Start Tracking Satellites with This Low-Cost Azimuth-Elevation Positioner

Tracking satellites and the ISS is pretty easy. All you really need is an SDR dongle or a handheld transceiver, a simple homebrew antenna, and a clear view of the sky. Point the antenna at the passing satellite and you’re ready to listen, or if you’re a licensed amateur, talk. But the tedious bit is the pointing. Standing in a field or on top of a tall building waving an antenna around gets tiring, and unless you’re looking for a good arm workout, limits the size of your antenna. Which is where this two-axis antenna positioner could come in handy.

While not quite up to the job it was originally intended for — positioning a 1.2-meter dish antenna — [Manuel] did manage to create a pretty capable azimuth-elevation positioner for lightweight antennas. What’s more, he did it on the cheap — only about €150. His design seemed like it was going in the right direction, with a sturdy aluminum extrusion frame and NEMA23 steppers. But the 3D-printed parts turned out to be the Achille’s heel. At the 1:40 mark in the video below (in German with English subtitles), the hefty dish antenna is putting way too much torque on the bearings, delaminating the bearing mount. But with a slender carbon-fiber Yagi, the positioner shines. The Arduino running the motion control talks GS232, so it can get tracking data directly from the web to control the antenna in real time.

Here’s hoping [Manuel] solves some of the mechanical issues with his build. Maybe he can check out this hefty dish positioner for weather satellite tracking for inspiration.

26 thoughts on “Start Tracking Satellites with This Low-Cost Azimuth-Elevation Positioner

  1. “But the 3D-printed parts turned out to be the Achille’s heel” sure it was, the whole thing was completely out of balance, what did you expect. To be honest, I did expect the worm gear to go first…
    Other from that if used properly it can be very functional.

    For those without a 3D printer AND do want some real strength on the cheap, try windshield wiper motors.
    If you don’t want to add additional gears (to lower the speed of the wiper) you can add some levers in the same way that the wipers on your car operate. This way you can move the dish pretty rapidly, though there is no need to do so. You do need some encoders though, otherwise you don’t know in what position the motor is.

    1. there are some good cheapish , metal gear servos for 4×4 rc cars too. i have some that can handle 40lbs each. cost me 15$ each. I purchased them to use on my large lens dslr setup for panorama stitching. since the camera body and lens+ filters weigh around 15lbs or so and originally where not very well set for cg.

    2. I used wiper mores in the 80’s for a robot that was a college project. I built the mechanics, another student made a C-64 interface. I wanted to used a flywheel for the base gear, but ended up making a wooden gear and used bolts as posts.

    3. Why not just use linear actuators or H to H motors that are already available and designed to aim antennas at satellites? Search for FTA or C band dish movers. Sure those are designed to track the clarke belt for geostationary satellites but it’s pretty simple to combine 2 of them to be able to aim anywhere in the sky and you can communicate with them by sending DiSEqC commands down the coaxial cable which also delivers the power and carries the received signals from the LNB. And those would be able to move your 1.2M dish, because that’s precisely what they are designed to do.

      1. ^This^ Amateur radio operators (and the rest of the world) have been doing this for decades… also, the satellite TV enthusiasts (check-out the 1980s/1990s BUG dishes) are very much into linear actuators. And the darn things are dirt cheap. But accolades for the DIY build.

    4. I stated in my Video that the bearing mount broke because the weight was out of Balance. The part on thingiverse is thicker then the on i used in my Video, so it should be more sturdy.

      The Wormgear slipped on the pipe, but that can be fixed with some normal bolts instead of grub screws. Otherwise the gears are fine what surpised me.

      The good Thing about Steppers is that you don’t need Encoders. DC Motors work, but without Encoders (or any other mehtod of knowing the position of the axis) they are useless for an AZ/EL tracker.

    1. that will not work xD

      they are not visible all the time and it would also not work when there are clouds around.

      Also the biggest Problem is the pointig of the antenna (Offset dish for example), it is easy to calculate where the sat is at the Moment.

    1. I used the satnogs tracker as an insperation, here are some Points that i don’t quite like about it:

      – Nema17 and no room for nema23
      – Frame out of two parts
      – Frame is out of different lenght Aluminium Extrusion

      The satnogs Tracker is way more finished then mine, but i think that a combination of both would be perfect!

      1. From is ISS? I’m not trolling, there must be stuff worth receiving, it’s just not clear what that is. If it’s weather maps, how are they better than those available online, or it the more about the thrill of the chase?

        1. Thrill of the chase, mostly, for the 137MHz APT feed… but the live gigahertz/LRPT feeds are very interesting for the weather professional and in-depth amateur, and not readily available elsewhere.

          I keep meaning to upgrade my station to one of these trackers, as APT is not being build into the next generation of POES birds.

    1. You can receive all sorts of satellites and also the ISS. The HRPT/AHRPT Images are quite high res, i think it is quite nice too look at them.

      some examples:
      – NOAA (US)/Meteor (RU) Weather satellite Images – APT/LRPT(~3km/pixel) in VHF
      – NOAA,Meteor,Fengyun (CN),Metop (EU) weather satellite images – HRPT/AHRPT(~1.1km/pixel) in L-band
      – ISS talks to Schools (voice in VHF, sometimes Webcam in s-Band)
      – ISS sstv Images (like collectible Cards, only while events)
      – ISS voice while spacecraft Docking / Spacewalks
      – Amateur Radio satellites (VHF/UHF mostly)
      – and many more….

      1. “– NOAA (US)/Meteor (RU) Weather satellite Images – APT/LRPT(~3km/pixel) in VHF”

        I’ve never caught a LRPT broadcast from a Meteor-M bird — rumor has it that the VHR LRPT transmitter is turned off over CONUS. Any advice?

        Of course, what I’d really like to catch is HRPT from NOAA POES and GOES satellites — but not possible with the equipment I have right now…

        1. The VHF transmitter of Meteor M2 should be on around the whole world.
          They changed the frequency to 139.900 after some time tho. Also the Signal from Meteor is quite weak, compared to the APT from the NOAA sats.

          HRPT is awesome, i was able to get some quite good Images already, but i still need to optimize my Setup in the future.
          I will upload a Video about that soon :)

          PS: You can see Images from MeteorM2 LRPT and HRPT on my Twitter.

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