Sometimes miracles DO happen! - Videokarma.org TV - Video

Zenith26kc20 · #1 08-24-2011, 12:55 PM

Saw this 12lp4 on our favorite auction sight and couldn't resist since my Admiral's 12 inch went to air (my fault, I pulled the base off of the poor thing when struggling with a stuck yoke) It had the copper pinch seal and I guess I damaged it. I bid and won the tube. It arrived about an hour ago in a box big enough for a 19 inch tube. It had the yoke (stuck like my Admiral), the focus coil and the double ion trap. As the Beltron shows, after about two minutes of being on, IT'S GOOD

Getters are nearly clear but it's good!!! Sorry for the poor focus but the flash would wash out the filament. I hate to destroy the yoke but a won't chance killing another tube. I'll try to disassemble it so it can be used for parts.

wa2ise · #2 08-24-2011, 03:13 PM

Quote:

Originally Posted by Zenith26kc20

I hate to destroy the yoke but a won't chance killing another tube. I'll try to disassemble it so it can be used for parts.

It's a long shot, but maybe that yoke is good and compatable with the Admiiral chassis. Compare the resistance readings to see if it's in the ballpark. If it looks good, then you could try it on the set.

Zenith26kc20 · #3 08-24-2011, 03:26 PM

I thought of that after I posted the thread. I tried a RAM MD-3 but it rang badly. The proper yoke is a DY-1. I don't know what Motorola yoke this crosses to. The yoke on it appears to have the damping network the Ram didn't. The network appears to be correct. I'll find out if I can get home early enough tonight.

***Eric H*** · #4 08-24-2011, 04:28 PM

A little heat should free up the yoke, warm it up with a heat gun or hair dryer.
You can also heat it by applying some juice to the windings but I'm not sure what voltage you need to use.

Electronic M · #5 08-24-2011, 04:36 PM

I believe that one should use a variac for that.

M3-SRT8 · #6 08-28-2011, 12:47 PM

I would clean up the exterior of that CRT and redag it.

Dude111 · #7 08-29-2011, 07:15 PM

Yes it looks definetly worth the time!!

Zenith26kc20 · #8 08-30-2011, 08:26 AM

Well, the yoke would not clear the socket no matter what. I carefully took it apart (about two hours of work) and saved the coils for replacements. I couldn't get the yoke while on the tube in the chassis because it is installed from the rear and the tube from the front.
Anyway, it works again! I still have to find out why the focus is at the end of the range (either too much or too little current thru the focus coil). The picture is clear and bright. The tube woke up faster than I ever expected. Pictures tomorrow!

zenith2134 · #9 08-31-2011, 07:48 PM

Has it been tested for gas, since the gettering is largely removed.