Im new myself but have done alot of research. The lower frq like 900 to 1.2ghz gineraly travel around obsticles better and travel further. Some frq will interfear with your rc link if it is close to the same freq. Like 2.4ghz and 72mhz. Some freq interfear with your gps more than others here is a page that describes different freqs and there advantages and disadvantages. scrole down about 1/3 of the page and it talkes about freq. http://www.rcexplorer.se/page14/FPV/FPV.html