Satgen 193 Comsats and Beacons in Low Earth Orbit by GM4IHJ 5 Dec 92 The BID of this msg is SGEN193 , please use that BID if you retransmit The situation regarding amateur radio comsats is much more satisfactory than that applying to Digisats (Sgen192 refers ). Perhaps it is significant that the Comsats are built by established amateur radio groups , and not by organisations whose first responsibilities lie outside Amateur Radio. For over 20 years a constant stream of LEO comsats has provided simple inexpensive entry to the world of Amateur satellites. Russian, Japanese and American Amateurs have provided 11, 2 and 4 orbiters respectively, to which should be added Oscar 8 which was a joint JA/W venture. Of these 18 satellites 3 Russian and 1 Japanese are operational in Dec 92, and are providing the following facilities :- RS 10/11 CW , USB Mode A , 145.86 to 145.9 Up , 29.36 to 29.4 MHz down RS 12/13 CW , USB Mode K , 21.21 to 21.25 Up , 29.41 to 29.45 MHz down RS 14 FM Voice Mode B , 435.016 Up , 145.987 MHz down Fuji2 AO20 CW,USB Mode JA , 145.9 to 146 MHz Up, 435.9 to 435.8 MHz down Fuji presently operating Wednesdays utc only. RS sats are on continuously Promised for 1993 is RS15 Mode A CW SSB, orbiting much higher than the other RS birds , able to see W6 and UK simultaneously ( as did Oscar 6 ). So the LEO Comsats offer a reasonable choice of simple beginner systems on RS10 and 12, with RS 14 providing an exciting new venture for those who enter amateur radio via the FM route. Fuji JA mode is one of the best Comsats we have ever had , but it is only on one day a week. I wish Jamsat would put it on more often. What more could a radio amateur want ? This particular amateur enjoys propagation experiments on the 29.358 and 29.408 beacons on RS 10 and 12. But soon they will be inaudible except when the sats are overhead, as we go down to the reduced maximum usable propagation frequencies experienced around Solar Sunspot cycle minimum. Last minimum we had Cosmos 1686 on 19.955 MHz. It would be very nice to have 1 or 2 watt beacons on 7, 14 and 18 or 21 MHz. Neither Radio amateurs or professionals have woken up to using satellite beacons. Lots of people talk about using beacons. Some pretend to do so - see Radio Communication Aug 92 page 44 upper figure which depicts US look down beacons - these beacons do not exist. Equally wrong is the emphasis on "look down" . As beacon experimenters know, sat beacons on HF provide a wealth of much more important oblique incidence propagation data. Even near sunspot minimum, Cosmos 1686 was sometimes putting 19.955 signals into UK when the sat was near the antipodes. So please satellite builder , keep on making mode A and K LEO comsats , and please please put a few beacons in them ( preferably sending a short call sign and then ten seconds or so of carrier only to allow for the all important doppler shift measurements which identify non great circle propagation. At the moment RS12 beacon is being tracked from satellite west of Alaska , near the Aleutian islands or Kamkatchka, to sat over UK ( around noon ). In addition several afternoon orbits sw beyond UK horizon have been heard. Which latter, take some explaining. 73 de John GM4IHJ @ GB7SAN