Propagation Characteristics
70-centimeter propagation characteristics lie midway between 2-meter and 33-centimeter (~900 MHz) bands. As frequency increases, building penetration improves. However, smaller obstacles may also block or reflect the signal. Higher frequencies also present a lower noise floor, making it easier to overcome both natural and artificial interference, especially prevalent in urban environments.
Atmospheric thermal ducting is often more intense at UHF, because shorter wavelengths have much greater refraction angles than longer ones. However, a much stronger thermal inversion is often required than is needed for ducting in the 2-meter band.
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