Re: Who remembers how bad analogue television was?

On 27/02/2025 08:10, Jeff Layman wrote:

On 27/02/2025 04:52, Sylvia Else wrote:

Leave aside the ghosting, which could largely be addressed by having a
decent antenna.
>
But my memory of a Philips Colour TV (1984ish) was that it had rubbish
automatic gain control (AGC), and odd interactions between brightness
and picture position.
>
The AGC should have been based on the amplitude of the sync pulses,
which was 30% of the total. I'm sure this could have been done, but my
experience was that instead it was based on the average amplitude of the
demodulated signal. A black image containing large white text, such as a
title screen, would show a clear darkening to the sides of the text,
while being decidedly grey over the rest of the screen.
>
I suspect this same poor AGC was responsible for a shift in the
detection of the sync pulse such that the text would be moved to the
right of its proper position, which could result in distortion of the
letters as the average brightness varied line by line.
>
In the early days of television, using thermionic valves, it was
probably a miracle that these things worked at all, but surely in the
transistor age, something better could have been provided.
>
Were studio monitors any better, anyone know?

 I suppose that's one of the problems with being "first past the post" - you get stuck with the system. The US had NTSC, valves, and 525 lines.

I always believed that made it impossible for them not to have newscasters with flesh that slowly shifted between ghastly green and purple tones (or was clamped to unnatural pale orange like the Donald's). NTSC was called Never Twice the Same Colour in the UK for good reason. PAL was self correcting. My Japanese sets could do both.
However, when I was in Japan I saw US style NTSC TV implemented correctly. It seems there was no reason that it could not be made to work well only that US makers couldn't be bothered to do it right.

In the UK colour broadcasting didn't start until over 12 years later - July 1967 - using PAL, transistors, and 625 lines. Most of western Europe was the same as the UK, but in France and eastern Europe it was SECAM and 819 lines. From what I understand, PAL was better than NTSC, and from what I remember, analogue colour in the UK wasn't bad at all.

Very early sets the colour was in pastel shades until they started doping the front screen with neodymium to take out the unwanted yellow component in the early phosphors (especially the blue). Barely gets a mention now but it made a big difference to colour saturation and purity. Put sets with and without Nd doping together and the difference was huge. But either one on their own would satisfy a punter. Premium price for the one with better more saturated colours.
https://en.wikipedia.org/wiki/Cathode-ray_tube#Constructions
Main problem though was reliability I recall the service engineer spending lots of time fiddling with valve swaps. ISTR the original valve EHT stack rectifier gave off X-rays and had a lead shield around it.
--
Martin Brown