it takes the micro/mini crystal...plenty of freqs to choose from:
of course you would match the crystal that comes with the FM Tx...which BTW is a standard crystal..bigger.So, any 72 MHZ FM TX you get..just match the freq it came with.
I'll answer anything I can, there are some really advanced pilots on here that have all the bells and whistles. But, I think they tend to stay away from biginners on starter systems. I had to read tons of info to get me started. So, ask away!