PROPAGATION - by AD5Q HOUSTON, TEXAS -- DECEMBER 1997


And the new cycle is just beginning! With solar fluxes swinging from the 80s to around 120 within a month, it was hard to forecast highband conditions in the CQWW. Geomagnetic conditions were disturbed in the phone portion, but solar activity was high enough to open 15 nicely. For the CW test the flux was also at the high end of its monthly range, but with QUIET geo conditions. Propagation was as good as could be expected from this young cycle.

Evening conditions on 20 Meters were somewhat improved, but it takes a higher flux to open the night paths at this time of year. Long path openings are better and more reliable, but these night paths span the southern hemisphere where it is late spring. The main path to Europe is in the morning, and is a daypath. With the daytime MUF often substantially higher than 14 MHz, the better path to Europe can be found on 15. This was the case during the contest, where many had good rates during runs. However there will still be days when fluxes are under 100, and where 20 will have the better daypath. Since we are now late in the DX season, the polar region is dark. We cannot expect much propagation over high latitude paths on 15 yet, so from W5 there won't be much in the way of Russian openings. Over these difficult paths 20 Meters should be preferred, both at sunrise and at sunset. Use the Antarctic path for southern Asia.

As I write this, the Ten Meter contest is approaching. We have already experienced brief openings to Europe here, mostly to the western parts. The openings to Japan have been better. During the CQWW, many made Asian long path contacts in the morning via the southeast. The east coast had a much better path to Europe with fairly good runs, but these occurred before the band even opened for the rest of us. At best, we can expect about the same conditions for the Ten Meter contest (hoping for high flux and low K-Index). For most of us, this will be mainly a stateside contest with lots of Sporadic-E propagation to provide high rates. We will surf the Caribbean looking for multipliers and pileups, and hope for an opening to Japan for DX runs. This is still a substantial improvement over recent years, and activity should be sharply up this year without the heavy reliance on weak signal backscatter.

The night band with the most quantity is still 40. Europe peaks best before sunset for us and after sunset for the east coast, but it is the same opening. In mid-evening we follow the sunrise across Russia and then Europe after midnight. The peak on 40 will follow the brief sunrise peaks on 80 & 160 to the same area.

The complete set of monthly articles (1988 to date) is available on the following Website: http://www.nol.net/~ids/prop.html

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