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-   -   Rediffusion mk1 (https://www.vintage-radio.net/forum/showthread.php?t=128855)

acottrell 16th Aug 2016 10:24 pm

Rediffusion mk1
 
1 Attachment(s)
Hi Guys
Thought you might like to see my new project. (Thanks to Mikey 405 for the service manual info) was very helpful.
Well HT cap had to be replaced. Also replaced cap across the switch, PY500A flashing away looking like the northern lights, Volume control. At this stage I had running colour. Adjusting the oscillator had no effect so was very lucky to find a replacement Crystal was all it needed. Just a bit of cabinet work and then onto my next MK1 which looks very similar only the speaker grill on the front is black cloth :)
Thanks
Ade

greg_simons 16th Aug 2016 10:57 pm

Re: Rediffusion mk1
 
Congratulations, nice bright picture there.
Greg

acottrell 16th Aug 2016 11:04 pm

Re: Rediffusion mk1
 
Thanks its the original mullard CRT as well :)

Mad Mal 19th Aug 2016 11:12 pm

Re: Rediffusion mk1
 
Saw many of these when i was doing my apprenticeship at Rediffusion. Easy Chassis to work on; fairly tolerant of whether a PL509 or a PL519 was used in the line output stage. On the 22/26 inch EHT Tower you could tell when the valve had gone Heater Cathode short as the small electrolytic acros the Cathode bias resistor went off with a bang. frightened the life out of customers. Word of advice. if you find that the low voltage electrolytics on the RGB panel need replacing (these were rated 50v on some boards) don't be tempted to use Tantalum caps as replacements. The bang when they fail is ****** loud. Before a mod came along to correct the issue; the Sylvana Delay lines on the Decoder board sometimes did an odd thing to the wane =form. And they could also "ring" from time to time, considering that they were mostly made of a large chunk of glass, the worked well enough.The moddle pictured usually had the prefix CU then the size of the screen and the last two digits were 10. (CU2210 fo example). The one with the Black cloth speaker covers were sometimes branded Doric. The black plastic fronted sets were CU2213 and CU2613's.

Tazman1966 20th Aug 2016 2:37 pm

Re: Rediffusion mk1
 
2 Attachment(s)
Nice one!

These do produce lovely colours too. The story of mine is over on Chris' forum. It's back in the workshop at the moment waiting for some attention - black level floating up and down problems.

Here's a pic of mine doing its duty as the kitchen set a little while back.

MALC SCOTT 20th Aug 2016 3:14 pm

Re: Rediffusion mk1
 
Nice looking set, not a very common model. Should last for years, Malc.

Neil Purling 20th Aug 2016 4:41 pm

Re: Rediffusion mk1
 
What year is this set? Were there two types: Aerial & Cable?
Are there any resources with the lists of Rediffusion monochrome & colour TV's?
Both lots of grandparents were customers of the company & the local NHS hospital had loads of Rediffusion DS monochrome sets, 'Dover' I recall.

MALC SCOTT 20th Aug 2016 6:09 pm

Re: Rediffusion mk1
 
This set (Mk1 chassis) was produced at the Rediffusion factory at St Helens, Bishop Auckland, Co Durham between 1973 and 1976. Both cable and aerial versions were made. Aerial sets had model numbers starting CU, cable versions were CH, Malc.

Clydeuk 21st Aug 2016 9:40 pm

Re: Rediffusion mk1
 
Just out of interest, what screen sizes did this set come in? Was there and 18 inch or 20 inch version?

I'm only asking as I have a distant memory from when I was about 5 years old of the first colour set we rented, somewhere I have a photo with a side view of the set in question, and it has a very similar look. I've not seen one of these since, and I'm sure the screen was smaller than 22 inch.

raditechman 22nd Aug 2016 7:59 am

Re: Rediffusion mk1
 
Malc Scott, Rediffusion also had a "factory" at Chessington. Did they make sets there too or was it just a distribution centre?
I remember going to Chessington to collect new sets.
I was never too fond of the Rediffion MK 1 colour set. Very heavy! I prefered the MK 3 or 4.
Nice to know that there are still some MK 1's about and working well.

John

slidertogrid 22nd Aug 2016 8:03 am

Re: Rediffusion mk1
 
Quote:

Originally Posted by Clydeuk (Post 872239)
Just out of interest, what screen sizes did this set come in? Was there and 18 inch or 20 inch version?

The Decca CS1810 1830 were very similar in appearance they were very popular as rental sets as was the Telpro which was 20". Same circuit but totally different layout.
Rich.

acottrell 22nd Aug 2016 1:40 pm

Re: Rediffusion mk1
 
Hi Guys
Well I have learnt more about my set and where it was made I think its early 1970s no dates anywhere on the caps etc :)
I was really lucky to find a Rediffusion collection sadly not kept in the best of conditions. I have another set which is the same as the one on the Pic but a black speaker cloth grill on the front thats my next one to repair.
I then have a cable version which came with a Rediffusion cable box not sure if that works and 7 black and white sets all with names on them (Devon, Avon, Blythe, Kinoch and Shannon ) these are a mixture of cable and aerial sets.
Then I have three MK3 sets different tube sizes. I was told this engineer only kept the ones with good tubes and so far this seems to be the case as i have a rediffusion Decca 30 which has a fantastic picture too :)
Will keep the pics coming as i complete them if you guys are interested
Many Thanks
Ade

acottrell 22nd Aug 2016 1:44 pm

Re: Rediffusion mk1
 
Tazman
A very nice set you have picture looks great on it . Its good to see a few around still working well

MALC SCOTT 22nd Aug 2016 4:40 pm

Re: Rediffusion mk1
 
When i started at Rediffusion w/shop in 1975, Chessington was mainly used for R & D. I think mono sets were produced there at some point. The Mk1 came in 20/22/26 inch screen sizes. I have a 20/22 inch models in my collection, also a Rediffusion 20 inch Mk3 prototype. A couple of 26 inch Mk3 and Mk4. A Rediffusion RT515/19 (Brc 3000) and a RT514/25 (Brc 3000 with doors complete my collection, Malc.

acottrell 22nd Aug 2016 5:08 pm

Re: Rediffusion mk1
 
Sounds like a great collection there Malc
Just a quick question why was there no MK2 or was there? Is there any MK5 out there I know they were going to realise them before Granada took over
Thanks
Ade

MALC SCOTT 22nd Aug 2016 5:26 pm

Re: Rediffusion mk1
 
The Mk2 was produced in kit form only. They were all exported to a company in South Africa called Barlow. The Mk5 was a 14 inch ctv portable first produced in 1982 (SP1) and later the SP2 came out. These sets were supplied in kit form from Sharp in Japan. These were very reliable sets which produced very good pictures. The Mk6 never made it into full production, a friend of mine who worked in the R&D at the St Helens factory still has one. Vey smart large screen ctv which sadly never made it before the factory closed down in late 1985. Cheers, Malc.

acottrell 22nd Aug 2016 5:44 pm

Re: Rediffusion mk1
 
Thanks Malc :)

Clydeuk 23rd Aug 2016 12:59 am

Re: Rediffusion mk1
 
Quote:

Originally Posted by slidertogrid (Post 872301)
The Decca CS1810 1830 were very similar in appearance they were very popular as rental sets as was the Telpro which was 20". Same circuit but totally different layout.

I remember the Telpro sets, I saw a couple of them in the late 80's. I will try and dig out the photo to see if anyone can ID the set we had as it's always intrigued me. It had a fault with the line hold which only showed up from cold in the morning (when I wanted to watch cartoons), finally locked after 20 minutes or so and stayed fine all day after that, even when switched off for a while. The repair men couldn't locate it as it always behaved when the engineer called and in the end my dad got fed up and sent it back.

I don't think it was a Decca, but I may not have seen all the variants.

Vintage Engr 25th Aug 2016 3:25 pm

Re: Rediffusion mk1
 
Hello all,
Rediffusion also had a factory at Dale Mill, in Rochdale.
I worked for Rediffusion in various places, but when I was Senior engineer at Surbiton, I used to visit Chessington quite regularly. I managed to scrounge enough parts to build a complete colour TV, it was a real hybrid using Bush CTV 25 line output, Rediffusion tuner & I.F., and Thorn decoder! I learnt a lot putting that lot together. The cabinet was a prototype, and came from RVS Chessington's 'Model Shop'. That was a fascinating place. They had a great cabinet department, and built me some L/s cabinets to my spec., nicely veneered in teak, to match the home-made TV.
Later I moved on to Top Rank Television, where we had a reciprocal agreement with Rediffusion to use a modified version of their TDUK 2 system (wired). When The MK1 Colour came out, I built a jig using a damaged MK1 cabinet & chassis, & became the 'chief board repairer' for our hotels division. It became very boring!
Happy days,

Well done on the restoration,

Dave.

Welsh Anorak 26th Aug 2016 1:28 pm

Re: Rediffusion mk1
 
Hi
To answer post #9 there was a 20" version but was a bit awkward to service as all the boards were folded up to make them fit!
The Mk1s I had were all the refurbished models with a regunned Mullard Colourex tube and lots of mods to make them BEAB approved - quite a feat for a hybrid set. They were put in a Mk3 cabinet with the same buttons and slider controls - the only visible difference from the front was the lack of the PIL logo. They could easily hold their own against the new Mk3 chassis and customers were none the wiser.
The ones I bought were from a new disposal outlet. I'm sure the owners were seen coming as they thought they had bought Mk3s. I got them for a knock-down price, sold them all and didn't see one back again!
Glyn


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