View Full Version : Rauland 12KP4 Aluminized CRT


cbenham
03-31-2011, 08:53 AM
There is a Rauland 12KP4 listed under item # 250796759073 at $145.00

The seller doesn't have a CRT test device but says the filament has continuity.

If it's in good condition, this CRT would be a brighter replacement for a 12LP4
in your old B&W roundie.
Disclaimer: It ain't mine, And I have no interest in it's sale.

Cliff

charokeeroad
03-31-2011, 12:53 PM
There is a Rauland 12KP4 listed under item # 250796759073 at $145.00

The seller doesn't have a CRT test device but says the filament has continuity.

If it's in good condition, this CRT would be a brighter replacement for a 12LP4
in your old B&W roundie.
Disclaimer: It ain't mine, And I have no interest in it's sale.

Cliff

If I really needed it I'd pay that much but got a couple spairs so I good for now. Thanks

Eric H
03-31-2011, 07:46 PM
He is offering a full refund if it's bad.

I picked up an excellent 12KP4 locally for $75, they make a superb picture and need no ion trap so they are an great replacement for the 12JP4 used in Dumonts and Andrea's and such.

mbates14
04-04-2011, 09:27 PM
hows that CRT holding up you got from me, cliff?

cbenham
04-05-2011, 12:40 AM
hows that CRT holding up you got from me, cliff?

It's the one with Superman on it in the Col-R-Tel on my Avatar!

Thanks again Mike...

Cliff

charokeeroad
04-05-2011, 05:09 PM
Does anyone know if a 12KP4 can be use in place of a 12UP4?

ohohyodafarted
04-05-2011, 05:54 PM
If you are puting it in a zenith porthole circa 1950, you will have to modify the chassis. There are some components toward the front of the chassis that need to be moved because the glass crt is wider than the 12UP4, and some of the components on the chassis will not allow enough room for the glass crt to fit. But it can be done, if you are willing to hack up your chassis. Otherwise you can wait around and pay the going price for a good 12UP4. They come up on ebay once in a while.

I paid over $200 for a good, EXTREMELY RARE 16EP4 several months back, and I would have paid even much more. As the saying goes, "if you wanna play you gotta pay".

charokeeroad
04-05-2011, 06:47 PM
If you are puting it in a zenith porthole circa 1950, you will have to modify the chassis. There are some components toward the front of the chassis that need to be moved because the glass crt is wider than the 12UP4, and some of the components on the chassis will not allow enough room for the glass crt to fit. But it can be done, if you are willing to hack up your chassis. Otherwise you can wait around and pay the going price for a good 12UP4. They come up on ebay once in a while.

I paid over $200 for a good, EXTREMELY RARE 16EP4 several months back, and I would have paid even much more. As the saying goes, "if you wanna play you gotta pay".

I contacted the seller and he says the CRT (12UP4) is good. ...Pheeuuuu!
I wouldn't want to go through all that.

jeyurkon
04-09-2011, 02:22 PM
I'm the one that bought the 12KP4 and it arrived yesterday.

I have an increased hatred of foam peanuts. I looked like the Stay Puft marshmallow man in Ghostbusters after unpacking it. Even though we had 100% humidity they were flying to me and sticking.

The emission tests good and there are no shorts. However, the G1 cutoff is low. I have four different CRT testers (not sure why I did that) and the emission shows good on all of them. The B&K465 is the least fussy about the cutoff, but it shows it being just below acceptable. The others treat it as obviously bad. It actually measures -22v and the the minimum acceptable is -27v.

I think it should actually work, but the contrast might be too high because of the low cutoff. Or it might show the hollow cathode effect.

I'll have to pop it into a set and see how it looks. It might be fine. If not it'll be a candidate for rebuilding if that becomes possible again.

I hope to try building a color wheel someday and that's why I picked it up.

John