Today's dip into the Mullard factory archives has come up with this photo of a suited gentleman testing valves using a Mullard High Speed Valve Tester (MHSVT). How many people wear a suit whilst valve testing - I wear a string vest and a lime green thong whilst testing our wares - however, I digress. The formal attire should give a clue for this is the MHSVT in the main transmitting room at BBC Alexandra Palace some time in 1953.
I think this photograph was taken during valve maintenence testing undertaken immediately prior to filming an episode of Jigsaw where a young art student from Perth, Australia, got an audition drawing cartoons - "Can you tell what it is yet, little girl.........?." said the art student. "Is that an 813 in your pocket or just a small digeridoo?" innocently trilled the pigtailled young lady.
Altogether, the BBC had 17 of these instruments, indeed, the fourth one off the production line of the first production run was bought by the BBC for use at Lime Grove studios where it was used for peridoic testing of a stock of 12000 valves.