Satgen484 Satellite Listening 2 by GM4IHJ (BID SGEN484) 1998-07-04 Continuing the overview of satellitte listening. Detailed examination of the LEO Low Earth Orbit amateur radio satellites , suggests a gradual deterioration in what is available . With only a few elderly satellites remaining. Several already exhibiting partial system failure. With RS10 non operational and RS16 sending telemetry but not responding to orders to operate its transponder . RS 15 has lost its beacon, though its transponder still produces DX from time to time , whilst RS12 is operational on the favoured mode A, but seems to have lost its excellent mode T operation. A surprisingly similar situation applies with the two Japanese Fuji satellites. Fo20 beacon has lost its telemetry and is sending only unmodulated carrier, although its transponder does appear to be working. While Fo29 is temporarily on mode JA whilst the problems with its digital operations are sorted out. Both F029 beacon/telemetry and transponder are working. But the mode JA of the Fuji satellites has never been as popular as the much simpler modes A or B. There is always the problem for first time users of mode J that the uplink on 145MHz is almost an exact submultiple of the 435 MHz downlink receive frequency. Any 3rd harmonic of the uplink reaching the receiver desenses it completely and worse still,often convinces new users they are hearing themselves coming back on the downlink, when in fact it is direct overload of their receiver front end by their own transmission on 145 MHz. Regular users of mode J fit a 435 MHz cavity filter in their receive antenna lead to obviate this problem, but it can upset newcomers and may account for the limited number of users of Mode J. Neither Fo20 nor Fo29 has anything like the number of users of say Ao27, the mode J single channel FM transponder, but unfortunately this satellites operating times have to be limited , to periods of about 18 minutes duration whilst the satellite is over the Northern Hemisphere and in sunlight. The clear popularity of this simple to operate mode is only spoilt by the illegal interference which often blocks the satellite when its over or near Spain or its possessions. Illegal taxi network operations in Madrid Spain are one of several major impediments to this mode over Europe. The authorities concerned have been informed and have done nothing, apparently oblivious to the fact that they are demonstrating their lack of simple law and order to the rest of the world. Changing the bad habits of some Europeans is likely to take a long time, but meanwhile, where communities are law abiding this Ao27 system has the potential to be a clear winner aboard satellites operating over the rest of the world.