Origins of the 405 line system.

[ppppenguin]

I know the "Black Book" details an electronic SPG but I still have this nagging feeling that some kind of tonewheel 405 SPG was used at some time. I'm pretty sure the servomotor scheme described by Gryphon for mains lock was used. AFAIK, all the early transmissions were mains locked. This was feasible in theory right up to the introduction of colour in 1967.

There is the additional question of why the early M-EMI system only allowed fades between cameras, not cuts. I've not seen this explained. The M-EMI cameras were co-timed and black levels were clamped so that wouldn't preclude cuts.