The VHF radio band for a commercial VHF two way radio is between 130 – 174 MHz. FM radio, two-way radios, and television broadcasts operate in this VHF range.
Both UHF and VHF radios are prone to line of sight factors, but VHF a little more so. The radio waves make it through trees and rugged landscapes, but not as well as UHF frequencies do. However, if a VHF wave and a UHF wave were transmitted over an area without barriers, the VHF wave would travel almost twice as far. This makes VHF easier to broadcast over a long range. Since VHF frequency waves are bigger, a VHF antenna must also be bigger.
If you are working mostly outdoors, a VHF radio is probably the best choice, especially if you are using a base station radio indoors and you add the external antenna. The higher you can place the antenna, the further you can transmit and receive. One exception to using a VHF radio outdoors is if you are using it in a heavily wooded area. Under these conditions a UHF radio may be able to transmit better though the trees.
VHF radios also have a smaller number of available frequencies. Interference with other radios could be more likely to be a problem. However, the FCC recently made this less of a problem when they opened up the MURS frequencies. The 150 MHz frequency is a Citizens Band radio spectrum that is called the MURS service. MURS stands for Multi-Use Radio Service. This service is for use in the United States and Canada. It is a low power, short range service in the VHF 150 MHz Citizens Band radio spectrum. There are 5 channels in the MURS frequencies with 38 privacy codes under each one that enable you to only pick up conversations from radios transmitting your code. The FCC does not require users of products for MURS to be licensed.
With MURS you can add a larger or external antenna to improve range. If you want to put an antenna on top of your building or a tower, you can do it with MURS. Some antenna manufacturers claim an external antenna can increase the effective radiated power of a transmitter by a factor of 4. These MURS intercoms can transmit up to four miles, and perhaps more with an external antenna depending on the terrain.
One benefit of VHF wireless radios is that battery life is almost always better than for similar UHF units. For handheld radios this is a plus.
In summary, if you are planning on using your two-way radios mainly inside buildings, then UHF is likely the best solution for you, but it in lots of applications VHF could still work fine. If you are mainly using your two-way radios for communication outside, then VHF would be a good choice, unless the area you are covering is heavily wooded. Either radio technology can work for you if you don’t really have a long range to cover. There are also repeaters you can install that relay a UHF signal. We’ll talk about those in the Accessories section.
For an excellent, free resource on VHF two way radios, click on this link: two way radio review
There is also an article about UHF Versus VHF by clicking the link in this sentence.