ORIGINAL: jlimey
OK, I am more than convinced by the radio manufacturers stated FAQ not to change crystals to another frequency. What about JR radios, where to adjust the tension on the sticks, you need to remove the back (and therefore the crystal). Is sticking the same crystal back in enough to ensure you have not modified anything. Seems like it - but makes me a little nervous.
You have not "changed" the crystal or retuned the RF section by any action you have described.
Let's try to understand what a crystal is. It's a "rock". OK, a fancy "rock". It's cut to a specific size and shape and then it is stimulated to vibrate (oscillate) at it base frequency. It's extremely hard to cut identical "rocks". So there are tiny deviation between any two "rocks" or crystals. This is part of what the tuning circuits have to adjust for. They compensate for the differences in the cuts and force the correct frequencies to be generated. You could buy two "identical" crystals off the production line made the same day by the same guy/machine and they will probably NOT oscillate at EXACTLY the same frequency but close.
It's easier, but not cheaper yet, to do this with a synthesizer.