Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site mgweed.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!harvard!talcott!panda!genrad!decvax!bellcore!sabre!zeta!epsilon!gamma!ulysses!mhuxr!ihnp4!mgnetp!mgweed!rjr From: rjr@mgweed.UUCP (Bob Roehrig) Newsgroups: net.ham-radio Subject: arrl propagation forecast bulletin nr 21 Message-ID: <16935@mgweed.UUCP> Date: Mon, 6-May-85 22:17:18 EDT Article-I.D.: mgweed.16935 Posted: Mon May 6 22:17:18 1985 Date-Received: Fri, 10-May-85 20:26:15 EDT Organization: AT&T Consumer Products - Montgomery Illinois Lines: 42 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