摘要 |
<p>From the frequency of the heterodyne oscillator it is possible to generate a further frequency by way of frequency-dividing or frequency multiplying facilities. The lower of the two frequencies serves as heterodyne frequency. The vibrations of the higher frequency are taken as a basis for counting, as long as the difference between the two frequencies is observed, preferably by appropriately reducing the cycle of the switching voltage, and, consequently, the measuring periods. The vibrations of the heterodyne oscillator can be delivered to the counter after frequency multiplication.</p> |