Satgen607 Strange Propagation by GM4IHJ (BID SGEN607) 2000-11-11 Just when it seemed that this Solar cycle maximum was not going to amount to much, all kinds of relatively rare propagation phenomena have been appearing in the last two weeks. Solar flux levels are nowhere near previous cycle peaks. But suddenly we get good 6m, low VHF DX TV and some spectacular radio auroras. Some of this is obviously due to our moving into the more settled winter season ionospheric conditions , but some recent event sequences did not happen even at famous solar cyle peaks. So does the satellite data give any clues ? RS13 has been travelling south from Scotland during daylight and it has produced a very regular pattern of sub horizon signals. Even before it disappears below the Scottish southern horizon , a second signal tone 2 or 3 appears over 500 Hz above the now very doppler low end of pass above the horizon T9 signal. This second signal then rapidly dopplers down continuing long after the primary signal has been lost at LOS, drawing out a beautiful doppler feather extending for several minutes after LOS. But what is important is where this feather starts. Day after day it appears at 41 or 42N latitude indicating the point at which the satellite overflies ( roughly zero doppler ) the enhanced density ridge in the ionosphere. So it should come as no surprise that this dense ridge is capable of propagating 6m amateurs and DX 48/49 MHz TV south to north into Scotland. The TV has the usual multiple echo overlapping picture usually associated with DX TV via F2, and its pictures show bearded announcers speaking Arabic. But RS13 is also putting signals into Scotland when it is over 45S to 60S latitude. Which presupposes a chordal hop carrying the signal about 47 degrees further north to the underside of the ionosphere which propagates it to Scotland. And, also, propagates terrestrial 6ms from South Africa to Scotland. Totally different from the above is a sequence of propagation, not seen in IHJ records which go back to 1970. This November 2000 has seen a pattern of evening events 2000z to 2300z ,whereby Auroral Es have brought near perfect TV pictures to Scotland from Arctic Norway and Sweden, and, Finnish radio amateur clear copy SSB on 6ms along with the much rarer signals from Jan Mayen and Svalbard ,( old Spitzbergen already locked in the Arctic Ice cap for another long polar winter). Again RS13 tracking provides some clues. Sub horizon satellite signals from tracks across the high arctic invariably ? show a typical pattern of auroral distortion on an FFTDSP display. Whereby this normal high arctic signal looks like a succession of overlapping roof tiles, as the signal rapidly dopplers down say 150 Hz in one or two minutes , only to jump back almost all the way to where it began to slide , starting a second then a third glissade down the display frequency scale . That has been the norm winter or summer, but these last two weeks the signal on the FFTDSP during these arctic passes has been say 60Hz wide T3 but relatively steady in its central frequency - no roof tiles. A situation accompanied by almost completely clear steady Arctic TV pictures and clear USB 6M. Probably some of this is due to the change to an ionosphere seeing the sun at a very low inclination angle. But why was it not like this last year or any other year since 1970?