Quartz Control for Frequency Stabilization in Short-Wave Receivers

For the purpose of stabilizing short-wave reception, experiments were made using quartz control in receivers. It was found that the use of a crystal which produces audible beats with the frequency of the transmitter quartz is practically impossible. In fact, the quartz-controlled oscillating detector caused too great a decrease in the tone volume, while in the case where a separate quartz-controlled heterodyne was used, the effect of temperature on the frequency of the crystals caused disturbances. In order to solve this problem, a method is described in which the superposition of the frequencies of the transmitter quartz and the receiver quartz produces an oscillation of high frequency. This intermediate frequency corresponds to a long wave and is made audible in a normal oscillating detector.