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Re:Show HN: A new protocol for packet radio including ECDSA ... by trothamel on Monday September 24, 2018 @12:15PM (#18058916)
Is there a good description of what those $100 in parts for satellite work are? Or better yet, something purchasable that's likely to work? I've been wanting to get into it, but I've never found a really accessible guide to getting started in satellite communication.
Re:Show HN: A new protocol for packet radio including ECDSA ... by brians on Monday September 24, 2018 @01:39PM (#18059655)
Sure! To talk to a satellite you need an antenna, a receiver, a transmitter, and maybe a computer—not for voice, but for text modes.

Arrow will sell you a great antenna: http://www.arrowantennas.com/arrowii/146-437.html , or you can google "tape measure yagi" and build an okay antenna.

Then you can get the transmitter and receiver together, in a package like the regrettable BaoFeng UV-5R: https://www.amazon.com/BaoFeng-UV-5R-Dual-Radio-Black/dp/B00... . This is a terrible radio. Their quality control is so bad that you sometimes commit a federal offense by pressing the transmit button—and for $100, you can't afford the test equipment to tell! So maybe use it as the receiver in a two-radio setup, and transmit with something like a Wouxun KG-UV9D.

A Kenwood TH-D72A is an excellent choice to do the transmitter and receiver jobs, but hundreds of dollars. A Yaesu FT-60 is a great choice too, but it won't have full duplex—so you can't be sure your signal is getting out without help.

To listen to a satellite you need even less: a crappy antenna and an RTL2832 USB software-designed radio: https://www.adafruit.com/product/1497

For all of these, you'll end up wanting miscellaneous coaxial cable and a bunch of ends. Hams tend to build up a library of crimpers and spare ends and such, so look to borrow from a friend or a club as you get started. The 75 Ω cable that's ubiquitous for television signals will totally work, but you'll have much less loss and much much less stress on components if you buy 50 Ω cable.

Why not try the tutorial at https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weat... ? If that works, you can expand from there: the tutorial teaches you a huge amount about aiming at satellites and the physical work necessary to capture signals from space.

Re:Show HN: A new protocol for packet radio including ECDSA ... by trothamel on Monday September 24, 2018 @05:12PM (#18061508)
Thank you! This really comprehensive. I'll probably start with the NOAA weather tutorial, and go from there.
Re:Show HN: A new protocol for packet radio including ECDSA ... by tjohns on Monday September 24, 2018 @01:46PM (#18059708)
In addition to the resources others have posted, I recommend picking up a copy of the AMSAT Getting Started book: https://www.amsat.org/product/2018-edition-of-getting-starte...
Re:Show HN: A new protocol for packet radio including ECDSA ... by lb1lf on Monday September 24, 2018 @12:23PM (#18058988)
I haven't looked into satellite work in fifteen years or so, but back then it was definitely possible to work the LEO FM repeater satellites using a handheld and a small yagi - typically two elements 144MHz, five on 432MHz if memory serves.

With handhelds being dirt cheap and a yagi cut from a measuring tape being an option, I don't think getting on satellite for $100 sounds undoable.

Re:Show HN: A new protocol for packet radio including ECDSA ... by DerekRobot on Monday September 24, 2018 @12:52PM (#18059211)
You could make a good tape measure yagi and use it with a cheap radio like the UV-5R. It needs to be dual-band (440mhz and 2m); AMSATs are usually duplex.

http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm