[njp]

Originally Posted by pocatello

Somehow i doubt those claiming inherent superiority of their old tv's are calibrating them with color calibration sensors.

I wasn't claiming "inherent superiority" for my TV, or his. I was saying that the claim that it couldn't possibly have a decent picture because it was 16 years old was nonsense.

Things like brightness and color cannot be compensated for past a certain point as the phosphors degrade in efficiency.

You are simply restating the point I have already addressed. Phosphors begin declining in efficiency as soon as electrons start hitting them.

Regardless of that the only mainstream crts with a decent dotpitch were the super fine pitch sony's, and those did not stay on the market very long at all, and are certainly not what he owns as none were made 16 years ago.

And now you have moved the goal posts. Nobody has claimed that the picture is high definition - only that these TVs gave a good SD picture when they were new, and continue to do so many years later.

[Kodaz]

Originally Posted by carrolls

CRT sets, especially old ones need to be deguassed (de-magnetized) every 6 months. On trinitrons, there is a button at the back to do this.

I have a Sony Trinitron portable, and I can confirm what others have said that it does this automatically- with a loud grunt- every time you turn it on. It also lacks a separate degausssing button or indeed any way to do it manually.

Originally Posted by carrolls

Apart from anything else, a 16 year old CRT cannot have a decent quality picture anyway. The phosphorus will be very uneven at this stage in its life.

Coincidentally, my Trinitron is 16 years old.

It has seen fair use over most of that time, has *never* been fixed or adjusted, and I can tell you that the colour and sharpness it's capable of with an RGB SCART signal is genuinely as good as I remember it ever being.

No apparent fringing or other defects, and the colours are as bright and solid as ever.

[pocatello]

That is the thing, people do not notice gradual decline of quality, let alone over 16 years. Its why we have to calibrate monitors with sensors, and not by eye. Unless you had a crt warped in from 16 years ago standing side by side you can't really say it hasn't changed.

[Nigel Goodwin]

Originally Posted by njp

You are simply restating the point I have already addressed. Phosphors begin declining in efficiency as soon as electrons start hitting them.

The aging mode of CRT's is more down to the electron guns losing efficiency than the phosphors - which is why regunned tubes still gave a perfectly acceptable picture.

[Kodaz]

Originally Posted by pocatello

That is the thing, people do not notice gradual decline of quality, let alone over 16 years. Its why we have to calibrate monitors with sensors, and not by eye. Unless you had a crt warped in from 16 years ago standing side by side you can't really say it hasn't changed.

True perhaps, but Carrolls' assertion was that "a 16 year old CRT cannot have a decent quality picture anyway".

My parents had an old colour TV for around 20 years and latterly I noticed the picture being a bit flat and lacking "punch" (though even it appeared improved after it had been adjusted following a repair). That might have been due to ageing.

This isn't the case with my TV; the colours are still in-your-face vivid (if using RGB), the picture is still as bright as I'd want it, and by the standards of SD CRT it's still a cracking picture. Period.

It's not (and wasn't meant to be) a professional-grade monitor. I'm sure if it was possible to measure it with a colorimeter when it was new and now there would be some minor difference, but nothing remotely like the deterioration that "cannot have a decent quality picture" would imply.

[prking]

I think you would be surprised how big the deterioration is.

But the point is you are happy with the picture quality and that is all that matters. Its important to have a set with a picture you like.

[njp]

Originally Posted by Nigel Goodwin

The aging mode of CRT's is more down to the electron guns losing efficiency than the phosphors - which is why regunned tubes still gave a perfectly acceptable picture.

Well, the specific point that was being claimed was that the picture "degraded" due to phosphor ageing. As you say, the electron guns will also lose efficiency. Furthermore, the glass substrate on which the phosphors sit will typically darken over time under electron bombardment. So there are a number of factors at play, and I wouldn't like to say which ones will dominate. But none of them mean that a 16-year-old CRT cannot possibly have a decent picture.

[Nigel Goodwin]

Originally Posted by njp

Well, the specific point that was being claimed was that the picture "degraded" due to phosphor ageing. As you say, the electron guns will also lose efficiency. Furthermore, the glass substrate on which the phosphors sit will typically darken over time under electron bombardment. So there are a number of factors at play, and I wouldn't like to say which ones will dominate. But none of them mean that a 16-year-old CRT cannot possibly have a decent picture.

The only one likely to prevent it is loss of emission in the electron guns, as I said before regunning such tubes restores excellent performance - but there's certainly no guarantee that ALL 16 year old TV's have low emission CRT's. However, the chances of a 16 year old TV not having reduced emission is pretty low.

[bobcar]

It must depend a great deal on what "fair use" means. For some people it might mean an hour a day whereas others might have it on for 6 hours or more, a massive difference that would make a 16 year old TV "younger" than a 3 year old TV.

[njp]

Originally Posted by Nigel Goodwin

However, the chances of a 16 year old TV not having reduced emission is pretty low.

I haven't disputed that. What I have disputed is that this automatically implies a poor quality picture! If the only thing that has suffered is the TV's ability to produce a picture which is far too bright, why should it? It's not like the convergence has gone to pot, or the geometry is any worse than it was when new, for example.

[Nigel Goodwin]

Originally Posted by njp

I haven't disputed that. What I have disputed is that this automatically implies a poor quality picture! If the only thing that has suffered is the TV's ability to produce a picture which is far too bright, why should it? It's not like the convergence has gone to pot, or the geometry is any worse than it was when new, for example.

What usually goes is the greyscale accuracy, on any remotely modern CRT set this is set automatically, and continually, by the TV - and it loses control as the set ages too far. Old tubes also lose sharpness, with pictures getting softer and softer, and more and more blurred.

It's not the same aging as a Plasma, where it's the phosphurs 'wearing out' that limit their life. Older Plasma's tend to go very 'pinky', so it's greyscale changes, but for a different reason.

[Kodaz]

Originally Posted by prking

I think you would be surprised how big the deterioration is.

I genuinely doubt that. What genuinely surprises me is how *small* the deteroration is given the age of the set.

Originally Posted by prking

But the point is you are happy with the picture quality and that is all that matters. Its important to have a set with a picture you like.

The original point was that a 16-year-old TV need not necessarily have degraded to the point of unwatchability.

I could take your comment above to be an acknowledgement of that. But though I'm perhaps reading too much into it, it did come across as a way to put down what I said with condescension in the guise of sounding deceptively agreeable, somewhat "yes deary, I'm sure your TV is still very nice and so long as you're happy that's what's important". True- but the unstated implication is that the other person's judgement is still pretty ropey and the agreeable-sounding non-agreer is the one who's right.

As I said, slap a colorimeter against the display, and I've no doubt it would register some difference.

But looking at white text (via the RGB SCART signal) and there's no noticeable misregistration or softness- the limiting factor is still the somewhat coarse-ish (compared to a monitor) line pitch. The picture still looks bright- unlike my parents' old one which seemed to lack punch- and the colours are almost garishly vivid in that pure way you only get via RGB (rather than composite or RF signals). (*)

Yes, you'll have to take my word for that, but that's no worse than the implication that we should take *your* word for it that I'm kidding myself.

(*) No, I don't have them turned up- for some reason this model doesn't let you adjust the colour saturation (nor the contrast) for RGB inputs.

[prking]

Actually, it wasn't supposed to be a put down. We all have different experiences and opinions. I hope you won't be offended but I think you read too much into things.

[Nigel Goodwin]

Originally Posted by Kodaz

(*) No, I don't have them turned up- for some reason this model doesn't let you adjust the colour saturation (nor the contrast) for RGB inputs.

There is no colour on RGB, so colour saturation doesn't apply - however, the contrast should work on RGB and does the same job.

[AidanLunn]

Originally Posted by Nigel Goodwin

It's a big heap of old gear in our attic at work

Early B&W TV's, early colour sets, the first teletext TV, VCR's, radios, cassette players - basically anything we think is worth keeping for historical reasons. We also, on occasion, provide old TV's for period dramas - they pay really well

How much i would love to have some of your collection

(I myself seem to have built up a little collection of older colour TVs and VCRs)

I'm guessing that your museum has a Sony KV-1320 or 1330UB?

For those who don't know these sets, they are probably the most reliable TVs I've encountered. They were made in the late 60s/early 70s and many are still living today, some of those have never broken down, even with everyday use!

I bet those things are showering down on tips in droves now. Bloody digital switchover! (I don't understand why it is not the law over here for every digital set top box to have an RF modulator built in, so that they will work with older TVs that don't have anything else except an RF input)

[Nigel Goodwin]

Originally Posted by AidanLunn

I'm guessing that your museum has a Sony KV-1320 or 1330UB?

Yes we do, and a 9-90UB (9 inch dual-standard B&W).

Many of the old Sony's are still working, but the chance of finding one with a decent tube is pretty unlikely.

[AidanLunn]

Originally Posted by Nigel Goodwin

Yes we do, and a 9-90UB (9 inch dual-standard B&W).

Many of the old Sony's are still working, but the chance of finding one with a decent tube is pretty unlikely.

I know, I'm trying to find one to add to my collection, but because these sets are so reliable, many collectors have told me that they were used to death, so the tubes in many of them have worn out.

[Sizewell Bee]

Originally Posted by Nigel Goodwin

Yes we do, and a 9-90UB (9 inch dual-standard B&W).

Many of the old Sony's are still working, but the chance of finding one with a decent tube is pretty unlikely.

I also have a Sony 9-90UB at this end.
Used to use it for Band 1 DXTV, as far as I know it still works.