Comparing the differences between AT and SC crystals and their impact on oscillator performance.
Inside of every quartz oscillator is something called a crystal blank. The crystal blank is the resonating element of the oscillator that when subjected to a voltage potential will begin to vibrate and oscillate at it’s "fundamental frequency.” As you can probably imagine, the way that crystal blank is manufactured can have a significant impact on the oscillators performance. One of the most impactful manufacturing steps to crystal, and therefore oscillator performance, is the orientation of the quartz when the crystal blank is cut.