The curious "New" Chinese CRTs that use PC CRT tubes

[tongshadow]

Many people have been talking about these lately but no solid info or footage. I stumbled upon this video where said CRT is being tested, the channel has more videos about it too:
https://www.youtube.com/watch?v=oi65TeKuShg

It seems like it's using a 17" PC CRT tube, it look very sharp after and the dot-trio type mask can be seen.

https://i.imgur.com/MEV9eBc.jpeg

But the geometry is way off and knowing the quality of such brands there may be other issues. I doubt it's a gamechanger for any enthusiasts.

It is very interesting though how they managed to run a PC tube on a TV chassis, as poor as it may be...

[jd213]

If it's saving tubes from going to landfills, then that can only be a good thing.

Hopefully it's possible to improve on the chassis, or replace it with the open source one someday ( https://github.com/tdaede/td-crt ). Or maybe the tube would be good to use in another chassis.

I'd probably add one to my collection if it was available locally.

[gray117]

probably old tube new chassis + shell or something... someone probably worth a hipster punt.

I can't imagine anyone bothering to make new tubes...

[jd213]

Yeah, I believe RetroTech USA contacted someone in China (the RetroCastle guy, IIRC) and confirmed that these are used tubes, possibly some of them are from Japan since China gets a lot of their e-waste.

This video also mentioned the "new" CRTs being sold on Alibaba and shows off the new chassis being sold on Aliexpress:
https://www.youtube.com/watch?v=MoqflFfvkR0

[BazookaBen]

With the geometry issues, I wonder if I thing to do might be to find an actual PC monitor that used the tube, look up the service manual, check the schematic in the deflection section, then copy the capacitors it uses.

Of course the deflection circuit is probably so different between the two it wouldn't be that easy. Thought I'm sure if you knew how to do the math you could find a way to get them more electronically similar.

[fernan1234]

It would be interesting to see inside that Neta TV from the first link, in particular to see if there are any pots in there to adjust some of the geometry. I wouldn't expect to see more than what you find in a typical late consumer TV chassis but who knows.

I've seen someone in China who frankenstein'd one of these 17'' PC CRT dot mask tubes into a JVC TM-H1750 chassis and case, and the results appeared to be pretty good. What comes out of these kind of tube transplant will mainly come down to the quality of the chassis it's paired with. That's what makes the open source CRT chassis project very exciting, even though it probably still has a long way to go.

[tongshadow]

With the geometry issues, I wonder if I thing to do might be to find an actual PC monitor that used the tube, look up the service manual, check the schematic in the deflection section, then copy the capacitors it uses.

Of course the deflection circuit is probably so different between the two it wouldn't be that easy. Thought I'm sure if you knew how to do the math you could find a way to get them more electronically similar.

I'm fairly sure the horrible pincushion is due to the chassis being designed to drive a curved tube, so I dont think it's a matter of simple tweaks on the horizontal circuit. Also, the guy never managed to find a service menu to make it less worse. Chances are that the manufacturer could only make it look that "good".

It would be interesting to see inside that Neta TV from the first link, in particular to see if there are any pots in there to adjust some of the geometry. I wouldn't expect to see more than what you find in a typical late consumer TV chassis but who knows.

I've seen someone in China who frankenstein'd one of these 17'' PC CRT dot mask tubes into a JVC TM-H1750 chassis and case, and the results appeared to be pretty good. What comes out of these kind of tube transplant will mainly come down to the quality of the chassis it's paired with. That's what makes the open source CRT chassis project very exciting, even though it probably still has a long way to go.

Found a post on reddit showing the inside:
https://www.reddit.com/r/crtgaming/comm ... _crtits_a/

It's pretty funny, the label says it's a 21" consumer type tube, but it's actually a 17" monitor type lol

[BazookaBen]

Ugh, maybe you could brute-force the corners inwards with some magnets on the yoke.

But of course that opens up a whole 'nother bag of worms with convergence