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Very High Frequency

Frequencies ranging from 30 MHz (30,000 kHz) to 300 MHz (300,000 kHz) are defined as Very High Frequency. One important characteristics of this spectrum is that they are not readily reflected by the ionosphere limiting their range of communication to the line of sight (the same reason restricting the range of coverage of   transmission from a TV transmission tower). This implies that taller is your antenna, further is the distance travelled by the radio signals transmitted from your radio transmitter. Very High Frequencies provide the most reliable short distance line-of-sight radio communication which is free from the control of other atmoshpheric effects. There are different atmospheric effects like that of due to the generation of patches of high ionization sporadicE-Clouds around the equator or other freak atmoshpheric phenomenons like temperature inversion and tropospheric ducting which extends the range of VHF communication beyond the line-of-sight. Ham radio operators are alloted the frequencies ranging from 144 MHz to 148 MHz (in India it is 144 to 146 MHz) and a limited frequencies in the 50 MHz range.VHF equipments can be designed compact in size which makes them handy during mobile operation. Either Passive or active relay stations are used to relay VHF signal to far away places.