Applications Satellite transmission is a growing medium of communications. It has been necessary to develop new transmission methods to take advantage of this new medium. One of the newest, the NBTDMA (Narrow Band Time Division Multiple Access) combines the advantage of the old methods (high performances, adaptability to transmission speed) with increased access capability. The transmission/reception equipment from the signal multiplexer up to the microwave antenna must meet these new performance requirements. The 5104C has been developed to cope with these new applications. Its frequency range (80 MHz - 130 MHz) and its spectral purity preserve the signal quality up to 11/14 GHz and up to 30 GHz for future applications. Analog transmissions • FDMA/SCPC Frequency stability: 18 Hz/day at 6 GHz Phase noise: -114 dBc at 100 Hz/Fc Digital transmissions • SMS/IBS Phase noise meets Eutelsat/lntelsat specifications Spurious 76 dBc • TDMA (narrow band, broad band) Phase noise : - 105 dBc à 10 Hz/Fc Low microphony Satellite positioning • Ranging Phase noise : - 136 dBc à 100 KHz/Fc phase stability: ^ 0.3%/h (option 01) standard BCD programmable (optional IEEE 488)