How universal are tubes if you swap Yokes with the chassis?

[Zebra]

I've heard it said that "tubes are mostly universal, it's the yokes that need to be matched to the chassis".

The implication being that you can use any tube of equivalent size as long as you have the right yoke for the chassis you want to install.

Is this true?

Could I, for example, replace the relatively low quality LG Philips flat tube on my 29"/27" Makvision tri-mode with the nice 29"/27" curved Samsung tube from my Kortek KT-2938f SVGA crt by switching the yoke and chassis?

If the above is not true, what makes a yoke compatible with a particular tube?

When people talk about chassis : tube compatibility they only seem to mention specs measured off the yoke and chassis. I can see that some yokes use a physically different connector but is there an electronic difference too?

 

[TSB]

It's my understanding that they will work if the tubes:
-Have the same socket
-Are Dimensionally the same

This includes Deflection Angle, Bell Depth (both needed to physically match up with the yoke angle & distance from the crt face), and Facial Curvature (partially handled by the chassis)...
so replacing a flat-faced tube with a curve-faced tube would require different electronics as well.

 

[Zebra]

It's my understanding that they will work if the tubes:
-Have the same socket
-Are Dimensionally the same

This includes Deflection Angle, Bell Depth (both needed to physically match up with the yoke angle & distance from the crt face), and Facial Curvature (partially handled by the chassis)...
so replacing a flat-faced tube with a curve-faced tube would require different electronics as well.

So could I assume that I could transplant any 27" flat crt arcade monitor yoke and chassis to any 27" flat tube as long as they have the same socket?

How many different types of socket are there?

 

[TSB]

How many different types of socket are there?

Here's a good reference for CRT sockets:

Pacific T.V. - Vacuum Tube Sockets

Vacuum tubes and vacuum tube sockets for radio, audio and amateur use. Over 1500 types with regular specials, online schematics, technical data, tube tester sockets, military tube sockets, valve sockets, CRT sockets, Nixie sockets, photomultiplier tube sockets, miniature tube sockets, sub...

www.pacifictv.ca

Most arcade monitors will have one of a handful of sockets, though.

 

[Zebra]

Here's a good reference for CRT sockets:

Pacific T.V. - Vacuum Tube Sockets

Vacuum tubes and vacuum tube sockets for radio, audio and amateur use. Over 1500 types with regular specials, online schematics, technical data, tube tester sockets, military tube sockets, valve sockets, CRT sockets, Nixie sockets, photomultiplier tube sockets, miniature tube sockets, sub...

www.pacifictv.ca

Most arcade monitors will have one of a handful of sockets, though.

Thanks.

If it's just a small handful of sockets that makes things easier (if having the same socket and same tube shape means it's compatible).

 

[ecwestjr]

Couple of other things to consider in a tube swap are the heater voltage, anode voltage, bias voltage for the color guns and the focus and screen voltages. Most of these are the same or close from tube to tube however the heater voltage may not. Use to high of a voltage on a heater and it will burn up. Use to low of a voltage poor picture.

Even if you have the same socket size the pin configuration could be different. How do I know this. I did a tube swap on a 25" K7000 and the green and blue color guns weren't the same pins as the tube that was being replaced. Odd thing was the picture looked the same. The way I found that the pin out for those 2 color guns was different was when I went to white balance the tube. The red controls on the neck board controlled the green and the green controls controlled the red

However in the end I ended up using a different tube as this was a customers game. I kept that tube to repair 25"K7000 chassis.

 

[Hydreigon]

This includes Deflection Angle, Bell Depth (both needed to physically match up with the yoke angle & distance from the crt face), and Facial Curvature (partially handled by the chassis)...
so replacing a flat-faced tube with a curve-faced tube would require different electronics as well.

Could I, for example, replace the relatively low quality LG Philips flat tube on my 29"/27" Makvision tri-mode with the nice 29"/27" curved Samsung tube from my Kortek KT-2938f SVGA crt by switching the yoke and chassis?

The whole "flat vs curved" tube deserves further investigation. How a chassis handles the facial curvature? I don't have a clue nor is there much discussions on this. Also the fitting of the plastic bezel matters too unless you want to go that extra mile to remove material. I originally planned on tube swapping flat CRTs for a twin Time Crisis 2 but ended up not doing so for rather specific reasons.

Not all yokes are created equal. Some chassi seem to have quite a large vertical inductance tolerance (at least the K7400). Some yokes seem to be designed for a specific tube in mind. This isn't a problem with an MS9 because these tubes are ridiculously durable but is a problem with poorly designed tubes that don't last very long.

Those two flat tubes (manufactured by Orion) I mentioned earlier I will plan on testing with a TC-L292 (I'm starting to think this is a K7400 clone) when the time comes and sufficient supplies arrive. That chassis is normally meant for curved tubes in mind. Stay tuned.

 

[DeLuSioNaL29]

Figured I'd mention it, but you can quickly type in the tube numbers to see what voltage and socket type they are here:

Tubular

tubular.atomized.org

Del

 

[TSB]

Regarding Flat-vs-Curved faces:
The geometry is just different between Flat-Faced and Curved-Faced CRTs.
Each chassis is designed to work with the geometry of the tube that it was intended for.

While this diagram isn't entirely accurate (there are also glass face differences), here's a basic image for reference:

 

[jlweatherly]

Figured I'd mention it, but you can quickly type in the tube numbers to see what voltage and socket type they are here:

Tubular

tubular.atomized.org

Del

Found this link in another thread here, it's a bit nicer UI than the public one.

http://tubular.atomized.org/2.0a1/index.html

 

[Zebra]

Regarding Flat-vs-Curved faces:
The geometry is just different between Flat-Faced and Curved-Faced CRTs.
Each chassis is designed to work with the geometry of the tube that it was intended for.

While this diagram isn't entirely accurate (there are also glass face differences), here's a basic image for reference:

View attachment 498579

I'm not sure about the geometry but the pic above (of the flat screen) is a good representation of what I've experienced with the mask on some flat CRTs.

I've seen a number of people complain about it with the LG tubes on the 29"/27" Makvision tri-mode monitors because it looks like the pixel grid is wider at the edges than in the middle.

My Tri-sync CRTs with flat Toshiba tubes don't display that pattern. At least not that I can see anyway.

I'm fairly sure it's not a geometry issue or adjustable because it's visible on my flat LG tubes even when the monitor is off. It's not yoke or chassis dependent.

My CRT projectors can use curved or flat screens but they have a whole lot more controls for convergence and pixel distribution (as they don't use masks).

Perhaps the potential issue with flat vs curved swaps is simply whether the chassis would allow enough geometry and convergence adjustments to generate an acceptable result.

I've only ever seen genuinely comprehensive adjustments on super high end broadcast monitors and high end CRT projectors. You're lucky to get straight edges on most large arcade monitors...

 

[Zebra]

Figured I'd mention it, but you can quickly type in the tube numbers to see what voltage and socket type they are here:

Tubular

tubular.atomized.org

Del

Thanks.

This will help me see if there is any use for the curved Samsung tube on my Kortek KT-2938f.

I'm beginning to think it's not worth the hassle though.

 

[Hydreigon]

Well, I made my attempt of a TC-L292 in a flat Orion tube...and didn't get very far :S.

I get some sort of interesting seizure like white screen which gets more erratic after seconds and the screen shuts down. Fortunately, no components blew and putting the chassis in a different tube didn't have any major issues. I may have to test the flat tube with a tube rejuvenator/tester sometime soon.

 

[Zebra]

Well, I made my attempt of a TC-L292 in a flat Orion tube...and didn't get very far :S.

I get some sort of interesting seizure like white screen which gets more erratic after seconds and the screen shuts down. Fortunately, no components blew and putting the chassis in a different tube didn't have any major issues. I may have to test the flat tube with a tube rejuvenator/tester sometime soon.

Did you switch the yoke over or just the chassis?

The methodology for checking chassis to tube compatibility is well understood, documented and measurable.

Using any chassis from a curved monitor with a flat tube would be fine if the yoke readings on the flat tube were in the required range for the chassis.

The question is about transferring the yoke as well as the chassis from the old monitor.

If you transferred the yoke from the TC-L292 to a flat tube with the same yoke socket and got no image, that would be useful data.

 

[Hydreigon]

Did you switch the yoke over or just the chassis?

The methodology for checking chassis to tube compatibility is well understood, documented and measurable.

Using any chassis from a curved monitor with a flat tube would be fine if the yoke readings on the flat tube were in the required range for the chassis.

The question is about transferring the yoke as well as the chassis from the old monitor.

If you transferred the yoke from the TC-L292 to a flat tube with the same yoke socket and got no image, that would be useful data.

I have switched the yoke over just to be sure (and tested with both yokes; nothing blew with the "incorrect" yoke installed). I'm starting to think I may have produced a situation similar to this: https://forums.arcade-museum.com/threads/star-wars-trilogy-deluxe-tube-replacement.486228/

Looks like the neck on this tube was arcing due to the tube being a dynamic focused CRT (my chassis on the other hand was not). I was rather lucky something didn't break or explode as a result of the arcing.

 

[Undarated79]

I hate to bump an old thread but regarding the curved vs flat tube I can give you some insight. I have a curved D9400 tube that came with a bad chassis. I ended up getting a NOS D9810 chassis which is for a flatscreen. It works and the colors and everything are fine but when it comes to the sides of the screen, there is some squishing. It's very apparent playing fighting games. 1 1/2 inches from the corner towards the middle you can visibly notice the fighter go back to normal size.