rjr@mgweed.UUCP (Bob Roehrig) (12/04/84)
qst de k9eui hr propagation forecast bulletin nr 49 from arrl headquarters newington ct december 3, 1984 to all radio amateurs bt the gradual solar flux rise reported last week continued through november 26. its peak value, 86, the highest since early september, came a bit late in the autumn season to be of benefit, but it brought a welcome improvement in dx conditions on 21 and 28 mhz. two major active areas of the sun responsible for this new lease on life have moved around the west limb now, dropping the solar flux to 79. another area is due back this week, so a large decline is imminent. it is unlikely that the solar flux will reach levels used for propagation charts appearing in qst for november and december, so look for maximum useable frequencies and duration of dx openings somewhat lower than predicted. only moderate peaks of geomagnetic activity are expected until december 12, so propagation should be fair to good until then. of special interest to users of 28, 50 and 144 mhz is the annual gemenids meteor shower peaking december 10 through 14. short term ionization produced by these meteors burning up (garble) but large peaks in signal levels on these bands, at distances up to about 1200 miles. american sunspot numbers for november 22 through 28 were between 17 and 43 for a mean of 31.1 ar
rjr@mgweed.UUCP (Bob Roehrig) (12/10/85)
qst de k9eui hr propagation forecast bulletin 49 from arrl headquarters newington ct december 9, 1985 to all radio amateurs bt between november 27 and december 8, the solar flux curve followed that for the same days of the previous solar rotation almost exactly. it held at 70 or 71 until december 4, then rose gradually to 75 on the 8th. if this tracking continues as expected, the flux will peak about december 13, then slide back to near quiet sun levels by the 24th. when solar activity is low and day to day chamges are small, geomagnetic activity is usually low and propagation is mostly good, but with low muf. we are likely to see a lot of this sort of thing for at least another year. even 14 mhz goes quiet early in the evening, but both 14 and 21 mhz can work well in the winter months. openings on 24 and 28 mhz are brief and widely scattered, unless the flux moves into the high 70s or higher. there is likely to be some improvement in the length and geographical distribution of dx on all 4 bands this week, but the shortening hours of daylight in the northern hemisphere work against major improvement. somewhat higher geomagnetic activity is expected this week. it will be most harmful in our more northerly states and in canada. transequatorial circuits may even work better at such times, especially on 21, 24 and 28 mhz. even 50 mhz should not be ruled out. one plus factor for the higher frequencies is the annual geminids meteor shower, peaking this week. this is no ragchewing mode, but it can pay off with fast vox or break in cw. the propagation charts published monthly in qst provide the best information on the most likely times for conventional dx work on the amateur bands. the actual muf for a given time, on a given day, may vary markedly, depending on the solar flux and the level of geomagnetic activity. the peak times are accurate, because they depend on the position of the sun with respect to the path in question. there was an error in the address recently given for the conductor of this column. the correct address is, edward p. tilton, w1hdq p.o. box 5529 spring hill, fl 33526 american sunspot numbers for november 21 through 27 were between 0 and 11 with a mean of 2.7. there were no sunspots visible for the week november 28 to december 4 ar