubes are OK. I would try tube substitution first.

+1 I should have said that too. I've had testers miss sweep and HV rect tube failures that substitution caught several times before.