>>1210325For an amateur repeater, you'll still need an amateur license.
You will need to go through FC (Frequency Coordinator) in your area so they can assign you a frequency pair. They'll generally want to know power output (not just power from the transmitter, but actual radiated power - factoring in insertion/cable losses, combiners/duplexers, antenna gains, etc), location (lat/long/elev) and antenna AGL, and mode (probably FM/FMN).
Repeater building isn't difficult, but there's more to it than most hams (or people in general) realize. Much more equipment than just a radio and an antenna or two. Making everything work well and reliably is almost an art.
GMRS is pretty much the same. Not real familiar with FC for that - i'd imagine there is something. Your local ham club may be able to point you in the right direction, or talk to the amateur FC about it who would probably know. Channels 15-22 are the only ones repeaters are allowed on, inputs are -5MHz from the outputs.
>>1210350Mostly right.
Nobody scans repeater input frequencies, regardless of what service/mode you're using. No reason to.
>>1210637Think of it more as three "groups" of channels. It's easier now after the reorg, but still somewhat confusing. Most equipment will automatically knock down power based on the freq, and very few consumer radios can do repeater splits.
Do not use the GMRS input freqs for simplex. (I have them in my radio as repeater channels and use talkaround).
