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CRT tv to arcade


mar.vel.ous

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I bought 4 new 21" TVs a couple of months ago from local place (Korean brand, Chinese design, supported locally in Thailand), and also got 4 CRT arcade chassis to match recently from Alibaba. The TVs were just for tubes to match the chassis (although I am hoping to mod the TV chassis to accept component inputs too).

 

HOWEVER, it was hard for me to find the right chassis supplier. Many simply couldn't help, "factory closed" was heard a lot. The ones I got may have been old stock, not sure. In any case, supply of generic arcade chassis seems to be drying up.

 

There are still plenty of new CRT TVs in China and SEA still, and I can even buy them online, although the tide is slowly but inexorably turning. The second hand market for CRTs is harder to access than in Australia.

 

Interesting aside: I checked out a few stores, a few times, before finally buying the 4 TVs (in Thailand). The male sales assistants I talked to kept trying to get me to buy some little shit LCD TV instead. Didn't really listen to me explain what/why I wanted. But when I talked to the female sales assistants, they'd just say OK, they might indicate the LCDs, I'd say no thanks. Then they ask why? I tell them. Then they'd understand, and tell me how many in stock! As you can guess, I bought in bulk from the chicks.

 

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They do infact have CRT TVs for sale on Ali however they are not new, they are an old recycled tube paired with a new cheap and nasty chassis housed in a new frame.

 

You can in fact still buy new CRT TVs on Ali and elsewhere, as noted in my post above.

 

Thing is, China still has many of these CRT TV factories all tooled up and with people to operate them. They aren't new factories, they are old ones whose value has been depreciated so much that the capital cost of operating them is very small. The cost of paying people to operate the factories is still small in China too. So it mostly comes down to just materials cost, and they'll keep pumping out cheap TVs until people stop buying them for minimum cost (or "marginal cost of production" in economist terms).

 

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No, you aren't reading it correctly :) It's not a CRT.

 

That Alibaba ad is, if you read it correctly, saying that they will make whatever TV you want within a range of specs, and the ad seems to be focused on CRTs.

 

The idea is that they can make a big bunch of them, to order. They also may have what you want in stock.

 

Alibaba is not like ebay, where you bid and "buy now". Works best if you find a company that seems to do what you want, then you can ask/tell them what you want. Chinese business is all based upon relationships, so you want to work towards that. I don't mean buying them dinner, I just mean communicating before ordering. Some companies are better than others. Look at other stuff the company is selling while you are there. I never buy anything directly, I usually ask them to prepare an invoice, which I pay through the site.

 

They will speak English, but you must keep your English simple, direct and polite at all times.

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Hey Zebidee if you could get a bulk order of decent quality NEW 4:3 CRTs we could use for arcade monitors I'm sure people would be willing to pre-pay for them, I know I would be in for at least one :)
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I was intrigued by the 'new' CRTs I spotted on Alibaba. I enquired with several distributors who all informed me of the same thing, used tube that they salvage from discarded TVs paired with a generic chassis.

 

I don't know of any existing factories still tooled up for vacuum tube production.

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I turned my old monitor out of the 20" Hankin into a Jamma test bed a decade ago, I'm now considering sending the chassis to Joey for re capping & adjustment. I've still got the original 12 pin CRT for it. With supply drying up I think it's an asset worth keeping.

 

I've sent @Jomac an email, think it's worth doing.

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I was intrigued by the 'new' CRTs I spotted on Alibaba. I enquired with several distributors who all informed me of the same thing, used tube that they salvage from discarded TVs paired with a generic chassis.

 

I don't know of any existing factories still tooled up for vacuum tube production.

 

I've noticed growth in DIY'ers pairing NOS CRTs with new TV chassis based on a basic Chinese design (similar to the ones I bought), and this seems particularly popular in developing countries where the option to get a cheap TV like that is attractive. I'm guessing the ads you've seen relate to that kind of market.

 

I wouldn't buy actual CRT tubes from Alibaba, esp 2nd hand. Aside from quality control, freight would be a killer, except maybe in a commercial quantity for a container-load or more of new product, and at that point I'd be dealing directly with the company instead.

 

Be aware that Alibaba sellers will often put a whole bunch of keywords into their ads, which may or may not reflect exactly what they are selling. It is designed to attract your attention (and search hits), and does not always reflect unscrupulousness (many trustworthy ebay sellers do the same). You have to do your homework and communicate with the ones that seem to be better.

 

The TVs I bought locally (in Thailand) had all new components and CRTs. Under warranty too! Guess I void that when I open the back up anyway :D Local support, although they never replied to my email asking for service manual. Manufacturing date 4/3/17. I was able to inspect the tubes quality before buying by watching Thai soap opera for a while.

 

Distar box.JPGDistar CRT.JPG

 

I've got one of the CRTs hooked up to one of the arcade monitors now. I'm not disappointed with the quality, looks pretty darn good, though quality not as good as a nice-brand RGB input TV or a SI chassis (I also attached an SI chassis as well to compare with same tube - SI was notably better with light greys, but the colours are good with Chinese cheapie).

 

DistarChina.JPGDistar sword.JPGDistar action.jpgDistar cleric.jpg

My "ghetto" testbed setup.

 

I had issues with the image "blooming" and related image distortions from light/dark changes when RGB input via video amp. I don't get blooming with RGB input direct (no amp), but the image is too dark. It may indicate poor HVR (high voltage regulation). It may also indicate that the chassis expects a larger CRT (21" is on small side) and/or that the Ultimarc amp is just boosting the signal too much.

 

It's almost impossible to capture the blooming in a video as the CCD light sensors in the camera saturate (bloom out) as well.

 

I attached 470uF capacitors onto the RGB inputs and that has help moderate the blooming a lot, seems to make the colours richer. I tried resistors inline and as termination (esp 75 ohms) but it didn't really seem to help.

 

VGA-AMP-CAP.JPG

Distar CRT.JPG

image1.JPG

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After looking at the schematics, I think your Sanyo TV would be difficult to mod, no RGB inputs on the jungle IC afai can see, and the OSD is build into the jungle so no way to tap into its inputs.

 

After you safely discharge the anode, remove the yoke connector (large, 4 pins in 2 pairs, with one pair a little larger, other end connects to yoke) from the PCB and measure the low-ohms resistance across each pair (put your multimeter probes into the female connector ends). Vertical is the pair with lower ohms. I find doing it this way easy as you can easily get a good test signal for the DMM.

 

You can also measure yoke impedance directly from the pins on the yoke, without removing the connector. Or even by just inserting your DMM probes into the back of the connector's pins.

 

Your tube looks like a 10-pin in the manual diagrams, but the socket part for the PCB looks like an 8-pin socket. Maybe it is both, CRTs don't always use all the pins. You may as well gently remove the neck board and count them.

 

Note that flat screens often have convergence issues that might not be obvious until you do RGB gaming stuff with them.

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The Sanyo doesn't look like an RGB mod candidate to me....however, it does have component YCbCr inputs. How about a JROK RGB to Component Video converter?

 

http://www.jrok.com/hardware/RGB.html

 

As we get more desperate for tubes I think component is a viable option.

@MarkOZLAD, I suggest that the OP waits just a little. I'm about to post up details of my PC RGB(s) to component conversion mod & TV input hack.

 

I won't go on about it too much right now as I'd like to discuss it on the new thread. But let me say that I have been following your inputs re: TV modding on the shmups forum (as a lurker) and was meaning to ask you stuff about your component input TV hack (though I think I've mostly answered my own questions since).

 

The results I'm getting are so impressive that I might not bother using the arcade monitor chassis I bought for the TV's tube. I used to routinely dismiss component video as blah vs RGB, but after this I'm thinking that anybody who can use a soldering iron can get themselves an (almost) RGB quality monitor.

 

On JROK: seems like a good product, but it costs too much ($US80). My mod cost less than $5 (OzBucks) in materials, though probably took up more than $5000 worth of my time (first researching, sourcing materials, then assembling & fiddling) to get it right.

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Keen to see details of your RGBS to component converter, quite a few of us have looked into it over the last couple of years. I'll save any questions until you post your thread.

 

I love RGB modding but I'm a pragmatist. Component YCbCr is a great option and there are so many late model chassis that take it, why make life hard to get a few percent improvement? Does it really make your enjoyment of the game that much better?

 

The TV I added component and S-Video to is a TEAC CTF-5151. It was composite only from the factory but I found it's TMPA88xx jungle and chassis were able to handle S-Video and Component. I studied the service manual and found that there was a setting to enable YUV in the service menu, once I confirmed that worked I studied the schematic and the chassis to work out what parts were missing and added them in. Really not difficult but was a nice change from RGB modding and made a pretty useless set something worthwhile. It helped that a friend had donated a not working set that had a very similar chassis that I could rob parts from.

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@MarkOZLAD, I think that your TV's jungle is almost identical to mine. I think I may even have used a manual for yours, as I couldn't find one for mine and in any case, mostly all in Chinese.

 

I've put up a new thread and first post, but so far it is all about the TV hack side of it. The next post I'll get into the RGB2YUV mod itself

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Good quality component comes in at 95+% of RGB, indistinguishable. Low quality comes in around 70-90% or so.

 

I've been doing RGB for 12 years or more, but my latest experiments with PC RGB => component TV have enlightened me. With good quality RGB2YUV conversion and minimial signal interference, component is very closely comparable to RGB.

 

I've been doing a lot of work on this lately. Check it out:

 

https://www.aussiearcade.com/showthread.php/96773-PC-RGB-to-component-converter-amp-TV-hack?p=1209500#post1209500

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They do infact have CRT TVs for sale on Ali however they are not new, they are an old recycled tube paired with a new cheap and nasty chassis housed in a new frame.

@Frank_fjs, I reported earlier (page 3 of this thread) that I'd bought 5 new 20" TVs with all new tubes and a cheap but fine Chinese generic TV chassis - but I'd only opened up one of the TVs to check.

 

Since then I've opened up another 2 of these TVs and found that they do, in fact, seem to have 2nd-hand or "refurbished" tubes. First one had a 21" tube, 2nd one was 20" and 3rd was 21" again. They put a new-looking sticker on the tube with a 4/3/2017 manufacturing date, but on the 2nd TV it was obviously 2nd hand as the tube still had remnants of old stickers. All have slightly different yoke impedance readings. I haven't opened the last 2 yet.

 

I'm not really all that disappointed, though a little surprised. So long as the tubes are good. I've setup many arcade monitors before using recycled tubes from old TVs.

Edited by Zebidee
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Hi,

 

What prerequisites does a crt tv need to have to be suitable for a conversion?

 

Is there any models one should steer clear from? Eg. LG flatiron or what not

 

Thanks

 

 

Sent from my iPhone using Aussie Arcade

 

If i were you, i would aim to convert the TV chassis to accept RGB input via the OSD or TELETEXT input, this way youre not stuffing around with a so called universal chassis and it will have generally speaking perfect compatibility.

 

It is the TV's chassis you need to concern yourself with, not the tube type.

 

Modding the TV chassis is generally very easy, provided the set takes it's OSD from an RGB source.

 

I think ive got about 14 consumer grade CRTs left here in varying sizes.

 

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@Frank_fjs, I reported earlier (page 3 of this thread) that I'd bought 5 new 20" TVs with all new tubes and a cheap but fine Chinese generic TV chassis - but I'd only opened up one of the TVs to check.

 

Since then I've opened up another 2 of these TVs and found that they do, in fact, seem to have 2nd-hand or "refurbished" tubes. First one had a 21" tube, 2nd one was 20" and 3rd was 21" again. They put a new-looking sticker on the tube with a 4/3/2017 manufacturing date, but on the 2nd TV it was obviously 2nd hand as the tube still had remnants of old stickers. All have slightly different yoke impedance readings. I haven't opened the last 2 yet.

 

I'm not really all that disappointed, though a little surprised. So long as the tubes are good. I've setup many arcade monitors before using recycled tubes from old TVs.

 

Those tubes couldve been rebuilt, wouldve been quite a while ago though.

 

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When using a crt tv how will it auto power up? Like a regular monitor

 

 

Sent from my iPhone using Aussie Arcade

Use a power distribution board inside your cab.

 

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How much quality loss is there between RGB, component RGB and S-video. RGB being 100%, what %ge do the other two fall at

 

 

Sent from my iPhone using Aussie Arcade

 

S-Video will vary a fair bit between TV sets, but it is total rubbish compared to RGB anyway. 25-30% tops. It is not much better than composite video.

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