PROPAGATION - by AD5Q HOUSTON, TEXAS -- DECEMBER 1996


This is old news by now, but conditions during the CQWW CW were, uh, anomalous. It has been some time since we've seen flux numbers over 100, and this was most welcome. Though this old-cycle activity doesn't signal the beginning of better times, we can hope it recurs for another solar rotation or two. Since the focus of these articles is on seasonal variations in propagation, we leave the forecasting of solar phenomenon to other writers and work whatever paths are open.

The higher flux numbers brought us better than expected conditions on 15 during the day, and on 40 at night. Still, much of Europe was weak on 15 from W5 with the notable exception of the Iberian peninsula. There was no shortage of multipliers on this band. The seasonal peak for fall high band propagation has past, and the entire arctic region has darkened. Openings to Europe and Asia will continue to deteriorate into winter and interest in this band will mostly dry up. This winter, however, we can hope for a return of the solar activity of the CQWW and exploit any temporary improvements in band conditions.

20 Meters remains the best daypath choice for propagation to remote corners of the world. This past month brought us another operation from Burma, which was workable via long path from here. Long path openings are not as consistent at the bottom of the sunspot cycle. At peaks, there is a regular following of stateside DXers watching these paths and signals are loud. Peak season for long path on 20 is in the late fall and through the winter (when night path propagation peaks in the southern hemisphere). It is good to know that the Antarctic paths are still workable, and that expeditions can and do exploit long path propagation to reach the areas of greatest need.

40 is in great shape. The best opening to Europe occurs before our sunset and before bedtime in Europe. Later, the MUF usually drops under 7 MHz for this path. This means there are fewer signals on the band during North American "prime time" - but this is when we have our best propagation to points further east (Russia, the Middle East) where the sun is rising. African contacts can be made at any point in the evening.

Much attention is focused on 80 nowadays, especially for SSB operators. The evening hours supply light activity from Europe, which is still primarily asleep. Several nice African countries appear regularly at their own sunrise. The east coast has a serious advantage over W5 for most evening DX, but after midnight things change. The east coast retires to bed as the sunrise peak sweeps across Europe. Later at night, the band is quiet and this DX is easily workable. Peak season for 160 Meter DX work is approaching.

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E-Mail: ad5q@kb5tes.#setx.tx.usa.na or ids@nol.net