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Philips Netherland 567 line TV Standard

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Forum » Radios and other type of sets (Physics) etc. » Television » Philips Netherland 567 line TV Standard
           
Wolfgang Scheida
Wolfgang Scheida
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08.Jul.06 13:36

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Reply  |  You aren't logged in. (Guest)   1 Dear Dutch Collectors

Did you have entrance to detailed informations about the philips Idea of introducing a competitive 567 line system in 1948 to 1950 ?

Why was this system canceled and not winning part at the CCIR discussions?

Please send me links or informations if you could do that.

Thanks Scheida

Present informations see:

One

+

Two


(Text in German only)
 



This article was edited 28.Dec.06 10:49 by Wolfgang Scheida .

Arno Brauer
Arno Brauer
 
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08.Jul.06 22:40

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Reply  |  You aren't logged in. (Guest)   2 Hallo Herr Scheida,

Warum genau der Vorschlag von Philips keine Berücksichtigung bei der CCIR gefunden hat kann man wohl vermuten, mir ist kein Dokument darüber bekannt, außer, dass die CCIR im Sommer 1951, sich auf keine Empfehlung, sondern nur - wohl auf Druck der Engländer - 4 Systeme "registriert" hat.
Das waren:
1. 405 Zeilen (engl.)
2. 525 Zeilen (us)
3. 625 Zeilen (Genfer Norm - Dänemark, Deutschland, Holland, Italien, Schweden und Schweiz)
4. 819 Zeilen (franz.)

Eine Empfehlung erging nicht zu einer Norm, (die damals erhoffte "Weltnorm") sondern es wurden "nur" Empfehlungen zu Kenngrößen gegeben:

Bildformat: 4:3
Zahl der Teilbilder: 2
Teilbildfrequenz: Unhabhängigkeit vom speisenden Netz (bis heute nicht erreicht)
Modulation des Bildsenders: Amplitudenmodulation
Hochfrequenzübertragung: Restseitenbandverfahren (Empfänger mit Nyquistflanke)
Begrenzung der Seitenbänder: Oberes oder unteres Seitenband (Träger ungeschwächt)

Lage der Trägerfrequenzen Bildträger 1,25 MHz
innerhalb des Kanals: Tonträger 0,25 MHz

Dämpfung der Seitenbänder: mind. 20 dB

Danach war die "Genfer Norm" der Philips Version aus versch. Gründen überlegen.

Eine ausführliche Abhandlung zu diesem Thema findet sich in:

Fernsehen
Vorträge über neuere Probleme der Fernsehtechnik
herausgegeben von Dr.G Leithäuser und Dr.Ing. F Winkel
erschienen im Springer-Verlag 1953

Seite 25 ff. "Der Stand der internationalen Normung der Fernsehsendungen" Von Prof. Dr.Ing. F. Kirschstein

Warum die "Philips Norm" so einfach von der Bildfläche verschwand, wird dort nicht explizit gesagt, aber durch die sehr ausführlichen Gegenüberstellungen der
"4 Registrierten Normen" kann man es nachvollziehen.

Bei Interesse bin ich gerne bereit Ihnen den Vortrag zu kopieren (scannen).
Gruß aus Kassel
Arno Brauer
Wolfgang Scheida
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11.Feb.08 18:06

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This is a mail answer from Jac Janssen a Dutch TV collector:
Hello Wolfgang,
 
Official reliable information on the 567-line standard is somewhat limited.
Fact is that Philips wanted to propose this standard seriously within Europe.
From a theoretical (and also practical) point of view, it looked like the ideal standard at the time. It gave a good compromise between picture quality and costs. It already contained FM sound, negative vision modulation, good sync pulses, 3x4 aspect ratio, etc. And most of all: it looked immediately technically feasible without excessive product costs.
But in the beginning Philips did very little to promote it extensively outside NL (we speak of 1947 and early 1948).
In the meantime most countries in Europe more or less proposed a 625 line standard. The UK had little choice than to keep the 405 line standard for some time to come, so they did not really participate actively in the discussions. (France has always preferred a unique choice for their own purposes and reasons.)
When eventually there was some more effort from Philips to advertise and promote the 567 line standard, the other countries unofficially had agreed upon 625 lines.
So for the CCIR committee Philips tried to use the 567 standard, but very soon saw that other countries would adapt 625 lines.
This would mean a very restricted sales market for Philips (NL and possibly the Dutch speaking part of B). Realising the consequences of using 567 lines in isolation and thus not be able to export television equipment and parts (who would buy from a baker who does not eat his own (625-line) bread?), Philips rapidly changed over to 625 lines (1950). And that was, prematurely, the end of 567 lines.
No mass production or regular tv transmissions (apart from the Eindhoven experimental transmissions in 567 lines) had yet started in NL, so there was no compatiblity problem.
In the mean time Philips was working hard on the engineering of their first mass produced (625 line) sets: the TX400U (22 cm CRT) and TX500U (identical chassis, but 31 cm CRT). Only a few hundred (TX400Us) were ready at the start of the "official" tv service, broadcasted with Philips equipment and Philips personnel from the centre of NL. The day of the opening was 2 Oct 1951.
The TX400/500 sets were completely different from the 567 line experimental ones. Special TV-valves had been developed in the mean time and all transformers (including the EHT/horizontal output) were also different.
Of the 567-line sets (already limited in numbers by it self) probably only a few have been adapted to the "new" standard. The complete VHF-part should be a bit different (wider bandwidth) as well as the line output stage. These 567 line sets have been exclusively used by Philips and Philips engineers for all kind of tests. Some of them were taken home and, after making reception reports, were again taken back to the labs for further tests and modifications.
 
Only experimental broadcasts have taken place in 567 lines.
The number of different tv sets for this standard consequently is also limited.
Philips themselves have made 2 different sets:
* projection TV (6 cm projection tube) with radio. This was used for tests as well as promotional purposes. You see the same picture(s) everywhere (405 line version). There is supposed to have been a 567 as well as a 405 and a 441/445 line version. The aspect ratio of the 405 line version would of course be different (still 4x5 at that time), but otherwise the external appearance of all versions was identical.
The 405 line receiver had a completely different vision chassis than the 567 line version.
* 22 cm direct vision, single channel (no tuning), table model
 
In order to give tv some popularity and allow the (engineering) public to become acquainted with television, a (Philips) booklet was issued by J. Jager in 1949 ("Een experimentele televisieontvanger"). This booklet described a tv set which could be built from basic parts. Almost all parts could be bought from Philips dealers and the design used ready made transformers from Philips. The booklet gave a proposal for the chassis and building of the tv.
Not many have been built, but it makes interesting reading material. Most amateurs who actually built a working tv set chose to use oscilloscope CRTs and make their own designs. Guided by publications in various magazines.
 
I am certain I have a (magazine?) article somewhere, explaining briefly the situation concerning the rapid changover from the 567 to the 625 line standard (under pressure from other countries). I'll see if I can find it and then make a scan for you. 
 
I hope the above helps a bit and sheds some light over the oscure 567 line period.
 
Best regards from Eindhoven,
.
Mail from Jac Janssen 4.1.2007

This article was edited 11.Feb.08 18:13 by Wolfgang Scheida .

  
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