General Radio Operating Instructions Type 1304-B Beat Frequency Audio Generator

General Radio Operating Instructions Type 716-C Capacitance Bridge L

General Radio Operating Instructions Type 1210-B Unit R-C Oscillator & 1210-P1

General Radio Operating Instructions Type 1112 Standard Frequency Multipliers

General Radio Operating Instructions Type 544-B Megohm Bridge M

General Radio Operating Instructions Type 1210-C Unit R-C Oscillator

General Radio Operating Instructions Type 1632-A Inductance Bridge C

General Radio Operating Instruction Type 1607-A Transfer-Function & Immittance B