RCA 21CT55 #8802897 is Dead

[Giulio Maiocco]

Hi everybody!

I'm sorry to hear about this mishap with the flyback transformer, I think it's one of the worst "oh no!" moments.

I don't know the color flybacks, but I rewound some B&W ones without problems, and from what I saw, they are less critical than one may be led to believe. I even rewound a couple that were wave-wound in a more conventional "layer" winding, these still work flawlessly. In my Bush TV22 I rewound both the primary (bad enamel on the magnet wire crumbling away, so I decided to fix it) and the EHT winding (this one was wave wound and covered in tar, but the acid in the tar corroded the copper). As a result the TV works very good, I'm 600-700 volts short on the EHT, unfortunately I ran out of wire while rewinding. Using a test pattern, I cannot detect image distortion or ringing, so I'm really happy with the results!

A question for John Folsom, if I may ask: what kind of substance do you use to keep together the winding when you pi-wind? Now I have a wave winding machine too and experimented with some shellac, it works, but it's quite slow to set.

Thanks

Giulio Maiocco

P.S.: Sorry about my so-so English...

[old_tv_nut]

Giulio, thanks for posting this information. Your work looks good - I know handling the fine wire is very difficult. Also, your English seems fine to me.

I wonder if you have an oscilloscope and high-voltage probe, and can check the shape of the flyback pulse?