Stubborn yoke removal
 

I'm trying to pull the 10BP4 out of an Admiral 20X1 chassis and I can't get the yoke past the CRT base :worried: The ion trap and focus coil were easy, but I swear the yoke must have shrunk with age!

It's tight but does just slide over the glass neck. I tried putting a little tape over the base thinking it was getting hung up on the plastic lip of the socket, but that didn't help.

If I can't get it off, I'll just work around it. I've no desired to force it and break something! I was really hoping to try out my 5AXP4 for the 1st time though.

Any suggestions?

I read in a old TV book to use Vaseline .
I had a hard time with a ion trap on a 10BP4 , same thing , it got to the CRT plug and that was about it .
I wa able to carefully spring the edges of the ion trap up and get it started over the plug .

By the looks of things it would probably not be possible to leave the yoke on the CRT either , unless you took the whole mounting base off the chassis .

Best of luck with it .

I'm working on it. I've been thinking about it while at work this morning........

Vaseline is a possibility. I suppose I could unsolder the base too, but that sounds really unpleasant.

This looks like a replacement CRT which makes me wonder how they managed. Of course, that was probably 50+ years ago.

I thought of unsoldering it too, it would be better than forcing it which we all know what happens when we do that. Like a good friend taught me, if you unsolder the socket or ever have to replace it, tack some wires onto the end of the leads with solder so you can pull them through the pins without worry of losing one or putting it in the wrong pin. Another fellow added by saying that each wire be longer than the last so they all will go straight in one at a time. Super glue the base when reinstalled.

Seized Yoke Removal
 

Hi,

Ages ago, I read in an old trade publication that applying a low voltage to the yoke would cause it to release.

Just enough to gently warm it. It worked for me at the time and neither the yoke or the CRT suffered any ill effects.

Darned if I can remember the voltage and at what amperage. Sorry !

Best Of Luck !

Bob Hodge

I wonder if it could be warmed with a hair dryer?

Sounds like a good idea . :scratch2:

The hair dryer did the trick! You guys rock :banana:

Here it is stuck.

http://www.bobandersen.com/images/20X122/yoke-1.jpg

About a minute under the hair dryer softened up the waxy inner surface of the yoke. It's not really all that hot - I'm holding it in my bare hand!

http://www.bobandersen.com/images/20X122/yoke-2.jpg

Now I can see that he rubber mounts have disintegrated. This is proving to be an interesting set to restore. The more I poke around, the more things I find to fix. I've never encountered so many bad resistors and caps before.

http://www.bobandersen.com/images/20X122/yoke-3.jpg

The set will be much easier (and safer) to work on now :)

http://www.bobandersen.com/images/20X122/yoke-4.jpg

The CRT only tests fair, but that's OK - I have a spare.

http://www.bobandersen.com/images/20X122/yoke-5.jpg

Thanks again for the tips.

Bob