A bank of TD/7s in S3, 1962. The small black box on the wall, just right of centre, carried a jack with a feed of 900Hz tone. This could be compared with the tone recorded on the discs to check that the turntable was running at the correct speed. The centre fader of each set of three was intended for use as a cubicle mic fader.
There were two ways of setting up a disc. First, the lever and drum method. The pick-up was lowered onto a revolving disc, and lifted with the lever on the right as soon as the required start point was found. The drum, on the left, was then turned to move the arm back a bit. The drum was calibrated to move the P/U back one groove per division on direct cut discs with 104 grooves per inch which was the standard used on Presto and BBC Type D disc cutters. To play the disc the pick-up was again lowered onto the turning disc.
The second method was the drop start. This was operated by a lever (or button on earlier models) which lowered three rubber pads which held the disc above the turntable and thus dropped the disc onto the moving turntable. Setting up was fiddly - remember that it wasn't possible to wind back the disc. To play from the start, the record was positioned with the label upright and the stylus placed in the 'first' groove. The disc was then started and the number of revolutions counted until programme was heard. It was then stopped, reset so that the label was upright again, the stylus replaced in the first groove and the disc played, once again counting revolutions. Half a rev short of the previous count the disc was stopped, ready to be played on cue.
