rjr@mgweed.UUCP (Bob Roehrig) (03/27/84)
qst de k9eui hr propagation forecast bulletin nr 13 from arrl headquarters newington ct march 26, 1984 to all radio amateurs the parade of sunspots across the solar disk mentioned last week appears to have run its course. the timing of their appearance indicates that active areas seen since early march are mostly new ones, not what was left of groups that caused the solar flux highs of january and february. the solar flux curve after about march 6 shows little resemblance to those for the two previous solar rotations. from 136 on mar 15, the solar flux dropped gradually to 112 on the 25th, and it appears likely to decline further during the forecast week. despite this drop, flux numbers are still above the base figure used for the propagation charts in march qst, so the forecast week should see generally good activity on 21 and 28 mhz. a mild geomagnetic disturbance, in progress at bulletin time, should clear by march 27, bringing better propagation in the higher latitudes for the next two days. another disturbance is expected about march 31. it is of interest to 50 mhz dx enthusiasts that their band has been open for transequatorial dx in the southern tier of states during at least six afternoons since march 5. the author of this bulletin worked tg9nx and several lus from his florida location sunday afternoon, march 25. watch for this condition during, or immediately after, periods of high k index, in the afternoon hours local time. high solar flux is not required. opportunities should continue through early april, at least. strong signals from southern 10 meter beacons is a good warning. look especially for vp8ade, in the british antarctic, on 28.283 mhz. american sunspot numbers for march 15 through 21 were between 84 and 107 with a mean of 95.4.
rjr@mgweed.UUCP (04/02/85)
qst de k9eui hr propagation forecast bulletin nr 13 from arrl headquarters newington ct march 31, 1985 to all radio amateurs bt the solar flux reached 80 on march 2 but fell back gradually in the past week, to 72 on march 31. it rose to 74 on the next day, and is expected to be in the middle to high 70s this week. probably because there were no large changes in solar activity, there were no severe ionospheric disturbances during march. propagation was generally better than is usual for this season but 21 and 28 mhz showed the effects of the quiet sun to a marked degree. the dx spectrum was largely 1.8 to 14 mhz, except for recent days, when all continents were workable on 21 mhz, and there was one day of 28 mhz propagation to africa, as well as to south america. activity in the sunspot group responsible for the late march flux rise dropped off markedly last week, but another active area is expected shortly. its principle effect may be increased geomagnetic activity, which will degrade east west propagation in the higher latitudes. te, or transequatorial circuits, especially to australia, new zealand, and the south pacific islands, will continue good on 14 mhz and lower frequencies. the te scatter mode is producing good results fairly often on 28 mhz, and occasionally on 50 mhz. te activity has been noted only after 2100 utc on 50 mhz but the possibility of morning openings should not be ruled out. traces of early spring sporadic e skip on 28 mhz point to the possibility of work by this mode soon on 50 mhz. it is not related to solar activity in any clear way and good seasons have been experienced in the lowest years of past solar cycles. it is most common in mid morning and early evening hours local time. skip distances can be anything up to about 1300 miles. signals may be very strong, but wide range fading and quick fade outs are common. when ionization is very intense there can be propagation on 144 mhz also, most commonly in june and july. another seasonal mode for vhf and uhf dx is tropospheric ducting, now beginning to show up in the gulf states. transgulf dx up to 1000 miles or more was worked on 144 and 432 mhz march 24 and 29. 1296 and 2304 mhz have also been used with this mode. american sunspot numbers for march 21 to 27 were between 21 and 0 with a mean of 13.1 ar