HOW CLOSE WILL A GOOD CRYSTAL OSCILLATOR STAY?
Until recently, a normal crystal oscillator with decent components would only stay to perhaps 75 Hz. per day. This was (as we now know) due primarily to the crystal and not to the oscillator. Crystal ovens were used where better stabilities than this were required. New crystal cuts now available are so exceptionally stable (without ovens) that even on 20M you can expect stability from “cold” to hours (or days) later of around 5 Hz. and better. This is well within the most stringent tolerances for autostart. 6. HOW MUCH- CAN A CRYSTAL BE SHIFTED? This depends on the frequency and the circuit being used, as well as the type of crystal selected. I was able to pull a normal 80M crystal over 3300 Hz. using every trick I could discover. Using these same methods, I got over 17,000 Hz. shift on a 20M crystal. As soon as you add the RTTY circuit, these figures change. If you follow the “rules”, you will have no trouble in pulling the crystal at least 850 Hz. on 80M, and have enough “pull” left
