» No. It must be on the same frequency range can talk to each other, but VHF136-174 MHz, UHF 400-470MHz. So a VHF radio not be able to communicate with a UHF radio.

» According to the electromagnetic theory, the higher frequency with shorter waves, and it's stronger to     get around or penetrating areas of interference and vice versa. In other words, VHF Radios are better for used outdoors; UHF Radios are better for indoors.

» Yes. Please let us know the frequency of your old radios so that we can match the same frequency for you.

» You can change it by programming cables, just connected the radio to your PC. If with keypad, you also can change it by the keypad directly.

» Each work group can have their own channel to minimize disruptions in other departments. For example, when the Security Department speaks on channel 1, the front office will not hear radio traffic if they are on channel 2. Most organizations have a common channel so that all users can hear the radio traffic in case of emergencies. So it depends on your work environment.

» A walkie talkie talk range depends on the power, antenna height, working environment etc. In general, a haneheld radio with 4/5W VHF/UHF can cover from 1-5 miles in radius. When use with a repeater can cover up to a 30 mile radius.