Sharp focus - apperture grille vs shadow mask

[andykara2003]

Hi,

I've collected quite a few shadow mask 15Khz consumer TV's (Panasonic, Toshiba, JVC etc.) in the interest of having a display with less pronounced scanlines than my consumer Trinitron. For this, they are great - the scanlines are really mellowed comparatively.

The only thing is that they're all less sharp than my Trinitron even after I adjust the focus.

Is this something that's just normal for 15Khz consumer shadow masks or are there some that are renowned for sharp focus?

Cheers.

[fagin]

Theoretically an Aperture Grill provides finer detail than a shadowmask, which in essence is what you're seeing with more pronounced scanlines and an apparant sharper focus.

I don't personally have enough shadowmask CRT's to comment, as to whether this is true en mass.

[andykara2003]

Theoretically an Aperture Grill provides finer detail than a shadowmask, which in essence is what you're seeing with more pronounced scanlines and an apparant sharper focus.

I don't personally have enough shadow mask CRT's to comment, as to whether this is true en mass.

Thanks Fagin - But aren't the pronounced scanlines of the aperture grille due to the fact that the phosphors are in a line rather than in a 'triad' formation like the shadow mask type?

I didn't know aperture grille TV's were theoretically sharper. Does anyone have real world experience of comparing good shadow mask consumer TV's to Sony Consumer Trinitrons re sharpness & focus? (obviously pre-100Hz & other processing)

[Xyga]

Why yes Trinitrons always look sharper.

But since most 'still working fine' trinitron TVs are flat tubes the geometry often sucks and is a bitch to fix.
So compared to some decent curved tube TVs (too many to give you just one example) trinitrons are not necessarily more enjoyable.

What I like the most is the Toshiba/Nanao combo from NAC's and Egret II's.

[andykara2003]

Why yes Trinitrons always look sharper.

Ok if that's the case I'll have to put up with the scanlines & go with the Trinitrons - Not keen on the scanlines but sharpness is more important to me.

(too many to give you just one example)

any preference between Panasonic, Philips, JVC & Toshiba Consumer TV's? These are the non-crap shadow mask TV's available here in the UK.

[fagin]

Theoretically an Aperture Grill provides finer detail than a shadowmask, which in essence is what you're seeing with more pronounced scanlines and an apparant sharper focus.

I don't personally have enough shadow mask CRT's to comment, as to whether this is true en mass.

Thanks Fagin - But aren't the pronounced scanlines of the aperture grille due to the fact that the phosphors are in a line rather than in a 'triad' formation like the shadow mask type?

What's with the "but"? What do you think happens to the overall image if all the colours are in-line....... it would appear sharper, ergo what you have found. This is because of the Aperture Grill.

[Xyga]

any preference between Panasonic, Philips, JVC & Toshiba Consumer TV's? These are the non-crap shadow mask TV's available here in the UK.

Nope. Too many models in the history of these brands and I don't know if there's one to be considered 'superior' by default.
What's more important today is to get some crt tvs in great shape with low mileage and good capacitors/transformer/etc.

I see many people struggling to get heavy run-down broadcast-grade crts they probably won't be able to service by themselves, when an entry level TV from the late 90's or early 2000's in great condition has good chances to display a cleaner image than a century-old PVM.

That's just my opinion but unless they know exactly what they're doing people shouldn't go for these broadcast monitors.
Or at least they should buy already-serviced ones from trusted sellers.

Used TVs are available in much greater numbers and sold for peanuts, just look around and buy some from second hand shops or flea markets until you get the right one(s).
The right one will be one you've tried at home or at the seller's place.
Just resell for 10£ or trash the no-good ones.

Let's be honest finfing a good crt today is like going cougar hunting with your fingers crossed in the hope you'll find a doable one that doesn't smell like rotten fish.

[andykara2003]

What's with the "but"? What do you think happens to the overall image if all the colours are in-line....... it would appear sharper, ergo what you have found. This is because of the Aperture Grill.

Sorry - I didn't fully understand your post - so if I understand correctly, it would be a trade-off between sharpness and scanline prominience. I could use my Trinitron which is sharp but has pronounced scanlines - Or a good quality shadow mask which will be less focused but mellower scanlines...

I just wonder if there are consumer shadow mask TV's which are known for being particularly sharp as far as shadow masks go...

[andykara2003]

I see many people struggling to get heavy run-down broadcast-grade crts they probably won't be able to service by themselves, when an entry level TV from the late 90's or early 2000's in great condition has good chances to display a cleaner image than a century-old PVM.

I think that's actually the crux of the matter - usage & age seem to have a huge effect on the picture.

[Xyga]

Totally.
It doesn't really matter who the manufacturer of the tube or chassis are if the set is too old and requires heavy maintenance and new parts to work fine.
To be fair it IS possible to renew a crt tv or broadcast monitor... but it's not for everyone.
I've seen too many people work months if not years on just one damn PVM and get nowhere, this is a job for experienced technicians, not really for amateurs.

By the way the best crt hunting places are schools, universities, administrations, retired people's houses, companies, etc.
2nd hand shops and flea markets are obvious places but they don't have the best stuff.

[andykara2003]

Just a thought - I know you can still buy new CRT multisync arcade monitors but I wonder if you can still buy new 15Khz only ones?

The only reason is that I've heard multisyncs don't display 15Khz too well:

Quote from Fudoh: "The tri-sync arcade CRTs I've seen don't have very nice 15khz pictures. They usually have extremely strong scanlines which distract from the actual graphics"

Fagin, do you know if there 15Khz monitors in 25/29" still available new?

[andykara2003]

By the way the best crt hunting places are schools, universities, administrations, retired people's houses, companies, etc.
2nd hand shops and flea markets are obvious places but they don't have the best stuff.

Great - stands to reason as they will have had much less consistent use. Cheers

Not sure how to approach places like these to persuade them to sell me their old CRT's though....

[Ed Oscuro]

Actually, my KV-27FS120 was a Goodwill find. It does have a slight white line at startup (which soon clears up) but otherwise the cabinet and picture are astounding and seem to show little use.

Of course there were many 16:9 sets at another thrift store I found somewhat nearby, parked in the back of the store - these were easy enough to look over and ignore.

It all depends on how much time you have to spend looking at the thrifts. If you are persistent, you should find something nice eventually.

BTW, some random thoughts on aperture grille vs. shadow mask:

Shadow Mask reportedly is heavier and more energy-hungry than aperture grille - I didn't notice this personally. I would like to do some comparisons with a kill-a-watt sometime, but I don't think it's an issue really.

Shadow mask ought to be more durable than trinitron, but in truth trinitrons are quite durable. I wouldn't expect either type to survive hard drops from a distance.

Shadow mask's scanlines might be "less harsh" but the details will also likely be much muddier. I would rather have the "sharp scanlines" - which look stunning in person IMO - than not knowing which pixel I am looking at.

[Xyga]

Not sure how to approach places like these to persuade them to sell me their old CRT's though....

Ask people you know who work at these places if they know someone who might know... etc

Or go straight at reception and state that you're offering to get them rid of old tvs and monitors. If you're lucky they may have some taking the dust in a storeroom. Offer to buy them a few £10s if they don't give them away.

Just ideas. But that's what the guys who own the nicest crts today do.
I know a crazy one who gathered so many he had to rent a garage to store them.

[andykara2003]

I would rather have the "sharp scanlines" - which look stunning in person IMO

I know what you mean. I would still rather have less pronounced scanlines for 240p 3D games (which I mostly play) but definitely not if it means having a muddy picture.

[andykara2003]

Just ideas. But that's what the guys who own the nicest crts today do.

Brilliant info, thanks - I'll definitely try this

[Crafty+Mech]

Strictly 15k Arcade CRTs are no longer being manufactured, but there are still nice used burn free tubes out there (at least in the US). Most come from gambling machines that have had strong production runs long after the arcades closed down.