See Satellites With A Simple Radio Telescope

Have you got a spare Dish Network antenna lying about? They’re not too hard to come by, either curbside on bulk waste day or perhaps even on Freecycle. If you can lay hands on one, you might want to try this fun radio telescope build.

Now, don’t expect much from [Justin]’s minimalist build. After all, you’ll be starting with a rather small dish and an LNB for the Ku band, so you won’t be doing serious radio astronomy. In fact, the BOM doesn’t include a fancy receiver  – just a hacked satellite finder. The idea is to just get a reading of the relative “brightness” of a radio source without trying to demodulate the signal. To that end, the signal driving the piezo buzzer in the sat finder is fed into an Arduino through a preamp. The Arduino also controls stepper motors for the dish’s azimuth and elevation control, which lets it sweep the sky and build up a map of signal intensity. The result is a clear band of bright spots representing the geosynchronous satellites visible from [Justin]’s location in Brazil.

Modifications are definitely on the docket for [Justin], including better equipment that will allow him to image the galactic center. There may be some pointers for him in our coverage of a tiny SDR-based radio telescope, or from this custom receiver that can listen to Jupiter.

16 thoughts on “See Satellites With A Simple Radio Telescope

    1. Yeah! Also, no Arduino, and you should’ve done this with no more than two transistors and three passives!

      I’ll post later to give you more helpful criticism.

      You’re welcome!

    1. If a satellite is silent 99.99% of the time and/or using ultra-wideband (pulse) communications below the thermal noise floor, they will be virtually invisible to most forms of detection. But they will always block out a tiny fraction of the cosmic background radiation and as such are tracked by sensitive scientific earth based experiments. Basically their penumbra and antumbra can not be hidden.

        1. Low VHF would work better. I’ve heard that the Brit’s WWII Chain Home radar (at about 26 MHz) could easily see the F-35, whose stealthness works best at microwave frequencies. Chain Home was not accurate enough to target ground-to-air missiles, but that did not keep the British from mounting an effective air defense. That is particularly true if you’re relying on fighters closing to visual range.

          Here’s a great documentary:

          1. Current gen SAM tracking has no problem with F35 especially Russian SAM which can track a hypersonic ICBM and deterrent most if not all it’s warheads. Russia is the only nation with a in-the-field hypersonic ICBM too.

  1. Hate to be negative but this seems like a project that should have been thought out more in advance and NOT have used 3D printed parts but something solid and working instead.
    Getting too obsessed about 3D printing clearly is a new kind of problem people suffer under.
    But then, this seem more intended to make a video than to achieve a map of the sky.

  2. I’m thinking about building a small scale radio telescope. I would like to add, that my expertise in the area of electronics is limited, but I do have an affinity for the sky above. If I find the right “recipe” for building a radio telescope, the end result would be that my new device detects radio waves. Does that mean I can listen to them as well and if so, what do I need for that?

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