Haruka Nakamura provides detailed
instructions for listening to satellites with the Listening Post. Check it out.
The Listening Post is really not an easy way to hear satellites, but it can be done. First, you must know when to listen. Knowing when to listen amounts to satellite tracking. You should download a satellite tracking program and learn how to use it. My favorite for Windows 95 is WinOrbit by C. D. Gregory, K8CG. You must be certain that your computer's clock is correctly adjusted. You must also configure your tracking program for the location of the Listening Post, rather than your home location. If you choose the city of Washington, D.C., you will be close enough to its location in Bethesda, Maryland.
The prefered audio format for listening to satellites is Speak Freely, rather than RealAudio™ . Speak Freely has less delay between the time you change the receiver's frequency and the time you hear a change in the audio on your computer. The prefered control method for using the Listening Post is with the Java control applet on the Java-enhanced page. The Java control applet lets you step up and step down in frequency.
When you believe you have tracked a satellite well enough to know when it is overhead of the Washington, D.C. area, you can try listening to that satellite by typing the fequency of its beacon into the "Enter frequency" line of the Java applet. Your tracking program should indicate the doppler shift of the satellite. Add that value to the beacon frequency to compensate for the relative motion between the Listening Post and the satellite. Choose the USB option and then click on the Manual Enter button of the Java applet. If the satellite is at an elevation of 30 degrees or more, and less than 4,000 Km away, you should have no problem hearing it. You can step up or down in frequency near the beacon frequency to compensate for small changes in doppler shift. Do this by entering a step size of 0.0002 for 200 Hz steps.
Hearing the beacon is not difficult when low earth orbiting (LEO) satellites are
overhead, e.g. 60 degrees of elevation or more. I regularly listen to RS-10/11,
RS-12/13, and RS-15 beacons. Listening to a QSO on the satellite is much more
difficult. You must enter a frequency in the passband of the satellite downlink,
then do small frequency steps until you hear a station. Even after you get a
station, choosing the appropriate step size to keep the station on frequency is
cumbersome. We are working on two ways to make tuning easier. First, we will
make frequency stepping smoother by modifying the radio. At the moment, frequency
steps are treated the same as a manual frequency entry: it jumps to the new frequency and
creates a noise burst while doing this. In the future, frequency steps will simulate
an operator smoothly turning the dial on the radio. Second, we will program the
Listening Post to track the satellite's frequency automatically.
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Last updated 25 January 1999