About the author

Werner Muller loved to tinker with electronics since he was a younster. Currently he enjoys SSB and CW contacts and satellites. He built a setup for an QO-100 geostationary satellite and have over 100 countries confirmed via this satellite. Recently Low Earth Orbiting (LEO) satellites started to interest him as well. He is a licensed amateur radio operator and the current President of the Namibian Amateur League. His callsign is V51JP.


In the previous 2 parts I covered building the Rotor controller with parts that are available from Ecorobotics (part 1) and the necessary antennas to point the antennas at the desired satellite and keep tracking the satellite from AOS to LOS (part 2).

In this part I will go over the software that makes the magic happen.


I looked at a few free options and eventually decided to buy PstRotator. The main reasons where the price and the features.

Here is a screen shot:

In the top frame the 2 rotator positions are displayed. The software interfaces with the rotators via the Arduino UNO.

In the bottom frame I can select the satellite I wish to use and the software interfaces via an Adafruit CP2102N Friend (also from Ecorobotics) with my Radio to allow for Doppler Shift. Here is a link to Wikipedia explaining Doppler Shift:

This is the little Adafruit:

The software also has a very neat map feature which lets you see where the selected satellite is and how the trajectory looks.

Here is a look at the ISS:

One of my very first contacts was via the ISS with 2 South African stations. I was lucky that a friend of ­­­mine who was visiting Namibia from Germany was listening to the downlink of the ISS and recorded the QSO.

Here is a link to the Video he sent me:

You will notice that he is using a hand held radio and you too can listen to the ISS using a low cost handheld radio or a SDR receiver with a small antenna. ­

Here is a link to a website that helps you predict when the ISS is over your location and on the frequency you should be tuned to:

I hope my little expedition into Satellite communication has sparked your interest.

For additional information:

Werner Muller

Call sign: V51JP

If you want to learn more about the fascinating Radio Amateur Hobby please visit:

Get startedLeo satelliteNamibia

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