OSCAR Designation:  Saudi-OSCAR 50     Oscar Number:  SO-50    
International Designator:  2002-058C     Norad Number:  27607    
Common Name:  Saudisat-1C     Satellite Type:  Microsatellite    
Launch Date:  20 December, 2002     Launch Location:  Baikonur Cosmodrome    
Launch Vehicle:  Dnepr     Apogee:  713.00    
Perigee:  603.00     Inclination:  64.56    
Period:  97.89     Dimensions:  ~25cm cube    
Weight:  10.000 Kg    
Organization:  King Abdulaziz University for Science & Technology

Frequency Information
Mode V/U (J) FM Voice Repeater: Operational
Mode V/U (J) FM Voice Repeater (Downlink is sometimes ~5 kHz lower): Operational
Uplink: 145.8500 MHz FM, PL 67.0 Hz.
Downlink 436.7950 MHz FM


Weekly Satellite Report

There have been unconfirmed reports on the amsat-bb remailer that SO-50 has
shifted downlink frequency as much as 5khz up. This both from Europe.

To switch the transmitter on, you need to send a CTCSS tone of 74.4 Hz. The order of operation is thus: (allow for Doppler as necessary)

1) Transmit on 145.850 MHz with a tone of 74.4 Hz to arm the 10 minute timer on board the spacecraft.
2) Now transmit on 145.850 MHz (FM Voice) using 67.0 Hz to PT the repeater on and off within the 10 Minute window.
3) Sending the 74.4 tone again within the 10 minute window will reset the 10 minute timer.

Detailed Description

SO-50 carries several experiments, including a mode J FM amateur repeater experiment operating on 145.850 MHz uplink and 436.800 MHz downlink. The repeater is available to amateurs worldwide as power permits, using a 67.0 Hertz PL tone on the uplink, for on-demand activation. SO-50 also has a 10 minute timer that must be armed before use. Transmit a 2 second carrier with a PL tone of 74.4 to arm the timer.

Recent reports indicate the downlink often deviates lower than the published frequency of 436.795.

The repeater consists of a miniature VHF receiver with sensitivity of -124dBm, having an IF bandwidth of 15 KHz. The receive antenna is a 1/4 wave vertical mounted in the top corner of the spacecraft. The receive audio is filtered and conditioned then gated in the control electronics prior to feeding it to the 250mW UHF transmitter. The downlink antenna is a 1/4 wave mounted in the bottom corner of the spacecraft and canted at 45 degrees inward.



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