Observations of Frequency-Modulation Propagation on 26 Megacycles

A simplified analysis is given which shows that the distortion occurring with two-path transmission of frequency modulation consists of the introduction of a new modulation frequency which is frequency-modulated and is not harmonically related to the fundamental modulation frequency. Results of observations at Riverhead, Long Island, New York, on 26.3-megacycle frequency-modulated transmissions from W9XA at Kansas City are shown and discussed.