APRS ..yms. radioamatööritoimintaa

ctg

Greatest Leader
Demonstrating what engineers and scientists get up to when they are riding out the current pandemic in their homes, the ESA team has put out a series of tutorials for Windows 7 and 10, macOS, iOS and Android, Ubuntu, and, of course, the Raspberry Pi, on how to pick up and decode Slow Scan Television (SSTV) transmissions from the orbiting outpost.

Those hoping for the latest and greatest HD video should look away now: think more ZX Spectrum loading screen than Netflix 4K cinematics.

Naturally, we had a crack at making it work (using the Windows 10 instructions) and succeeded in viewing the test image after delving into the dark arts of the Windows sound mixer. Pay close attention to the instructional video on setting up the Stereo Mixer (we didn't).
 

ctg

Greatest Leader
Amateur radio operators have always been at the top of their game when they’ve been hacking radios. A ham license gives you permission to open up a radio and modify it, or even to build a radio from scratch. True, as technology has advanced the opportunities for old school radio hacking have diminished, but that doesn’t mean that the new computerized radios aren’t vulnerable to the diligent ham’s tender ministrations.

A case in point: the Kenwood TH-D74A’s firmware has been dumped and partially decoded. A somewhat informal collaboration between [Hash (AG5OW)] and [Travis Goodspeed (KK4VCZ)], the process that started with [Hash]’s teardown of his radio, seen in the video below. The radio, a tri-band handy talkie with capabilities miles beyond even the most complex of the cheap imports and with a price tag to match, had a serial port and JTAG connector. A JTAGulator allowed him to probe some of the secrets, but a full exploration required spending $140 on a spare PCB for the radio and some deft work removing the BGA-packaged Flash ROM and dumping its image to disk.

[Travis] picked up the analysis from there. He found three programs within the image, including the radio’s firmware and a bunch of strings used in the radio’s UI, in both English and Japanese. The work is far from complete, but the foundation is there for further exploration and potential future firmware patches to give the radio a different feature set.

This is a great case study in reverse engineering, and it’s really worth a trip down the rabbit hole to learn more. If you’re looking for a more formal exploration of reverse engineering, you could do a lot worse than HackadayU’s “Reverse Engineering with Ghidra” course, which just wrapping up.
 

ctg

Greatest Leader
Todella hieno



There’s no denying that the reach and variety of internet radio is super cool. The problem is that none of the available interfaces really give the enormity of the thing the justice it deserves. We long for a more physical and satisfying interface for tuning in stations from around the globe, and [Jude] has made just the thing.

RadioGlobe lets the user tune in over 2000 stations from around the world by spinning a real globe. It works by using two absolute rotary encoders that each have a whopping 1024 positions available. One encoder is stuck into the South Pole, and it reads the lines of longitude as the user spins the globe.

The other encoder is on the left side of the globe, and reads whatever latitude is focused in the reticle. Both encoder are connected to a Raspberry Pi 4, though if you want to replicate this open-source project using the incredibly detailed instructions, he says a Raspberry Pi 3 B+ will work, too.

In the base there’s an LCD that shows the coordinates, the city, and the station ID. Other stations in the area are tune-able with the jog wheel on the base. There’s also an RGB LED that blinks red while the station is being tuned in, and turns green when it’s done. We totally dig the clean and minimalist look of this build — especially the surprise transparent bottom panel that lets you see all the guts.

There are three videos after the break – a short demo that gives you the gist of how it works, a longer demonstration, and a nice explanation of absolute rotary encoders. Those are just the tip of the iceberg, because [Jude] kept a daily vlog of the build.

Maybe you just long for a web radio that dials in vintage appeal. This antique internet radio has a lot of features, but you wouldn’t know it from the outside.
https://hackaday.com/2020/07/27/radioglobe-takes-the-world-of-internet-radio-for-a-spin/
 
Top