Unusual CRTs: 5JP4 and others
 

I was at a place that sells used electronic junk today that I go to often, they have a big yard full of all kinds of stuff. There is a falling down shack in one corner with a bunch of old round CRTs in it. I had checked it out years ago, and all I found were mostly P1 and P7 tubes, and not a single white phosphor tube, there's about 20 to 30 of them and they range from 3-12". I wasn't really interested in any of those and hadn't looked back there since. Well part of the shack collapsed and revealed some more tubes, I found 1 P4 tube, this 5JP4 which appears to be an electrostatic tube with the connections for the deflecting plates on the side of the neck, instead of at the base. It has long ago gone to air, so I don't think it could be of any use, but I brought it home, just because I was curious if anyone had ever seen a set that used one of these.

Apex???

Charles

That's it, I've never found an old set there, but it seems like the kind of place where there might be a good one someday. That and I just like walking around and looking at all the wierd stuff they got there.

There were a couple of 630-style chasses outside, across from that row of coffee vending machines. They were all rusty and missing tubes, so worthless. But at least it was hope! I haven't been out back there for a couple years, so they may be long gone. Also they had a fairly decent RCA TV camera film broadcast chain. Too big, would take up a whole room!

Charles

You said 3 to 12 inch round?
The 9AP4 and 12AP4s in early TVs have not been rebuildable yet and I had found 9 and 12 inch round radar CRTs that could be rebuilt and used as
the 9 and 12AP4s. So are any 9 or 12s Mag deflection and about a 40 degree
deflection angle?
Even the 7DP4s used in RCA 621s, I had found a AIR FORCE CRT with a P4 that could replace them at Fair Radio surplus. There was no clue in the Air Force number that it was a P4.
Might be gold in that pile?????
Can you get any numbers from the tubes???

5JP4, different with plates on the neck but very early CRTs had it that way and with a anode lead it should have a brighter screen than the 5BP4s.

Dennis Choinski See Steves ETF site

ADAM you never PM back about the 730 chassis so I found another one?????

I'd really like to go with you next time you go to this place, Adam. It sounds like an interesting place to look at.

David

dtuomi - Just send me a PM sometime you want to go, it's only few miles from here, and I'm free on the weekends and most Fridays, and I still got your portacolor tubes.

prewtv- Now that I know there's some interest in these, I'll take down the numbers next time I'm there and post them here. I still got that chassis, basically it got stuck in the back of a friend's car the whole time I was out of town, late Aug - early Oct. and the box got beat up a bit, so I would have to re-pack it if you still want it, but if you don't that's fine with me too, it saves me the trouble of packing it again, and I also already dug up the 10BP4 I was looking for.

Ever go back yet? Never know what you will find.

Just found a new in the box 21AXP22 for someone at a place like this.