Fudoh's ode to old display technology

[MKL]

Oh, that's excellent news. I don't think this is mentioned at all in the service manual. I haven't opened the TV yet (need to carry it downstairs, ugh...) but can you point it out on the board here?

Spoiler

The black area halfway on the right side in the above pic (CN807).

[Tempest_2084]

Yeah, those little screw adjustable pots and the wheels are what you're looking for. Did you have a look at the service manual for your TV? Often it just contains a generic copypasted description of the yoke, but sometimes there's detailed info. Those are very useful for dialing in dynamic convergence without messing with the yoke, so much more precise and easy.

And yeah, please take some pictures, would be neat to see

How do you adjust them though? If you look at the second picture there's a plastic piece over the end (which also holds the thing inside the tube) that won't allow it to move with that wheel. I recall having that problem last time.

Also, how do you take pictures of the screen without getting the 'refresh shadows'? I used to be able to do it on my old phone but my new iPhone shows them all the time. There just be some adjustment somewhere.

[maxtherabbit]

Everybody, please help:



So 90s Sony TVs here in Europistan often have issues with horizontal centering for NTSC consoles. They got it mostly worked out by the time they got to the X5, but this lovely Sony X1 certainly doesn't shift far enough. Picture is as good as gets with the service menu

I'm about to mess with this TV again after not using it for a while, and I wonder if there's anything I can do to improve this while I got it open. I know I can fix the shift at the source on a MiSTer or RaspberryPi and there are shifter boxes available for RGBS/SCART, but can I just fix this in the TV? Is there maybe a calibration pot or even some resistor I can swap or whatever to let me shift more or a different range?

Thanks!

are you using a sync stripper? try switching to csync, the strippers delay the sync a little

[ASDR]

The black area halfway on the right side in the above pic (CN807).

Oh, of course, thanks! I'm surprised it's that easy, fantastic. I'll have to open the TV soon anyway, the previous owners must've really ran this one into the ground, tube is rather dark. Maybe some G2/SCREEN adjustment will make it look a bit brighter. Sub-contrast in the service menu does nothing on this set, weird.

are you using a sync stripper? try switching to csync, the strippers delay the sync a little

That's a PS1 with sync-on-luma. This TV looks like this with all sources, even for my AV-modded Famicom over composite it was impossible to properly center the image.

How do you adjust them though? If you look at the second picture there's a plastic piece over the end (which also holds the thing inside the tube) that won't allow it to move with that wheel. I recall having that problem last time.

Start with just the pots, all you need is a screwdriver. If you keep doing this invest in some ceramic screwdrivers, you can get them for a few bucks from AliExpress and they reduce the risk of zapping yourself or shorting something out to zero.

Also, how do you take pictures of the screen without getting the 'refresh shadows'? I used to be able to do it on my old phone but my new iPhone shows them all the time. There just be some adjustment somewhere.

Every year they add a million useless camera features but never a CRT mode... You can use the live photo mode where you can scrub through like the last second or two and I also found that the HDR mode doesn't seem to catch the screen at a bad moment, maybe because it combines multiple exposures?

[Tempest_2084]

Start with just the pots, all you need is a screwdriver. If you keep doing this invest in some ceramic screwdrivers, you can get them for a few bucks from AliExpress and they reduce the risk of zapping yourself or shorting something out to zero.

But how do you adjust that element? Like I said there's a plastic clip that holds the rod in the tube and clips over the bed. As far as I can tell there's no way to adjust that dial without breaking that clip.

[Tempest_2084]

Before I mess with my CRT I decided to take some 'before' pictures to show exactly what I'm dealing with. I actually haven't messed with this TV in a few months and was surprised that it wasn't as bad as I remember, still it needs some work to make it presentable. At first glance the grid pattern doesn't look too bad. You can see the bottom right has some bad convergence issues and an upward curl that needs to be fixed and the bottom center of the grid has some convergence issues as well. The bottom center convergence issue can be seen in games or screens that use lots of thin lines like the bottom of the Genesis Everdrive cart menu (see picture). What the grid doesn't show very well that the monoscope pattern shows (I'll try and get a better screen shot of that) is the bad convergence on the left side of the screen (mostly red) that can easily be seen in the Genesis Everdrive menu text.

So it appears that I need to first fix the super bad geometry in the lower right corner and maybe try and fix the 'yoke sag' issues in the center of the screen. After that I need to play with the convergence and see if I can at least get that to an acceptable place. Any suggestions on how to tackle this? I was going to manipulate the yoke then play with the H-Stat and Focus.

Spoiler

[ASDR]

Start with just the pots, all you need is a screwdriver. If you keep doing this invest in some ceramic screwdrivers, you can get them for a few bucks from AliExpress and they reduce the risk of zapping yourself or shorting something out to zero.

But how do you adjust that element? Like I said there's a plastic clip that holds the rod in the tube and clips over the bed. As far as I can tell there's no way to adjust that dial without breaking that clip.

Don't know, I assume you can somehow adjust the core of this particular inductor to change its magnetism, but I'm not sure you're supposed to or need to. I'd just stick to the trimpots on top of the yoke.

Before I mess with my CRT I decided to take some 'before' pictures to show exactly what I'm dealing with. I actually haven't messed with this TV in a few months and was surprised that it wasn't as bad as I remember, still it needs some work to make it presentable. At first glance the grid pattern doesn't look too bad. You can see the bottom right has some bad convergence issues and an upward curl that needs to be fixed and the bottom center of the grid has some convergence issues as well. The bottom center convergence issue can be seen in games or screens that use lots of thin lines like the bottom of the Genesis Everdrive cart menu (see picture). What the grid doesn't show very well that the monoscope pattern shows (I'll try and get a better screen shot of that) is the bad convergence on the left side of the screen (mostly red) that can easily be seen in the Genesis Everdrive menu text.

So it appears that I need to first fix the super bad geometry in the lower right corner and maybe try and fix the 'yoke sag' issues in the center of the screen. After that I need to play with the convergence and see if I can at least get that to an acceptable place. Any suggestions on how to tackle this? I was going to manipulate the yoke then play with the H-Stat and Focus.

Spoiler

I'd start with re-seating the joke. Then geometry in the service menu. Then messing with convergence strips and other magnets that affect geometry. After that static convergence (center, HSTAT and yoke rings), then dynamic convergence (borders, yoke tilt and the pots/adjustable magnet pieces on the yoke) and then finally corner convergence with convergence strips. It's a lot stuff, feel free to stop or leave things for another time when you can't seem to make things better.

[ASDR]

Guys, I just calibrated this bad boy to near perfection:



Am willing to trade for an FW900 or D-series BVM. Only serious offers, I know what I got.

[Tempest_2084]

I'd start with re-seating the joke. Then geometry in the service menu. Then messing with convergence strips and other magnets that affect geometry. After that static convergence (center, HSTAT and yoke rings), then dynamic convergence (borders, yoke tilt and the pots/adjustable magnet pieces on the yoke) and then finally corner convergence with convergence strips. It's a lot stuff, feel free to stop or leave things for another time when you can't seem to make things better.

I hope I don't have to mess with the rings. That's the one thing I really don't want to do. I do have them marked if that ends up being the case though.

[ASDR]

Update on the Sony X1, got around to fixing it up.

This has to be the dustiest CRT I've had so far



I guess there's a reason why Sony stopped putting top vents on their TVs sometime in the mid 90s. Took quite a while to clean.

Now about the infamous centering switch I just learned about from MKL...







Maybe it was a switch at some point, but I guess somebody realized a jumper would be cheaper. Does its job fine, though. Setting shown in picture is worst, pull it out for middle, switch to other position for the good one.

Centering is great now, thanks again for the tip!



Also took the liberty to adjust focus, HSTAT (there's one unlike successor models like the X5/C5) and G2/SCREEN. Not much luck with the latter, seems like it was in the optimum position already. Guess this older screen is just dimmer and the previous owner also ran it into the ground for thousands of hours in a dust apocalypse. Also holy crap there's so much hot glue on the CCA and DY spacers etc., this is like some eBay console mod, guess caulk had not been invented in 1995. There's a super faint purity issue in one of the corners, but there was already a purity magnet from the factory and I left it alone.

While doing all this the Sony logo fell off. TV is saying 'please let me die, buy an LG OLED like a normal person!'. No.

[Tempest_2084]

Nice! I hope I can get my Sony looking even halfway as good. Hopefully I can get to that this weekend, but "Real Life" keeps getting in the way lately.

BTW when inserting strips under the yoke, is there any part that I should avoid touching? I know the neckboard has dangerous voltages as does the cap, but what about the various parts of the yoke? I think the last time I tried playing with the strips I got scared off because I could literally hear the static and humming when I got close to it and I was afraid I was near somewhere I shouldn't be touching. I think that's just part of being near a giant CRT thats powered on, but I want to check and be safe rather than crispy.

[ASDR]

Nice! I hope I can get my Sony looking even halfway as good.

If you're persistent enough you can get those consumer tubes to look quite good. They'll never be PVMs or PC CRTs, but that totally warped, busted, tilted, saggy corner shit that most TVs show from the factory can be made way better. These CRTs are really held back by a quick & dirty setup at the factory.

Sony FX30


Sony LT1


Sony X5


All I got is time and OCD

BTW when inserting strips under the yoke, is there any part that I should avoid touching? I know the neckboard has dangerous voltages as does the cap, but what about the various parts of the yoke? I think the last time I tried playing with the strips I got scared off because I could literally hear the static and humming when I got close to it and I was afraid I was near somewhere I shouldn't be touching. I think that's just part of being near a giant CRT thats powered on, but I want to check and be safe rather than crispy.

I'm not really an expert at this, so I try to exercise as much caution as possible. But, generally, the people who designed TVs seemed to at least try to keep service technicians from getting killed. One question is of course always the condition of the TV. If you look at the dusty picture of that X1 I posted, you can see how it's caked in dust. Dust attracts humidity and humid dust is a lot more conductive than air, insulation and fiber board. The dielectric grease sealing that anode cap has surely dried out and if you look closely you can see a piece of tape around the EHT lead, like the insulation was nicked. That is real scary and I avoid getting withing arcing distance of any of this.

From what I understand, the only really bad thing on the neckboard is the focus voltage coming directly from the flyback, but that is generally routed to the tube socket in a way that it's nowhere directly exposed and can't be easily touched. You can get zapped by the neckboard and terminals on the yoke, but to the best of my knowledge nothing there should be really dangerous. You can hear humming & whining from the coils and even feel the vibration in a magnet if you hold it close, but that's nothing to be concerned about.

I'd just have some healthy respect for any of the actual high voltage stuff coming from the flyback and the open-frame power supply. You can also do sensible things like only use one hand, use insulated / ceramic screwdrivers, an isolation transformer for older hot chassis TVs, gloves won't hurt etc.

[Tempest_2084]

I'm not really an expert at this, so I try to exercise as much caution as possible. But, generally, the people who designed TVs seemed to at least try to keep service technicians from getting killed. One question is of course always the condition of the TV. If you look at the dusty picture of that X1 I posted, you can see how it's caked in dust. Dust attracts humidity and humid dust is a lot more conductive than air, insulation and fiber board. The dielectric grease sealing that anode cap has surely dried out and if you look closely you can see a piece of tape around the EHT lead, like the insulation was nicked. That is real scary and I avoid getting withing arcing distance of any of this.

From what I understand, the only really bad thing on the neckboard is the focus voltage coming directly from the flyback, but that is generally routed to the tube socket in a way that it's nowhere directly exposed and can't be easily touched. You can get zapped by the neckboard and terminals on the yoke, but to the best of my knowledge nothing there should be really dangerous. You can hear humming & whining from the coils and even feel the vibration in a magnet if you hold it close, but that's nothing to be concerned about.

I'd just have some healthy respect for any of the actual high voltage stuff coming from the flyback and the open-frame power supply. You can also do sensible things like only use one hand, use insulated / ceramic screwdrivers, an isolation transformer for older hot chassis TVs, gloves won't hurt etc.

Oh yeah I always have one hand behind my back when possible and try to only touch the plastic ring on the yoke. I think the hum and whine of the coils was what was freaking me out.

Someone had told me that it's dangerous to adjust the focus knob on the flyback by hand. Is that true? I know the flyback is dangerous, but I can't see how touching a plastic knob could hurt.

[bobrocks95]

Well, in a live chassis just about anything could have the potential to hurt if you're close enough to something else...

Dynamic convergence on my Sony FV-310 is so bad I basically gave up on CRTs. I keep it around for composite stuff and PS2 for 480i but that's about it. I don't live in an area where you can get any PVMs or BVMs, or really see many consumer sets even anymore, so it's what I've got, not that it isn't a nice set. Those sets look really nice.

[ASDR]

Someone had told me that it's dangerous to adjust the focus knob on the flyback by hand. Is that true? I know the flyback is dangerous, but I can't see how touching a plastic knob could hurt.

That's kinda what I was getting at with the comment about the 'condition' of the TV. Normally, touching the flyback and anode cap etc. should be perfectly safe. But look at this:

https://www.youtube.com/watch?v=UpyT_Bf0Rsg

Basically if the insulation has been damaged and it's all caked in humid dust, who knows... I just don't touch the flyback and turn those knobs with a ceramic screwdriver.

Well, in a live chassis just about anything could have the potential to hurt if you're close enough to something else...

True, but unless you're into some real vintage TVs I don't think you'll actually encounter something really problematic where like all the metal parts are at line voltage. I have an older PVM that warns about a live chassis inside the service manual and on the device, but in reality all the metal parts are fully grounded and ultimately it boils down to a few things on the power supply board to not be touched. And they even put a plastic shield over it and you probably should't go near any live open-frame power supply anyway. Since there's no isolation transformer and if there was some kind of major fault in the TV more parts of it could be energized, so there's that. A ~150VA isolation transformer is like 50EUR here, might be worth getting.

Dynamic convergence on my Sony FV-310 is so bad I basically gave up on CRTs. I keep it around for composite stuff and PS2 for 480i but that's about it. I don't live in an area where you can get any PVMs or BVMs, or really see many consumer sets even anymore, so it's what I've got, not that it isn't a nice set. Those sets look really nice.

I don't really know much about US TVs (strange how we got such very different designs), but in my experience here the really large and fancy TVs have a ton of adjustments for convergence, unlike the smaller models which generally have nothing in the service menu and max. a few pots on the yoke and neckboard. From the KV-36FS70 service manual:



Looks like a fun afternoon

But yeah, you have to have realistic expectations about the quality of consumer TV CRTs. While I got my sets all looking quite acceptable, it's very clear that even Sony did not really apply high quality standards to these displays.

I'm mostly interested in the 1995-2005 era of CRTs and tried to get all of the major chassis etc. from Sony from that time period. I don't have the space to collect all those >=30" behemoths, so I'm probably missing out on the real fancy highend stuff. But what I noticed is that quality & progress over these ten years is not really as you'd expect. I mean from 2006 to 2016 we went from low-contrast, cloudy backlight glow, motion blurred, 1080p LCDs to pretty much modern 4k HDR OLEDs. Over the same time span I'd say consumer CRT TVs made some steps sideways and a bit forwards & backwards. Like some model fixes an annoying issue but it's back again in a later model. Or they add all kinds of controls to the yoke & service menu, but then they also go to flat screens which have more issues to begin with, it's kind of a wash.

If I compared a mid-90s Sony X1 to a mid 2000s FQ10 (pretty much the last chassis Sony designed before the end of CRT era?), what really is the difference? I mean I appreciate that on the FQ10 I don't have to open the thing and adjust a stupid jumper and I don't have to manually spin the joke if I place it NS instead of EW, but the ones I've seen have worse geometry/convergence, have that horizontal line wobble that was not present on the predecessor chassis (and barely visible on the X1). Guess the FQ10 is brighter, but that might just be the high hours on the X1 tube.

So, yeah, tempered expectations and not really the kind of progress one would expect. A great 90s PC CRT can do 2048x1536 and completely blow any TV out of the water in terms of geometry/convergence/linearity/sharpness. Or a late 80s PVM that's still in good condition will just look way better than even a low-hours FQ10 from 2005.

[Tempest_2084]

That's kinda what I was getting at with the comment about the 'condition' of the TV. Normally, touching the flyback and anode cap etc. should be perfectly safe. But look at this:

https://www.youtube.com/watch?v=UpyT_Bf0Rsg

Basically if the insulation has been damaged and it's all caked in humid dust, who knows... I just don't touch the flyback and turn those knobs with a ceramic screwdriver.

Yikes!

This TV is in really good shape and isn't dusty inside (other than the standard very thin layer that you can't avoid but I cleaned that out). I assume that since I haven't been zapped yet it's safe, but I'll just use the plastic screwdriver I have to be safe.

But yeah, you have to have realistic expectations about the quality of consumer TV CRTs. While I got my sets all looking quite acceptable, it's very clear that even Sony did not really apply high quality standards to these displays.

I've learned this over the years. Obviously it's normal to want to have good convergence and geometry that isn't totally out of whack, but I swear there are people who spend more time adjusting their CRTs for that mythical perfection than they do using them. I can remember having to wait for the old TV to warm up before I could see the entire picture (the top would be chopped off a bit until the set warmed up) and thinking that was completely normal. How did we survive back then?

[ASDR]

@ASDR, do you know whether any of those Trinitrons have NTSC comb filters similar to those included in American sets of that era? I have a 13" set from 2003 that uses a simple notch filter by default as far as I can tell, but not sure if higher end models like the X5 tried a bit harder.

When I was first looking for a small Sony I was pretty disappointed to learn that most of those smaller TVs seemed to be fairly low-end kitchen/nightstand type devices. None of them even had NTSC decoding. AFAIK they only started to get better once the FD Trinitron (flat screen) era began, where you have the 14LT1 and then 14CT1. Those use the same chassis as their larger, fancier counterparts and have most of the features.

Comb filters seem a bit rare around here. It was quite shocking to me how much better composite & S-Video look on a nice PVM simply due to how much better these monitors handle those signals. The 14LT1 is an FE-2, doesn't have it. I have FQ10s and they have the same BX-1 chassis as the 14CT1. I haven't had time to check them out, though, but look at the service manual:



So, the 14CT1 might be the only small consumer Trinitron that I know of that has it. But I haven't confirmed it for myself, there's a lot of weird crap in those menus that doesn't do / mean anything Generally, I get the impression that the only Sony TVs here that have comb filters are either those shitty 100Hz digital picture-in-picture things or very large & highend TVs, none of which I own or looked at.

btw, I've never tried composite on any of my X/C5s, but I don't even need to look at the service manual to assure it won't have a comb filter. I think that TV/chassis was like the swan song for curved trinitrons and it has nothing and is pretty dumb. And I mean that it in the most positive way. There's little to adjust in the service menu, there's little to adjust inside and it's pretty sparse and simple, the user menus are spartan and the front AV3 is just routing things to AV2. But it looks great! Of the half dozen or so I've owned and played around with even the worst looked quite good out of the box, I can overlook the wobble & noise and the thing is just the simple, stupid perfection of a 90s Trinitron. Highly recommended

But yeah, you have to have realistic expectations about the quality of consumer TV CRTs. While I got my sets all looking quite acceptable, it's very clear that even Sony did not really apply high quality standards to these displays.

I've learned this over the years. Obviously it's normal to want to have good convergence and geometry that isn't totally out of whack, but I swear there are people who spend more time adjusting their CRTs for that mythical perfection than they do using them. I can remember having to wait for the old TV to warm up before I could see the entire picture (the top would be chopped off a bit until the set warmed up) and thinking that was completely normal. How did we survive back then?

If you had rich parents you would've been gaming on a D-series BVM which of course have a feature to counteract that pesky problem



I think it's important to make a distinction between playing on CRTs and enjoying to mess with CRTs. I have a few spots where I can set up a tube and connect it to original hardware or various emulation solutions. I usually put a new CRT there, set it up once and the play on it for months without ever tweaking anything on it. I can spend a weekend just fixing and calibrating things, but I can also spend a weekend just playing games without ever thinking of service menus.

[Tempest_2084]

I think it's important to make a distinction between playing on CRTs and enjoying to mess with CRTs. I have a few spots where I can set up a tube and connect it to original hardware or various emulation solutions. I usually put a new CRT there, set it up once and the play on it for months without ever tweaking anything on it. I can spend a weekend just fixing and calibrating things, but I can also spend a weekend just playing games without ever thinking of service menus.

Hopefully I can get my TV fixed and never have to play with it again. Of course since I have all my old systems connected to it, just when I think i have it all perfect a different system will show issues that another system doesn't.

[tongshadow]

In my experience, comb filters smear the look of 240p games too much for my tastes. Barebone TVs without it makes games look better on composite.

[bobrocks95]

Dynamic convergence on my Sony FV-310 is so bad I basically gave up on CRTs. I keep it around for composite stuff and PS2 for 480i but that's about it. I don't live in an area where you can get any PVMs or BVMs, or really see many consumer sets even anymore, so it's what I've got, not that it isn't a nice set. Those sets look really nice.

I don't really know much about US TVs (strange how we got such very different designs), but in my experience here the really large and fancy TVs have a ton of adjustments for convergence, unlike the smaller models which generally have nothing in the service menu and max. a few pots on the yoke and neckboard. From the KV-36FS70 service manual:



Looks like a fun afternoon

Pots? Here's all I've got in my service manual for dynamic convergence, on the supposed "top of the line" consumer Sony CRT



Above my paygrade to say the least. I might buy some permalloy strips for the corners if anyone knows where to get them anymore though

[ASDR]

Hopefully I can get my TV fixed and never have to play with it again. Of course since I have all my old systems connected to it, just when I think i have it all perfect a different system will show issues that another system doesn't.

I wish CRT TVs had memory like PC CRTs where they save the sizing/centering etc. for each pixel clock so you can adjust everything separately. PVMs often have settings for overscan/underscan you can abuse and some later TV chassis have a completely different sets of geometry settings for normal & widescreen so you can abuse that as two configs for different systems.

The 14CT1 was actually the model I was using I remember seeing that mention of a comb filter in the service manual, though I'm not sure it actually has one (or it's disabled by default for some reason, only works with PAL? I don't know how to read these manuals). The NTSC test patterns I looked at anyway showed the kind of attenuation around 3.58 MHz that you'd only see with a notch filter, and overall a similar look to my PVM using its trap filter.

I have multiple sets with BX-1 chassis, I'll have a look if they have better composite handling than my other TVs and how they do with S-Video. I also have a PVM with a switchable trap filter so I can probably compare that as well. I'm really curious now how this will play with my AV modded Famicom...

That's interesting, as I had heard the X5 was one of the best, if not the best curved Trinitron we got here, though like you said, simple doesn't mean bad.

Many say that. Wouldn't disagree. They're not perfect, but need fairly little tweaking and certainly have that exact 90s Trinitron look many people want. And they're really basic & simple. Yoke:



Doesn't even have six rings! The purity rings are just this weird fork looking contraption. But then again I've never seen one with purity issues, so guess simple & stupid works!

The only optional 'extra' my X5 had in the case was this:



How nice of Sony to include a spare solder joint! It doesn't seem to have fallen off anywhere I can tell, just glad I found it before it shorted anything out.

In my experience, comb filters smear the look of 240p games too much for my tastes. Barebone TVs without it makes games look better on composite.

I think that's a pretty common opinion, comb is maybe best for video content?

Pots? Here's all I've got in my service manual for dynamic convergence, on the supposed "top of the line" consumer Sony CRT



Above my paygrade to say the least. I might buy some permalloy strips for the corners if anyone knows where to get them anymore though

Really, WTF? I always thought the FV310 was this god tier US TV model and they make you tilt the yoke like a peasant? I would've expected some giant service menu with dozens of convergence things to tweak and like 5 more pots to adjust on the yoke. How strange.

You can buy pricey convergence strips on eBay or make them yourself:



Top is the eBay strip. Bottom two are what I made. Just buy these credit card sized prying tools and cut them into strips. Then double sided tape at one end and that 3M permalloy magnet tape at the other end with some Kapton tape wrapped around for good measure. I've also read you can use box cutter blade pieces. I made one but haven't gotten around to trying it, maybe it works better, we'll see.

I don't really know exactly what type of magnets / material are the right kind etc., I'm just trying things out and play around till the picture looks good :/

[tongshadow]

Converging by tilting the yoke vertically is useless anyways because there's only one position to get proper parallel (not straight!) horizontal lines.

[Tempest_2084]

Converging by tilting the yoke vertically is useless anyways because there's only one position to get proper parallel (not straight!) horizontal lines.

Yep, yoke adjustment is mostly for geometry. I need to fix my horizontal convergence...

[bobrocks95]

It is at least nice to confirm my suspicions that probably the most I could manage to do tilting the yoke is mess something up! Always assumed I'd do more harm than good.

Really, WTF? I always thought the FV310 was this god tier US TV model and they make you tilt the yoke like a peasant? I would've expected some giant service menu with dozens of convergence things to tweak and like 5 more pots to adjust on the yoke. How strange.

Well, the picture's lovely as long as you only look at the middle of the screen where the static convergence is good lol. Don't think I could do without a high voltage regulator to stop bright colors from blooming at this point.

Wish I could find another since we did bang up the plastic getting it home (32" and heavier than it has any earthly right to be). But I don't think that'll ever happen.

I don't really know exactly what type of magnets / material are the right kind etc., I'm just trying things out and play around till the picture looks good :/

I tried what, a piece of a tin can I think once? Absolutely not the right material haha. I did find permalloy like sheets you could buy and cut, I think that'd be the ideal solution.

[Josh128]

I bought some permalloy and cut it, it works.

[ASDR]

Converging by tilting the yoke vertically is useless anyways because there's only one position to get proper parallel (not straight!) horizontal lines.

I found when I had terrible convergence because of a poorly positioned yoke I also had at least a little bit of htrap distortion or so, so maybe you're right. It's probably rare to have a TV with perfect geometry but terrible convergence anyway.

Well, the picture's lovely as long as you only look at the middle of the screen where the static convergence is good lol. Don't think I could do without a high voltage regulator to stop bright colors from blooming at this point.

Wish I could find another since we did bang up the plastic getting it home (32" and heavier than it has any earthly right to be). But I don't think that'll ever happen.

You know they made 40" WEGAs? Must be >150Kg. It seems the truly high-end sets with all those PVM/Monitor like features are all >= 30", but I just can't carry or transport them without special arrangements and could at best fit one of them. I think 25" (is that 27" by US measurements?) is the sweet spot for me since I can just about get my arms around that kind of case.

Good point about the HV regulator. That's just what I mean with my comment one expectations with CRT TVs. Even if you have perfect geometry all it takes is a single bright spot to distort everything around it.

I don't really know exactly what type of magnets / material are the right kind etc., I'm just trying things out and play around till the picture looks good :/

I tried what, a piece of a tin can I think once? Absolutely not the right material haha. I did find permalloy like sheets you could buy and cut, I think that'd be the ideal solution.

I bought some permalloy and cut it, it works.

The strips I've shown were just using permanent magnet tape, which is apparently the wrong material but can still be useful. From what I've read, box cutter blades should be permalloy. I made a few strips out of that but have yet to try them. And yeah, you can buy sheets of permalloy on eBay.

I honestly don't really know what exactly the point of putting a specific non-magnetized piece of metal near the yoke is. Permalloy is 'permeable', so I would assume that unlike lead etc. it lets the magnetic field from yoke go right through it? How would that help? I guess I could see if those strips were blocking/guiding the magnetism from the coils, but what is the point of something that neither has its own magnetism nor affects the existing one? If anybody here could clear that up for me, much appreciated

[Josh128]

I honestly don't really know what exactly the point of putting a specific non-magnetized piece of metal near the yoke is. Permalloy is 'permeable', so I would assume that unlike lead etc. it lets the magnetic field from yoke go right through it? How would that help? I guess I could see if those strips were blocking/guiding the magnetism from the coils, but what is the point of something that neither has its own magnetism nor affects the existing one? If anybody here could clear that up for me, much appreciated

Magnetic permeability of a material near a coil changes (increases) the coils inductance. This is the same principle all high efficiency transformers utilize and why they have an iron or ferrous core. These strips affect the magnetic field produced by the DY in the area under the coil in which they are placed. This affects how each cathode ray is deflected in that region of the tube. Permalloys super high permeability makes it effective even in thin strips required to slide under the yoke. That said, expect to be frustrated when using strips-- most of the time, you can only get limited benefits as a strip affects all the cathode rays, not just one. If your red is separated in the top right corner from your blue and green, they will all move when you play with a strip underneath them, which also affects geometry in that corner. By using different depths and angles of the strip, sometimes you CAN get corner convergence a bit better, but its often difficult, frustrating, limited, and not the magic bullet you might be hoping it is.

Also, despite what others have said, tilting the yoke does work for adjusting dynamic convergence, its actually the most effective way to do it when you dont have PVM-like adjustment coils and controls. Thing is, its like an art. Its ULTRA sensitive. You may need to tilt the yoke 1mm up, down, or diagonally to pull a red or blue extruding beam back into the white line where its supposed to be. THEN you have to place the wedge under it then tighten the clamp to hold the yoke there all without anything moving. THEN you have to re-examine other areas of the screen that you werent having a problem with to see if youve introduced a problem. In other words, its not easy.

[H6rdc0re]

On my Sony PVM I had to remove the anti glare filter because it was damaged. Now I find the brightness to be much higher and the black levels are much worse. Does anyone know if it's possible to use a different anti glare filter from for example a car window?

[Tempest_2084]

I noticed on my flyback there's a SCREEN knob below the Focus. What does that do?

[Josh128]

Increases or decreases screen voltage. ie it will brighten or darken the screen.