Tequila wrote:
...Technically you need an FCC license to use these although few bother...
"technically" in the same way a driver's license is technically needed. both are codified law, one state and the other federal. odds of being caught by the FCC? slim to none but if caught penalties can be stiff. all that is required for a
10-yr GMRS license is a form and a check for $70.
the install requirements for a GMRS radio are the same as for a CB, ham radio, commercial 2-way radio, etc. you need a good ground plane or an antenna that is designed for non-metallic surfaces, a 12v power supply and a place to mount the transceiver.
be careful when operating on GMRS frequencies. GMRS rules allow for repeaters but they are privately owned and most of those require permission and sometimes a fee from their owners to use. there are some open GMRS repeaters that are available for use by anyone.
it will pay to bone up on the rules, regulations and operating procedures if you're going to use GMRS.
https://www.fcc.gov/general-mobile-radio-service-gmrsWhy Do I Need A GMRS License?Wikipedia Article