8xp4 crt
 

Someone said in a post somewhere that while I could use a 8xp4 test tube in place of the 8dp4 for the RCA personal tv , the 8xp4 will get ion burns because it's not aluminized so what does that mean could the burns occur if the set is left on for long periods of time or short times. Would it really be worth the effort to use this tube, will it fit, will it perform well, does anyone know how the fit will be and the performance would be. :scratch2:

I have one of those RCA 8" personal portables and the 8DP4 tube is not aluminized either. The set uses an ion trap.

Did you try giving it a hit with a rejuvenator?
If it was never rejuvenated, it might turn out good. :thmbsp:
I never heard where there was an issue with an ion burn on a non-aluminized CRT vs an aluminized one.
The important thing was proper setting of the ion trap.

All the CRT's of the time, aluminized or not used ion traps.
The straight gun types, which became popular in the later 50's, 21CBP4 et al didn't need an ion trap. :scratch2:

Somewhere here there is a post and that's what was said that the 8xp4 test tube would work but would get burns if used in the RCA personal, but would work,IIRC.

Yes, I said that. Neither the 5AXP4 or 8XP4 test CRT are aluminized or use ion traps. They state in the original packaging that they are not intended for extended use. Just how long it will take for the burn to become noticeable I do not know.

I do know that I purchased mine used and they have burns.

I thought the 10FP4 and 12KP4 appeared around 1949?

Even earlier. The 1947 GE 802 used a 10FP4. Yes, they are straight gun and don't use ion traps.

It is curious they didn't go that rout with the test CRT's. Likely was a cost vs functionality decision, possibly even to keep techs from doing exactly what the OP is proposing. :)

Very likely cost. Look at how few early TVs used aluminzed CRTs. 10BP4 and 12LP4 were far, far more common. I'm curious what the price different was back then.

It's so much easier to setup an aluminized CRT. No need for a trap magnet or all the time fiddling around to get it positioned correctly.

Are you having trouble finding an 8DP4? I have a couple of those sets for parts, CRTs might be good, if you're not set on using an 8XP4 already.

just thought about having a good spare, the one in the set is good but didn't test as high as I would have liked it to.

I had only mentioned the 8XP4, as I seen it done. It was used in an Emerson 1232 TV/Radio combination. It was done by someone else.
I don't remember seeing an 8DP4 on any rebuilders price list, so possibly they had to be purchased new, for a much higher price. :sigh: