Disk recording: in the early 1960s there were no
tape machines in studios so short items were cut onto 78rpm disks so
that SMs could play them on the grams.
The picture shows a Presto disc-cutter photographed in E4, Bush, on
16th August 1962. These American machines were initially obtained under
Lease/Lend during the early part of the war and were still in use at
Bush until the mid-1960s: they were equipped with BBC cutter-heads. A
bit clumsy in use, the main problem being inadequate clearance of swarf
(the ribbon of lacquer removed when the groove is cut - it is extremely
inflammable) which meant that a pile-up could clog up the recording.
The microscope was for examining the grooves to adjust the cut depth
(groove to 'land' ratio to be 2:1).
Below, a blank disk label.
© Roger Wilmut. This
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