rjr@mgweed.UUCP (Bob Roehrig) (05/23/84)
qst de k9eui hr propagation forecast bulletin nr 21 from arrl headquarters newington ct may 21, 1984 to all radio amateurs bt as of may 20, the solar flux has been higher than at the same point in previous solar rotations continuously for 30 days. in addition, the daily flux average for all of 1984 to date is some 15 percent above the 1983 daily average. the flux was rising at bulletin time, but at a slower rate than in april, so the flux curve is likely to drop below that of a month ago during this week. as in late april, major solar flares are occurring frequently. these will bring degraded propagation on all hf bands may 21 through 26 and 28 through 31. a major geomagnetic storm in progress as this bulletin was in preparation brought auroral conditions on 50 and 144 mhz in the northeastern u.s. there was also a late season transequatorial 50 mhz opening to south and central america on may 19. sporadic e propagation was almost a daily occurrence on 28 and 50 mhz after the middle of may. it will reach a broad peak during june. american sunspot numbers for may 3 through 9 were between 25 and 79 with a mean of 48.9 ar
rjr@mgweed.UUCP (Bob Roehrig) (05/07/85)
qst de k9eui hr propagation forecast bulletin nr 21 from arrl headquarters newington ct may 5, 1985 to all radio amateurs bt there is little to be said for the period april 20 to may 2 except that, if your interest in amateur radio survived those two weeks, you need not worry about anything much worse to come. the generally low muf and the preponderance of weak signals and severe fading also showed that higher solar flux and sunspot numbers do not necessarily make for improved long distance communication. during late april solar activity came in sudden surges, mostly of short duration, resulting in very high surges in the earths magnetic field. this is about the worst thing that could happen for hf propagation in the higher (garble). the severity of these disturbances was such that almost total blackouts of wwv reception were observed in the writers florida location for the first time in several years of part time southern living. somewhat improved propagation can be expected this week, but not because of higher solar flux or sunspot numbers. on may 3, 4 and 5 the solar flux curve is superimposed on the curve for april at 71, 70 and 70. as in early april we should be moving into periods of more stability and better hf propagation, especially may 10 through 16. this will affect 14 mhz and lower frequencies mainly. on may 5 we had our first good sporadic e skip on 28 mhz, and there were a few contacts on 50 mhz as well. more of this will be showing up later this month, but the real peak usually comes late in june. most likely hours are mid morning and early evening, but e skip can come at any time. multiple hop propagation may extend the skip range to transcontinental or even transatlantic distances, though a few hundred miles is much more (common). sporadic e skip openings are not directly related to sunspot numbers or the solar flux level. american sunspot numbers for april 25 to may 1 were between 35 and 19 with a mean of 27.1 ar
rjr@mgweed.UUCP (Bob Roehrig) (05/29/85)
qst de k9eui hr propagation forecast bulletin nr 21 from arrl headquarters newington ct may 26, 1985 to all radio amateurs bt may brought a marked reversal of the downward trend in solar activity that began last fall. in fifteen days ending may 22 the solar flux was 80 or higher daily. the major disturbed periods of april did not recur in may, so hf propagation was generally better than had been expected. if similar sun conditions prevail in the fall, the dx picture could improve markedly, especially on frequencies above 14 mhz. at bulletin time the sunspot groups responsible for the higher solar flux had gone around the west limb, or had shrunk in size. the solar flux dropped from 93 on the 16th to 74 on the 26th. an area that was active april 28 to may 1 is in view again, but showing no important activity thus far, so no major hf propagation change is expected this week. sporadic e skip was much in evidence on 28 and 50 mhz, and this upward trend will continue. since may 14, kf4ms, a 10 meter beacon in st. petersburg, fl, has been heard in the writers connecticut location daily since may 14, usually for several hours at a time. the bermuda beacon, vp9ba, has been logged nearly as often. the 50 mhz band has been waking up, and multihop contacts out to 2000 miles or more have been reported. the number and duration of e openings will increase through june. high density sporadic e can affect lower frequencies adversely, but it is great for 28, 50 and possibly 144 mhz, in the summer months. transatlantic qsos may be possible on 50 mhz now that several european countries permit operation on that band after about 2200 utc. american sunspot numbers for may 16 through 22 were between 43 and 21 with a mean of 30.3 ar