A Compact Radio Field Strength Meter

This paper describes a compact portable field strength meter for frequencies in the broadcast band. The range of the instrument is from one volt per meter to one millivolt per meter. The theory of the resonant circuit is elaborated, and on the basis of the theory a novel method for calibrating the detector circuit is developed. A minimum of calibration is required for the instrument as a whole. The voltmeter may be calibrated on audio-frequency alternating current; and any loop used may be calibrated by the instrument itself in the field.