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The Propagation Corner Get Ready For Superb Autumn DX Openings!
by Tomas Hood, NW7US |
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Autumn is right around the corner, bringing a radical improvement in radio propagation conditions. At the end of September, the sun will be directly over the equator. On the autumnal equinox, everywhere in the world, the hours of daylight are equal to the hours of darkness, resulting in an ionosphere of similar characteristics over large areas of the world. That, in turn, makes it the best time of the year for long DX openings between the temperate regions of the northern and southern hemispheres on all shortwave bands. You can expect a vast improvement on the higher frequencies (22 meters up through 11 meters) with more frequent short-path openings from mid-September through mid-October between North America and South America, the South Pacific, South Asia, and southern Africa. The strongest openings will occur for a few hours after sunrise and during the sunset hours. Many international shortwave broadcast stations will soon change from their summer schedule to a winter schedule, taking advantage of this change in propagation. Long-path openings also improve during the equinoctial periods. A variety of paths are opening up on 31 and 22 meters. Expect a path from southern Asia around sunset, daily morning openings from southern Asia and the Middle East, expanding to Africa. Also look for signals from the Indian Ocean region long-path over the North Pole. Afternoons will fill with South Pacific long-path, and then extend to Russia and Europe. Look for possible long-path openings on 31, 41, 49, 60, and 75 meters for an hour or so before sunrise and just before sunset.
The winter DX season is slowly approaching,
making for exciting DX conditions. While the weather is still warm and
fair, tighten up the hardware on your antenna system, check coax cables,
and fine tune your radio station. Get ready to reap the DX. Since the second peak (November 2001) in this double-peaked cycle (the first peak was in April 2000), the smoothed numbers are showing a consistent and somewhat rapid decline in solar activity. The Royal Observatory of Belgium, the world’s official keeper of sunspot records, reports an observed monthly mean sunspot number of 55 for May 2003, down five points from April. The 12-month running smoothed sunspot number centered on November 2002 is 151, down eight points from October. The sunspot minimum for May 2003 was 17 on May 10. The sunspot maximum of 99 occurred on May 1. |
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