Who makes the Crystals?
Our receivers and transmitters cystals all seem to be in standard configurations. All the cases are the same, the spacing on the connector pins are the same. There are little differences such as some have be protected from grounding both pins at the same time (a little black electricians tape takes care of that).
So who makes the crystals? Don't say JR or Futaba or HiTec. They all sell them that's for sure. I have one sheet from Tiawan that shows compatibility. It intimates that some crystals are closer in tolerance than others. That does not surprise me from my days of industrial engineering where quality screens can be set so that some buyers get the cream of the crop and others get what is left over. Good aold statiscal analysis will do that for the buyer.
Crystals do not have positive or negative shift. The just vibrate at specific frequencies. Multiples of those frequencies (harmonics) are used to regulate the oscillators in the receivers and transmitters. Crystal control oscillators do not drift because of the crystal. True, newer technologies are around like Phase Loop Lock that work just as well but cost a little bit more to build into the receiver (and transmitters like Polks Tracker II).
So if we can unlock the manufacter, we can escape some of the excess prices charged by some brands.
Cheers,
Chip