A #GeneralRadio 1421-JS air-variable #capacitor, from the glory days of the greatest US #electronic #TestEquipment manufacturer. Rotor and stator machined from solid aluminum, fiberglass shaft, ball bearings, and large-diameter polystyrene insulators for low dielectric loss. #GenRad #electronics #radio #dielectric
#dielectric #radio #electronics #genrad #testequipment #electronic #capacitor #generalradio