Another 1958 (roughly) Experimental Colour TV: Ekco CT100M
After seeing Davids thread I'm reminded of another superb, really early colour set. I'm sure David won't mind me saying but this one is far prettier than his. Its been brought back to health by none other than the early CTV guru himself, Mike Bennett (Mikey405).
I hope Mikey does not mind me showing these photo's of his cracking early CTV, also a link to his as ever superb right up on its repair. As I've mentioned before and elsewhere, following the work of Mike and Taz was instrumental in converting me over to CTV repair four years ago now. A great double act and I for one miss their threads.
The repair thread http://www.vintage-radio.net/forum/showthread.php?t=36175
Compared with the Pye CTV the Ekco CT100 is a much better looking set. It actually it looks like a giant version of the Ferranti T1002 mono set of 1958 which was made by Ekco. Also, it is a lot better electrically and has the advantage of being a 625 line PAL receiver. I believe the decoder employs the "simple PAL" system, that is, no glass 64microsecond delay line is used for error correction. We're uncertain how the set started out, was it initially a 405 NTSC receiver? Didn't the BBC commence 625 line NTSC test transmissions in 1961? We all knew the game was up for 405 by then although we know that some ITV companies were still keen to continue with 405 colour experiments with the view to full time transmissions.
Do we know the age of this set for certain? PAL wasn't demonstrated until 1963, so it couldn't have been designed, let alone built, as a PAL set before this.
Also, until the Pilkington committee decided in favour of 625 line broadcasting and killed the idea of 405-line colour, all work in this country was aimed at 405-line NTSC.
The first public demonstration en-masse was at the Earls Court Radio Show in 1960 - the first one I ever attended at the age of 14 - and all the sets were 405-line NTSC.
Even after the move to 625-lines, the BBC were still firmly in favour of NTSC and I can't think which a British company would want to design and build a colour TV that could only have worked in Germany!
I think that set is a twin of the Ekco 625-line NTSC set we had at college (no legs, though!) around 1964. However, the BBC switched to PAL transmission in May 1965 and Ekco came up with a mod to convert the set to Simple PAL and, as I've mentioned elsewhere, I was given the job of doing it!
I would suggest that this set followed a similar career path - unless, of course, it is actually a 405-line NTSC set.
The set was experimental and was originally designed as a 405 line NTSC receiver. It was factory modified in 1964 to 625 line NTSC and then again in 1965 to PAL-S. If Mikey drops by I'm sure he could provide much more info, as can be seen from his UKVRRR thread, he's spent a great deal of time bringing it back to excellent working condition.
The set was experimental and was originally designed as a 405 line NTSC receiver. It was factory modified in 1964 to 625 line NTSC and then again in 1965 to PAL-S.
PAL-S was how we used to run picture monitors in the studios in technical monitoring positions; not only did it get rid of the 1-line delay transition on some test signals but it immediately showed up any diff. phase errors.
The set does have a UHF tuner which is similar to the type of unit fitted to early UK 625 line receivers like the Ekco T398 and Pye V700D. Imported from Germany and possibly made by R. E. Hopt. I'm sure the valves employed in it are either PC88 & PC86 or EC88 and EC86. That dates the set to be about 1961. The VHF tuner is the usual Ekco unit which was used from the mid fifties and even finished up in the Pye model 11 of 1962.
Mikey kindly gave me a copy of the circuit diagram, certainly the set pre-dates the introduction of the PL505/509 line output valves. It uses a pair of PL300s, the valve of choice for early 60s experimental colour receivers. My Pye has two PL36 and two PY81s.
From the Radiomuseum: www.radiomuseum.org/tubes/tube_pl300.html
The EL300 and PL300 was designed in France.
Till Eulenspiegel said
The set does have a UHF tuner which is similar to the type of unit fitted to early UK 625 line receivers like the Ekco T398 and Pye V700D. Imported from Germany and possibly made by R. E. Hopt. I'm sure the valves employed in it are either PC88 & PC86 or EC88 and EC86. That dates the set to be about 1961.
Extract from the Wireless World report on the National Radio Show at Earl's Court in 1961: