Satgen 552 RS13 Sub Horizon DX by GM4IHJ (BID SGEN552) 1999-10-23 Worldwide satellite QSOs via RS13 are coming back on the menu , as the rise in solar activity provides ionosphere assistance to would be satellite DXers. But there are a few points which must be appreciated if the result is to be success rather than frustration. a. The signals coming back from RS13 on its 29.460 to 29.50 MHz downlink are often very rough. T2 rather than T9. Worse still you will have to compete with, radio amateurs using FM voice who do not believe in bandplans, and pirate Russian taxi nets. So CW is the preferred mode for QSOs rather than SSB voice. b. The 21.260 to 21.300 MHz uplink is shared with lots of stations looking for QSOs 21 to 21 MHz . Most of them quite unaware that satellite mode K uses the frequencies , and as a result these 21 MHz users access the RS transponder and appear calling CQ on the 29MHz downlink . So while it is a waste of time calling them , it is worth while avoiding the frequencies they are using if you can, and, keeping a ear cocked for any CW from genuine mode K sat users who may be operating from the region from which you hear RS relaying terrestrial 21 MHz QSQs. c. The path to a sub horizon RS is not always great circle. In the last solar cycle an RS mode K satellite over the Equatorial Pacific was worked from England aiming north over the pole , not the 315 degs azimuth that the great circle suggested . Indeed RS in this position provided the first G - ZL QSO in this way. Both station being sub horizon to RS. d. Near antipodeal DX of the sort now likely to be available usually means you can get excellent signals into X, when everyone in X has been asleep for some time. Sociable hours for you are unlikely to be sociable hours for someone half a world away. This latter situation was very apparent recently . RS was being heard in GM when it was around 48S 228W at 1317 utc on Tuesday 19th October. Unfortunately the signal was hopelessly auroral in tone with a random doppler shift of up to 60 Hz produced by its passage somewhere in the ionosphere. RS was coming into range of South Australia as it headed north, but careful search for VK stations was nearly impossible. Hopefully however these conditions will recur and perhaps improve as this solar cycle progresses. VK comes in range like that with the satellite over a thin ionosphere and darkening ocean south of VK , but seeing the underside of the sunlit ionosphere 5000 kms further west and north on the way to UK, for about 1 month every 5 months or so as RS orbit plane precesses westward producing either ascending or descending paths over the region at a suitable time for propagation. Similar situations will exist for other parts of the world and their antipodes, at local times suitable to them ie local noon v local midnight.