In a nutshell if you do not have a current 2-way radio system, we would recommend UHF over VHF.
First some basics:
VHF – VHF stands for very high frequency. VHF signals occupy the low end of the frequency spectrum, usually from 89.00 MHz to 216.00 MHz. The very first wireless transmissions were made from the low frequency band, which is still being used today. Because of this this band with extremely populated.
UHF – UHF stands for ultra high frequency. UHF operates in the 400 MHz frequency range. Although UHF is also populated, it provides a few more options than VHF especially when it comes to community repeaters.
Low frequency AM broadcast radio signals will travel far beyond the horizon and can be reflected back to earth for reception at great distances. UHF signals don’t travel quite as far outdoors as VHF signals, but they do a better job of penetrating wood, steel, and concrete, giving you better range and performance in urban environments and around buildings. VHF signals travel farther, absent obstructions, and tend to “hug” the earth better, providing better performance outdoors or in hilly terrain.
UHF or higher frequency television or FM commercial broadcast stations are absorbed by the earth’s atmosphere and are therefore limited to line of sight transmission.
Because there are more options when it comes to UHF, especially with community repeaters, UHF is our choice for new 2-way radio systems.