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SecretSquirrel
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Re: Stumbled on a new project this weekend.

Wed Apr 03, 2019 11:40 am

Pictures from after cleaning the display tube. The worn spots on the DAG existed prior to the bath, they were just not as visible due to the layer of grime. All-in-all, it looks way better and its much nicer to handle and work with now. Tonight I shall start putting it back together, or at least that's the plan.

Image
Image
Image
Image

--SS
 
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Re: Stumbled on a new project this weekend.

Wed Apr 03, 2019 12:21 pm

Other than the splotches of rust here and there, it's looking almost new.

Can only imagine the combination of grease, tar, and nicotine that came off that thing (and the smell...ick).
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Convert
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Re: Stumbled on a new project this weekend.

Wed Apr 03, 2019 2:19 pm

This just keeps getting better, thanks for sharing SS!

If you need to get a new tube, how do you source that? Just used ones that are still in good shape?

I googled around and came across this article: https://gizmodo.com/as-crt-supplies-van ... 1792968855

I've thought about building an arcade cabinet before, but I always assumed it would be an LCD. After googling some side by sides and watching the video at the end of the article, I can't see myself using an LCD.
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SecretSquirrel
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Re: Stumbled on a new project this weekend.

Wed Apr 03, 2019 6:46 pm

Convert wrote:
This just keeps getting better, thanks for sharing SS!

If you need to get a new tube, how do you source that? Just used ones that are still in good shape?

I googled around and came across this article: https://gizmodo.com/as-crt-supplies-van ... 1792968855

I've thought about building an arcade cabinet before, but I always assumed it would be an LCD. After googling some side by sides and watching the video at the end of the article, I can't see myself using an LCD.


You can still find NOS displays from time to time, but they will be the single most expensive thing you put in a cabinet. Figure $300-400 for a new 19" display. The other option, if you are capable and so inclined is to start trolling recycling and resale centers for old tube TVs. You have to know what you are after and be willing to deal with taking the risk of taking the back of the TV you just bought for $10, to find out that the tube isn't the right kind.

I will probably start watching for a replacement tube as the burn in on mine is bad. But, it's not a priority as its not bad enough to impact game play.

--SS
 
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Re: Stumbled on a new project this weekend.

Wed Apr 03, 2019 10:44 pm

I didn't kill the display!!!

Image

Yes, the colors are off, and it looks like it needs to be degaussed, but it's alive and the cap job definitely helped straighten the display.

Before (rotated so the screen orientation matches the after):
Image

After:
Image

I just temporarily put things back together to make sure it was going to work. Now I need to repair the width coil former, then go through and check/adjust things. I get to go to bed happy tonight though.

--SS
 
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 6:34 am

Pretty neat, wouldn't know where to start. Keep it up!
 
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 7:29 am

Loving this thread, thank you. :o
 
The Egg
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 7:42 am

This is making me more curious about the details of how places like Galloping Ghost handle their display issues. Some of their displays are clearly in need of repair, but at the same time, the majority of them are not, so they must have a fairly robust method for repairing old CRTs on a large scale (they're at 708 games now).

Also, you would expect someone, somewhere to consider making small numbers of CRT displays again to meet pent-up demand (and make a nice premium doing it).
 
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 8:20 am

The Egg wrote:
This is making me more curious about the details of how places like Galloping Ghost handle their display issues. Some of their displays are clearly in need of repair, but at the same time, the majority of them are not, so they must have a fairly robust method for repairing old CRTs on a large scale (they're at 708 games now).

Also, you would expect someone, somewhere to consider making small numbers of CRT displays again to meet pent-up demand (and make a nice premium doing it).
There is no money to be made with repairs. Video Games is a niche market at best in this day and age. I don't know about Galloping Ghosts, but the days of walking into the arcade is very much behind us. It's all about plopping some quarters in at the Dave & Busters while waiting for your food or playing some air hockey at most.
 
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 8:21 am

BIF wrote:
toki wrote:
I always see people talk about a tron game that you stood up to play, but the tron game I remember is one that you sat in it to play. Tron man, tron! lol

Battletech had a clustered set of pods you could sit in and play against others. There were screens high and low in each pod and they had sound wired in each. Literally, you would sit INSIDE of these and shut the door behind you.

The only place I saw them was at Dave & Buster’s. But there were 6 or 8 pods, and you had joystick and throttle controls, as well as the ability to form teams and do battle with each other. Great fun!

If you're ever in Minneapolis there is a set of pods here at the Fallout Shelter Arcade. It's spendy but fun.

Also, thanks for all the extra work in sharing the rebuild/refurb project. I'm enjoying seeing the progress.
 
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 8:43 am

Very cool. I'm really enjoying this thread too, even though I will probably never attempt such a restoration myself.
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SecretSquirrel
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 9:21 am

The Egg wrote:
This is making me more curious about the details of how places like Galloping Ghost handle their display issues. Some of their displays are clearly in need of repair, but at the same time, the majority of them are not, so they must have a fairly robust method for repairing old CRTs on a large scale (they're at 708 games now).

Also, you would expect someone, somewhere to consider making small numbers of CRT displays again to meet pent-up demand (and make a nice premium doing it).


Repairing a CRT based arcade display is pretty straight forward and parts are easy to find, except for two things. The displays are pretty simple beasts, at least the older ones are. The boards are entirely discrete parts, and other than the voltages involved, there is nothing really exotic about them. Replacing all the electrolytic caps would be the most common thing. Various transistors can go bad, or get blown out if caps go bad. The two parts that are scarce are tubes and flyback transformers, with tubes being the hardest to come by for old displays.

There isn't much you can do about burn in as you can't re-coat the tube.

--SS
 
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 11:40 am

You can still buy CRT televisions on Amazon, so not OEM equipment, but you could probably substitute if necessary.
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SecretSquirrel
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 12:37 pm

FireGryphon wrote:
You can still buy CRT televisions on Amazon, so not OEM equipment, but you could probably substitute if necessary.


Yeah, there are a number of options. Eventually, one of two things will happen. There will be enough demand that someone makes a replacement, or more and more will switch the LCD replacements. LCDs don't have the same visual feel to them, but they aren't horrid either. If someone does start selling replacement displays, I can guarantee that they will cost as much as the entire rest of the cabinet put together.

--SS
 
SecretSquirrel
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 12:42 pm

Got to spend a little time with Ms Pac before work today.

Rotated the drive and cutoff pots through there complete range a couple of times, then set to midpoint and powered up. That alone made things better. Let it sit and then checked B+. 128.4V, so I left it alone. Spec is 127V and I didn't want to jack with the pot for an approx 1% adjustment.

Mild adjustments on the cutoffs, but nothing drastic. Same for the drive. Ended up having to bring the red up just a hair. Set the screen pot so things are a bit bright, sitting on the bench as it is going under smoked plexiglass.

Luckily, I didn't have to adjust the width coil since this is a vertically oriented display. Width was adjustable via a pot, as is horizontal position. Adjusted the focus a bit while I was at it.

It's not perfect, but its a good sight better than before. There is a slight color shift in the lower left quadrant. You can just make it out in the "game over" maze picture. It's possible that's from the power supply transformers which are on that side of the display.

This evening, I'll repair the width coil former, now that I know things work. Then I'll button the chassis and frame up and call it good. Much to my wife's chagrin, I'll probably start trolling the local resale shops and boards for 19" TVs. Not so much because I need to replace this tube right now, though the burn in is starting affect the image a bit, but because I want a spare so I can keep this thing going as long as possible. Plus, the other cabinet I really want, to keep Ms Pac company, is a Galaga, which is also a 19" display.

Image

Image

Image

Image

Image
 
Captain Ned
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 1:05 pm

FleaBay has several 19" CRTs available.
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 1:07 pm

SecretSquirrel wrote:
FireGryphon wrote:
You can still buy CRT televisions on Amazon, so not OEM equipment, but you could probably substitute if necessary.

Yeah, there are a number of options. Eventually, one of two things will happen. There will be enough demand that someone makes a replacement, or more and more will switch the LCD replacements. LCDs don't have the same visual feel to them, but they aren't horrid either. If someone does start selling replacement displays, I can guarantee that they will cost as much as the entire rest of the cabinet put together.

--SS

I bet with a suitably fast LCD and some clever post-processing of the video signal, you could simulate the feel of a CRT. Kind of tricky to do it in a way that doesn't introduce too much latency though. Would need to do single-buffered rendering in the post-process step to avoid an extra frame of lag, and the LCD itself will introduce some latency as well.
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Re: Stumbled on a new project this weekend.

Thu Apr 04, 2019 2:53 pm

Could you get clear plexi and just blackout the areas that aren't in front of the screen itself? (not sure how close the screen is to the plexi.
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thegleek
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Re: Stumbled on a new project this weekend.

Mon Apr 08, 2019 9:16 am

FireGryphon wrote:
You can still buy CRT televisions on Amazon, so not OEM equipment, but you could probably substitute if necessary.

Captain Ned wrote:
FleaBay has several 19" CRTs available.


it's not as cut-n-dry as you think. Just because arcade games use 19"monitor's doesn't mean you can drop and replace.

Most common (90%+) crt's used in pac-man games were Electrohome G07-CBO's and Wells-Gardner K4600's and K4900's. These tubes are rarely found in home-consumer TV's.

There are many factor's to consider: size (19"), chassis mount, filament voltage, socket adapter, G1 voltage, bias, and yoke resistance. Just to name a few...

This site was created to match up the internal tubes with others: http://tubular.atomized.org/

Also, I would procure a TPG (Test Pattern Generator) from CraftyMech's site ($89). Best tool ever used in monitor repair => http://craftymech.com/
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The Egg
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Re: Stumbled on a new project this weekend.

Mon Apr 08, 2019 9:44 am

Even as it sits, SS's repairs and adjustments have made a tremendous improvement over where the display was originally.
 
SecretSquirrel
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Re: Stumbled on a new project this weekend.

Mon Apr 08, 2019 8:50 pm

thegleek wrote:
FireGryphon wrote:
You can still buy CRT televisions on Amazon, so not OEM equipment, but you could probably substitute if necessary.

Captain Ned wrote:
FleaBay has several 19" CRTs available.


it's not as cut-n-dry as you think. Just because arcade games use 19"monitor's doesn't mean you can drop and replace.

Most common (90%+) crt's used in pac-man games were Electrohome G07-CBO's and Wells-Gardner K4600's and K4900's. These tubes are rarely found in home-consumer TV's.

There are many factor's to consider: size (19"), chassis mount, filament voltage, socket adapter, G1 voltage, bias, and yoke resistance. Just to name a few...

This site was created to match up the internal tubes with others: http://tubular.atomized.org/

Also, I would procure a TPG (Test Pattern Generator) from CraftyMech's site ($89). Best tool ever used in monitor repair => http://craftymech.com/


As thegleek noted, swapping tubes is a fiddly business and that's once you get beyond the hair straightening high voltage.

My Ms. Pac has a WG K4600 in it. It would be like striking gold (well maybe silver) to find a drop in tube replacement. If anyone has an 80's or 90's 19" Panasonic or JVC TV, drop me a line :)

To give you an idea of the specs you have to know to get a drop in replacement:

neck pinout: CR-23
heater voltage: 6.3V
G1 (brightness): 50V

The above are relatively easy. The below are the hard part

Horizontal deflection coil: 8.2ohm/18.8mH
Vertical deflection coil: 2.5ohm/2.09mH

If all the above match, then you can just drop in the new tube. If everything but the coils match, then you have a decision to make. If the difference is small, maybe 10-20%, you might get away with it. You might also blow a horizontal drive transistor. Once you get too far out, you have to re-use the original yoke. This adds to complications. First, the physical geometry of the tube neck and yoke have to match. Otherwise you'll never get a good picture. Second, you get to deal with purity rings and dynamic convergence. Yuck. :-?

I'm actually picking up a few donor TVs to check out. Maybe I'll hit the lotto. If not, I'll probably stay with the current tube for now. If I do have to do a tube only swap, I'll definitely be getting a test pattern generator. The white test grid in Ms Pac is good enough for adjusting color balance, and you could do convergence with it in a pinch, but proper tools for the job...

--SS
 
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Re: Stumbled on a new project this weekend.

Mon Apr 08, 2019 9:55 pm

This thread is awesome. I can't add much more than that, but this work is inspiring.
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SecretSquirrel
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Re: Stumbled on a new project this weekend.

Mon Apr 08, 2019 9:59 pm

Strike 1!

A48JLL90X tube.
Narrow neck, 8 pin tube. Haven't checked the pinout yet (assuming CR-31). The good news is that it might be a good match to a K7000 chassis as the yoke readings are right in the ballpark.

--SS
 
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Re: Stumbled on a new project this weekend.

Tue Apr 09, 2019 12:29 am

SecretSquirrel wrote:
If all the above match, then you can just drop in the new tube. If everything but the coils match, then you have a decision to make. If the difference is small, maybe 10-20%, you might get away with it. You might also blow a horizontal drive transistor. Once you get too far out, you have to re-use the original yoke. This adds to complications. First, the physical geometry of the tube neck and yoke have to match. Otherwise you'll never get a good picture. Second, you get to deal with purity rings and dynamic convergence. Yuck. :-?

I'm actually picking up a few donor TVs to check out. Maybe I'll hit the lotto. If not, I'll probably stay with the current tube for now. If I do have to do a tube only swap, I'll definitely be getting a test pattern generator. The white test grid in Ms Pac is good enough for adjusting color balance, and you could do convergence with it in a pinch, but proper tools for the job... --SS


check these minty babies out, $100/tube with NO BURN-IN! WOW! ===> https://detroit.craigslist.org/mcb/vgm/ ... 66539.html

(and just in case they sell and the CL ad goes away, i'll post the photos for preservation - click on any photo to see the super hi-res larger image):

Image

Image | Image | Image
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The Egg
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Re: Stumbled on a new project this weekend.

Wed Apr 10, 2019 2:20 pm

just brew it! wrote:
Given your location, if you like good burgers you need to hit Burger Antics if you haven't already.

It should be criminal, but I only just finally went there today. A tad expensive to eat regularly, but they do make one hell of a burger.

Also had quite a few interesting beers on tap, which I had to keep distracting myself from, due to being on the clock. :cry:
 
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Re: Stumbled on a new project this weekend.

Wed Apr 10, 2019 6:58 pm

The Egg wrote:
just brew it! wrote:
Given your location, if you like good burgers you need to hit Burger Antics if you haven't already.

It should be criminal, but I only just finally went there today. A tad expensive to eat regularly, but they do make one hell of a burger.

Yes, a little pricey. We go only 2-3 times/year due to both cost and distance. For high-end burgers, Crusade Burger Bar in Yorkville is a little closer to us, but Burger Antics is better.

The Egg wrote:
Also had quite a few interesting beers on tap, which I had to keep distracting myself from, due to being on the clock. :cry:

Looks like they've expanded the number of taps since the last time I was there. Guess we're about due for a visit. :wink:
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SecretSquirrel
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Re: Stumbled on a new project this weekend.

Wed Apr 10, 2019 11:13 pm

Haven't had a whole lot of time with the Ms in the last week. Had to finish insulating the garage doors last weekend so that it would be tolerable to work in there as spring progresses.

Decided I should go ahead and tackle repairing the width coil. As a re, reminder, it began its self destruction while being removed from the frame mount.
Image

After taking physical measurements, I turned a dowel down to the appropriate diameter.
Image

A couple layers of plastic wrap as a separator.
Image

Then fiber glass. On something this small, you will get strings, you just can't help it.
Image

Focus is bad... But, once you sand the result, all the strings are gone and you have a nice fiber glass tube.
Image

The form was sized so that when the finished tube was sanded down, it would just slide inside the old cardboard coil form. Cut the tube into sections, one for each end of the tube.
Image

Image

Turns out there was no way I was going to get the metal retaining clip off the short end of the tube. At least not without destroying it. Seemed like every time I looked at it, it disintegrated a bit more. The long end fit well though.
Image

In test fitting the fiber glass tube, I realized that the tuning slug was quite long and the new support tube would interfere with adjusting it any further out of the color (narrower width). While considering my options, I decided I should probably take electrical measurements of the coil. This was a good, and bad decision.

For reference, without the tuning slug, the coil is 43uH. DC resistance is 0.4Ohms. With the slug in position for my monitor, the coil is 257uH. In removing the tuning slug, the coil continued its disintegration. Up to, and including, the slug itself falling apart. These things really don't age well. So, left with no tuning slug, what now? Might as well finish deconstructing the coil.
Image

Image

I haven't measured how long the wire is, but it should be between 9 and 12 feet.

Since original coils are unobtainium, I'm going to have to fabricate a replacement. At one time, I had a collection of scavenged parts, including every manner of inductor and coil. Over the years, occasional fits of organization and "why have I been keeping this for the last 10 years?" have cleaned most of it out. Of course now I need it.... Not that I would have expected to find the actual coil, but a viable stand in would have been likely. I dug through what I had and found a toroid that was about 125uH.
Image

Being a smaller inductor, the horizontal width is reduced slightly (vertical since Ms Pac is a vertical game). But, its functional and not a terrible size.
Image

Unfortunately, I cannot leave the game on for any length of time with that inductor. The DC resistance is way too low -- read 0 on my meter -- and it gets hot fast. Still, it gave me a good idea of what the adjustment range looks like.

I did some internet scrounging last night and have sourced 1/4" straw coil forms and 1/4" ferrite tuning slugs. Both are on their way, along with some 24AWG and 25AWG magnet wire. I need to do a little testing to see which is more appropriate. I have winding parameters for both. The original coil wire looks like Litz wire and I might actually try and count the strands. My initial go is going to be with solid wire though as it is much easier to come by.
 
thegleek
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Re: Stumbled on a new project this weekend.

Wed Apr 10, 2019 11:23 pm

SecretSquirrel wrote:
Since original coils are unobtainium,

I'm going to have to fabricate a replacement. At one time, I had a collection of scavenged parts, including every manner of inductor and coil.

I did some internet scrounging last night and have sourced 1/4" straw coil forms and 1/4" ferrite tuning slugs. Both are on their way, along with some 24AWG and 25AWG magnet wire. I need to do a little
testing to see which is more appropriate. I have winding parameters for both. The original coil wire looks like Litz wire and I might actually try and count the strands. My initial go is going to be with solid
wire though as it is much easier to come by.


Not true. WG K4600's were made in the millions. It's one of the top 3 most common made tubes (others being K4900, G07, EZ-20) in the entire arcade industry.

And you can buy replacement coils 24/7 for around $20 without going thru hours of effort with no ROI. Just dish out the $20, sometimes buying schnitt is way easier then reinventing the wheel.

https://www.arcadepartsandrepair.com/pr ... dth-coils/

thank you
––•–√\/––√\/––•–– nostalgia is an emotion for people with no future ––•–√\/––√\/––•–-
 
SecretSquirrel
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Re: Stumbled on a new project this weekend.

Thu Apr 11, 2019 7:42 am

thegleek wrote:
SecretSquirrel wrote:
Since original coils are unobtainium,

I'm going to have to fabricate a replacement. At one time, I had a collection of scavenged parts, including every manner of inductor and coil.

I did some internet scrounging last night and have sourced 1/4" straw coil forms and 1/4" ferrite tuning slugs. Both are on their way, along with some 24AWG and 25AWG magnet wire. I need to do a little
testing to see which is more appropriate. I have winding parameters for both. The original coil wire looks like Litz wire and I might actually try and count the strands. My initial go is going to be with solid
wire though as it is much easier to come by.


Not true. WG K4600's were made in the millions. It's one of the top 3 most common made tubes (others being K4900, G07, EZ-20) in the entire arcade industry.

And you can buy replacement coils 24/7 for around $20 without going thru hours of effort with no ROI. Just dish out the $20, sometimes buying schnitt is way easier then reinventing the wheel.

https://www.arcadepartsandrepair.com/pr ... dth-coils/

thank you


Find me a 9A2795-003 width coil. None on that site. While 9A2838-003 is likely a compatible coil, electrically, it is not physically.

I checked the original wire. Its 10/35 Litz. Ordered a spool of 16/36 as it is available and of similar cross section -- equivalent to 24AWG.

--SS
 
thegleek
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Re: Stumbled on a new project this weekend.

Thu Apr 11, 2019 8:29 am

SecretSquirrel wrote:
Find me a 9A2795-003 width coil. None on that site. While 9A2838-003 is likely a compatible coil, electrically, it is not physically.

I checked the original wire. Its 10/35 Litz. Ordered a spool of 16/36 as it is available and of similar cross section -- equivalent to 24AWG. --SS


Ok so I guess I've been lucky with my K4600 chassis so far... I didn't realize those coils were impossible to find. Others have mentioned they use the K7000 coils (9a2838-001a) in their K4600 with no issues:

https://www.arcadepartsandrepair.com/st ... idth-coil/
––•–√\/––√\/––•–– nostalgia is an emotion for people with no future ––•–√\/––√\/––•–-
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