rjr@mgweed.UUCP (Bob Roehrig) (11/27/84)
qst de k9eui hr propagation forecast bulletin nr 48 from arrl headquarters newington ct november 26, 1984 to all radio amateurs bt after ten weeks at close to quiet sun levels, the solar flux started upward november 17. from 72 it rose to 85 by the 25th, and may continue upward another day or two. this rise came as geomagnetic activity was declining, making for some of the best propagation 0f the autumn dx season. improvement was most marked on 21 mhz. on 28 mhz, there was some propagation to africa from eastern usa, and north south conditions were good. geomagnetic activity will be rising after about the 27th, and propagation will be more variable through about december tenth. the major geomagnetic disturbance of mid november will recur, probably at lower levels about december 13 to 15. it is too early to tell if the new solar activity in recent days is more than a brief event. it could signal a critical period in which predictions based on the rotational period of the sun become unreliable. more on this later in subsequent bulletins. the updated table of ten meter beacon stations announced in bulletin number 46 is still available. send an sase to ed tilton, w1hdq, po box 137, canton, ct 06019 ar
rjr@mgweed.UUCP (Bob Roehrig) (12/03/85)
qst de k9eui hr arrl propagation forecast bulletin nr 48 from arrl headquarters newington ct december 2, 1985 to all radio amateurs bt september through november, normally a good time for hf dx in the northern hemisphere, provided almost textbook examples of the effects of solar activity on our dx bands. the september solar flux high was 73, and that on the first day. with an average of 69.5 the month was rough on the users of 21, 24 and 28 mhz. even 14 mhz was marginal most of the time. early october was worse, with a flux average of 66.9 for the first 13 days, none of them above 69. funeral arrangements were being made for cycle 21, until it came alive on the 14th and the flux climbed steadily to 95 in the third week. the 21 mhz band was jumping by this time, and activity began to pick up on 24 and 28 mhz again. november was quieter, but the flux was 75 or higher more than half of the time, reaching 86 at mid month. as predicted the last week of november brought low geomagnetic activity and exceptional signal levels on all frequencies (garble). we enter december with the solar flux at 70, but with prospects for a gradual rise, peaking about the 12th. the area of the sun now facing earth has been giving us mostly good propagation, with only minor disturbances. the wwv k index should be watched closely this weekend and next. k values of 2 or lower particularly with a downward trend make for strong stable signals on high latitude paths. flux levels are not too critical at this season, except as they move into the low 70s or high 60s. even these low values will not wipe out 21 and 24 mhz entirely, but they limit 28 mhz coverage severely. the best of december is likely to be the 18th through the 24th. watch 28 mhz and the vhf bands for signal bursts from the geminid meteors. peaking december 10 through 14, this is one of the more intense and reliable meteor showers. ar.