PRD Electronics Type 650-B Universal Power Bridge Operating Instruction 1961

Polytechnic Research PRD Type 219 Standing Wave Indicator Operating Instructions

Polytechnic Research PRD Type 809 Klystron Power Supply Operating Instruction

General Radio Type 544-B Megohm Bridge Operating Instructions 458-K 1956

Polytechnic Research PRD Type 277 Standing Wave Amplifier HandBook & Operation

Polytechnic Research PRD Type 277A Standing Wave Amplifier Operating Instruction

PRD Type 812 Universal Klystron Power Supply Operating Instructions 1961

General Radio Type 874-UB Balun Operating Instructions Form 803-B 1956