Text 32091, 59 rader
Skriven 2009-05-04 22:44:01 av Michiel van der Vlist (2:280/5555)
     Kommentar till en text av Ward Dossche (2:292/854)
Ärende: TV Systems
==================
Hello Ward,

On Monday May 04 2009 13:14, you wrote to me:

 Mv>> It was even worse. Although the Flemish used s 625 system, it was
 Mv>> different from the 625 line system used in Germany and The
 Mv>> Netherlands. (Positive vs negative video modulation).

 WD> I am no that certain.

I am very sure that the system used in Flandria was not the same as the system
used in Germany and The Netherlands. The analog televison set in my caravan did
not work in Belgium amd France. It did wrk in Germany. Im the UK I got picture,
but no sound.

 WD> one day we put an extra-antenna on the roof which was different in
 WD> shape than the one used for Flemish [..] . It enabled us to capture
 WD> images from the Dutch transmitter in Goes

If you lived near where you live now that is no big deal. It is only 45 km from
Goes to Antwerp.

 WD> Well, maybe it was already included in the technology ...

The the receiver must have been dual capability ands auto sense. Not really a
big deal, it is only reversing one diode..

The Flamish system was different from the Dutch, I am sure. It is confirmed by
my 1956 "Electronisc jaarboekje". I used to buy one every year. It contained a
wealth of information for the electronics man. The section about TV contains a
list of the systems in use in Europe and the countries where they were used.

Germany and the Netherlands used the CCIR-B system. Where in Flandria the
CCIR-C system was used. They both have 625 lines but the differ in the polarity
of the video modulation. B uses negative modulation (black is full power) and C
uses postive modulation ( white is full power). So if you can get it to
synchronise, you get a negative image. Also the sound is FM modulated for
CCIR-B and the modualtion is AM for CCIR-C

This gem from the past also reveals that although the French part of belgium
used 819 lines, it was NT exactly the same as the 819 line system used in
France.

                   nr of  video        channel    Offset for
                   lines  bandwidth    distance   sound carrier


France:   CCIR-E   819     10 MHz      14 MHz     11.15 MHz
Wallonia: CCIR-F   819      5 MHz       7 MHz      5.5  MHz

So the Wallons used a pimped down version of the French system. Semi compatible
but no the same. Less bandwidth, lower resolution. Probably to make it easier
to produce dual capability receivers. A very silly choice from the techincal
POV. They got the worst of both worlds....

Cheers, Michiel

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