Behind the scenes UK experimental colour transmission 1957

[Sandy G]

I watched 'em again....Wow...Still never have understood why color TV wasn't available in Blighty & the rest of Yoorup til so late, except for bureaucratic intransigence...And, of course, the desire on the part of some interests to tweak RCA's & America's collective nose a bit...

[wa2ise]

Originally Posted by Sandy G

Still never have understood why color TV wasn't available in Blighty & the rest of Yoorup til so late, except for bureaucratic intransigence...And, of course, the desire on the part of some interests to tweak RCA's & America's collective nose a bit...

Maybe they waited until some of the important patents on color TV expired?

[ppppenguin]

Originally Posted by Sandy G

I watched 'em again....Wow...Still never have understood why color TV wasn't available in Blighty & the rest of Yoorup til so late, except for bureaucratic intransigence...And, of course, the desire on the part of some interests to tweak RCA's & America's collective nose a bit...

The UK was the first country outside the US (and Japan?) to have CTV.

Some good reasons for taking so long:
Never Twice Same Colour
Cost - at both RX and TX ends

Actually NTSC can work perfectly well with modern technology and a lot of care.

[NewVista]

Originally Posted by ppppenguin

Actually NTSC can work perfectly well with modern technology and a lot of care.

P-P-P Penguin is R-R-R Right, as long as the Diff Phase spec is good in signal path, no problem. Early B&W transmitters (used for early color) prone to this problem.

US in 1940s should have taken the advice of some (Philco) and gone with higher res (700, 800 lines) but still, 525/60 NTSC would have been a good evolution from 405/50 for England in the late 50's as well as an original system for Aust/NZ (completing NTSC for the Pacific Rim). Would have made program distribution distribution a lot easier. To hell with non-English-speaking Continental Europe, let them keep their 625/50 (frame rate too slow for good motion) and their PAL (w/ its "Hanover Blinds" & half vert chroma resolution) and they can keep their Euro currency - which England wisely rejected.

[tubesrule]

Originally Posted by NewVista

US in 1940s should have taken the advice of some (Philco) and gone with higher res (700, 800 lines) but still, 525/60 NTSC would have been a good evolution from 405/50 for England in the late 50's as well as an original system for Aust/NZ (completing NTSC for the Pacific Rim). Would have made program distribution distribution a lot easier.

Keep in mind England was considering 405/50 NTSC not changing to 525/60. It's nearly impossible to run the frame rate of the television at a different frequency from the AC power. (at least for crt based sets) This is why all 50Hz power countries use a 50Hz field rate, and 60Hz countries use 60Hz.

[old_tv_nut]

Originally Posted by tubesrule

It's nearly impossible to run the frame rate of the television at a different frequency from the AC power. (at least for crt based sets) This is why all 50Hz power countries use a 50Hz field rate, and 60Hz countries use 60Hz.

Well, it was nearly impossible to do at a reasonable price with tubes at the time. Obviously eventually doable at reasonable cost with more sophisticated solid state power supplies, as demonstrated by millions of computer monitors.

[NewVista]

Originally Posted by tubesrule

It's nearly impossible to run the frame rate of the television at a different frequency from the AC power. .

You hear this now and then but I can't see how it's scientific - more an "Urban Myth".

Using systems with 25fps is unenlightened (based on 1920's 24fps film). It should not have been television spec by the 1950's.

[ppppenguin]

Originally Posted by tubesrule

.....It's nearly impossible to run the frame rate of the television at a different frequency from the AC power. (at least for crt based sets) This is why all 50Hz power countries use a 50Hz field rate, and 60Hz countries use 60Hz.

Japan has both 50Hz and 60Hz power which must have made things a bit interesting for their TV service.

Colour made it impossible to use a mains (power line) locked field frequency. In the early days most systems relied on this to minimise the visibility of hum effects. Not sure which is more annoying; a slow moving hum bar or a 10Hz effect.

[tubesrule]

Originally Posted by ppppenguin

Japan has both 50Hz and 60Hz power which must have made things a bit interesting for their TV service.

Interesting Jeff. I didn't know Japan still used mixed frequencies. Perhaps after the war everything was converted to 60Hz?

The US had a mixture of 25, 50 and 60Hz power but had mostly settled on 60Hz by the time of commercial electronic television. You can still find 50Hz based US clocks from the 20's and 30's.

Originally Posted by old_tv_nut

Well, it was nearly impossible to do at a reasonable price with tubes at the time. Obviously eventually doable at reasonable cost with more sophisticated solid state power supplies, as demonstrated by millions of computer monitors.

Hi old_tv_nut. This is what I was referring to but you did a better job elaborating. It was certainly doable with the power supplies of the time, but not practical or cost effective. Solid state based crt monitors did eliminate the ripple effect from the power supply, but you still had to deal with stray magnetic fields that could distort and ripple the image.

Originally Posted by NewVista

Using systems with 25fps is unenlightened (based on 1920's 24fps film). It should not have been television spec by the 1950's.

This isn't quite the same comparison. 24fps film would look horrible and flicker badly if projected at 24fps. They realized this very early on and use a 2X or 3X shutter in the projector which fools the viewer into seeing 48fps or 72fps thus eliminating the flicker. Of course the content is still at 24fps so motion won't be as smooth giving it that "film" look.

[colorfixer]

It's more than power supply filtering. Watching 50Hz video under 60Hz non incandescent lighting can be bothersome due to differing flicker rates. In my office, when I watch a 50Hz/Pal feed, the screen noticeably flickers when I light the room with fluorescent lighting. With good ol' inefficient incandescent lighting, it isn't nearly as bad. I'd suspect it's probably not as bad the other way around.

I won't even touch the fact that to some 60Hz viewers, a 50Hz video source flickers no matter what, until they eventually become used to it.

[NewVista]

Originally Posted by ppppenguin

..(power line) locked field frequency. In the early days most systems relied on this to minimise the visibility of hum ..

I don't know what GB did in the 30's but can't see how they would achieve the necessary H/V relationship starting w/ 50hz ref. I would like to see a reference/link on this early SPG scheme.

[ppppenguin]

Originally Posted by NewVista

I don't know what GB did in the 30's but can't see how they would achieve the necessary H/V relationship starting w/ 50hz ref. I would like to see a reference/link on this early SPG scheme.

Any SPG was a complex thing in the 1930s. Some were mechanical, like a Hammond tonewheel organ, others used lots of valves (tubes) to do frequency division. FOr 405 you start at 20250Hz. Divide by 2 to get 10125Hz for line pulses, divide by 405 for 50Hz field pulses. 405 = 3*3*3*3*5 The small numbers were essential for early frequency dividers. The 20250Hz master oscillator could be locked to 50Hz mains using a slow acting phase lock.

the sad part of the UK not moving into colour broadcasting with 405 NTSC is that all those great programs from the early 60s from the Beeb were only made in b/w

And many of the tapes were wiped for re-use because they were so expensive. I believe that in the US many shows were shot on film. This was rare in the UK, possibly due to the high cost.

[NowhereMan 1966]

Originally Posted by ppppenguin

The UK was the first country outside the US (and Japan?) to have CTV.

Some good reasons for taking so long:
Never Twice Same Colour
Cost - at both RX and TX ends

Actually NTSC can work perfectly well with modern technology and a lot of care.

IIRC, I think Cuba was an early adopter of NTSC TV in 1957, IIRC. Havana had a color station before Miami did.