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1983 Philips 26CS3890/05R Teletext & Printer
MRG Systems ATP600 Databridge
Teletext Editing Terminal
Microvitec Monitor 1451MS4
BBC Microcomputer TELETEXT Project
Viewdata, Prestel, Philips
Philips Model Identification
1976/77 Rank Arena AC6333 – Worlds First Teletext Receiver
PYE 1980s Brochure
Ceefax (Teletext) Turns 50
Philips 1980s KT3 – K30 Range Brochure
Zanussi Television Brochure 1982
Ferguson Videostar Review
She soon put that down
1983 Sanyo Brochure
Wireless World Teletext Decoder
Unitra Brochure
Rediffusion CITAC (MK4A)
Thorn TRUMPS 2
Grundig Brochure 1984
The Obscure and missing Continental
G11 Television 1978 – 1980
Reditune
Hitachi VIP201P C.E.D Player
Thorn 3D01 – VHD VideoDisc Player
Granada Television Brochure, 1970s
Long Gone UK TV Shops
Memories of a Derwent Field Service Engineer
PYE Australia Circa 1971
Radios-TV VRAT
Fabulous Fablon
Thorn TX10 Chassis
Crusty-TV Museum, Analogue TV Network
Philips N1500 Warning!
Rumbelows
Thorn EMI Advertising
Thorn’s Guide to Servicing a VCR
Ferguson 3V24 De-Robed
Want to tell us a story?
Video Circuits V15 – Tripler Tester
Thorn Chassis Guide
Remove Teletext Lines & VCR Problems
Suggestions
Website Refresh
Colour TV Brochures
1970s Lounge Recreation
CrustyTV Vintage Television Museum
Linda Lovelace Experience
Humbars on a Sony KV2702
1972 Ultra 6713

Hi Steve,
interesting point you bring up there! I've done two quick checks on the "38,9 MHz emergence".
In the 1952 Philips Electronic Application Bulletin that introduced the intercarrier concept, the reference design is still based on the then standard 23,5MHz VIF as used by Philips. Which indicates that intercarrier introduction and 38,9MHz standardization were not linked. Although it effectively was within Philips: the 1953 TX1720 chassis introduced both these innovations.
Nevertheless, in my early Philips TV history I have made the link by stating:
In an inter-carrier receiver the video and sound remain combined throughout the entire IF chain up to and including the video detector. The output of that detector will now be the video baseband signal as usual but with the modulated sound on a sub-carrier at 5,5MHz, the picture-sound distance in the Gerber-norm. (In other standards the video-sound distance differs of course). The advantage is then that the remaining audio chain is much more low frequency up to the FM detector, avoiding more complex IF circuitry. The down side is that the combined video plus audio IF chain needs to be more wideband to pass both signals. Probably as a consequence of this the IF frequencies further moved upwards to a picture carrier of 38,9MHz and a sound carrier of 34,4MHz.
I then did a quick check on Radiomuseum.org on the VIF of German and Dutch (Philips) TV sets from 1951 to 1955. I will make a more detailed table one day for my site, but the summary is as follows:
1951: Philips 23,5, Metz 23,75, Schaub 25,7, Telefunken 25,75, Saba 26,2, Grundig 26,75, Greatz 27,75, Loewe 37,5
1952: Philips 23,5, Blaupunkt 25,5, Telefunken 25,75, Nordmende 26,0, Nora 26,5
1953: Blaupunkt Saba 25,5, Lorenz Schaub 25,7, Braun Telefunken 25,75, Grundig 27, Loewe 28,75, Graetz 29
Siemens 35,35, Metz 38,5, Philips 38,9
1954: same as 1953
1955: Kreft, Metz, Loewe, Neckermann, Nora, Saba, Schaub, Tekade all switched to 38,9
This seems to mean, to my total surprise, since I have not seen any reference to this fact, that Philips introduced the 38,9MHz. At least when looking at Germany and the Netherlands, which were jointly the biggest CCIR-B market. Whether this was purely a "follow the leader" mechanism (Philips was establishing itself as a leading brand in Europe), or that Philips proposed this value to some (CCIR?) standardization body and the others followed, or that such a body had proposed the 38,9 and Philips was the first to adopt, is not clear yet and deserves some further research.
Other observations:
- the Loewe 37,5MHz in 1951 seems to have been a one-off case, since on the next chassis they were back at 28.75MHz.
- as in the UK chassis, Philips was originally on the lowest IF of all, but then in one go made the jump to the standard high value
- it seems there was some industry consensus that higher IFs were better but not (yet) prescribed, see the values of Siemens and Metz in 1953. I would expect there is a conference or journal paper from around 1951/2 analysing this need, and driving this consensus. I haven't found that yet.
Interesting topic! I'll try to find more data on this.
Cheers, Pieter

To recap on previously posted items:
The EBU TV IF survey of 1952-54, of which a précis was provided in Wireless World 1954 July, showed 38.9 MHz as the expected future VIF for Germany and the Netherlands.
The Fewings & Fife BIRE paper of 1955 included this in its bibliography:
W. Holm and W. Werner, "Choice of an intermediate frequency for television receivers to suit the C.C.I.R. standard," Funk und Ton, 8, pp. 129-138, 1954.
As far as I know, both authors were Philips employees, but Funk und Ton was a German publication. I imagine that the article included the calculations that pointed to the choice of 38.9 MHz as the VIF for the CCIR system (later system B). That may explain why it was labelled as being the “CCIR IF”. But whether it included any information about which organizations, if any, adopted it as a standard is hard to say. Whereas in the RTMA and BREMA cases, each trade organization commissioned the development work, in the 38.9 MHz case, it might have been a Philips initiative that then became a de facto standard, and possibly a de jure standard.
The CCIR started reporting TV IFs in 1959 Los Angeles meeting report. Whilst it noted the trend towards national standardization, in general it did not record who the standards issuing authority was in most cases, EIA (nee RTMA) being an exception. A reasonable inference is that the CCIR itself was simply reporting, and not promulgating standards or apparent standards.
Cheers,
Steve

In a posting last December, I said:
“Yes, I plan to compile a tabulation. In fact I have had several attempts at it so far, none with a satisfactory outcome. My thinking now is to have three tables. One would be a simple list in ascending VIF order, each entry with a comment to indicate with which system(s) it was used, where it was used if it was “geographical”, approximately over what period it was used, and whether or not it was an actual standard number.
“The second list would be ordered by system, using the CCIR letter designations, and would show standard and other IFs used for each system.
"The third would be a list of standard IFs and their direct and indirect derivatives.
"I’ll probably need to be selective about the inclusion of pre-standardization IFs, with just a representative sampling.”
I have now done the first draft of the first list mentioned therein, attached as a .png derived from an original spreadsheet. (I think it is readable if one selects open image in new tab.)
I believe that I have captured all of the standard and quasi-standard IFs, along with (what appear to be) the more important combinations used for multistandard receivers.
As suggested above, the list of pre-standard IFs is not complete, and is intended to be representative only.
Cheers,
Steve
Hi Steve, is it possible to repost the table in a vector format such as pdf? The resolution of the png is insufficient for reading.

I don’t think that the forum allows .pdf attachments. At least it won’t allow me to upload them.
Strange doings with the .png, though. My original is 138 kB, and quite readable if I enlarge it to give a convenient font size on-screen. When I download the posted version though, it comes in at 309 kB, but is not really readable when similarly enlarged – it gets very fuzzy.
I’ll have to find another way to do this.
Cheers,
Steve

Posted by: @synchrodynedon’t think that the forum allows .pdf attachments. At least it won’t allow me to upload them.
That is partially correct, 11-years ago when the forum was founded a decision was made to only allow images as attachments to forum posts. I won't bore you with why, you can read here. Suffice to say it has served us well since VRAT formed.
That said, members can share PDF's via the private messaging system.
The files attached to a pm will only live for 24-hours, after that period the message and attachment, self-destruct. The recipient will receive a notification of a received message and has those 24-hours, to view and save the file. This is more than adequate time for them to do so.
Posted by: @synchrodyneI’ll have to find another way to do this.
It's simple, why have such a behemoth of an image in the first place, all you had to do was simply snip it into three, so sundog and others could read. See below. Took me all of a couple of minutes to do. Perfectly readable, no need to go looking for a solution to a problem that is not really there.
Edit:
Attached demo images removed, as they have now been superseded (see 2nd post down) and we need to conserve disk space.
CrustyTV Television Shop: Take a virtual tour
Crusty's TV/VCR Collection: View my collection
@crustytv Thank you Chris, It's perfectly readable now. And a big thank you to Steve.
Since you were able to split the file, I presume the uploaded file was preserved in reasonable definition; it's the serving of the file that limits the definition?






Lots of information to consider in the previous posts, thanks. 👍
Frank







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