How Come Early CRTs contained more Ions? - Page 4 - Videokarma.org TV - Video

jhalphen · #46 02-19-2010, 05:48 AM

Good day Gentlemen,

2 pictures of a pre-war TV with severe ion burn. Since, the CRT has been rebuilt by RACS.

Photo credit: courtesy Eckhard, Thanks!

Best Regards

jhalphen
Paris/France

Tubejunke · #47 02-20-2010, 09:33 PM

Quote:

Originally Posted by bgadow

I have a 10BP4 that came out of my porthole; the screen has dark blotches without any real pattern; I'll have to dig it out someday and take a photo. That tube is entirely used up, with basically zero emission left.

To me, it sounds like this tube has 'gone to air' or lost its vacuum. Many times when this happens the white phosphur on the screen begins to peel or flake away. Naturally there will be zero emission.

bgadow · #48 02-20-2010, 10:40 PM

It would show an image, if I zapped it with a rejuvanator and viewed in a dark room. All used up.

Tubejunke · #49 02-20-2010, 10:58 PM

Hello Bryan, I didn't even realize who I was quoting until I saw this. I know I wasn't telling you anything that you don't already know! It's been a wonderful winter for electronics projects, but the money just isn't there... I wanna recap something SO bad!! LOL

bgadow · #50 02-21-2010, 09:55 PM

Been tight here...though time has been tighter than cash. Getting to be a long time since I have brought one back from the dead.

mattdavala · #51 02-21-2010, 11:44 PM

Quote:

Originally Posted by bgadow

Been tight here...though time has been tighter than cash. Getting to be a long time since I have brought one back from the dead.

Wow and I thought it was just me who was having a hard time finding funding for projects. Work is slow during the winter months. During my flight training I was told that flight instruction is the best part time job, and the worst full time job.

Maybe this summer I'll finally get a new project and become more active again in the Vk forums! I miss it sooo much.

See ya,
Matt Davala

Jeffhs · #52 02-22-2010, 11:36 AM

Quote:

Originally Posted by bgadow

It would show an image, if I zapped it with a rejuvanator and viewed in a dark room. All used up.

I didn't realize it was possible to completely "use up" the cathode in a television CRT unless the set was used 24 hours a day at nearly maximum brightness for years on end, and never shut off. I've heard of tubes with very low emission after years or decades of use, but this is the first time I've ever heard of one with absolutely zero cathode emission. The only other way this can happen, that I can think of anyway, is if someone tried to rejuvenate the tube and had the rejuvenator set so high it stripped the barium oxide coating right off the cathode.