rjr@mgweed.UUCP (Bob Roehrig) (07/03/84)
qst de k9eui hr propagation bulletin nr 27 from arrl headquarters newington ct july 2 1984 to all radio amateurs bt the solar flux average for june was 100.4, the lowest this year, though there were two months below 100 in 1983. perhaps more significant is that there was only a 19 point spread during june. these facts emphasize the difference in the character of the sun in the low years of the solar cycle. there will be less day to day variation in the solar numbers in the next few years. this will improve f layer propagation on the lower amateur frequencies, at the expense of the higher bands. though this summer has been poor for sporadic e activity on 28, 50 and 144 mhz, this is not necessarily the result of declining sun spot numbers and lower solar flux. the w6jkv 50 mhz expedition to greenland this past week produced a surprising number of qsos over a greater expanse of territory than had been expected. then at the weeks end, there was a surprise transatlantic opening to the channel islands from northeastern u.s. and adjacent canada. reception of the gibraltar 6 meter beacon zb2vhf, and the british beacon gb3six, was reported over a wide area in this country. for the forecast week, generally poor hf conditions are expected through july 5, improving july 6 and july 9 to 12. american sunspot numbers for june 21 to 27 were between 39 and 54 with a mean of 47.9. ar
rjr@mgweed.UUCP (Bob Roehrig) (07/09/85)
qst de k9eui hr propagation forecast bulletin nr 27 from arrl headquarters newington, ct july 7, 1985 to all radio amateurs bt active areas of the sun responsible for solar flux peaks in early may and june have been on the visible disc of the sun again since july 1. the lead group is shrinking, but the second is larger and more complex than during its june appearance. the solar flux rose from 74 on july 1 to 95 on the 7th, its highest since july of last year. all visible activity is now in the western half of the solar disc, so the flux and sunspot numbers will be lower this week. as predicted last week, geomagnetic activity associated with the more active sun made for erratic dx conditions on our lower frequencies. more stable propagation and lower muf are expected after about july 9. transatlantic dx was worked on 50 mhz during the evening of july 2, and again around midday on the 7th. there was also 50 mhz work to south and central america on the latter date. we may have passed the early summer peak for e layer dx on 28 and 50 mhz, but there will be frequent openings during july. there is no close tie in with solar flux peaks or valleys for the e layer mode, but the four week solar rotation period is worth noting. on that basis we expect a fall off in the middle of july, and a final upsurge at the months end. a gradual change to f layer propagation and longer skip distances will be noticeable on 21 mhz and lower frequencies in august. as e skip drops off, 28 mhz will seem quiet but there is a good possibility of long haul f layer work on that band in the fall months. more details on this prospect will be given in a few weeks. ar