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A general thread for uncommon monitors. Common monitors should probably get their own threads, like this

Alright School Me Please - Nanao MS2930/31/33 Tube Swap

Anyway, we're heading into the twilight years of finding CRT tubes out in the wild. I've been monitoring the local craigslist for CRT TVs for years, and pickings have gone slimmer every year. Now's the time to act if you still want a burn free tube for your arcade cab.

Today's project is a Hantarex Polo 25" (59cm) 25kHz monitor out of a Sega Rally upright. Here it is:

01.jpg
03.jpg

Sega Rally has a pretty terrible attract screen for burn in. They really didn't think that one through. You have a credit text and counter, the manufacturer and date, and a high score board that's like 50% of the time visible on the screen. A linked cab will mix it up with a '2 Player Racing' text. Inevitably after years of operation the tube will look like this:

05.jpg

Yikes.

The original Hantarex tube is a Philips A59EAK552X44. From what I've understood Philips tubes are paired with their yokes. You can't put a Philips yoke on another brand of tube and you can't put another brand of yoke on a Philips tube. So I need a Philips tube. Measuring the original yoke with the BSIDE ESR02 Pro I get 0.37mH for the horizontal and 6.06mH for the vertical. Cross referencing that with the deflection yoke data on consumer TV's found here I can see there's a TV set (A59ESF002X42) that could work (although the horizontal is 15% off), but I bet the chance of finding one will be slim to none. So instead I'm going to look for a compatible tube and swap the yoke. Notice how there is no yoke ring set on these. I think there's a single ring on these that has been permanently magnetized with all the necessary corrections. That means if purity and and static convergence are off with the donor tube, there's no way to fix it.

Here are our candidates for the tube swap:

04.jpg


Philips TVs will (always?) have a Philips tube inside of them, but the Samsung was a lucky discovery. Samsung also make their own tubes, but inside this Samsung CX-5937AN was a Philips A59EAK71X01 tube. I will henceforth refer to these tubes as Samsung (left) and Philips (right).

Eyeballing the Samsung tube it was a perfect match. Exact same size and curvature, and the yoke looked exactly the same (only looked, the horizontal inductance was way off). The model numbers are different, but I'm going to put that down to manufacturing date, the factory it was built in and the different yoke. This bodes well. Here are the two tubes stripped:

06.jpg

I plunked the original yoke from the Hantarex on the 'Samsung' tube. Original dag wire and degauss coil were also swapped. It's just way easier than putting new connectors on the 'Samsung' ones. Connected the tube to the chassis and the whole shebang to the cab. Turned on the cab and

07.jpg


it looks great! I didn't even need to mess with the picture controls at all! I was expecting the geometry to be off, but it's absolutely fine. I had my doubts, but it's a complete success.
 

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Inspired by this, surely the other tube could work as well? The Philips TV (25PT5321) has a slightly newer tube (A59ESF002X11). The size and curvature are again exactly the same. The dog ears are at the correct depth. However, it is slightly different looking (notice the wider metal band) and the yoke is different. Similar, but different. Both tubes stripped with their yokes:

09.jpg

Original Hantarex yoke was dropped on the Philips tube. Again, I wanted to keep the original dag wire and degauss coil. This created a problem because the Philips tube is missing the horizontal slits on the metal band for mounting these. I reused the plastic hooks found inside the TV for the degauss coil. They go over the dog ears and hold the coil in place. As for the dag wire, I drilled a small hole in the metal band for the spring:

10.jpg

Probably not what they teach you to do in TV repair school. Anyway, that's those sorted. Now for testing! Connected everything up and turned it on. Fingers crossed and

11.jpg


uh oh. Huge purity issues. No amount of degaussing will make these go away.

Oh well, at least one success story out of these two. So for Philips yokes that have a single yoke ring, if you have an exact tube match the likelyhood of success is good. If you don't, it probably won't work.
 

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This one is for @nassekova. A Hantarex Polo 28" out of my Baldazzi Styl Art Capcom Q Sound cabinet ("Euro Big Blue").

Here it is:

hantarex_28_1.jpg


Tube is a Videocolor A66ECY13X01. The tube isn't actually all that bad. Good colors, good focus, just some minor burn in. I'm going to keep this as a spare. Anyway, Videocolor tubes are super common in European 28" televisions, like this:

hantarex_28_3.jpg

A Finnish Nokia 7156 television, with a Videocolor A66EAS13X01 tube insde. The tube has a different curvature, but since the bezel in the Euro Big Blue only goes over the frame and not the glass, it doesn't matter. The Nokia is actually more curvy, which I'm a big fan of. Flat displays belong in LCDs!

Here are the tubes side by side, Nokia on the left, Hantarex on the right:

hantarex_28_4.jpg

The BSIDE ESR20 tells me the yokes are an exact match for horizontal. It's just a case of swapping yoke leads. Original leads on the Hantarex on the left, then transplanted to the Nokia on the right:

hantarex_28_5.jpg


(If someone is copying this, I had both horizontal and vertical reversed. Correct order is orange, yellow, brown & red)

I then put the original dag wire and degauss coil on the Nokia and the tube inside the frame. Connected the monitor to the cab and a after a slight fiddle with the adjustments on the remote I have this:

hantarex_28_7.jpg

:thumbsup:
 

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Awesome thread great work. On your second example with the polarity problems did you try an independent degassing coil? An independent coil is much more powerful than the built-in one you drilled the hole for and may fix the problem.
 
Yeah, I have an external degaussing wand. I did try it just be sure, but the tube reverted back to its rainbow self.
 
I was waiting for a thread like this

This gives me faith to try a 25” JVC donor.
 
I was waiting for a thread like this

This gives me faith to try a 25” JVC donor.
Wish I could find any 25" sets around here.

People don't know how to take a picture of the damn model sticker and so they just list things on CL and FB as 'TV' or something equally difficult to filter on.

Thought I found one the other day--the person specifically said it was a 25" in the listing--went and picked it up and it was a 27".
 
It's funny how the situation is completely the opposite here versus you guys in the US. Here's what I have loads of (European / Japanese sizes)

19" tubes (48cm) with a B10-277 neck
25" tubes (59cm). I even have tubes that should be drop-in with compatible 0.300mH yokes for a MS8
28" tubes (66cm)

However, I can't for the life of me find

19" tubes (48cm) with a 8-pin B8-294 neck for a K7000 (in four years I've found 1... out of a Bang & Olufsen)
26" (63cm)
29" (68cm) (again, in four years I've found 1)

Guess what tubes I need way more of?
 
Finally managed to snag an A63 this weekend; no bonded yoke and has a set of purity/convergence rings, so we're off to a good start. Need to measure the yoke inductance still, though. Also, picked up 3 A68s over the last couple weeks but they're going back on FB marketplace--they all have bonded yokes and a preset convergence magnet.

I've found tons of A68s here, but almost all of them have had bonded yokes and preset convergence magnets so they're not suitable for swaps.

Also, not all Phillips TVs (in the States, anyway) have Phillips tubes. I've definitely picked up some A68s and an A59 that were Funai.
 
Inspired by this, surely the other tube could work as well? The Philips TV (25PT5321) has a slightly newer tube (A59ESF002X11). The size and curvature are again exactly the same. The dog ears are at the correct depth. However, it is slightly different looking (notice the wider metal band) and the yoke is different. Similar, but different. Both tubes stripped with their yokes:

09.jpg

Original Hantarex yoke was dropped on the Philips tube. Again, I wanted to keep the original dag wire and degauss coil. This created a problem because the Philips tube is missing the horizontal slits on the metal band for mounting these. I reused the plastic hooks found inside the TV for the degauss coil. They go over the dog ears and hold the coil in place. As for the dag wire, I drilled a small hole in the metal band for the spring:

10.jpg

Probably not what they teach you to do in TV repair school. Anyway, that's those sorted. Now for testing! Connected everything up and turned it on. Fingers crossed and

11.jpg


uh oh. Huge purity issues. No amount of degaussing will make these go away.

Oh well, at least one success story out of these two. So for Philips yokes that have a single yoke ring, if you have an exact tube match the likelyhood of success is good. If you don't, it probably won't work.
No amount of adjustment will fix this? I ran into a similar issue with a PF swap, but I haven't done much in the way of ring/yoke adjustment.
 
Nope. The problem in that case was that the tube and yoke were of different series. EAK is regular, ESF is apparently 'Super Flat'. Can't mix the two.

What tube were you throwing the PF yoke on?
 
Nope. The problem in that case was that the tube and yoke were of different series. EAK is regular, ESF is apparently 'Super Flat'. Can't mix the two.

What tube were you throwing the PF yoke on?
It was a 27 flat tube out of a late model toshiba tv. Oddly the tube inside was an LG. Hard to get a good cap with the phone camera.
 

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Has anybody in here successfully removed a bonded yoke from a consumer tube and replaced it with a yoke from an arcade monitor?

I have two JVC 27” consumer sets with beautiful pictures and a high-TVL count that I would love to throw into an Astro City if possible, but the yoke impedance is way off and to do a swap I will need to figure out how to remove the bonded yoke.

Just wondering if this will be worth my time or if I’m in for a world of pain.
 
Thought I found one the other day--the person specifically said it was a 25" in the listing--went and picked it up and it was a 27".
I had this exact case today :cursing: Need to start asking the serial number before making the deal. I had this one delivered to my door so not much lost there, but still now I need to a) Get rid of this b) Find storage for it.

This was supposed to be 20" model (even said 19" tube on the sell pitch). This was going to go on my @hursit Mini Cute but it is 21" instead of 20" so it is 53cm wide and will not fit :thumbdown:

IMG_2892.jpeg


IMG_2893.jpeg
 
1) Ask for a pic of the sticker on the back. From the dozen or so 20/21" TVs that have passed through my hands the model number has always accurately stated the tube size (in the model above, 21PT). I think Samsung might have 20" tubes with TVs that have 21 in the model number, but I haven't personally seen one.

2) Check the corners:

20_21_tube_difference.jpg


21" on the left, 20" on the right. Square corners, 21". Round corners, 20". It works. Pic taken from here: https://wiki.arcadeotaku.com/w/CRT_designation_systems#Size_Chart_.28Color_Picture_Tubes.29
 
Square corners, 21". Round corners, 20". It works.
Do you mean that this 21" tube is the same size than 20" and it should work in Mini Cute? That only difference is that 20" has round corners and thats why it misses that one inch? ?( That would be great!

Or did you mean that "get the one with the round corners, it works" ? :D

This seems to be 51cm tube, I thought it must be 48cm exact?
putki.jpeg



EDIT: 51cm does not fit :thumbdown:

A 51cm tube (21" European) will not fit, not because it's too deep (it probably isn't), but because the diagonal is too large.
 
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Yeah, that won't fit. What I meant with working is looking at the corners. It's a sure fire way to spot which is 20" and which is 21". Round corners are the ones you want!

Sorry to get your hopes up!
 
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