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The
Atlantic City Conference of the International
Telecommunication Union (ITU) in 1947
subdivided the radio frequency spectrum. Each subdivision of the radio
frequency spectrum has its own propagation
characteristics through the land,
water and
atmospheric envelope
covering the earth. For example it has been experimentally observed
that VHF usually penetrates the ionosphere
and are lost into space, while the HF (short wave) are reflected back from the
ionosphere
3-30 KHz
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VLF (Very Low
Frequencies)
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30-300 KHz
|
LF (Low
Frequencies)
|
300-3000 KHz
|
MF (Medium Frequencies)
|
3000-30,000 KHz (3-30MHz)
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HF (High Frequencies or short waves)
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30-300 MHz
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VHF (Very High Frequencies)
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300-3000 MHz
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UHF (Ultra High Frequencies)
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3000-30,000 MHz
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SHF (Super High Frequencies)
|
30-300 GHz
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EHF (Extreme High Frequencies)
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