Mobile Transmitter Gets Internal GPS And Bluetooth

While [Selim Olcer] was relatively happy with his Kenwood TM-D710a radio, he didn’t like the fact that it needed a bulky external GPS “backpack” for APRS location data. So he decided to crack open the head unit and see if he couldn’t integrate his own GPS hardware (machine translation). Not only did he succeed, but he even threw in Bluetooth compatibility for good measure.

With the repair manual circuit diagrams in hand, it was no problem to find the GPS RX and TX lines that were being broken out to the external connector. Unfortunately, the radio’s electronics are all 5 volts and the GPS module [Selim] wanted to use was only 3.3 V. So he came up with a small PCB that included not only the voltage regulator to power the GPS module, but also some voltage-dividers to level shift those signals.

Since the Kenwood TM-D710a was already designed to accept a GPS upgrade module, he just needed to change some configuration options in the radio’s menus for it to see the new hardware. Technically the project was done at this point, but since there was still room in the case and he had a GPS module spitting out NMEA sentences, [Selim] tacked on a common Bluetooth serial module so he could see the position information on his smartphone. With an application like APRSdroid, he now has a nice moving map display using the position pulled from the radio’s GPS.

With this modification done it looks like the head unit is ready to go, but that’s only the beginning for a mobile rig. Now we want to see how he integrates the whole thing into the car.

A Hybrid Helical Antenna For The Es’hail-2 Geosynchronous Repeater

Amateur radio operators like to say that working a contact in space can be done with a simple handheld transceiver and a homemade antenna. And while that’s true, it’s true only for low Earth orbit satellites such as the ISS. If you want to reach a satellite in geosynchronous orbit it’ll take a little more effort, and this dual-feed helical “ice cream cone” antenna could really help.

Until recently, the dream of an amateur radio repeater in geosynchronous orbit remained out of reach, but that changed with the launch of the Qatari satellite Es’hail-2 last year. Since then, hams from Brazil to Thailand have been using the repeater, and UK-based [Tech Minds] has been in the thick of the action. The antenna he presents is a hybrid design, needed because of the 2.4-GHz band uplink and 10-GHz downlink on the satellite, also known as QO-100. Both require a largish dish antenna, with the downlink requiring a low-noise block downconverter (LNB) and feed horn. The uplink side of [Tech Minds]’ antenna is a helical design, with three-and-a-half turns of heavy copper wire and a tuning section of copper strapping that attaches directly to an N-type connector. The helix is just the right size for the feed horn of an LNB for the downlink side, nestled in a hole in the helical antenna’s aluminum reflector disc. There are 3D-printed parts to support everything, plus a cone-shaped radome to keep it all safe from the elements.

It looks like a great design, but sadly, North American and East Asian hams can only dream about building one, since QO-100 is below the horizon for us. We’re jealous, but we’re still glad the repeater is up there. Check out this article for more on how Es’hail-2 got the first geosynchronous ham repeater.

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High-End Ham Radio Gives Up Its Firmware Secrets

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. Watch for the class videos soon. Continue reading “High-End Ham Radio Gives Up Its Firmware Secrets”

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Hackaday Links: June 28, 2020

You can imagine how stressful life is for high-power CEOs of billion-dollar companies in these trying times; one is tempted to shed a tear for them as they jet around the world and plan their next big move. But now someone has gone and upset the applecart by coming up with a way to track executive private jets as they travel across North America. This may sound trivial, but then you realize that hedge fund managers pay big money for the exact same data in order to get an idea of who is meeting with whom and possibly get an idea of upcoming mergers and acquisitions. It’s also not easy, as the elites go to great lengths to guard their privacy. Luckily, the OpenSky Network lists all ADS-B traffic its web of ground stations receives, unlike other flight monitoring sites which weed out “sensitive” traffic. Python programs scrape the OpenSky API and cross-reference plane registrations with the FAA database to see which company jets are doing what. There are plenty of trips to Aspen and Jackson Hole to filter out, but with everyone and his little brother fancying themselves a day trader lately, it’s another tool in the toolbox.

We got a nice note from Michelle Thompson this week thanking us for mentioning the GNU Radio Conference in last week’s Links article, and in particular for mentioning the virtual CTF challenge that they’re planning. It turns out that Michelle is deeply involved in designing the virtual CTF challenge, after having worked on the IRL challenges at previous conferences. She shared a few details of how the conference team made the decision to go forward with the virtual challenge, inspired in part by the success of the Hack-A-Sat qualifying rounds, which were also held remotely. It sounds like the GNU Radio CTF challenge will be pretty amazing, with IQ files being distributed to participants in lieu of actually setting up receivers. We wish Michelle and the other challenge coordinators the best of luck with the virtual con, and we really hope a Hackaday reader wins.

Amateur radio is often derided as a hobby, earning the epithet “Discord for Boomers” according to my son. There’s more than a grain of truth to that, but there are actually plenty of examples where a ham radio operator has been able to make a big difference in an emergency. Case in point is this story from the Western Massachusetts ARRL. Alden Jones (KC1JWR) was hiking along a section of the Appalachian Trail in southern Vermont last week when he suddenly got light-headed and collapsed. A passing hiker who happened to be an emergency medical technician rendered aid and attempt to contact 911 on his cell phone, but coverage was spotty and the dispatcher couldn’t hear him. So Alden, by this point feeling a little better, pulled out his handy talkie and made an emergency call to the local repeater. Luckily the Western Massachusetts Traffic Net was just about to start, so they went into emergency mode and coordinated the response. One of the hams even went to the rescue staging area and rigged up a quick antenna to improve the signal so that rescuers could finally get a helicopter to give Alden a ride to the hospital. He’s fine now, and hats off to everyone who pitched in on the eight-hour rescue effort.

And finally, there are obviously a lot of details to be worked out before anyone is going to set foot on the Moon again. We’ve got Top Peopleā„¢ working on all the big questions, of course, but apparently NASA needs a little help figuring out how and where the next men and first women on the Moon are going to do their business. The Lunar Loo Challenge seeks innovative designs for toilets that can be used in both microgravity and on the lunar surface. There is $35,000 in prize money for entrants in the Technical division; NASA is also accepting entries in a Junior division, which could prove to be highly entertaining.

Tackling Trunked Radio With Software

For those starting to wade into radio as a hobby, one of the first real technical challenges is understanding trunked radio systems. On the surface, it seems straightforward: A control channel allows users to share a section of bandwidth rather than take up one complete channel, allowing for greater usage of the frequency range. In practice though it can be difficult to follow along, but now it’s slightly easier thanks to software defined radio.

This guide comes to us from [AndrewNohawk], who is located in San Francisco and is using his system to monitor police, fire, and EMS activity. These groups typically used trunked radio systems due to the large number of users. For listening in, nothing more than an RTL-SDR setup is needed, and the guide walks us through using this setup to find the control channels, the center frequency, and then identifying the “talk groups” for whichever organization you want to listen in on.

The guide goes into great detail, including lists of software needed to get a system like this started up, and since [AndrewNohawk] is a self-identified “radio noob” the guide is perfectly accessible to people who are new to radio and specifically new to trunked systems like these. Once you get the hang of it, it’s not too hard to scale up, either.

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Hackaday Links: May 3, 2020

In a sign of the times, the Federal Communications Commission has officially signed off on remote testing sessions for amateur radio licensing in the United States. Testing in the US is through the Volunteer Examiner Coordinator program, which allows teams of at least three Volunteer Examiners to set up in-person testing sessions where they proctor amateur radio licensing exams. The VEs take their jobs very seriously and take pride in offering exam sessions on a regular schedule, so when social distancing rules made their usual public testing venues difficult to access, many of them quickly pivoted to remote testing using teleconferencing applications. Here’s hoping that more VEs begin offering remote testing sessions.

Another aspect of life changed by COVID-19 and social distancing rules has been the simple pleasure of a trip to the museum. And for the museums themselves, the lack of visitors can be catastrophic, both in terms of fulfilling their educational and research missions and through the lack of income that results. To keep the flame alive in a fun way, Katrina Bowen from The Centre for Computing History in Cambridge has recreated her museum in loving detail in Animal Crossing: New Leaf. For being limited to what’s available in the game, Katrina did a remarkable job on the virtual museum; we especially like the Megaprocessor wallpaper. She even managed to work in that staple last stop of every museum, the gift shop.

To the surprise of few, “spatial computing” startup Magic Leap has announced that it is laying off half its workforce as it charts a new course. The company, which attracted billions in funding based on its virtual retinal display technology, apparently couldn’t sell enough of their Magic Leap One headsets to pay the bills. The company is swiveling to industrial users, which honestly seems like a better application for their retinal display technology than the consumer or gaming markets.

And finally, as if 2020 hasn’t been weird enough already, the Department of Defense has officially released videos of what it calls “unidentified aerial phenomena.” These videos, taken from the head-up displays of US Navy fighter jets, had previously been obtained by private parties and released to the public. Recorded between 2004 and 2015, the videos appear to show objects that are capable of extremely high-speed flight and tight maneuvers close to the surface of the ocean. We find the timing of the release suspicious, almost as if the videos are intended to serve as a distraction from the disturbing news of the day. We want to believe we’re not alone, but these videos don’t do much to help.

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Hackaday Links: April 5, 2020

Git is powerful, but with great power comes the ability to really bork things up. When you find yourself looking at an inscrutable error message after an ill-advised late-night commit, it can be a maximum pucker-factor moment, and keeping a clear enough head to fix the problem can be challenging. A little proactive social engineering may be in order, which is why Jonathan Bisson wrote git-undo, a simple shell script that displays the most common un-borking commands he’s likely to need. There are other ways to prompt yourself through Git emergencies, like Oh Shit, Git (or for the scatologically sensitive, Dangit Git), but git-undo has the advantage of working without an Internet connection.

Suddenly find yourself with a bunch of time on your hands and nothing to challenge your skills? Why not try to write a program in a single Tweet? The brainchild of Dominic Pajak, the BBC Micro Bot Twitter account accepts tweets and attempts to run them as BASIC programs on a BBC Microcomputer emulator, replying with the results of the program. It would seem that 280 characters would make it difficult to do anything interesting, but check out some of the results. Most are graphic displays, some animated, and with an unsurprising number of nods to 1980s pop culture. Some are truly impressive, though, like Conway’s Game of Life written by none other than Eben Upton.

The COVID-19 pandemic is causing all sorts of cultural shifts, but we didn’t expect to see much change in the culture of a community that’s been notoriously resistant to change for over a century: amateur radio. One of the most basic facts of life in the amateur radio world is that you need a license to participate, with governments regulating the process. But as a response to the pandemic, Spain has temporarily lifted licensing requirements for amateur radio operators. Normally, an unlicensed person is only allowed to operate on amateur bands under the direct supervision of a licensed amateur. The rules change allows unlicensed operators to use a station without supervision and is intended to give schoolchildren trapped at home an educational experience. In another change, some countries are allowing special callsign suffixes, like “STAYHOME,” to raise awareness during the pandemic. And the boom in interest in amateur radio since the pandemic started is remarkable; unfortunately, finding a way to take your test in a socially distant world is quite a trick. Our friend Josh Nass (KI6NAZ) has some thoughts about testing under these conditions that you might find interesting.

And finally, life goes on during all this societal disruption, and every new life deserves to be celebrated. And when Lauren Devinck made her appearance last month, her proud parents decided to send out unique birth announcement cards with a printed circuit board feature. The board is decorative, not functional, but adds a distinctive look to the card. The process of getting the boards printed was non-trivial; it turns out that free-form script won’t pass most design rule tests, and that panelizing them required making some compromises. We think the finished product is classy, but can’t help but think that a functional board would have really made a statement. Regardless, we welcome Lauren and congratulate her proud parents.