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Yoke and tube specs for monitors

Thanks. So I unplug the yoke and measure wich pairs? I see 4 values in these lists.
Lh lv rh rv how can I find out which is the right one?

Thanks.
 
hardyhell said:
Thanks. So I unplug the yoke and measure wich pairs? I see 4 values in these lists.
Lh lv rh rv how can I find out which is the right one?

Thanks.
Click to expand...
LH -> Inductance in horizontal coil
LV -> Inductance in vertical coil

You need to read mainly these previous values.

There is also:

RH -> DC resistance of horizontal coil
RV -> DC resitance of horizontal coil

These ones can be read with a common multimeter in resistance mode.

For inductance, you need an special meter. I used a cheapo one from China that probably is not the most accurate, but it gives an approximate vision of what has.
 
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Unplugged it and tested all combinations.
Red / blue gave me 2ohm and L=1.32mH
Green/yellow 6.6ohm and L=18.7mH

Used the Bside ESR02Pro
 
Chassis/MonitorLh (mH)Lv (mH)Rh (ohm)Rv (ohm
Nanao MS9-290.3314.00
The list here says this for Nanao ms9

So I guess my lh and lv on this yoke is to high. Will not work then? Did not find the resistance for the ms9 in the list there
 
Yes, looks like the inductance in your yoke is a bit high for both coils. Really don't know if that difference could be in the working range, or it is too much.

About the resistance, RH should be around ~1 Ohm and RV should be around ~6-8 Ohms but, as I said before, inductance is the key in order to know yoke compatibility.
 
So basically I just need to find a tv with a coil that has the right inductance. I thought that this toshiba tv which is hard to come by here in Germany would be good because it’s the right brand. Well then it’s basically all about the coils and the right neck board connector.

Does anyone else perhaps know if the inductance is still in range there?

Thanks
 
Finding a replacement tube with compatible yoke for the MS9 is a bit of a challenge. Most TVs that only do 240p are going to have a horizontal inductance way too high for the MS9. It is only once you start getting into the 480p and higher resolution TVs that you start finding the very low impedance horizontal yoke. The problem is these 'high def / 100Hz' CRTs tend to be flat glass and not curved, so needing a curved tube with a really low horizontal inductance is a rare bird. Finding a tube with the right curvature and right neck connector (CR-23) is not too big of challenge. You can then hunt down one of several yokes with a ~300mH horizontal inductance and have a go at doing a yoke swap. This is somewhat hit or miss since that yoke wasn't designed specifically for that tube you might never get good alignment and spend days fiddling with purity and convergence, never happy with the final product.

I remember someone clued me into the Phillips Blackline CRTs. This was a curved, 100 Hz (high-def) 27/29" CRT TV that was found in Europe. That seemed like just the rare bird you needed if you wanted a drop in CRT/yoke that was both curved and had a low horizontal inductance.
 
Oh great. I will hunt for the black line then. Never thought that these 100hz TV sets could be any good for this ms9.

Thanks.

If I use the ms9 on the toshiba i have here will it damage the tv or the ms9?
 
I would imagine the chassis would not be too happy about it. With that horizontal yoke you are roughly 4x higher inductance (1.3mH / .3 mH) than the chassis expects.
Roughly speaking, the voltage across an inductor is given by 'V = L(di/dt)' . If the chassis is trying to maintain a certain di/dt, then the voltage needed to do that will also be 4x larger. Hopefully some protection circuit would be in place to keep it from blowing the HOT instantly, but its too large of discrepancy where I would feel comfortable testing it.
 
Thanks for your explanation. I will better look for these Philips tubes then. Have some other TVs I will check the values tomorrow.
 
I would try swapping a MS9 yoke on the Tosh tube that you found.
 
nem said:
I would try swapping a MS9 yoke on the Tosh tube that you found.
Click to expand...
it is a hell of work to get the picture right then? with the yoke added to another tube? did that with a naomi monitor one time. never got it back good :(
 
hardyhell said:
it is a hell of work to get the picture right then?
Click to expand...

Possibly, but your best chances are with a tube that has a similar shape. Of course, I can't say if the shape is actually an exact match, but at least it's from the same manufacturer.
 
Has anyone in the US been able to successfully tube swap and MS9 from a consumer TV donor? Where screen curve is an exact match and depth of the tube does not produce convergence/purity/focus issues?

My experience with the MS9 is finding a suitable donor tube from a consumer TV is impossible. I've found tubes that match the screen curve. But of all those that have matching screen curve, the dimensions in the back of the tube are too deep to fit into an MS9 frame with the chassis installed. You'd have to modify the chassis tray so it sits further back on the frame to have enough clearance for the tube to be mounted without it touching the chassis.

Once you solve the physical challenges, of course you have to do a yoke swap. I have yet to find a yoke from a 29" TV that is compatible outright. The yoke swap isn't a big deal. But now once that is solved, then you have the challenge of the MS9's beam being very short (distance from the gun to the screen). All the consumer TV's I have tried will have purity and convergence issues that are impossible to solve.

I have only found a suitable MS9 donor from a lesser brand arcade monitor. My opinion is if you use a consumer TV as your MS9 donor, you are looking at a tube that is is flatter. More suited for an MS293x. You'll then have to mask the gaps between the screen and bezel. I've went through like 40 donors and zilch are suitable for the MS9. That has been my experience in the US anyway.
 
question (for @nem ! ) :
I have a spare A68KSA30X (MS9-29SU) with a scratched glass.
I might be able to pick up a NOS A68ACT00X tube tonight.

Does the fact that tubular list them identical mean I can swap them? There is no yoke on the tube.
 
nem said:
Yeah, you should be able to swap them. Neck connector and heater voltage match, so it should fire up.

However, you're trading a Hitachi manufactured tube for a Zenith.

Is there anything else wrong with the tube apart from the scratches? You do know you can sand and buff the glass?

https://www.arcade-projects.com/threads/polishing-a-scratched-monitor.11302/
Click to expand...
Lol ! Tell us how you really feel about Zenith?!

hey it's in the box and I passed on it a bunch of times but really, my name is on it so I'm just going to grab it !
IMG_4198.jpg


I have a spare ms9-29 board giving me a black screen that I need to investigate. Hopefully I'll fix it and use it but really, I am missing a yoke that will work there.
I'll dig in and see if I can find one ...
 
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Hi. I found 3x Toshiba 100 Hz HD CRT with:
1. PICTURE TUBE, A68LTF356X, 27VPFV2, 104° deflection DEFLECTION YOKE TDY-629SA.
2. PICTURE TUBE, A68LTF356X, 27VPFV2, 106° deflection DEFLECTION YOKE TDY-629SA.
3. PICTURE TUBE, M68LWM356X, 27VPFRACSEMIFINE, 104° deflection, DEFLECTION YOKE, TDY8296A

My friend has Toshiba D29CQ51, PB9929 Chassis with burn-in A68LTF356X:
Сan he swap his crt tube to another from HD CRT? His crt tube has no problems other than burn-in.
Is it necessary to replace yoke?
Crt tube with what deflection to choose? Сan anyone tell me what is the value of the original crt tube?

I also found a lot of HD CRT with A68LZU185X - will they fit?

Thanks
 
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wwse said:
Is it necessary to replace yoke?
Click to expand...

You'll have to measure the yokes.

wwse said:
Сan anyone tell me what is the value of the original crt tube?
Click to expand...

Good question.

a68ltf356x_deflection_angle.jpg


I tried a Samsung tube with a deflection angle of 110° (A68QCP693X) and the original Tosh yoke. Result was a rainbow of colors.
 
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