Sujet : Who remembers how bad analogue television was?
De : sylvia (at) *nospam* email.invalid (Sylvia Else)
Groupes : sci.electronics.designDate : 27. Feb 2025, 05:52:40
Autres entêtes
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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?
Sylvia.