All About Ham Satellites

How hard is it to build a ground station to communicate with people via a satellite? Probably not as hard as you think. [Modern Ham] has a new video that shows just how easy it can be. It turns out that a cheap Chinese radio is all you need on the radio side. You do, however, benefit from having a bit of an antenna.

It isn’t unusual for people interested in technology to also be interested in space. So it isn’t surprising that many ham radio operators have tied space into the hobby. Some do radio astronomy, others bounce signals off the moon or meteors. Still others have launched satellites, though perhaps that’s not totally accurate since as far as we know all ham radio satellites have hitched rides on commercial rockets rather than being launched by hams themselves. Still, designing and operating a ham radio station in space is no small feat, but it has been done many times with each generation of satellite becoming more and more sophisticated.

While it is true you’ll get better results with a directional antenna, it is possible to make some contacts with a fairly modest one. Back in the 1970s and 1980s, tracking when the satellite was overhead was a major task, but the modern ham just needs a cell phone app.

If you have images of hams sitting at their radios having long-winded discussions, you haven’t seen a typical satellite pass. You don’t have much time, so the contacts are fast and to the point. In fact, this video dispels a lot of ham stereotypes. A young guy shows how you can do something exciting with ham radio for very little investment and it doesn’t matter if you have deed restrictions because all the gear would fit in your garage when you aren’t using it.

The downside is that [Modern Ham’s] demo didn’t show him making any solid contacts although he was clearly hearing the satellite and people were hearing him. He admits it wasn’t his best pass. The second video below shows a much more typical pass with the same kind of setup. If you want to see what results you can get with a more modest antenna, check out this video.

In addition to satellites built by hams, some have started life doing a different task and been taken over by hams later. If you don’t have a ham license (and, by the way, they are easier to get than ever), you can still listen in to some very interesting space communications.

28 thoughts on “All About Ham Satellites

  1. Awesome… I need to watch the videos.

    I just 3D printed my first telescoping yagi antenna, telescoping antenna element piece I designed using SolidWorks for the first time with double checking over the holidays with the free OnShape Student server side app. I used for the first time too.
    https://drive.google.com/open?id=1eKZxw7lE6aiynAXuInP4g3eEDd-Ks1pk&fbclid=IwAR3mlDNBSgzJnXVRPiz654m8jdoxrANp5wbkqN47eAkjlB8dB87UAM94v6g

    The connector is kind of bulky and needs holes drilled out since seeing how some of these 3D printers are (I’m new to using also)… I’m going to have to post process the part anyway. However, this is suitable for the telescoping boom and folding telescoping antenna elements goal I wanted for overboard picky mechanical antenna tuning capabilities. (The plan is to etch the optimal tuned lengths into the boom and antenna elements and color code for each frequency relative position).

    Seems like this can be modified for the sat com antennas easily if anyone wants to.

    1. I’m no way finished with itemizing the components and other details (though technically the impedance matching element original thought is linear and adjustable… though have an idea for a rotary one also that I am not sure about effectiveness… scope creep…. yep, I know…)… however, I dropped the files and started the hackaday.io Project for what I noted above to create a single resource others may enjoy:
      https://hackaday.io/project/163219-telescoping-yagi-antenna-with-folding-elements

    1. I have found the Heavens Above smartphone app and website to work well for pass predictions.
      https://www.heavens-above.com/AmateurSats.aspx

      For detailed information on the status and radio equipment for each satellite SATNOGS DB https://db.satnogs.org/ is awesome. You can also listen to the recordings made by the various SATNOGS ground stations of each sattelites transmission, and even decode digital transmissions using the audio file and the relevant software

  2. Of course, a long term goal is a satellite in a higher orbit, to get more than a few minutes use at a time.

    I thought there was finally a geostationary launch at the end of November, but I’ve not seen anything since. I’m not sure what I saw, since this has been a long term goal, since the mid-seventies at least, but it didn’t get much coverage. Of course, it may still be under test, and the coverage does not include North America.

    Michael

  3. Back in the early 70’s and probably earlier, hams use the free satellite called the “moon”. Easy to track – just look up into the sky!
    Hams used to bounce the signal off the moon – unsurprisingly it was called moon-bounce. IIRC they were using around 492MHz.

    1. That takes a setup with a bit more power than your standard HT… but people still do it…

      While the station isn’t usually terrible portable, you do get the benefit of the coverage area being roughly half the planet vs the few hundred miles you get from a LEO sat…

    2. Moon bounce, or EME (Earth-Moon-Earth) is still used.
      The first USA-Europe moonbounce was on 432MHz.
      Bands from 21MHz up to 24GHz have been successfully used and 77GHz echoes have been heard, but there’s a lack of stations on 77GHz for a proper two-way contact. I’m unsure about 47GHz and IIRC 140GHz has only had ISS echoes/bounce.
      IIRC currently the more popular bands are 144MHz, 432MHz, 1296MHz and 10.368GHz.

    1. Suggest you not buy those. You will be disappointed and possibly transmitting on frequencies you shouldn’t be. The Chinese HTs being referred to are poorly engineered and likely not legal to import into the US.

      Buy a Yaesu, Kenwood or Icom and know you have a well-designed product that will perform as the manufacturer claims.

      1. They are ok entrylevel radios for playing around.
        It makes it possible to have a low commitment to the hobby for testing it oput, without dropping money on Yaesu/Icom/Kenwood rig right of the start. Not that the entrylevel transceivers from them arent a good value.

        Think less 26year old engineer or 65year old retiree and more like a 16year old high school student attempting to get in to the hobby. The difference between 25eur and 125eur matters.

        At the same time, baofengs are not the best radios out there, you really do get what you pay for.
        But you get a lot of radio for that 25eur.
        I usually demonstrate adjacent channel rejection and out of band rejection when I teach the licence class about receiver architectures to show how Low-IF and Zero-IF radios differ from traditional superhets.
        By putting a baofeng (Low-IF), wouxun (traditional superhet, but cheap) and a motorola (traditional superhet, expensive) UHF radio side by side on 433.550MHz.
        And then transmit with my 427MHz TETRA handheld (lovely hammering TDMA) at ~1W and start walking closer to the radios.
        Some baofengs start to produce noise even across the room, the wouxun when you hold the radio less than 15cm away and the motorola does nothing. :)

        1. If it was all about performance I would agree with you. Use what you can afford and upgrade later when you can if you want to. My own first radio was a decades old HT I bought of eBay when I was in college. It had apparent damage like the battery pack had caught fire at some point. It’s output was so weak I could only really reach one repeater and that was because my apartment was nearly in the shadow of it’s antena. It’s not about that though.

          The operative part is this “and possibly transmitting on frequencies you shouldn’t be”.

          That’s the one cardinal rule you never want to break. If too many hams are transmitting off frequency that will be the end of all our fun when that privilege goes away. More importantly you could end up interfering with something important like firefighting or ambulance services. The odds are small but non-zero that transmitting out of band could cost someone’s life.

          1. I dunno about the others, but the Baofeng I have (BF-F8HP) can easily be frequency-limited using software and a USB cable. Agreed, it’s vitally important to be paying attention and making sure you’re following the appropriate laws and rules. But that’s the job of the operator, not the hardware.

          2. The licensed individual should be aware of the frequencies they are allowed to transmit on, to begin with.
            And nowdays itäs easy to lock the transmit range of a baofeng with CHIRP.

            But it is true that more legit offerings from amateur radio oriented manufacturers come locked to amateur radio bands out of the box and have to be modified to transmit out of band, be it software or clipping a wire.

            It also used to be that chinese transceivers sold for amateur radio service ware restricted to the amateur bands.
            This included the baofengs.

  4. Even in the 2010s we had several walkie talkie sats, AO-27 I think was called easysat, maybe AO-50 as well as the ISS when it was in a useful mode like BBS or crossband repeater.
    My rig was a repaired true dual band DJ-580T(you could open up 800/900mhz and air band rx too with a snipped wire)
    a wooden broomstick, some snipped fence wire 3 elements for 2m, 5 for 70cm and Jpole antennas run to a band splitter made with a few caps and coils to band pass up and down.
    I also had an old Sharp Zaurus running a very good sat tracking app also on the stick to help me tune the changing doppler on 70 and estimate where to scan in the sky for my bird.
    I have not played in years but for a while it was all CW/SSB transponders vs FM which is the obviously best tech as it permits multiple users but correct me please there are no cheap new or used vhf/uhf SSB HT rigs around and especially UHF you start to run into the spooky inductance and capacitance issues which you simply ignore when brewing for HF and lower.

  5. Alright, so I built mine. And used orbitron and a diy rotator. The problem I had was there was no way for me to accurately sync the clock in my pc with the real time so I always missed the sat by 3 mins either way.
    Puts on tin foil cap for humors sake:
    I figured i got on some list and lost time sync privileges.

    Anyone figure out how to remedy this? or has it since fixed itself?

    1. I haven’t got to yet… though is on the agenda from my last looking at stable oscillators and external sync… I figured eventually I’d go GPS sync if I don’t find a better standard cost effectively.

      http://w8bh.net/avr/clock2.pdf

      Here are two articles from a quick search that might help for now:
      http://www.laptopgpsworld.com/3235-pc-clock-synchronization-using-gps
      https://www.groovypost.com/howto/synchronize-clock-windows-10-with-internet-atomic-time/

      There is one other article online I’m thinking of… that I am not finding at the moment relating to using a GPS for the systems in general and I’ll see if I can find.

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