ALT In a photo from the 1970s, engineers gather around one of the Voyager spacecraft before it was launched.
ALT Balloon with 144 -Mc /s Transponder. -Karl Meinzer, DJ4ZC, who was responsible for constructing the I.A.R.U. Region 1 OSCAR (now waiting to be launched in the United States) has lent a 144 -Mc /s transponder to Albert Chisholm, W5UJF, of Alamogarde, New Mexico, who is preparing it for a balloon flight from Holloman Air Force Base near his home during the next few weeks. The instrument is similar to that installed in OSCAR (Orbiting Satellite Carrying Amateur Radio) and the purpose of the flight is to give radio amateurs experience in tracking and communicating via airborne transponders in preparation for future OSCAR flights. The launch will be made in the early evening and the flight is expected to last 12 hours. About six hours of the flight time will be spent at the maximum flight altitude of between 100,000 and 130,000 feet. The input passband is centred on 144.1 Mc /s and the output on 145.9 Mc /s. The U.K. OSCAR co-ordinator is W. H. Allen (G2UJ), 24 Arundel Road, Tunbridge Wells
ALT An Inspectrum waterfall showing some real world secondary surveillance radar reply messages and the annotations of ADS-B messages decoded by more1090.
