Quote:
Originally Posted by Kevin Kuehn
Although that seems backwards it may actually be normal for these early RCA sets. There's a note on my 621 schematic saying counterclockwise is full brightness, but I don't see a similar note on the 721 schematic. In any event are you getting a raster now?
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Full clockwise is full brightness on this set. I haven't tried the set with the CRT hooked up for a bit but before I started messing with changes to the wiring to get sound from the speaker (successful) resulting in the voltage issues with the CRT, I did have a good picture using my pattern generator so there's no question the TV works. Unfortunately, the CRT on the 721 is not strapped to the chassis. It is fixed in place only when it is in the cabinet held by 4 brackets mounted on the inside of the cabinet front. It's almost impossible and downright dangerous to work under the chassis with the CRT in place. I've searched for the 5" technician CRT created for this and other TV s of the era with the same issue but I haven't come across any as of yet. Even if one became available, I've already spent a significant amount of money on this thing (just purchased $100 of cloth wiring in original colors to replace all of the crumbling wires in the set!) and my wife is justifiably concerned with the cash that's going to Digikey, Mouser, Tubedepot, Amazon etc in service of restoring this TV. My goal is to take the time over the course of the rest of the year to completely restore this TV to 100% factory fresh. The CRT tests good and they are readily available should I run this one into the ground! I even have a NOS, backup transformer I intend to install! But for now, a good picture with sound is goal #1!