CTC-5 with Wounded 21AXP22
 

I located a CTC-5 with a wounded 21AXP22 CRT. Looking for feedback on the likelihood of the CRT being any good. Does it look like the CRT has gone to air? Can it be fixed? Is the brown material around the plastic socket rust or ? Any and all feedback is much appreciated. I do not want to purchase this TV if the odds are high the CRT is toast.

Looks like the end cap is a little broken up, that's all. You have a tester?

Thanks for the feedback. I do have a tester and would use it if I could to confirm CRT health, but this is a long distance purchase and the sellers are clueless and close to pulling the chassis and converting the cabinet into a mini-bar!

Looks like adhesive from the cap that didn't come off when the base was damaged. The getter I can see however looks to indicate it's still under vacuum.

That brown stuff is *not* rust, it is the old formulation of base cap cement used for decades in the tube-building industry. This old thread suggests many repair substitutes as well as giving the formula for the old cement :
http://www.videokarma.org/showthread.php?t=261452


jr

I had one with a tube like that...busted base and the tube tested like NEW on all guns...emissions, life and cutoff.

I also have Another round tube in the same shape base-wise and also very good otherwise. It is waiting on pickup from another member at this time.

So..a busted base does NOT mean a bad tube. that CTC -4 I had had a tube with a perfect base....but it had gone to air anyway.

What you need to look for is behind the convergence assy and yoke. If there is a way you can get this guy to remove it and get a picture of the neck, in front of the yoke...there is a "peak a boo slot" that should NOT be white in ANY way. If it IS--(as mine was a bit) the tube has gone to air. It it is silverish or brownish--the tube might be ok air-wise.

Others here might be able to speak better of this situation than me..

Another concern with a base that has taken a hit like that is *broken wires*.... in many cases they can be repaired, but if broken off *flush* with the glass nub, repair can be very difficult.

jr

Here's a photo of the peekaboo slot in my dead 21AXP22:

http://antiqueradio.org/art/RCACTC-4CRTGetter.jpg

The white area is getter material that changed color after the tube leaked and let air inside.

With a little adaptation, it's possible to substitute a newer all-glass CRT for the 21AXP22. That's what I did with my CTC-4.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Looking again at the base of your tube...it does NOT appear to have gone to air.I see what looks to be getter at the base of the glass. if it was air...that would be white or clear.

That's not Getter material in the base, I believe it's residue from the heaters, often seen in high hours tubes.
The Getter in a 21AXP is in the neck as seen in Phil's photo.

On a good day the chances of a 21AXP not having gone to air seems to be about 50/50, one that's been abused and badly stored is even less likely to be good.