The amateur radio community has exploded with activity lately especially in the software-defined radio (SDR) area since it was found that a small inexpensive TV tuner could be wrangled to do what only expensive equipment was able to do before. One common build with these cards is monitoring air traffic, which send data about their flights out in packets over the radio and can easily be received and decoded now. It turns out another type of vehicle, SpaceX’s Falcon 9 spacecraft, reports data via radio as well and with some slightly upgraded hardware it’s possible to “listen in” to these flights in a similar way.
Reddit users [derekcz] and [Xerbot] used a HackRF module to listen in to the Falcon 9’s data transmissions during its latest launch. While the HackRF is a much more expensive piece of equipment compared to the RTL-SDR dongles used to listen in on aircraft, it is much more capable as well, with a range from 1 MHz to 6 GHz. Using this SDR peripheral as well as a 1.2 m repurposed satellite dish, the duo were able to intercept the radio transmissions from the in-flight rocket. From there, they were recorded with GNU Radio, converted into binary data, and then translated into text.
When [Kenneth Keiter] took apart his Starlink dish back in November, he did his best to explain the high-level functionality of the incredibly complex device in a video posted to his YouTube channel. It was a fascinating look at the equipment, but by his own admission, he wasn’t the right person to try and explain the nuances of how the phased array actually functioned. But he knew who could do the technology justice, which is why he shipped the dismembered dish over to [Shahriar Shahramian] of The Signal Path.
Don’t be surprised if you can’t quite wrap your head around his detailed analysis after your first viewing. You’ll probably have a few lingering questions after the second re-watch as well. But that’s OK, as [Shahriar] still has a few of his own. Even after cutting out a section of the dish and putting it under an X-ray, it’s still not completely clear how the SpaceX engineers managed to cram everything into such a tidy package. Though there seems to be no question that the $500 price for the early-access hardware is an absolute steal, all things considered.
Most of the video is spent examining the stacked honeycomb construction of the phased antenna array, which as expected, holds a number of RF secrets if you know what to look for. Put simply, there’s no such thing as an insignificant detail to the trained eye. From the carefully sized injection molded spacer sheet that keeps the upper array a specific distance from the RF4-like radome, to the almost microscopic holes that have been bored through each floating patch to maintain equalized air pressure through the stack up, [Shahriar] picks up on fascinating details which might otherwise seem like arbitrary design decisions.
But a visual inspection will only get you so far. Eventually [Shahriar] has to cut out a slice of the PCB so he can fit it into the X-ray machine, but don’t feel too bad, the dish was long dead before he got his hands on it. While he hasn’t yet completed his full analysis, an initial examination indicates that each large IC and the eight chips surrounding it make up a 16 channel beam forming module. Each channel is further split into two RX and TX pairs, which provides the necessary right and left hand polarization. That said, he admits there’s some room for interpretation and that further work would be necessary before any hard conclusions could be made.
Between this RF analysis and the initial overview provided by [Kenneth], we’ve already learned a lot more about this device than many might have expected considering how rare and expensive the hardware is. While we admit it’s not immediately clear what kind of hijinks hardware hackers could get into once this device is fully understood, we’re certainly eager to find out.
While SpaceX’s constellation of Starlink satellites is nowhere near its projected final size, the company has enough of the birds zipping around in low Earth orbit to start a limited testing period they call the Better Than Nothing Beta. If you’re lucky enough to get selected, you have to cough up $500 for the hardware and another $100 a month for the service. Despite the fairly high bar for getting your hands on one, [Kenneth Keiter] decided to sacrifice his Starlink dish to the teardown Gods.
We say sacrifice because [Kenneth] had to literally destroy the dish to get a look inside. It doesn’t appear that you can realistically get into the exceptionally thin antenna array without pulling it all apart, thanks in part to preposterous amount of adhesive that holds the structural back plate onto the PCB. The sky-facing side of the phased array, the key element that allows the antenna to track the rapidly moving Starlink satellites as they pass overhead, is also laminated to a stack-up comprised of plastic hexagonal mesh layers, passive antenna elements, and the outer fiberglass skin. In short, there are definitely no user-serviceable parts inside.
Beyond attempting to analyze the RF magic that’s happening inside the antenna, [Kenneth] also takes viewers through a tour of some of the more recognizable components of the PCB; picking out things like the Power over Ethernet magnetics, a GPS receiver, some flash storage, and the H-Bridge drivers used to control the pan and tilt motors in the base of the dish.
It also appears that the antenna is a self-contained computer of sorts, complete with ARM processor and RAM to run the software that aims the phased array. Speaking of which, it should come as no surprise to find that not only are the ICs that drive the dizzying array of antenna elements the most numerous components on the PCB, but that they appear to be some kind of custom silicon designed specifically for SpaceX.
Students from the Indian Institute of Science Education and Research combined a commercial satellite dish, a satellite finder and an Arduino, and produced a workable radio telescope. The satellite dish provides the LNB (low noise block) and the associated set-top box is used only for power. Their LNB employs an aluminum foil shield to block extraneous signals.
In addition to the hardware, the team built Python software to analyze the data and show several practical applications. They used known geostationary satellites to calibrate the signal from the finder (digitized by the Arduino) to determine power per unit voltage. They also calculated the beam width (about 3.4 degrees) and used the sun for other calibration steps.
Satellite dishes are a common site these days, although admittedly most of them are Ku- and Ka-band dishes. The older C-band dishes are still around, though, just less frequently in people’s yards. [Greenish Apple] decide to cut the cable and start watching free TV so he built a C-band dish. The trick is, he made the dish out of wood.
The design is the offset type, not a prime focus dish–that is, the electronics are not in the center of the dish but on the side. Wood isn’t particularly good at reflecting RF, of course, so over the wooden skeleton, he used flashing.
Love the classic brick Game Boy, but hate the low-contrast LCD, terrible battery life, and the inability to play Pokemon Emerald? This one’s just for you. It’s the ultimate DMG Game Boy – a Game Boy Advance SP stuffed (is it stuffed if it’s taking up more room?) into the classic Game Boy enclosure. Forum thread.
Zooming in to a microchip. It starts off with a DSLR and ends up on a scanning electron microscope. This is an older chip, and the CPU you’re using right now probably has much smaller features.
Every movie and every TV show set in space invariably has space helmets with LEDs pointing towards the face. Think how annoying that would be for an astronaut. Here’s how you add LEDs to a space helmet for a nice theatrical effect. Just don’t use it on a real EVA.
Everyone’s favorite crowdfunded space probe can apparently be detected with an 8-foot dish. That’s the same size as an old C-band dish, a.k.a West Virginia wildflowers. We know some of you have one of these out there, so go make a ~2GHz feed horn, grab a USB TV dongle, write it up, and send it in.
Alright, MAME cabinets. Say you want to go old-school and have a CRT. Some arcade games use a vertically oriented display, while other, slightly more modern games use a horizontally mounted display. How do you fix this? Get a big bearing, of course. This one allows a 19″ CRT to be rotated 90 degrees – all you need, really, if you’re switching between Pacman and Mortal Kombat.
Hone your survival skills by harnessing the sun’s rays to cook your meals. [Robert] and his daughter turned an old satellite dish into a solar cooker. The image above shows them baking some potatoes, but the temperatures inside the cast iron vessel are high enough to let you cook most foods.
The dish was originally used for satellite television but has been collecting dust in the shed for quite some time. When [Robert] came across a roll of foil tape in his workshop he decided to give the project a whirl. His daughter helped out by peeling away the tape backing (this can be much harder than it sounds) while he applied the reflective material trying to keep it free of wrinkles. After a close call [Robert] donned a pair of welding goggles when positioning the dish. If the light intensity can get the pot up as high as 428 degree Fahrenheit we’re sure it can cause flash blindness.
Unlike other dish cookers we’ve seen, [Robert] didn’t use the original mount for holding the dish in place. He just set it on three bricks and directed it by hand. To keep the intensity focused on the kettle he had to reposition it every 15 minutes.