It is amazing how many vintage CRT'S are still great!!

[tvcollector]

Nope, tube clearly stats 21CYP22A, and has the metal back over the base of the tube..

[Charlie]

I believe you will find that the metal in question is not part of that tube. I have never R&R'd a 21CYP, but it appears that is nothing more that what holds the CRT in place.

If I am not mistaken, you lay that set on it's face, remove the nuts and clips in the four corners, and that metal ring will come right out of there... and the glass CRT will remain until you lift it out.

The 21CYP22 in one of my CTC-9's was replaced during the mid-60's... it now has a 21FBP22 in there. That same metal "base" you mention is what holds my 21FBP in there.

[Eric H]

That is a metal shield, my CTC7 has that. the 21CYP is an all glass tube.

[sampson159]

i have a ctc 9 with a 21cyp22.it is an all glass tube.the metal cover you speak of is a shield and not part of the crt.if this was the case,you would have the only metal 21cyp22 in history.glad you got the set all in one piece.post pics of progress

[kramden66]

To this day i can't stand it when someone here or someone i know runs the tv for noise , i keep saying thats what a radio is for but it doesn't sink in.

as far as running a tv as long as i can remember the 61 or 62 era zenith 23" b&w console was run and run , either cartoons , movies , sports , that set was run until like 72 or so when it was replaced with a chromacolor II 19" hybrid , then that set was run and run , the 62 was then moved to a different room where in 85-87 era was tossed because the fly went but crt still strong , the chromeacolor was still going till 94 when it was tossed because it was given up on in 93 and a move to a new home , again crt still strong.
so it is possible that some sets were run even back in the day for as long as possible , this would explain the weak crt and multiple tubes in the set changed , a friend who was in the repair business said he saw more rca roundie crts go bad then zenith , perhaps the way they were made ?
the type of crt makes a difference ? both me and a friend found more 10bp4 crts to be good or useable compared to the 12lp4 crts , and 16gp4s are as bad as 12lp4s more bad then good so in the case of those tubes maybe it was just the design.

mike

[Charlie]

Originally Posted by Eric H

That is a metal shield, my CTC7 has that. the 21CYP is an all glass tube.

So then, this does not hold the CRT in place? Just curious... as I have not removed a CYP yet.

[DaveWM]

I have a test jig that uses that method of CRT retaining (metal shield), on my CTC-7 there was a metal ring with rubber feet that mounted mid way up the bell and was secured with 4 legs to the bezel. In my case the problem with using a FJP in lieu of a CYP was the anode button of a CYP is much closer to the face. The ring mount on my setup happened to be about 1" away from the anode, so you need a really good tight fitting HV cap to keep it from arcing.

[Eric H]

Originally Posted by Charlie

So then, this does not hold the CRT in place? Just curious... as I have not removed a CYP yet.

I think it does actually, can't remember for sure if it holds the CRT or is just there to shield it.

[tvcollector]

I wasn't aware of an actual tube made out of metal.. I thought metal back like this people were referring to this setup as a metal tube..

[Charlie]

Originally Posted by tvcollector

I wasn't aware of an actual tube made out of metal.. I thought metal back like this people were referring to this setup as a metal tube..

Yes, there are actual metal cone CRT's. The entire cone section is metal. Ya don't want to put your hands in there by it... it will HURT!

See here...

http://evilfurnaceman.tripod.com/id16.html

[tvcollector]

I've seen pictures of something like this before and thought maybe it was some kind of coat that's a metal color or something.. Never paid much mind to it...

[reeferman]

That is a metal shield held in place by 4 of the 8 bolts holding the CRT to the faceplate. Plain and simple.
Phil

[tvcollector]

Originally Posted by reeferman

That is a metal shield held in place by 4 of the 8 bolts holding the CRT to the faceplate. Plain and simple.
Phil

This has been already said... Thanks for the reminder...

[kx250rider]

I see plenty of excellent-emission CRTs from the 40s to the 90s. I think there could be some truth to the idea that lots of them are bad, in that people would keep repairing TVs until the tube went bad; then shove it in the garage or basement. But if someone just decided to upgrade to a bigger set, or a newer one because they were tech nuts or just wanted to spend $, the old set would be put in a back room and seldom (but SOMETIMES) fired up; keeping the tube good. How do I come up with this? : I seldom see a bad CRT in a TV with other major problems. I usually find the tube bad in a set which probably had a good working chassis 40 years ago, then the caps dried out since. If the flyback is shot, the CRT is usually fine....

Charles

[jr_tech]

If only these old TVs could talk! I bet that many would have interesting stories about how they survived. I always *try* to get the background story behind each set that I collect, but actually find very few with a known history.

jr