The first thing you need to know is UHF radios will never be able to communicate with VHF radios. Choosing the wrong frequency means you could lose money and delay your work. If you already have radios and are looking to purchase additional units, be sure to select the same band. Just remember, UHF to UHF ,VHF to VHF !
UHF radios
UHF, short for Ultra High Frequency operate on frequencies from 400 to 512 Megahertz (MHz). UHF radios work best for most two-way radio users because the waves are shorter and can get around or penetrate areas of interference found in buildings, thickly wooded or hilly areas and urban outdoor settings.
UHF walkie-talkies with a good-sized antenna and enough power will reach further into a building and push through and around steel, concrete, wood and earth. If your two-way radios are going to be used exclusively indoors or if they’ll need to go indoors and outdoors, UHF is, hands down, your best choice.
VHF radios
VHF, short for Very High Frequency, operate between 136-174 Megahertz (MHz). The advantage to a VHF walkie-talkie is that it can cover more distance with less power because VHF waves are longer and remain closer to the ground. VHF radios work best when there’s a clear line-of-sight between the sender and the receiver with little obstruction.
VHF radios are used exclusively in aviation and marine communications where signals are sent across open bodies of water or between the sky and the ground. VHF band walkie-talkies are also great for open fields, golf courses, landscaping and for outdoor security situations with few obstacles.