PROPAGATION - by AD5Q HOUSTON, TEXAS -- DECEMBER 1998


November brought us the finest solar conditions to date in the new cycle. Best of all, this occurred on the weekend of the CQWW CW Contest. The flux approached 170 with quiet geomagnetic conditions, and all bands played well except 160. This more than makes up for the low solar activity we found in the SSB portion of the contest. This time, the 10 Meter window to Europe was in excellent shape.

The really high latitude countries were mostly available in the early morning. 10 does close shortly after sunset - just as the band opens for us. The polar region is mostly dark, and we can expect these paths to be difficult on 10 this late in the season. The higher flux does keep them open on 15, and the DX continued to run past noon at good rates. After dark on our end, high latitude openings to Asia can be found just before the band closes. Predictably, these opportunities are better on 15 than on 10.

As night falls over Europe, the MUF along the path drops and the opening moves to lower frequencies. 20 closes up later in the evening, but in the early evening DX paths are open from the northwest around to the southern hemisphere (where 20 is open all night). This is also the way the band closes: from the northwest around to the south. In the early evening we get an opening deep into Asia, and Europe gets an opening to North America in their evening. When the MUF across the Atlantic drops below 14 MHz, propagation begins to peak on 40.

Though 80 & 160 are at their best at the bottom of the sunspot cycle, the MUF on 40 drops below 7 MHz in the winter. Europe works North America in the evening, and in the morning after sunrise. With the higher solar flux, 40 is open to Europe all night - as it was in the contest. It is now the optimum night band. Areas closer to the polar night (e.g. Scandinavia) are workable well past midnight. They call it morning, but the sun is still low in the sky at northern latitudes - extending the lowband opening into the darkness.

20 is not the optimum band for either day or night paths, but works well in the late afternoon, early evening, and morning. You work into other areas of the northern hemisphere that is in these time periods, or into and across the southern hemisphere where the band never closes. It is a good idea to check the morning long path several times per week, because there really is a lot of exotic activity on the band regularly.

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