Re: Who remembers how bad analogue television was?

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Sujet : Re: Who remembers how bad analogue television was?
De : Jeff (at) *nospam* invalid.invalid (Jeff Layman)
Groupes : sci.electronics.design
Date : 27. Feb 2025, 09:10:08
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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. 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.
--
Jeff

Date Sujet#  Auteur
27 Feb 25 * Who remembers how bad analogue television was?36Sylvia Else
27 Feb 25 +- Re: Who remembers how bad analogue television was?1Edward Rawde
27 Feb 25 +* Re: Who remembers how bad analogue television was?6Don Y
27 Feb 25 i+* Re: Who remembers how bad analogue television was?2bitrex
27 Feb 25 ii`- Re: Who remembers how bad analogue television was?1Don Y
11 Mar 25 i`* Re: Who remembers how bad analogue television was?3Joerg
12 Mar 25 i +- Re: Who remembers how bad analogue television was?1Don Y
12 Mar 25 i `- Re: Who remembers how bad analogue television was?1john larkin
27 Feb 25 +* Re: Who remembers how bad analogue television was?4Jeff Layman
27 Feb 25 i`* Re: Who remembers how bad analogue television was?3Martin Brown
27 Feb 25 i `* Re: Who remembers how bad analogue television was?2KevinJ93
2 Mar 25 i  `- Re: Who remembers how bad analogue television was?1Edward Rawde
27 Feb 25 +* Re: Who remembers how bad analogue television was?11Liz Tuddenham
27 Feb 25 i+* Re: Who remembers how bad analogue television was?9john larkin
27 Feb 25 ii`* Re: Who remembers how bad analogue television was?8john larkin
27 Feb 25 ii `* Re: Who remembers how bad analogue television was?7Lasse Langwadt
27 Feb 25 ii  +- Re: Who remembers how bad analogue television was?1john larkin
27 Feb 25 ii  +- Re: Who remembers how bad analogue television was?1Don Y
28 Feb 25 ii  +* Re: Who remembers how bad analogue television was?2Sylvia Else
28 Feb 25 ii  i`- Re: Who remembers how bad analogue television was?1Don Y
28 Feb 25 ii  `* Re: Who remembers how bad analogue television was?2Tom Del Rosso
1 Mar 25 ii   `- Re: Who remembers how bad analogue television was?1john larkin
28 Feb 25 i`- Re: Who remembers how bad analogue television was?1Sylvia Else
27 Feb 25 +* Re: Who remembers how bad analogue television was?9KevinJ93
27 Feb 25 i`* Re: Who remembers how bad analogue television was?8Martin Brown
28 Feb 25 i `* Re: Who remembers how bad analogue television was?7KevinJ93
28 Feb 25 i  +* Re: Who remembers how bad analogue television was?3Jeff Layman
2 Mar 25 i  i`* Re: Who remembers how bad analogue television was?2Edward Rawde
2 Mar 25 i  i `- Re: Who remembers how bad analogue television was?1John R Walliker
28 Feb 25 i  `* Re: Who remembers how bad analogue television was?3Martin Brown
28 Feb 25 i   +- Re: Who remembers how bad analogue television was?1Jeff Layman
28 Feb 25 i   `- Re: Who remembers how bad analogue television was?1Joe Gwinn
28 Feb 25 +* Re: Who remembers how bad analogue television was?3Don Y
28 Feb 25 i`* Re: Who remembers how bad analogue television was?2Martin Brown
28 Feb 25 i `- Re: Who remembers how bad analogue television was?1Don Y
28 Feb 25 `- Re: Who remembers how bad analogue television was?1Bill Sloman

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