Real Radar Scope CRT Shows Flights Using ADS-B

April 15, 2023 by Dan Maloney 9 Comments

Real-time flight data used to be something that was only available to air traffic controllers, hunched over radar scopes in darkened rooms watching the comings and goings of flights as glowing phosphor traces on their screens. But that was then; now, flight tracking is as simple as pulling up a web page. But where’s the fun in that?

To bring some of that old-school feel to his flight tracking, [redacted] has been working on this ADS-B scope that uses a real radar CRT. As you can imagine, this project is pretty complex, starting with driving the 5FP7 CRT, a 5″ round-face tube with a long-persistence P7-type phosphor. The tube needs about 7 kV for the anode, which is delivered via a homebrew power supply complete with a custom flyback transformer. There’s also a lot going on with the X-Y deflection amps and beam intensity control.

The software side has a lot going on as well. ADS-B data comes from an SDR dongle using dump1090 running on a Raspberry Pi 3B. The latitude and longitude of each plane within range — about 5 nautical miles — is translated to vector coordinates, and as the “radar” sweeps past the location, a pip lights up on the scope. And no, you’re not seeing things if you see two colors in the video below; as [TubeTime] helpfully explains, P7 is a cascade phosphor that initially emits a bright-blue light with some UV in it, which then charges up a long-persistence green phosphor.

Even though multicolored icons and satellite imagery may be more useful for flight tracking, we really like the simple retro look [redacted] has managed to pull off here, not to mention the hackery needed to do it.

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Review: XHDATA D-219 Short Wave Radio Receiver

March 15, 2023 by Jenny List 109 Comments

As any radio amateur will tell you, the world of radio abounds with exciting possibilities. Probably the simplest pursuit of them all is that of the SWL, or short wave listener, who scours the airwaves in search of interesting stations. SWLs will often have fully-featured setups with high-end general-coverage communications receivers and tuned antenna arrays, but it can start with the cheapest of radios at its bottom end. Such a radio is the subject of this review, the XHDATA D-219 is a miniature portable receiver that costs under ten dollars, yet is currently the talk of the town in SWL circles. This interest is in no small amount due to its being an especially low-price way to get your hands on a shortwave radio using one of the SIlicon Labs integrated software-defind radio receiver chips. We don’t often review a consumer radio here at Hackaday, but with an avid eye for unexpected gems at the cheaper end of the market this one’s worth a second look.

What Do You Get For Your Tenner?

A picture of the radio on my bench — This form factor is very typical for cheap “world band” radios.

I ordered my D-219 from the XHDATA website, spending about £10 including the postage from China. The usual wait ensued before the package landed on my doormat, and inside was the radio in its box with an instruction leaflet. It’s a small unit about 135 mm x 75 mm x 30 mm, and it follows closely the form factor of other similar radios.

On the top is the extensible antenna with an on-off switch and sockets for headphone and 5 V power, on the side are side-on knobs for tuning and volume, while on the front is the speaker and old-style multi-band tuning display.

On the back is a flip-up stand and a hatch for a pair of AA cells. There’s a band switch covering AM, nine different shortwave bands from 4.75 MHz to 22 MHz, the east Asian FM band from 64 MHz to 87 MHz, and the international FM band from 87 MHz to 108 MHz. The tuning indicator is very old-school, a vertical bar that moves across a frequency scale with the tuning knob. Continue reading “Review: XHDATA D-219 Short Wave Radio Receiver” →

Hackaday Links: March 12, 2023

March 12, 2023 by Dan Maloney 38 Comments

With a long history of nearly universal hate for their products, you’d think printer manufacturers would by now have found ways to back off from the policies that only seem to keep aggravating customers. But rather than make it a financially wiser decision to throw out a printer and buy a new one than to buy new ink cartridges or toners, manufacturers keep coming up with new and devious ways to piss customers off. Case in point: Hewlett-Packard now seems to be bricking printers with third-party ink cartridges. Reports from users say that a new error message has popped up on screens of printers with non-HP cartridges installed warning that further use of the printer has been blocked. Previously, printers just warned about potential quality issues from non-HP consumables, but now they’re essentially bricked until you cough up the money for legit HP cartridges. Users who have contacted HP support say that they were told the change occurred because of a recent firmware update sent to the printer, so that’s comforting.

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Pulling Data From HDMI RF Leakage

March 7, 2023 by Jenny List 25 Comments

A long-running story in the world of electronic security has been the reconstruction of on-screen data using RF interference from monitors or televisions. From British TV detector vans half a century ago to 1980s scare stories about espionage, it was certainly easy enough to detect an analogue CRT with nothing more than an AM broadcast radio receiver. But can this still be done in the digital age? It’s something [Windytan] has looked into, as she reconstructs images using leakage from HDMI cables.

The tale starts with a mystery RF noise, soon identified as not unlike the scanning frequencies of a video signal. Plotting the noise intensities while treating the supposed scanning frequencies as video synchronization yields a shadowy version of her Raspberry Pi desktop, so she’s on to something. It’s important to note that this isn’t a video signal she’s receiving, but the noise associated with the bit transitions in an uncompressed digital video stream, so she quickly concludes that trying to resolve color would be futile.

It does however leave the tantalizing possibility of using this as a medium to wirelessly export data from a compromised machine, and it’s down this route she goes. She finally arrives on a scheme of encoding data as lines of individual colors that look like interference patterns over a desktop, and from there can send and retrieve files. It works for digital audio streams, and as shown in the video below, even an MJPEG video stream, hidden in the noise from a video signal. That’s impressive work, by any standard!

We covered those BBC detector vans in detail a while back.

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A Linux Distro For All Your Ham Needs

February 23, 2023 by Bryan Cockfield 29 Comments

For anyone new to the world of ham radio, one of the things that takes a little getting used to is visiting the websites of authoritative experts in various fields and feeling like you’ve traveled back to the Internet of 1999. As a hobby that lends itself to extremely utilitarian amateurs, the software side can feel a little left behind like that. [Andy] aka [KB1OIQ], on the other hand, is also a Linux enthusiast and has been putting together a complete Linux distribution with everything needed to operate a radio in the modern era.

While most ham radio software seems to be developed for Windows, there is a lot available for Linux. It just takes a bit of tinkering and experimentation to get everything configured just right. Andy’s Ham Radio Linux, or AHRL, takes a lot of the guesswork out of this. The distribution includes everything from contact logging software to antenna modeling, propagation forecasting, and electronic design. While tools like this are largely optional for operating radios themselves, there are also tools included to allow the user to operate various digital modes as well, which require some sort of computer interface to use.

The other design consideration [Andy] made was something that most hams consider when choosing software, which is that it should be able to run on extremely modest hardware. To that end, the distribution is based around Xubuntu and can run on ten-year-old machines with as little as 2 GB of RAM. And, for those interested more in software-defined radio specifically, there is another Debian-based Linux distribution called DragonOS that we’ve featured a few other times as well which is also worth checking out.

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SDR Scanner Listens To Everything

February 6, 2023 by Al Williams 39 Comments

In the old days, scanners would listen to a bunch of channels in a round-robin fashion. If a signal breaks the squelch, the scanner stops and scanning continues scanning after a few seconds of inactivity. But with modern SDRs, you don’t have to listen to one channel at a time. You can listen to all of them. [Tech Minds] shows RTL-SDR Scanner on Linux to record up to 20 MHz of the band simultaneously. It records all the channels in the band of interest. The actual project is on GitHub.

Once recorded, you can use a web interface to listen to the channels and see some statistics about them. [Tech Minds] tried recording aircraft traffic. It worked, but the program doesn’t know how to demodulate AM yet so if you want to record the entire shortwave band, aircraft, or other AM sources, you’ll have to wait a bit before this software is ready for your use case.

If you need to run the program under Windows like [Tech Minds] did, you can use VMWare Workstation Player to get a free copy of Linux on Windows. We wondered if WSL version two might work, too, but we don’t know. Once you have Linux running, Docker makes the installation straightforward. Since the interface is a web interface, you could probably run this on a small computer on the network and then access it at your leisure from another computer.

Of course, old-fashioned scanners were often used to listen to police and fire radios. Those have all gone trunked these days. This isn’t a new idea, but it did seem like a well-packaged solution.

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A Single-Resistor Radio Transmitter, Thanks To The Power Of Noise

January 27, 2023 by Dan Maloney 36 Comments

One of the great things about the Hackaday community is how quickly you find out what you don’t know. That’s not a bad thing, of course; after all, everyone is here to get smarter, right? So let’s work together to get our heads around this paper (PDF) by [Zerina Kapetanovic], [Miguel Morales], and [Joshua R. Smith] from the University of Washington, which purports to construct a low-throughput RF transmitter from little more than a resistor.

This witchcraft is made possible thanks to Johnson noise, also known as Johnson-Nyquist noise, which is the white noise generated by charge carriers in a conductor. In effect, the movement of electrons in a material thanks to thermal energy produces noise across the spectrum. Reducing interference from Johnson noise is why telescopes often have their sensors cooled to cryogenic temperatures. Rather than trying to eliminate Johnson noise, these experiments use it to build an RF transmitter, and with easily available and relatively cheap equipment. Continue reading “A Single-Resistor Radio Transmitter, Thanks To The Power Of Noise” →