A Wide-Band Wattmeter for Wave Guide

A direct-reading wattmeter is described which uses a directional coupler and one or more thermocouples to monitor the power transmitted by a wave guide or a coaxial transmission line. It was used in connection with a 1000-watt magnetron transmitter which had a tuning range of 8 to 12 centimeters, and the calibration was substantially constant over this range.