Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [space-weather]

Questions relating to variability in the Sun-Earth system and the impacts on radio communications.

Space weather is a catch all phrase describing short and long time scale variations in solar activity. This included changes in the ionising EUV flux emitted primarily from sun spots that is the primary driver of the strength of the ionosphere. Geomagnetic storms, X-ray flares, coronal hole high speed solar wind streams are other examples of short time scale events that can impact radio communications.

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Why is the solar-flux index measured at 10.7 cm?

Why is the solar-flux index measured at 10.7 cm? What makes that such a special frequency?
Dan
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What is the cause of this unusually long period of terrible HF band conditions?

I've been a ham for over 40 years, but never has there been such a prolonged period of such poor propagation. This has been especially the case over the past six months or so, and they continue to deteriorate. What could possibly be the cause? This…
Mike Waters
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Are ionospheric predictions useful in practice for ham radio operators?

A number of government agencies around the world provide ionospheric predictions, such as vertical foF2 or oblique path useable frequency range advice. Examples include IPS, SWPC and DIAS. Typically, the major customers of these agencies are in…
Bogdanovist
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What factors (out of operator control) can affect the range?

Some factors, such as the antenna type and power output can be easily adjusted by an operator to manipulate the range of a radio signal. However, others (such as the weather) are out of operator control. What such factors can affect the range of a…
berry120
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What frequency ranges are most common for Amateur radio astronomy and why are most parabolic antennas tuned to such high frequencies?

What frequency ranges are most common for amateur radio astronomy? I am mostly interested in radios for the purpose of astronomy. In general I was expecting that the lower frequencies would be more useful, since hams usually can receive and transmit…
Hack-R
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How does one know when band conditions are optimal and what factors to consider?

On many of the DX sites, one will find many variables for solar weather to include flux, A, K, sunspots, etc… I’d like to know how to read those and know what to look for. As I understand it, the sun’s activities affect the ionosphere which affects…
Ender
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How and why sunspots affect propagation in HF bands?

How and why do sunspots affect propagation in HF bands?
Timtech
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