PROPAGATION - by AD5Q HOUSTON, TEXAS -- JULY 1996


It is now mid-summer, and most DX activity is concentrated on 20 Meters. The low bands are noisy with weather-related QRN, though 40 is in good shape otherwise. Higher frequency bands are suffering the effects of an overheated ionosphere: lower daytime MUFs. Nighttime MUFs, however, are at their seasonal peaks.

At the high end of the solar cycle, July is the trailing end of a spectacular DX season on 15 where signals span both day and night. This year's openings have been very marginal and usually unnoticed. European openings occur in the afternoon, with Asia later in the evening. In order for contacts to be made on these paths, somebody has to call a CQ and somebody has to hear it. Most of us have written off 15 Meters. WARC band enthusiasts will find better conditions on 17 Meters, and certainly more activity.

On 20 Meters, we find the band open nicely to Asia in the morning for several hours. There usually aren't many signals on the band, but the DX stations are often of the exotic variety. Contacts with HS, 9V, V85, BV, VS6, 9M, BY, JT, etc. are routinely worked by those who regularly tune this opening looking for wishful stuff like XX, A5, 9N, XU, S2, XZ, XW, BS7, VU4 and others. The latest P5 rumor has come and gone. This morning DX window to the northwest is an important one from North America, and can open beyond Asia.

Long path openings on 20 are marginal through the bottom of the sunspot cycle, and most who watched these paths regularly a few years ago have gone on to other things. This means that pileups are uncommon. Season- ally, 20 LP openings peak on Antarctic paths from the fall through the spring, while during the summer they shift to the north. In the morning we get an east-west path to the southern parts of Africa. But it is the northwest LP opening that is especially interesting for us. This path skips completely across Asia into the South Indian Ocean. The list of countries in that remote corner of the world is very short, and very rare: (FT/W/X/Z, ZD9, 3Y, VK0 (Heard) and ZS8). ZS8IR is currently active on this path.

The main European opening on 20 occurs in the late afternoon, though there is a marginal opening during much of the day. In the evening, this becomes a polar opening into Russia and Siberia which includes a path to the Middle East. The late evening opens marginally into the European sunrise area and west into Asia and the Pacific (where it is late afternoon). DX is workable on 20 well after midnight, and will be for another couple of months.

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