Again, operating in the Ham Bands doesn't hold the R/C guy to these specs as he can or might have "rolled his own."
However the specs show good engineering practice which as an Amateur he should aim toward. He really has no recourse except that others try to work with him. Crystals are often available through ham swapa and online auctions... >From the WattFlyer RC Electric Flight Forums: "Hitec no longer sells 50/53 mhz equipment. FMA and Airtronics do. I never run across anyone any more who flies on 53 mhz since it is for the old wide band stuff (100 khz spacing). 50 mhz is for modern narrow band equipment." Like AM vs Sideband ... it becomes a gentleman's agreement, after reasonable evaluation of his receiver's bandwidth LW.
