Hi, I cannot find fix value of crystal like 38KHz, 7.68MHz. But I got 10MHz, 12MHz so on. Can't I adjust or decrease the friquency of this crystal in fix Hz? Can I add capacitor in parallel to decrease the friquency?
Try Googling 'Phase Locked Loop'. This is a circuit that runs on a fixed value of crystal, but mutiplies the frequency up or down to provide a stable frequency that is a multiple of the reference crystal. At 10MHz, this should be quite easy to do. Pick a PLL that is near to the frequency you want as there are plenty that will handle GHz frequencies (and will be way too complicated)
In the past, amateur radio operators, and probably others, would lap the crystal after removing it from the holder - or they would pencil on some carbon. Most modern crystal containers/packages do not allow for this. I tend to find these old crystals at hamsfests - usually considered trash by some but I grab them if the price is right.
In the past, amateur radio operators, and probably others, would lap the crystal after removing it from the holder - or they would pencil on some carbon. Most modern crystal containers/packages do not allow for this. I tend to find these old crystals at hamsfests - usually considered trash by some but I grab them if the price is right.