Red painted wooden double concave cone, part of whriling body demonstration using whirling stand (that we don't have). Small metal hook at top with attached string
modular valve unit (late 1950s?) Black aluminium case with rear connector and valves projecting and covered in screening cans. Counting unit Racal Eng. Ltd. Type no. CU 542 D Ser. No. N1681. 4 valves: 3 off 12AU7/ECC82; ECC82/12AU7