THP Semifinalist: Cheap Satellite Transponder

In 2016, a communications satellite will be launched into geostationary orbit somewhere over the middle east. Normally, this is fairly ordinary occurrence. This satellite, however, will be carrying two amateur radio transponders for hams all across europe, africa, the middle east, and India. [2FTG] is building a satellite transponder to talk to this satellite, and he’s doing it with junk sitting around his workbench.

The uplink frequency for this satellite will be in the neighborhood of 2.4 GHz, and [2FTG] needed a way to deal with the out of band interference in this part of the spectrum. The easy and cheap way to do this is with filters made for the WiFi band. Instead, [2FTG] had a few cavity filters in his junk box and decided to go that route. It meant he had to retune the filters, a process that should be annoyingly hard. [2FTG] did it in thirty minutes.

Antennas are another matter, but since [2FTG] has a supply of metal coffee cans, this part of the build was just a matter of soldering a bit of wire to an SMA connector, drilling a hole (using a log as a drill stop, no less), and soldering the connector to the can.

SpaceWrencherThe project featured in this post is a quarterfinalist in The Hackaday Prize.

7 thoughts on “THP Semifinalist: Cheap Satellite Transponder

  1. It’s a finalist, and you didn’t read the description? It’s not going to talk to the satellite, it’s a dummy transponder that he can use to test something else that he builds to talk to the satellite…

  2. Lets launch APRS digipeater satellites & high altitude balloons that operate in the 23cm ham band for the uplink frequency. The satellite / ballon downlink frequency would remain on 145.825MHz. This would allow really compact / portable directional and hemispherical antennas to be used for transmitting up to APRS satellite and balloon digipeaters. Imagine being able to walk around while transmitting APRS beacons up to a satellite or ballon without bulky antennas.

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