Re: Who remembers how bad analogue television was?

On 27/02/2025 19:58, KevinJ93 wrote:

On 2/26/25 8:52 PM, Sylvia Else wrote:

Leave aside the ghosting, which could largely be addressed by having a decent antenna.
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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.
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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.
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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.
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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.
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Were studio monitors any better, anyone know?
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Sylvia.

 Are you sure that 1984 date is correct? By 1970 in the UK colour TVs used transistor signal processing stages and many had already changed to transistors for the power stages such as line and frame output as well as using chopper stabilised power supplies.

The first two colour TVs I recall owned by friends or family were about the time of Apollo 8 in 1968. Memorable for the Earth rise shot. Both were entirely valves and my uncle's caught fire leaving a nasty brown burn mark on their wool carpet and smoke damage on the ceiling.
The earliest was at a school friends house and was in pastel shades pre Nd glass. It was in colour but only just... Joe 90 launch was the first programme I can recall watching there in colour. Test cards in shops don't count.
I'd believe 1974 as a date for hybrid colour TVs that almost worked correctly and didn't need a service engineer visiting them every other week. By 1980 I'm pretty sure they were almost entirely semiconductor based.

Typically they used some form of gated AGC to not be affected by the video modulation.

I recall sound on vision being a bit of a problem too with certain types of check or dogtooth suits or other high contrast periodic fabrics.
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Martin Brown