Does the tube in a CRT TV play any part in sync/resolution?

[thetallguy24]

I'm trying to learn more about the technology of CRTs.

What determines the resolution of a CRT?

For example, the Makvision tri-sync monitors. Do they have a special tube or is the chassis/board what determines what signals are accepted?

Could you move the chassis from a Makvision tri-sync to a standard consumer CRT tube and and that would make it tri-sync? Does the type of tube matter?

Can a PVM 14L5/20L5 use any old tube as long as the chassis and all other boards in them remain the same? Would the number of TV Lines stay at 800?

Thanks in advance

[NoAffinity]

While I cant answer all of your questions, i can tell you that chassis and tubes are not universal. At a minimum the tube yoke has to be compatible with the neckboard (yoke socket) both in terms of physical fitment and electrically/electronically. Googling "crt tube swap" or something similar could add some color to this.

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[thetallguy24]

While I cant answer all of your questions, i can tell you that chassis and tubes are not universal. At a minimum the tube yoke has to be compatible with the neckboard (yoke socket) both in terms of physical fitment and electrically/electronically. Googling "crt tube swap" or something similar could add some color to this.

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I guess what I meant was, if the size of a consumer tube is exactly the same as an arcade or PVM tube, then does the tube matter? Could a tube from a 15khz consumer CRT perform at 31khz with the right chassis and boards?

[NoAffinity]

The short answer is: yes the tube matters. Comparable size is no guarantee of compatibility. Some basics: https://arcademonitor.com/Arcade-Monito ... e_tube.php

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[buttersoft]

The chassis determines the sync rate range and how well-controlled the focus and grid voltages are, but the tube determines how well the focus voltage can be applied to actually focus the image. This combines with the physical spacing of the phosphor stripes on the visible surface of the tube, along with the mask or grille behind, and dictates how fine the details of an image on the tube can get. Higher TVL tubes have more stripes and show more detail. More expensive sets/monitors have better chassis. Most consumer 20" sets are about 300 TVL, i think it is. 20" PVM's start at about 400 and go up to 800, with BVM's going as high as 1000TVL.

Trinitron tubes work differently to other tubes in that they have slightly different yoke/neck assembly controls, i believe, but even if you could get a consumer trinitron tube of the right size and connections it still might use different voltages to a PVM tube, some complications of which would be tricky to overcome.

Tube swapping in general isn't hard, you just need to make sure of compatibility.

[thetallguy24]

The chassis determines the sync rate range and how well-controlled the focus and grid voltages are, but the tube determines how well the focus voltage can be applied to actually focus the image. This combines with the physical spacing of the phosphor stripes on the visible surface of the tube, along with the mask or grille behind, and dictates how fine the details of an image on the tube can get. Higher TVL tubes have more stripes and show more detail. More expensive sets/monitors have better chassis. Most consumer 20" sets are about 300 TVL, i think it is. 20" PVM's start at about 400 and go up to 800, with BVM's going as high as 1000TVL.

Trinitron tubes work differently to other tubes in that they have slightly different yoke/neck assembly controls, i believe, but even if you could get a consumer trinitron tube of the right size and connections it still might use different voltages to a PVM tube, some complications of which would be tricky to overcome.

Tube swapping in general isn't hard, you just need to make sure of compatibility.

So it's theoretically possible for a tube from a 15khz tv to handle a 31khz signal?

[Classicgamer]

The chassis determines the sync rate range and how well-controlled the focus and grid voltages are, but the tube determines how well the focus voltage can be applied to actually focus the image. This combines with the physical spacing of the phosphor stripes on the visible surface of the tube, along with the mask or grille behind, and dictates how fine the details of an image on the tube can get. Higher TVL tubes have more stripes and show more detail. More expensive sets/monitors have better chassis. Most consumer 20" sets are about 300 TVL, i think it is. 20" PVM's start at about 400 and go up to 800, with BVM's going as high as 1000TVL.

Trinitron tubes work differently to other tubes in that they have slightly different yoke/neck assembly controls, i believe, but even if you could get a consumer trinitron tube of the right size and connections it still might use different voltages to a PVM tube, some complications of which would be tricky to overcome.

Tube swapping in general isn't hard, you just need to make sure of compatibility.

So it's theoretically possible for a tube from a 15khz tv to handle a 31khz signal?

Yes and not just theoretically. It was / is common enough for people to replace a CGA chassis with a dual or tri-sync. If just has to be comparable with the neck / yoke etc.

There is a guy in Australia selling custom arcade chassis's for this purpose. The way he tells it, you tell him the make and model of your TV and he makes a comparable arcade chassis for it.

HD crt tubes usually have a finer pitch to resolve the extra detail but it isn't necessary just to display a higher res signal. Crt screens have no fixed resolution. It's all about how much bandwidth it has for the guns to draw the required number of lines per second.

[thetallguy24]

The chassis determines the sync rate range and how well-controlled the focus and grid voltages are, but the tube determines how well the focus voltage can be applied to actually focus the image. This combines with the physical spacing of the phosphor stripes on the visible surface of the tube, along with the mask or grille behind, and dictates how fine the details of an image on the tube can get. Higher TVL tubes have more stripes and show more detail. More expensive sets/monitors have better chassis. Most consumer 20" sets are about 300 TVL, i think it is. 20" PVM's start at about 400 and go up to 800, with BVM's going as high as 1000TVL.

Trinitron tubes work differently to other tubes in that they have slightly different yoke/neck assembly controls, i believe, but even if you could get a consumer trinitron tube of the right size and connections it still might use different voltages to a PVM tube, some complications of which would be tricky to overcome.

Tube swapping in general isn't hard, you just need to make sure of compatibility.

So it's theoretically possible for a tube from a 15khz tv to handle a 31khz signal?

Yes and not just theoretically. It was / is common enough for people to replace a CGA chassis with a dual or tri-sync. If just has to be comparable with the neck / yoke etc.


There is a guy in Australia selling custom arcade chassis's for this purpose. The way he tells it, you tell him the make and model of your TV and he makes a comparable arcade chassis for it.

HD crt tubes usually have a finer pitch to resolve the extra detail but it isn't necessary just to display a higher res signal. Crt screens have no fixed resolution. It's all about how much bandwidth it has for the guns to draw the required number of lines per second.

Who does it in Australia?

[energizerfellow‌]

Crt screens have no fixed resolution. It's all about how much bandwidth it has for the guns to draw the required number of lines per second.

To that end, Technology Connections' Television Series is mandatory viewing if you're interested in getting into the technical side of analog TVs.

HD crt tubes usually have a finer pitch to resolve the extra detail but it isn't necessary just to display a higher res signal.

The real difference between the SD and HD tubes are the newer fast-decay SMPTE-C phosphors and higher TVL vs the classic P22 phosphors you'll see on 15khz SD TVs. This faster phosphor light emission decay and finer dot pitch are why HD CRTs flicker so bad. Illumination persistence and rise/fall times also get into why motion blur and stutter are an issue on modern flat panels.

[MKL]

The tubes used for arcade monitors with 31khz capability (either 15-25-31 or 31-35-38) are TV tubes that only differ from those used for 15KHz in the deflection yoke. They're exactly the same tubes used in 100Hz TVs as opposed to 50Hz TVs. They are not like bigger PC monitor tubes.

[thetallguy24]

The tubes used for arcade monitors with 31khz capability (either 15-25-31 or 31-35-38) are TV tubes that only differ from those used for 15KHz in the deflection yoke. They're exactly the same tubes used in 100Hz TVs as opposed to 50Hz TVs. They are not like bigger PC monitor tubes.

So would you need to adjust the yoke or replace it altogether to convert a 15khz CRT to 31?

[MKL]

You need a chassis that can do 31khz and a tube with a yoke that is compatible with it.

[buttersoft]

There is a guy in Australia selling custom arcade chassis's for this purpose. The way he tells it, you tell him the make and model of your TV and he makes a comparable arcade chassis for it.

That's Jomac. He modifies existing universal chassis, and only within reason. He also does arcade chassis repairs, and there is no one better. He only works inside Aus, however.