However, haven't the MPX transmitters been certified in a manner that
allows crystal swapping???
When I had/flew the MPX 3030 for two and a half years,most of the TX crystals were available, and you were encouraged to plug them into the module. That was a selling point. However, not all the 72mhz channel crystals were ever available, and I stopped waiting for my spare freqs. after two years , and sold the radio. Bill G.