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Wei-Ya C31291A / samsung a68kvl74x02

Posted: April 3rd, 2019, 5:21 am
by Hackcell
Hi,

I have this OK Baby cabinet. It came with a samsung a68kvl74x02 tube. By checking online, this tube support trisync using a C31291A Chassis, which is in longer in production. Also, I read that some astro city cabinets were shipped with that tube, nevertheless it doesn't mention what kind of chassis... i can't picture a sega oem cabinet with a wei-ya chassis.

Having said that, does anybody know a suitable chassis for this tube, or anybody has a spare c3129ia and is willing to sell it? :)

Thanks!

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: April 3rd, 2019, 8:54 am
by grantspain
i thought ok baby had rodotron 288 chassis fitted, in any case you need to read the yoke impedance and inductance to get an accurate match

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: April 5th, 2019, 2:22 am
by Hackcell
grantspain wrote:
April 3rd, 2019, 8:54 am
i thought ok baby had rodotron 288 chassis fitted, in any case you need to read the yoke impedance and inductance to get an accurate match
V yellow/green returns between 7.8 and 7.9 ohm
H red/blue returns 1.1 and 1.4 ohm

Not sure how to measure the other thing.

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: April 5th, 2019, 9:40 am
by grantspain
you would need an inductance meter

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: April 5th, 2019, 5:05 pm
by Hackcell
I guess this should do the trick


Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: April 9th, 2019, 2:13 pm
by Asure
Uni-T 603 from Ali Express or Ebay or perhaps Amazon does the job as well. Or some cheaper ones like $25 models. Search for LCR meter to get more hits.. :awe:

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: May 12th, 2019, 8:09 am
by hexplus
Hi, I also have a Samsung a68kvl74x02.

Hackcell, did you find an alternative chassis for it? Thank you!

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: May 12th, 2019, 10:46 am
by Asure
Tube sticker says nothing about the yoke on the tube. You'll need an LCR meter to better measure the yoke values and find a chassis to match those.

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: May 14th, 2019, 1:05 pm
by mukurop
I Have a Samsung tube A68kvLX01 with a sanwa MP 1745c chassis, this tube - yoke works well with Nanao ms9 chassis and also have same ms9 Toshiba tube curvatur. On my yoke the horizontal inductance is 0.400mh

The A68kvlX02 shoud be the same but with bonded yoke. You need to test the yoke inductance to be sure.

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: May 14th, 2019, 4:10 pm
by PrincessPrinPrin
I think that's incorrect. A68KVL74X01 is a Samsung CRT for standard TVs (not 100Hz) and 15KHz arcade monitors. Accordingly, the line coil is well above 1.0mH. Here's a snapshot from an Intervideo manual:
A68KVL74X01.jpg
It wouldn't work with a MS9 chassis which requires a 0.300mH line coil. Also I'm pretty sure the curvature is the kind that matches a Naomi bezel for Sanwa 21E31S, a Blast City, Windy II but not an Astro City or an Egret II. I've found it in quite a few TVs and if they had been a perfect match for MS9 I would have kept them.

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: May 14th, 2019, 6:30 pm
by mukurop
As you can see it is a sanwa pm1745 15/24Kz the tube is Samsung and this yoke-tube setup work well with ms9 alhtough with some pcb you must play with H.limit to fill the screen horizontally.
Here some photos of the monitor.

The tube have the same curvature as nanao ms8/9 A68JUA68X and the yoke rvalues very close.

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: May 15th, 2019, 3:02 am
by PrincessPrinPrin
Yole swap is likely.

Re: Wei-Ya C31291A / samsung a68kvl74x02

Posted: May 16th, 2019, 3:50 pm
by mukurop
Nope this tube is labeled as 27Z21C Sega Enterprise assy.