RE: Hobbico Freq. Checker
There are a LOT of signals that can interfere with R/C models....pagers, fleet communications, radio-controlled cranes, and so on. The 72 MHz band is designated for commercial use, and the R/C channels are intereleaved between the commercial channels. They are allowed up to 1,000 Watts of power, R/C tranmsitters are allowed up to 0.750 Watt of power.
A high-power user as many as 3-4 channels away, so to speak, from your channel could cause interference and loss of your model. If one of those users can be shown to affect R/C channels, then the only alternative is to find R/C channels that are not affected. FCC regulations give R/C users lower priority than the commercial users.