In late 1968,TC1 had very recently returned to service after being colourised with EMI 2001s.  Did TC1 ever work 405 lines or was it always 625?

Alec Bray

TC1 was capable of 405 line TX.

Ian Hillson

TC1 "Opened in April 1964 with EMI 203/6 cameras and was converted to colour with EMI 2001 cameras in 1968" so I would guess that early on it would have produced 405 for BBC1 shows, maybe even up until March 1968 when NC1 went 625 and had a converter put on its output to feed the BBC1 transmitters.

I joined AP in April 1968 and they had just stopped originating 405 to feed BBC1 – meaning that you no longer had to change standards and check (mono) camera lineup between BBC1/2 Tx’s.  The EMI 201 B/W vidicon CCUs had been modded with those concentric home stereo pots with a 405/625 changeover relay so you didn’t need to tweak scans, and things, every time you changed standard.

The TV News studio in the bowels of BH extension still continued the multi-standard tradition though, as it produced inserts for the regional news opt-outs which were still in 405.