PROPAGATION - by AD5Q HOUSTON, TEXAS -- MAY 1998


So conditions have cleared following two weeks of severe geomagnetic activity. Now conditions are excellent, as we are in the peak of the DX season for late spring. I make no forecasts regarding when (and if) the disturbed conditions will return, and leave that to other propagation gurus more focused on solar statistics. I do fear that conditions in the upcoming WPX contest will suffer. In any case these forecasts are predicated on stable conditions in the ionosphere, and highlight seasonal influences.

As I write this, the 3B7 operation is still active. Geographically, they enjoy easy access to nearly all the world's population of DXers with the exception of the Pacific coast of North America (where the path is polar). Even here, seasonal conditions are ideal because the polar paths are wide open on 20. This expedi-tion is also exploiting long path opportunities to North America, though the Antarctic paths needed for contacts with the west coast are drifting out of season.

The ionosphere is heating up and thinning as we move toward summer, lowering daytime MUFs. In May, this closes high latitude paths on 10 Meters which have been marginal anyway. This phenomenon will not adversely effect 15 until July, and there are benefits we can enjoy now. The MUFs rise slowly in the morning and drop slowly at night, making for excellent conditions on 20 Meters. There is also limited nightpath activity on 17 and 15. As this sunspot cycle progresses, the late spring nighttime activity on 15 and 17 will not be so limited. For now, these higher bands are worth checking at night. The 3B7 was recently copied on 17 for two hours past midnight from various long path directions (northwest to southwest).

In late afternoon, we can also work into areas where it is night. Some Europeans are coming through on 15 along with the usual opening to Japan. This EU path is better on 17 and best on 20 (and in the winter we find it on 40).

The most awesome propagation is currently on 20, along with the most activity. All polar directions are open throughout the evening, with Europe opening again late at night (their morning). Morning long path openings are becoming more westerly due to the Antarctic winter, so we tune more for Africa and enjoy the short path pipeline to Asia that lasts for several hours after sunrise. 40 Meters is getting noisy (though conditions are still very good), and most activity has moved to 20. The Cubans, with their unique operating style, are still on 40 ;-)

http://www.nol.net/~ids/prop.html
E-Mail: ad5q@kb5tes.#setx.tx.usa.na or ids@nol.net