Operators on the "HAM" frequencies are limited to the same "less than 1 watt INPUT" as on 72 or 75MHZ!
Not that it matters, 72/75Mhz is limited to 750mW, per FCC Part 95 Sub C. USA Amateur Radio Operators (hams) are allowed 1W on 50/53Mhz, per FCC part 97.
For R/C applications, neither may use anything fancier than a whip antenna on the Tx. Furthermore, unlicensed 72/75Mhz users are NOT allowed to modify ANYTHING related to the transmitted signal, including antenna tweaks.
There are commercial licenses available that will allow more power (special FCC part 90 license) on 72Mhz, such as is used by industrial equipment operators. These frequencies are offset from standard R/C freqs (those under channel 41) by 10Khz.