Listening to Satellites: A Journey with My RTL-SDR V3

My grampa was a ham radio guy and he told me a lot of things. I was really amazed by shortwave and how radio could travel long distances by bouncing off the ionosphere. He also gave me a shortwave radio and I remember tuning into weird stations that would just say numbers in a funny voice (&quot;numbers stations&quot;). He even had a ham radio in his car and could dial phone numbers remotely through it.<p>I never really got into ham, I&#x27;m still not much of a radio person (I prefer wired) but I still had fun playing with RTL-SDR; listening to my car&#x27;s tire pressure monitors and various other things in the ISM band. Antennas are still fairly spooky magic to me, though.

That&#x27;s nicely written. Can&#x27;t imagine how hard it must be building this stuff and getting all the components when you&#x27;re living in Iran, it always reminds me that sanctions and such things are not only &quot;hurting&quot; the government but also, and probably most, all the normal people who just want to live a normal live.

One thing that is so critical in RF exploring is antenna design, and you can see where the author learns that very quickly.<p>It&#x27;s kind of like the old adage in audio where you can have the best sources, AMPs, scalers, etc... but your speakers are the crucial component.<p>In RF, it&#x27;s really is about the antennas.

It&#x27;s amazing how RTL-SDR has ushered a new era of accessible RF hacking.<p>After many years of playing with SDRs I&#x27;ve actually went the other way around and got licensed as a ham radio operator, even though it&#x27;s obvious that the old school rag-chewing is soon to be a relic of the past.<p>I&#x27;m super interested to see what the next generation of RF hackers and ham radio operators will look like, given the ongoing consolidation of RF applications into software.

Originally I got interested in radios when I learned to deploy wifi for industrial applications. The big thing with industrial applications is interference and reflection. You typically have a lot of large structures made of metal or other materials that block the waves. Also, there’s a bunch or rotating equipment that emits emf as well (interferers). This can make antenna placement critical.<p>I wish I had gotten into it earlier, but I was discourage by a university professor who basically told my senior design groups that radios were too finicky for us to tackle.<p>Now I participate in amateur radio and I suggest anyone who finds the topics interesting to do the same.

The 137 MHz band is sadly abandoned and the days of current satellites in the sky are counted. So if you are planning to experiment with satellite reception, HRPT is recommended at 1.7 GHz instead. Needs a more capable SDR device (however the RTL-SDR v3 might still fit if cooled properly), needs a more complex antenna, but the resolution is much better:<p><a href="https:&#x2F;&#x2F;www.rtl-sdr.com&#x2F;a-comprehensive-beginners-guide-to-hrpt-weather-satellite-reception&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.rtl-sdr.com&#x2F;a-comprehensive-beginners-guide-to-h...</a><p>Actually even the HRPT streams are seem to be phasing out, but will be supported on the MetOp line for a long time (MetOp-B has been launched in 2012, the -C in 2018, and the satellites generally have a 15 years of lifetime). Future live streams will be transmitted in the 5 GHz+ range, which needs an even more complex antenna and probably a downconverter.

I&#x27;ve seen these DSP radio receivers on AliExpress that have SDR, a touch screen — all in a small form factor. I&#x27;m not aware though if there are any intuitive, well crafted software for them that would allow a novice to play around with them, perhaps even call up satellite imagery like the blog post.

Really fascinating and impressive!

some cool videos on this topic by saveitforparts on YT