The Routine Measurement of the Operating Frequencies of Broadcast Stations

The method of making "zero beat" measurements of the operating frequencies of broadcast stations in the Second Radio District is described, showing the method of comparing the received signal from a broadcasting station with a signal of known frequency, obtained from a 10-kc multivibrator controlled by a 90-kc quartz crystal. There is also given a description of the method used in reducing the measurement to a flexible routine procedure while still maintaining an accuracy well within the 500-cycle limit established by the Federal Radio Commission.