Rediffusion Mk1 CU2213.

[malcscott]

Hi, first of all many thanks to everyone who transported this set from Neil in Wales. On first inspection the PL509 was cracked, a new one fitted and mains applied. After a few minutes eht could be heard and a very dark blured raster was obtained. The RGB panel had smashed drive pots so a nos panel was fitted. This improved things, a picture was displayed but very blured, focus pot was at one end. A new one sorted the focus problem. I realigned the decoder and re-converged it and it is now running on soak test. The crt is a bit low on the red gun but i am sure it will ride up with wear. Further work is reguired eg- several convergence pots need replacing as well as the pincusion amp pot. I am very happy with it, been after one for years. Cheers, Malc

[colourmaster]

Hi Malc
That was quick work . Have you any photos of your set displaying the picture? .
Regards.

Gary.

[malcscott]

Hi, after two days soak testing, various faults have appeared. The width was overscaned and when the EHT voltage was checked was found to be 29kv !! R502 (330k) on the eht tower pcb was found to be o/c. R501 (1m5) was also very high in value and was also replaced together with the line shift pot RV501 (100R). The eht voltage could then be adjusted to 25.5kv. After a few more hours the video vanished, scope checks showed that TR005 (BF197) on the i/f deck was b-e o/c. This was a Mullard lockfit device so no surprise there! It is now back on soak test, awaiting further faults to occur. Cheers, Malc.

[crustytv]

As usual not even out of the starting blocks on mine. http://www.radios-tv.co.uk/1973-rediffusion-cu2213/

[marc]

As usual not even out of the starting blocks on mine.

Haven't even arrived at the running track to have a look yet !

Marc.

[colourmaster]

Hi everyone
I thought that I would take a look at mine . I bought it as a worker so I feel a bit of a fraud .
It has a good crt and only needs the two R/G amp convergence pots replacing. I'll keep running it to see if anything happens.
Regards.
Gary.

[Katie Bush]

Hi Gary,

Nothing wrong with that! I can't speak for anyone else, but right now it's as much about collecting, or saving if you will, sets as it is about restoring them.. My wonky back makes restoration impossible at the moment, but by heck, I can't half hoard (hurrumph... collect) them for future restoration.

I suspect though, if you push that set, it will start to push back, so even if it is a worker today, it could still be harbouring a grudge. It'll be interesting to see if it lasts, or if it will develop an assortment of entertainments for you.

Marion

[Refugee]

There is some tinkering to do on it.
There is the convergence at the top and a decoupling cap on the green drive circuit to get the green drive back up on the right hand side.

[crustytv]

After a couple of days chasing my tail finally I beat mine into submission, its awake Now I await the fur-balls it will undoubtedly cough up.

[malcscott]

Hi Chris, what was the problem? Malc.

[crustytv]

Long winded and to save hijacking your thread, its all detailed in the repair blog.

[malcscott]

Update, after 4 days soak testing, the set is still working fine. There were half a dozen faulty convergence pots which have been replaced with nos ones. A fault to look out for is varying grey scale tracking, R700 on the convergence board 680k o/c. Be nice to hear how the other Mk1 sets are doing, Malc.

[marc]

Be nice to hear how the other Mk1 sets are doing, Malc.

Hi Malc,

Nice to hear the success you've had with your MK1, I'm hoping to start on my set shortly so with any luck it'll be joining the ranks of yours, Chris's and Gary's as a worker too.

Marc.

[colourmaster]

Hi Everyone,

Today i have replaced the R/G AMP convergence pot that had an open circuit track knocking the convergence at the top of the picture way out .

I had a nos 10ohm pot in my toolbox from years ago so fitted that . It has made a massive difference to the convergence , these sets seem to converge very well . I've set up the grey scale and cleaned up the cabinet . I will now run it to see if anything develops .

I wonder if Malc could tell us how reliable these MK1 sets were when out in service as they are very well built.
Regards .
Gary .

[Rebel RafterMembership Retired]

Hi, all, RR here. It's nice to see the inside of a MK1 again after so many years. I used to fix them when I was on work experience at Rediffusion's service department at Rochdale in 1978 and I've had a few of my own, and I must say they were by far the most thoroughly well built set I've ever seen, especially the power supply, they're built like the proverbial battle ship. I think the only other set I've seen which came anywhere near close in similar build standard was some of the old Sonys in the 70's. But of course the Mk1's were British! and in a class of their own, just like Rolls-Royce and Jaguar and Rover P6's, etc.Some of them were built to work on the old 8.9MHz cable system in Rochdale, you can recognise them as they have a big male octal connector at the back coupled by two big 1000pF polystyrene capacitors. And if I remember right weren't some of them built to work on both cable and UHF as well? It's all a long time ago now. I didn't like the Mk3's very much with their inefficient tubes, not the early ones anyway. I thought the Mk4 was a better chassis, but nothing like the magnificent Mk1's. One thing I could never understand at the time is was there ever a Mk2 and has anyone got any pictures of one? RR.

[malcscott]

The Mk 2 was exported to South Africa to a company called Barlows. I think it was sent in kit form. Only ever seen one, a long time ago. Rediffusion also produced a Mk6, never made full production, Malc.

[crustytv]

Some of them were built to work on the old 8.9MHz cable system in Rochdale, you can recognise them as they have a big male octal connector at the back coupled by two big 1000pF polystyrene capacitors.

I have a wired chassis and intend to get it running so I have two examples of the MK1 in the collection. Though I need the Rediffusion Frequency translator box for this one.

[Rebel RafterMembership Retired]

Hi, folks, RR here again. Did Rediffusion also make a down converter box? I've never heard of that one. I knew they had an up converter box called an "inverter" which allowed a UHF set to work on the cable system. Surely you only need a tuner and aerial socket and an IF panel, if you can find them, unless of course you want the "wired" set to stay like it is. The audio side of the cable system worked a bit like the old 70 volt line system but over much longer distances with the sound going straight in through a matching transformer and a volume pot which usually had the rather oddball value of 85k. Try finding one of them. The one exception I saw was some Thorn b&w wired sets which amplified the sound. The speaker was usually a great big thing on the wired sets too. And I never knew there was a Mk6 colour set, I knew there was a "Mk5" which was really a Sharp portable apparently. RR.

[crustytv]

There was/is a specific box Rediffusion supplied that allowed for a wired set to be used on UHF. As stated the box enabled a wired cable TV to be used for normal TV reception. The box was called a Rediffusion "Frequency Translator" and was more commonly known as a "TeleBox". This device takes a UHF TV signal and converts it to the Rediffusion cable TV standard. Perhaps Malc or one of the other Rediffusion engineers might like to comment

I already have the UHF version and yes I want to keep this second example as a wired set but usable, hence needing a telebox.

This is the only cct I could find of the translator and is quite unreadable. If anyone has a good scan I would very much like a copy. If anyone has a telebox spare I would be interested.

[marc]

Hi all,

I've finally made a start on my CU2213 but so as not to hijack Malcs thread I've started a new one.... viewtopic.php?f=5&t=12084

Marc.

[malcscott]

Hi, whilst searching my stores today i found a brand new boxed chrome centre pillar stand for a Rediffusion Mk1. These were intended for the 20 inch version but it looks good on my 22 inch set and is quite safe.

[malcscott]

A couple of more pic, inc the faulty bits. The focus is much better than shown on the pics, Malc.

[marc]

Hi Malc,

The stand certainly suits the MK1, looks good

Marc.

[ntscuser]

Hi, whilst searching my stores today i found a brand new boxed chrome centre pillar stand for a Rediffusion Mk1. These were intended for the 20 inch version but it looks good on my 22 inch set and is quite safe.

That's a beautiful stand, especially considering its age!

[Tazman1966]

Looks terrific!