A Direct Reading Radio-Frequency Meter

The method used is the well known one of reading a radio frequency by measuring the beat note produced with a calibrated crystal oscillator. A new type of direct reading audio-frequency meter having a scale of 2.0 to 4.5 kc per second makes the device automatic. The meter scale divisions are 0.1 kc apart, and under reasonable conditions, the accuracy of the reading is of this order.