Signedon dial: GENERAL RADIO CO. / CAMRBIDGE, MASS.
etched and white filled on top panel: AIR CONDENSER / TYPE 101L SERIAL No 1147 / GENERAL RADIO CO. / CAMRBIDGE, MASS.
Inscribedin green on top panel: R. PHY.
in orange and white on top panel: RPS-II
FunctionThe frequency of transmission or reception of a radio circuit is inversely proportional to the square root of both its capacitance and inductance. variable capacitors are one of the methods used to alter a circuit's frequency, by altering the circuit's capacitance.
In this particular case, the capacitor consists of two groups of semicircular metal plates arranged in parallel. By turning the knob, the user is adjusting how much the two groups of metal plates are overlapping.
Historical AttributesUsed for teaching Physics at Radcliffe College.
Cruft
ProvenanceFrom the Cruft Laboratory, Harvard University.