Starlink Satellite Dish X-Rayed To Unlock RF Magic Inside

January 11, 2021 by Tom Nardi 15 Comments

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.

The layered antenna works on multiple frequencies.

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.

Continue reading “Starlink Satellite Dish X-Rayed To Unlock RF Magic Inside” →

Bringing Modern Control To An Old Radio

January 11, 2021 by Adam Zeloof 13 Comments

The modern ham radio shack can take many forms. Some are shrines the “boat anchor” radios of old, named for their considerable weight. Others are simply a small, unassuming software-defined radio (SDR) hooked up to a laptop. Nowadays, many shacks fall somewhere in the middle. It’s not uncommon to find a sleek Icom IC-7300 sitting atop an ancient Hallicrafters SX-115 (which sounds suspiciously like the author’s setup). When a ham wants to work a digital mode such as FT-8, they will undoubtedly reach for a newer radio complete with USB (Universal Serial Bus in this case, not Upper Sideband) rig control — but what if the newest piece of equipment they have is a thirty-year-old Kenwood?

If that sounds like you, then fear not because [Steve Bossert] has you covered. He took his trusty Kenwood TS-50, a classic radio from 1993 whose most advanced feature is fuzzy logic, and upgraded it with USB (again, the serial bus) control.

When Kenwood designed the TS-50, they had computer control in mind. There’s a hidden port on the bottom of the unit which reveals a connector that mates with Kenwood’s proprietary (and expensive) set of serial control cables. Thankfully, the engineers over at Kenwood decided to use UART for PC communication, so slapping a USB port in the radio’s case isn’t as daunting as it may sound. [Steve] picked up a CP2104 USB-TTL UART Serial Adapter and wired it up to the radio’s control port. After a bit of drilling, screwing, and gluing, the radio had an upgraded (and non-proprietary!) interface compatible with the ever-popular hamlib. While this doesn’t cover all radio control functions, it gets you tuning, which is pretty important. For a fully modern radio experience, [Steve] suggests using the 8-pin mic connector along with an interface such as Rigblaster or Signalink. This adds PTT and audio signal routing.

If you want to try this for yourself, be sure to check out [Steve]’s extremely well-documented writeup. You could even take this a step further and control your TS-50 from your smartphone with this HTML5 interface we saw a few months back.

Solar Flares And Radio Communications — How Precarious Are Our Electronics?

December 30, 2020 by Al Williams 38 Comments

On November 8th, 2020 the Sun exploded. Well, that’s a bit dramatic (it explodes a lot) — but a particularly large sunspot named AR2781 produced a C5-class solar flare which is a medium-sized explosion even for the Sun. Flares range from A, B, C, M, and X with a zero to nine scale in each category (or even higher for giant X flares). So a C5 is just about dead center of the scale. You might not have noticed, but if you lived in Australia or around the Indian Ocean and you were using radio frequencies below 10 MHz, you would have noticed since the flare caused a 20-minute-long radio blackout at those frequencies.

According to NOAA’s Space Weather Prediction Center, the sunspot has the energy to produce M-class flares which are an order of magnitude more powerful. NOAA also has a scale for radio disruptions ranging from R1 (an M1 flare) to R5 (an X20 flare). The sunspot in question is facing Earth for the moment, so any new flares will cause more problems. That led us to ask ourselves: What if there were a major radio disruption?

Continue reading “Solar Flares And Radio Communications — How Precarious Are Our Electronics?” →

A Tracker For Radio Sondes

December 27, 2020 by Anool Mahidharia 12 Comments

Radiosondes – the telemetry packages carried aloft by sounding balloons for atmospheric weather data measurements – are regularly used by weather bureaus around the world to collect data, and there are quite a number of launches daily. Most of them are in Europe, but they also happen at many locations in North and South America, Japan, and Australia. The balloons burst when they reach a high enough altitude, the radiosonde falls back, and most often there is no effort made to recover them since they are deemed “expendable”. So it’s Finders Keepers, and rich pickings for any hacker who is fortunate enough to grab the fallen radiosondes. For successful recovery, you need to first be able to track those radiosondes, and that’s why leet guy [Robert Stefanowicz aka p1337] built his Weather ballon tracker (sic) project.

The hardware is all off-the-shelf, packaged in a pretty cool 3D printed package designed to make it look like the hand held radio that it is. At its heart is the ESP32 based TTGO T-BEAM V1.0 which has almost everything needed for this project. Add an OLED display, 18650 Li-Po cells, antenna and connectors and you can put it all together in an evening over your favourite beverage.

[DL9RDZ] wrote the software which runs on the T-Beam, available at the RDZ-Sonde repo on Github, that allows hunting these balloons. Setup is straightforward, and you need to fiddle with just a couple of well-explained config parameters. Once connected to your WiFi, config and settings can be accessed via convenient web URL’s and the single user action button on the TTGO offers quick access to different functional modes. At the moment, the software is written to decode signals from the widely used Vaisala RS41, Graw DFM06 and Graw DFM09 radiosondes. This LINK provides details for some of the popular radiosonde models.

Once you’re done building this piece of hunting gear, you’ll need some additional help finding out when and where the launches are taking place. If you’re in Europe, you luck out – there is a live radiosonde tracker map, thanks to the great work done by [Michał Lewiński – SQ6KXY]. If you live else where and know of similar resources, let us know in the comments. As a side note, Wikipedia tells us there are about 1300 launch sites worldwide and twice a day missions, so there’s quite a number of fallen pieces of hardware lying around just waiting to be picked up. At the very least, each will have a GPS module and temperature and humidity sensors that you can recover.

So, what do you do with the recovered radiosondes ? Here’s a tip on a “Fallen Radiosonde reborn as active L-band antenna“. And If you’d like to get the skinny on radiosondes, check out “Radiosondes: getting data from upstairs”

Thanks for the tip, [Alex aka MD23F3].

Fox Hunting With Software-Defined Radio

December 26, 2020 by Bryan Cockfield 7 Comments

Fox hunting, or direction finding, is a favorite pastime in the ham radio community where radio operators attempt to triangulate the position of a radio transmission. While it may have required a large amount of expensive equipment in the past, like most ham radio operations the advent of software-defined radio (SDR) has helped revolutionize this aspect of the hobby as well. [Aaron] shows us how to make use of SDR for direction finding using his custom SDR-based Linux distribution called DragonOS.

We have mentioned DragonOS before, but every iteration seems to add new features. This time it includes implementation of a software package called DF-Aggregator. The software (from [ckoval7]), along with the rest of DragonOS, is loaded onto a set of (typically at least three) networked Raspberry Pis. The networked computers can communicate information about the radio waves they receive, and make direction finding another capable feature found in this distribution.

[Aaron] has a few videos showing the process of setting this up and using it, and all of the software is available for attempting something like this on your own. While the future of ham radio as a hobby does remain in doubt, projects like this which bring classic ham activities to the SDR realm really go a long way to reviving it.

Continue reading “Fox Hunting With Software-Defined Radio” →

Indoor Antennas Worthy Of 007

December 26, 2020 by Al Williams 21 Comments

Many ham radio operators now live where installing an outdoor antenna is all but impossible. It seems that homeowner’s associations are on the lookout for the non-conformity of the dreaded ham radio antenna. [Peter] can sympathize, and has a solution based on lessons of spycraft from the cold war.

[Peter] points out that spies like the [Krogers] needed to report British Navy secrets like the plans for a nuclear boomer sub to Russia but didn’t want to attract the attention of their neighbors. In this case, the transmitter itself was so well-hidden that it took MI5 nine days to find the first of them. Clearly, then, there wasn’t a giant antenna on the roof. If there had been, the authorities could simply follow the feedline to find the radio. A concealed spy antenna might be just the ticket for a deed-restricted ham radio station.

The antenna the [Kroger’s] used was a 22-meter wire in the attic of their home. Keep in mind, the old tube transmitters were less finicky about SWR and by adjusting the loading circuits, you could transmit into almost anything. Paradoxically, older houses work better with indoor antennas because they lack things like solar cell panels, radiant barriers, and metallic insulation.

Like many people, [Peter] likes loop antennas for indoor use. He also shows other types of indoor antennas. They probably won’t do as much good as a proper outdoor antenna, but you can make quite a few contacts with some skill, some luck, and good propagation. [Peter] has some period spy radios, which are always interesting to see. By today’s standards, they aren’t especially small, but for their day they are positively tiny. Video after the break.

Continue reading “Indoor Antennas Worthy Of 007” →

SpaceAusScope Team Listens To The Galaxy

December 23, 2020 by Al Williams 2 Comments

Australia has always had a reputation for astronomy. It is a great site low in the Southern hemisphere and there are lots of sparsely inhabited areas free from light and radio interference. Some of the first video from the Apollo 11 landing, for example, came in from “the dish” — a very large radio telescope down under. Australian hobbyists have formed a group, SpaceAusScope, where teams across Australia are building radio telescopes with the plan — which has been delayed by the pandemic — of collecting data and providing it for public analysis.

A secondary goal of the group is to provide better documentation for amateur radio telescope builders. So even if you don’t live in Australia, you might want to check out their website. It looks as thoughthe documentation will arrive in the future, but there is a very informative blog post from one team member about the helical antenna design most of the teams are using to eavesdrop on the hydrogen line.

Continue reading “SpaceAusScope Team Listens To The Galaxy” →