howto:hambasics:sections:propagation
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howto:hambasics:propagation [2019/11/24 20:24] – [Scattering] ve7hzf | howto:hambasics:sections:propagation [2021/01/03 08:06] (current) – va7fi | ||
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====== Propagation ====== | ====== Propagation ====== | ||
Radio wave propagation describes the way in which radio waves travel from one point to another. | Radio wave propagation describes the way in which radio waves travel from one point to another. | ||
+ | |||
+ | {{ youtube> | ||
====== Direct Waves (Line Of Sight) ====== | ====== Direct Waves (Line Of Sight) ====== | ||
{{ lineofsight.png? | {{ lineofsight.png? | ||
- | VHF radio waves (above 50 MHz) travel more or less in a straight line, and so cannot go much beyond the horizon. | + | VHF radio waves (above 50 MHz) travel more or less in a straight line, and so cannot go much beyond the horizon. |
- | For example, | + | For example, |
For direct waves to occur, the height of the antenna needs to be many times greater than the wavelength of the radio wave so that the signal doesn' | For direct waves to occur, the height of the antenna needs to be many times greater than the wavelength of the radio wave so that the signal doesn' | ||
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+ | ===== Animation ===== | ||
+ | Here's the animation if you want to move the dials and experiment with it yourself. | ||
+ | |||
+ | {{ggb>/ | ||
===== Meteor Scattering ===== | ===== Meteor Scattering ===== | ||
When meteors enter the ionosphere, they create intensely ionized columns of air that can scatter radio waves for very short periods of time (from a fraction of a second to a couple seconds per event). | When meteors enter the ionosphere, they create intensely ionized columns of air that can scatter radio waves for very short periods of time (from a fraction of a second to a couple seconds per event). | ||
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Scattering can also allow HF signals from the skipzone to be heard. | Scattering can also allow HF signals from the skipzone to be heard. | ||
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+ | ===== References ===== | ||
+ | * [[https:// | ||
+ | * [[http:// | ||
====== Questions ====== | ====== Questions ====== | ||
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- | [[sections | + | [[waveinteraction |
howto/hambasics/sections/propagation.1574655889.txt.gz · Last modified: 2019/11/24 20:24 by ve7hzf