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 

red1 red2

red4 red5 red6

Early B&W Sets


2 Replies to “Rediffusion”

  1. 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.


  2. 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.


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