1972 Zenith Hybrid

[davet753]

Originally Posted by JohnCT

Worked on a lot of those bad boys over the years.

Resist the urge to do a dynamic convergence if you can help it. The convergence coils run hot by design and the blue plastic bobbins turn to cracker over time. One turn with a hexaligner and the coil is unspooling itself across the floor as you chase it swearing up a storm. The wirewound pots are also prone to disintegrate when turned.

John

I saw quite a few come thru the shop when I first started, but they were reaching the end of their useful life. When the price of 20LF6's shot sky-high about 1989, these models were tossed pretty fast.

The blue convergence was off, but a slight turn of the blue thumbwheel adjustment on the convergence yoke brought it back in line. You're right about the convergence coils; I wouldn't want to chance one disintegrating trying to turn it. I had to adjust the vertical linearity, size, and centering...and I held my breath when turning those pots. Fortunately, this looks to be a pretty low-hours set, so it all worked out fine.

It's been close to 30 years since I've had one of these sets on the bench, and it was fun to get it back up to snuff again. I even remembered how to adjust the APC on the colorburst module (flip the switch and adjust for minimum movement of the color bars). Odd I can remember stuff like that from years ago, and I couldn't tell you what I did last week.