Hello,
Where can I find detailed description about the sound and tuning
circuits of the TV?
What is the best book about the TV internal design ( especially the
sound)
Are there online sites that deal with that ?
Gratefully:
[email protected]
I had some good books 35 years ago...
TV has now advanced to digital, you know.
As for the analog I can speak only for PAL(as a professional broadcast
engineer):
In PAL (in Europe that is), sound is transmitted FM modulated
on a carrier 5.5 MHz above the video one.
Sometimes (some stereo system) a second slightly higher carrier is used
dont remember, sum and difference channel to make it stereo, or
second language perhaps.
In (the old analog) receivers there were basically 2 ways to handle it:
1 intercarrier sound, wide IF, video detection, take the 5.5MHz from the
AM demodulated video with a small tuned cicuit, and limit amp, ratio detector.
A second 5.5 stop in the video to get rid of the sound there.
Later TVs used quadrature detectors (TBA120 was a common chip here).
The other system was to split of in the IF, have a sepate (3x MHz) IF limiter
amp for the sound, IF curve so no sound in the video for the video IF.
Philips used this latter system, it is claimed to give better video
rejection in the sound.
Modern analog TVs use SAW filters and have really good IF curves.
When I was a kid, 'v Aisberg's books about television and radio learned
me a lot.
My own TV design used intercarrier sound.
But that was more the 50 years ago
OK, I saved you the book, now send me the $$$$$$$$$$$$$$$$
PS
Now it is going digital, apart from how it is transmitted
(different ways for satellite cable etc..), it is a packetized stream.
transport packets with in it packets for many audio channels,
teletext (ceefax videtext), subtitles, access information, network info,
what not, video (in mpeg2 format).
ieee has likely some documents, else look up etsi.org.
JP
