Crystal oscillators and circuits. (All About).

It is often required to produce a signal whose frequency or pulse rate is very stable and exactly known. This is important in any application where time or exact measurement is crucial. It is relatively simple to make an oscillator that produces some sort of a signal, but it is another matter to produce one of relatively precise frequency and stability.

AM radio stations must have a carrier frequency accurate within 10 Hz of their assigned frequency, which may be from 530 to 1710 kHz. SSB radio systems used in the HF range (2-30 MHz) must be within 50 Hz of channel frequency for ...

Read the rest of this article with a Free Trial at HighBeam Research.