CT-100 on eBay

[ChrisW6ATV]

Originally Posted by ohohyodafarted

RE: Beltron,

I just wanted to relate an experience I had with a 21cyp22. Upon testing it with a B&K 465 crt tester, the tube was devoid of all emission. I had very little hope of bringing the tube back to life...

IF this 15GP22 still has a good vacuum, and the tube has weak emission, it is very likely that it can be brought back to very good performance with the Beltron. When you get the chassis up and running, see if someone in your area has a Beltron that could come over and test and possibly clean or restore your tube. You will need to build a 20 pin to 14 pin adapter to use the Beltron 14 pin socket. It can't hurt and it will possibly restore the tube to a very good performance level. At the very least it will improve it.

Good Luck and keep us posted on your progress.

I appreciate the notes about the Beltron process. I have also heard that the newer B&Ks (467 which I have, and 470,480,490) and the Sencore CR70 are safe and (maybe) effective; the 467 has definitely worked well on the many B&W CRTs I have done. When I get that far, I will check around for anyone who has a Beltron here in the San Francisco area.

[Username1]

"
By the way, I have often wondered why RCA didn't try to do something to equalize the phosphor efficiencies in the 15GP22 (by reducing the green and blue efficiency with some sort of mixture of inactive material) in order to balance the gun currents better. There is probably some practical reason not to try it, but I don't know what that would be. "


This is an easy one to answer, Think of how contaminants will act over time and possibly really degrade the tube's performance. Also as the tube ages why degrade a color performance new, and then possibly have that gun weaken, and need to be turned up, you limit yourself. I think back then fighting short tube life was a concern always.