Transmission Characteristics of Transponders

The Japanese Medium-scale Broadcasting Satellite for Experimental Purpose(BSE) was successfully positioned in a geostationary orbit on 26 April 1978. Various kinds of transmission characteristics were periodically measured every half year. Those were frequency responses and input-output characteristics of each electronics unit which made up a high power, 100W, transponder. No significant degradation of their characteristics was observed for about 2 years, and the characteristics of the in-orbit satellite transponders almost coincided with the designed values or the values measured at GE prior to launch. FM television signal(FM-TV) transmission characteristics were also measured periodically. From these measurements we concluded that the qualities of the television picture and sound were not reduced to any extent by the high power transponders.