Measurement of transmitter harmonics

A topic of concern in the measurement of “antenna conducted” spurious and harmonic outputs of transmitters is the means of coupling the measuring instrument to the output line when the output is coaxial. A variety of techniques is observed in current specifications and practices. Essentially, they amount to a “probe” method, in which an inductive or capacitive pickup device (this includes waveguide-below-cutoff “Tee” attenuators) responds to the field in the line, a directional coupler which is connected to respond to the forward wave, or some sort of attenuator or voltage-divider network which is integral with a dummy load.