memory aid: the question and answer both have the words 'amateur' and 'satellite' in the answer. the wrong answers do not have both.

There are no special requirements as far as licensing goes for talking to a satellite; it's a station like any other, it just happens to be in a very remote location. As long as you are allowed to transmit on the uplink frequency (the frequency the satellite listens on) you can communicate through it.

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Tags: satellite operation control operator space station license class

This is a good rule of thumb in any case; never use more power than you actually need, and particularly not when communicating over a long distance. The reason is that the more power you use the more likely you are to cause inadvertant but harmful interference to other stations.

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Tags: transmit power satellite operation space station

Amateur Radio Satellites don't do phone patches or relay GPS information; the advantage to a amateur radio satellite is that it can be "seen" by stations who are too far away from each other to hear each other, and those stations may be able to communicate with each other through the satellite.

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Tags: satellite operation radio operation

There are no special requirements as far as licensing goes for talking to a satellite or space station; it's a station like any other, it just happens to be in a very remote location. As long as you are allowed to transmit on the uplink frequency (the frequency the satellite listens on) you can communicate through it.

Since any amateur radio operator with a Technician or higher class license can operate on the 2 meter and 70 cm bands, that means that those operators can also make contact with a station in space.

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Tags: license class 2 meter 70 cm

A beacon provides us with a gauge to determine how much power we should use. If you transmit your signal and compare it to the beacon strength, you can then adjust your power up or down to match the beacon. That would be the optimum transmitting power for your station. The next thing that the beacons provide us with is a schedule of the satellite's activity. It might tell you that it is on during a particular time period and off during others.

The beacon can also help us tune our radio to compensate for doppler shift. Since we know the beacon is supposed to be on a certain frequency, we can calculate where our signal will be based on the current reception of the beacon (http://www.amsat.org/articles/houston-net/beacons.html)

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Tags: satellite operation definitions

Satellite tracking programs are programs that have been designed to keep track of where in their orbit a given satellite is at any given time; based on that information you know when you are likely to be able to access it from your location.

One might expect that a telescope could be used as a manual method for tracking the location, but remember that this would be extremely difficult if not impossible in daylight hours when the light reflected from a satellite through the earth's atmosphere is insignificant.

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Tags: satellite operation space station

The most common references to the doppler effect (or doppler shift) refer to sound; one of the most common examples used in highschool science classes involves a fire engine (or other vehicle with a siren) whose siren seems to drop in pitch drastically when the vehicle passes you. The producer of the sound does not actually change frequency, but the relative speed of the vehicle producing the sound to the object (you) receiving the sound makes it seem to you that it does.

The same principle applies to a radio frequency signal; the relative motion between a satellite and the earth station can cause a shift in the frequency at which you can receive the signal depending on what its position and momentum are relative to the receiving station.

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Tags: satellite operation frequencies

"mode U/V" is short for "mode UHF/VHF" -- meaning that the uplink is UHF, meaning 70 cm, and the downlink is VHF, meaning 2 meters. There are of course other UHF and VHF amateur bands, but those below 1 GHz are not available for amateur satellite operation.

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Tags: 70 cm 2 meter satellite operation

Memory aid: 'spin' = 'rotation'

Satellites are not stationary in space; they are constantly moving, and generally they are rotating as well. As they turn, the antennas on the satellite change position relative to your location. The signal may fade if the antennas are directional, or even if omnidirectional, if they are obscured by the rest of the satellite.

This is referred to as "spin fading" because the fading is caused by the satellite spinning around.

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Tags: propagation satellite operation antenna directional antenna

Just remember that we are talking about a satellite; this question could be a bit tricky if you haven't seen it before, but LEO refers to the position, not to any operation. It is, as the answer indicates, Low Earth Orbit.

Although a Low Earth Orbit is highly elliptical to escape the Earth's gravity at the low point (perigee), the question is asking what is the satellite, not what type of orbit is the satellite following.

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Tags: satellite operation

Most amateur satellite communication takes place on 2 meters or 70 cm, though 15 meters is also used at times. With both 2m and 70cm, FM is the most common mode, and so FM packet is the most logical mode to use.

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Tags: digital modes frequency modulation satellite operation