Just for completeness as there’s not a lot of info around, I include a batch of B&W Rediffusion set at the foot of this page.
I have the above MK.1 set in my collection. To follow its repair click here
Early B&W Sets
When I started work with Rediffusion we had some MK3’s and 4’s. the Mk 7 was an awful set, with plug in PCB’s. Lots of intermittent contacts! I only worked on the aerial versions the Mk7 cable may have been more reliable. I wonder if any Mk 7 aerial sets survive.
The Mk 8 and Mk 9 I think were Plessy chassis, the Mk 8 was fairly reliable. The Mk 10’s had a solenoid for system switching, pity that none of the Rediffusion monochrome sets had black level correction. AC coupling normally being used for video.
We must be of the same era! I wonder which workshop you were at?
Somewhere I have a circuit diagram for a WRS101. I Also worked on the series 2 ,3 & 4’s & series 7. Also the MK8 etc, yes they were a Plessey chassis.
In 1964 whilst the workshop manager was on holiday, I used a stock CAV/17/4B also an early Plessey chassis, as the basis for a ‘conversion’ to 625 line UHF. This particular version also had VHF F.M. as a separate I.F. strip, so provided the base for demodulating the 6Mc/s intercarrier sound. I modded the Line Output stage, added some S-correction, drilled a large hole in the side of the cabinet & fitted a rotary UHF tuner. It worked tolerably well, albeit with some horizontal line compression, I don’t think the LOPT enjoyed running at 15,625Kc/s.The problem was of course that none of it was 405/625 switchable, I’d re-aligned the vision I.F on the Samwell & Hutton wobbulator, so the whole thing was now a 625 -only set. As there were only experimental test transmissions at the time, this didn’t seem to matter to me. However, when the Service Manager (SVE) returned from holiday, he was not amused! He said he could have rented it out until I’d modified it. He did however note my enthusiasm for modifying equipment, and I did quite a good number of modifications to the 405 line Sheerline ranges. They used a ghastly Sidney Bird push-button tuner, which was incremental, like the Fireball. However, they used long plastic sliders with contacts that made (intermittently) with the tuning coil studs. When customers complained about the intermittent tuning, I used to replace these with a small rotary VHF tuner as used in many Pye TV’s I seem to remember that they were made by NSF. It was partly because of my interest in design/modification of TV’s etc, that got me out of domestic T.V. servicing, and into Broadcast engineering.
Happy days, with real engineering, where one could actually repair things.
Yes I remember the awful tuner in the MK 7 Sheerline set. We never put rotary tuners in ours. I started at Hounslow workshop in 1964, it was behind the showroom. (All demolished now) later the workshop outgrew back of the shop premises and we moved to a new 2 storey workshop at Hampton Hill. Showroom downstairs and set storage behind. Workshop upstairs, we had a manually operated dumb waiter to hoist sets between floors! . Component stores were also upstairs plus an operators room for taking telephone call from 5.30pm until 10.00pm, this had about 8 positions for the telephonists to sit. I always felt sorry for the girls answering the calls as Rediffusion advertising made it seem that as we worked until 10.00pm if their set went wrong they would get someone that evening, of course we were always full with enough calls already, so they had many irate callers when they were told it would be the next day or evening.
The Hampton Hill building is still there and a charity shop now occupies the old showroom, whilst the upper floors have been converted to flats with and extra floor added.
I did some time at Surbiton, and also occasionally visited Harrow branch. We sometimes went to Chessington to collect new sets. We went into London SW14 and as far as Weybridge to the west, Hayes and Southall to the north and Hampton Court/Molesey/ Cobham/ Oxshot to the south.
Only set I ever modified for 625 was an early Bush, not a Rediffusion model.
John
Off the last topic and not at all technical. I remember back in the 1950. When I started work, my mother used the redifusion speaker as a very reliable alarm signal. The engineers used to promulgate a 1 kcycle tone to test the lines. It never failed and the old man and I never missed the bus.
In the 1960s there was a RediffusionTV junior director named Malcolm Evans. He later was a Director in Seltaeb, the Beatles U.S. merchandise company in the ’60s. This was NOT the Mal Evans who was a roadie/associate of The Beatles on tour, etc. Kinda confusing because they had the same names. I was wondering if anyone had info on the Mal Evans-Rediffusion/Seltaeb person? Thanks so much!
I bought a 22 inch Rediffusion TVRM Mark 4 Manual Colour Tv in the Summer of 1984 and was disappointed with the picture quality as It was hard to achieve acceptable Brightness and Contrast settings unlike the Rediffusion Mark 3 that displayed an excellent Colour Picture. Rediffusion Engineers paid quite a few visits and even took the set back to the workshop for adjustment with little improvement. I kept the set for 4 years and then sold it on after buying a 51 cm Sony Black Trinitron that displayed excellent pictures for 20 Years.
That Scotch Videotape Skeleton looks a tad sinister there!
There was a redifusion portable, can’t remember the model without looking for the service manual, that was just a badged up Sharp TV, not sure if it want the Mk 5??
Yes, Mk5 badged Sharp, reliable but not particularly good picture as I remember.