Quote:
Originally Posted by mr_rye89
Well I feel dumb. I found another 3BU8 (agc keying/sync sep/noise limiter) in my tube stash and swapped it in and the picture is back. I woulda tried this earlier but I hate throwing tubes at a TV set.
The tube tested ok in my tester, but it was slow to get into the green zone  |
If you look at the pin-out of the tube in a tube manual, you'll see it's a rather unique design with a few common elements. I don't think it can be checked properly with a tube checker. Best is substitution.
IIRC, the circuit is a Zenith design, as they used it first.