VHF is 30 to 300 MHz, but most people consider VHF to be in the 150 MHz range.
There are a lot of VHF handhelds (HT) around that were called "dot" radios, like "red dot":
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270102684017
The dot refers to the frequency, for Red Dot it's 151.625. All red dot radios can talk to each other, but there are other frequencies. I believe you are supposed to get a license from the FCC.
Most HT's are a maximum of 5 watts, which limits range. VHF is line of site. Expect to get 5 miles in open country, and only a couple of miles in the city, or woods.
If you live in a city, there are other options though. One is Amateur radio. 2M is in the 145 MHz band, and has similar ranges, but they also can have repeaters.
There are many repeaters that amateurs put up, and allow anyone to use, for non-business purpose only! With a repeater, you can see 25 miles coverage to HT's, and 50+ mile coverage to mobiles. Repeaters are rebroadcast the weaker signals of the HT and mobiles. there receiving antenna is usually very high (100, 200... 500 feet or more), and have transmitters retransmitting at high power (200 watts+). Anyone can get an amateur license, check arrl.org for more info.
GMRS is another option. It's not VHF, but UHF, but also has repeaters. You also need a license, and it is also for non-business.
2007-03-28 14:54:59
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answer #1
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answered by megaris 4
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VHF is Very High Frequency. It's used in a very wide range of applications, from cordless phones to military radios.
VHF is line-of-sight, but the range depends mainly on the antenna height. To get the range in miles, multiply the antenna height in feet by 1.5, then get the square root of that number.
As for "normal people"...VHF can be used in certain frequency bands by amatuer radio operators.
2007-03-28 10:46:40
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answer #2
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answered by BDZot 6
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