I'm getting a SC500 4 tube hybrid!

[Jon A.]

Do you have a lot of electrical wires laying around? Try re-routing and bundling them, and unplugging any unnecessary ones. I've had electrical wiring cause weird intermittent problems that I spent weeks chasing. I moved one for an unrelated issue and presto, problem gone.

[zeno]

There may be 2 AGC controls but I just dont remember.
One is RF AGC or AGC delay. Its the one I mentioned & only
changes the RF gain.
The other is for IF gain, look for it. It may not have both.
The IF strip also has a C-2 adjust pot. Its basically a video
output level.
You can try that too but since the set worked OK for a while
I am leaning tward small 'lytics now.

73 Zeno
LFOD !