50 år sedan den första amatörradiosatelliten Oscar-1! Det firas av AMSAT i USA:
This Week 50 Years Ago: OSCAR 1 in Orbit AMSAT News Service Bulletin 352.04 From AMSAT HQ SILVER SPRING, MD. December 18, 2011 To All RADIO AMATEURS BID: $ANS-352.04 The AMSAT News Service is re-running the Project OSCAR Newsletters to commemorate the 50th anniversary of OSCAR 1. During the November/ December 2011 time frame you will be able to share the excitement of the launch campaign that started it all 50 years ago. This week is the last installment in the replay of these historic newsletters. The Newsletters were hand-typed back in 1961. Thanks to Don Ferguson, KD6IRE for scanning the original documents announcing OSCAR 1. ----- <Begin Commemorative Message> O S C A R N E W S L E T T E R December 21, 1961 As of December 19, 1961 (one week in orbit) the amateur radio satel- lite Oscar I had completed 104 revolutions about the earth on a North- South-North orbit. Reports are beginning to pour into the Oscar Head- quarters. A total of 296 reports from ll foreign countries have been received, with radio messages indicating more are on the way. Mail has been delayed because of the Christmas rush, but it is hoped that future reports will reach us more rapidly. Reports have proven to be consistent and accurate enough for use in generating tracking predic- tions. Telemetry information provided by the keying rate indicates that Oscar I is running a fever. Recent data establishes the tempera- ture of the package to be l25°F. The following is a summary of the Oscar 1 satellite: + Frequency: Approximately 144.983 Mc. Power Output: 100+ milliwatts + HI-rate: Proportional to temperature. (IO HI's in 30 seconds = 64°F). + Tumble rate: Approximately 20 seconds. + Apogee: (Point farthest from the earth) - Approximately 275 miles. + Perigee: (Point closest to the earth) - Approximately 150 miles. + Orbital Period: Approximately 92 minutes. + Total Doppler Shift: Approximately 6.5 kc.(Frequency received-is higher than transmitted when satellite is approaching your station; lower when going away). + Transmitter: Transistor crystal oscillator on 72.5 mc., transistor amplifier and "Veri-cap" diode doubler to 145 mc. Keyer consists of transistor multi-vibrator and counters with diode logic. Oscil- lator is keyed in base circuit. + Power Supply: Mercury batteries. Expected life of batteries: 3 to 4 weeks. + Antenna: 1/4-wave monopole, about 19 inches long. + Dimensions and weight: 12" x 10" x 8". Weight: 10 pounds. All daytime passes are from North to South: All nighttime passes are from South to North. A preliminary review of a sample of reports for one pass provides some interesting information. The acquisition times and fade-out times correlate closely among all the receiving stations in the same area. Further, the correlations have improved noticeably for the later orbital passes. This emphasizes that opera- tors are gaining experience and that the predictions have been suffi- ciently accurate to permit early acquisition. Many amateurs have been surprised at the great range which may be spanned by this beacon, whose output power is about 1/4 that requir- ed to light a flash-light bulb. Reports indicate reliable reception up to a distance of about 1400 miles from the satellite path. On an overhead pass, signal reports of 40 decibels above noise level are common! The Oscar Data Reduction group has reported a few messages indicat- ing 'that the last dot of the letter "I" has been missing. Anybody noticing this who has a tape recording of the "missing dot" is re- quested to air mail it to the Association as soon as possible. Reports of the "HI" rate are urgently requested. If the temperature inside the package continues to rise, it is possible that the opera- ting life of Oscar could be cut short by a high temperature failure of some component. The temperature rise does not seem linear, so all reports will be welcome! Also, please monitor the frequency in off- hours to determine if Oscar can be heard by unusual propagation modes at great distances! Orbital data is being broadcast by W1AW (see QST for schedules) and by the Voice of America "Space-Warn" program on various frequencies (9.525, 11.79, 11.83, and 15.29 mc) at 0330 GMT, Monday through Sat- urday. Send all reception reports of Oscar to: Project Oscar Association, Box ---, Sunnyvale, California, U.S.A. Thanks for your splendid cooperation and keep up the good work! 73. <End of Commemorative Message> [ANS thanks Don Ferguson, KD6IRE and Project OSCAR for the above information]
