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question to the experts. Would it be possible to match a Sanwa 29E31S Chassis with a Nanao MS2930 tube if I use the convergence ring and yoke from the Sanwa?
 
I tried to use a 2930 chassis on a nanao 2932 tube and it works, also on nanao 2934 tube

but never tried sanwa on nanao
 
Would it be possible to match a Sanwa 29E31S Chassis with a Nanao MS2930 tube if I use the convergence ring and yoke from the Sanwa?
Yes, because the neck connectors are the same.

Have you ever swapped yokes before? Just saying that it's not easy at all to get right. Maybe practice with a junk TV set before. Take off the yoke rings, yoke and the rubber wedges holding it. Try to get it back to looking good.

Personally, I would suggest finding a MS2930-34 chassis for the tube.
 
I was under the impression that a 2932 has a different neck connector then a 30,31, and 34. Am I wrong here?
 
I was under the impression that a 2932 has a different neck connector then a 30,31, and 34. Am I wrong here?
Same neck connector. The tube has a different curvature though, so with the wrong chassis is might look off in the corners.
 
Very nice site for checking tube spec. Simply type in number on tube Id sticker shows you all most important info easily. Not curvature but screen volts connector type etc http://tubular.atomized.org
 
Yes, but sometimes you can run into issues with tube number/connector type. The tube used with the 2932 is the same tube used in I believe a NAC, but the connector on the neck is totally different.
 
Yes, but sometimes you can run into issues with tube number/connector type. The tube used with the 2932 is the same tube used in I believe a NAC, but the connector on the neck is totally different.
Do you have pics of this by chance? I've never heard of this and it doesn't make sense to me. Tube will have to follow standard pinout especially on exact same model. Your claim is: company making the tube decide part way through manufacturing to rearrange neck pinout to accommodate one of many completely different non related 3rd party chassis manufacture? Seems not accurate no?
 
thank you for all the great information.
I have this Nanao 2930 Tube with a 2930 chassis. Somehow there was a grounding issue and I got some high voltage arching in the neckboard area. After that the monitor was dead, no neckglow, nothing. Then I got a 2931 chassis but I am not sure if it works. There I get little sparcs in the tube and possibly the yoke. So I don't know if the tube is toast or just the chassis or even the yoke. Now I have the option to get a Sanwa tube with chassis that was necked.

I have already removed the yoke from the 2930, so that went well. Is there a way to check if the yoke is still in ok shape, now that I have removed it from the tube?
 
Yes, but sometimes you can run into issues with tube number/connector type. The tube used with the 2932 is the same tube used in I believe a NAC, but the connector on the neck is totally different.
Do you have pics of this by chance? I've never heard of this and it doesn't make sense to me. Tube will have to follow standard pinout especially on exact same model. Your claim is: company making the tube decide part way through manufacturing to rearrange neck pinout to accommodate one of many completely different non related 3rd party chassis manufacture? Seems not accurate no?
What I'm saying is that a 2932 chassis from certain Naomi setups comes with a a68kju96x and @djsheep said that tube is in both of his Astros. If the same tube is in both cabs and they use different chassis, they must have a different pin layout no? If they had the same pins on the neck everyone would be converting NUCs over to 15k using Astro ms9s.
 
In this case the tubes would in fact be interchage. You could easily use one for other. Here is very important part; tube manufacture are different from chassis manufacture. That tube maybe used in tv set, maybe used in arcade, maybe elsewhere. But tube itself will not change if EXACT model number (sticker direct on tube). keep in mind that tube model will have different model within it as you see here. Not sure what each model within is exactly but all will be electrically function the same as all will follow same kneck pin. In this case CR-23. So pin 9-10 heater, pin 8 red cathode, pin 11 blue cathode, pin 6 green cathode, pin 7 G2, Pin 1 focus, pin 5 G1.
A68KJU96X (4F) - Astro City (MS8 chassis, so not fully compatible...)
A68KJU96X (6B) - New Astro City (MS9 chassis)
A68KJU96X (6C) - Egret 2 (MS9 chassis)
A68KJU96X (6E) - Egret 2 (MS9 chassis)
A68KJU96X (7C) - Windy (PB6643-1 chassis)
A68KJU96X (7D) - Windy (chassis tbc...)
A68KJU96X (7F) - Egret 2 (MS9 chassis)
A68KJU96X (7I) - unknown (MS9 connections)

This expand on that idea now. Here is also very important part; yoke and chassis are pair together from other random company...not necesarily tube and chassis paired. example nanao get bare tube from hitachi and have to create chassis and yoke that match. That is how you get many compatible tube with one set chassis and yoke (assuming correct size, correct heater voltage, correct g1 voltage, and correct neck connnector). In massive number of arcade mon tubes you will be either CR-23 or CR-31 neck connector. very standard. grab 100 arcade tubes and you will get almost all of them that. They will follow pinout throughout other same series say CR-23 tubes. It very very common to see 6.3v heater, 50v, cr-23 to use a tube. You have to know these number when connect tube test machine check emmision. So you get screen same size aka "a63" 25inch, "a68" 27inch, (Axx = cm view area first numbers of tube) and you will be able to use chassis at least from electrical point view. When you run into flat screen crt, weird curve, viewable line, etc you will have convergence geometry issue as well... not chassis problem as far as it know. You can easily pull yoke off tube (while still hoooked to chassis) and chassis still run exact same it see no difference. in fact you can pull yoke off while running and see yourself. Tube still does it's thing. Still electron gun firing, still heater etc because it follow standard pinout and kneckboard still provide those values, only deflection will be crazy off. Don't do that though because you will burn phosphur at tube face since you have no deflection. It'll just fire straight dot and light one small very center area that will burn. Some of that make sense?


Here is CR-23 diagram that all CR-23 tube need to follow (or else they wouldn't be CR-23)
qtANjiL.jpg



Here is real world example with written on kneckboard location each (this from WG D9200)
eBu2e7E.jpg




Hopefully that's all correct for you, maybe little mistakes in there but gist is there.
 
I have this Nanao 2930 Tube with a 2930 chassis. Somehow there was a grounding issue and I got some high voltage arching in the neckboard area. After that the monitor was dead, no neckglow, nothing. Then I got a 2931 chassis but I am not sure if it works. There I get little sparcs in the tube and possibly the yoke. So I don't know if the tube is toast or just the chassis or even the yoke.
Funny story, a similar thing happened to me. I had a perfectly working, nice looking MS2930. I bought a replacement MS2931 chassis from Yaton. I thought I might as well test the thing. I connected the chassis to the tube, double checked everything, turned it on and saw a spark near the yoke, inside the tube. Turned it off instantly. Didn't think much of it, thought that the chassis is faulty. Connected the original working chassis back, turned it on, and surprise, no picture. There's some sparking in the neck. Connected the tube to a B+K CRT analyzer. Analyzer gives absolutely zero readings on the guns.

Tube is dead.

It's likely yours is too.

Also, great post @brad808! You went in to it in waay more detail than I would have!
 
Thanks for sharing that story. I also think the tube is dead.

Only option I have lying around is a Hantarex Polo 2 but that is an 28". So I have to build some custom brackets to mount it. This way I can at least use the cab until I find a replacement tube or monitor.
 
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