How can a 72MHZ receiver crystal go bad?
Futaba R127DF receiver on channel 45 has worked fine for many, many years in same airplane. Receiver crystal obtained from Tower years ago. Plane has been flown off and on every few months since built and is stored inside our home. Tried to fly last week but got no response from transmitter. Hmmmm.... Trouble shooting at home by checking batteries, connections, etc. No luck. Swapped in a new receiver on same channel. Works fine. Receiver problem. On a whim, pulled crystal and substituted one from another receiver. Aha, bad receiver now works fine. Put "bad" crystal in known good receiver....doesn't work. To be sure, tried same type swaps with still another receiver...same results. Conclusion is crystal went belly-up. How can that be? Didn't think anything could possibly go wrong with a crystal. (And no, no obvious corrosion or damage to it.) Ideas anyone?