[Balint] is starting a software-defined radio tutorial series

A few months ago, we saw a hack where a $20 USB TV tuner was transformed into a software-defined radio capable of reading GPS signals, listening to radio transmissions between aircraft and a control tower, and even a simple FM radio. This project is a perfect introduction to the RTL-SDR and Ham radio scene, but getting these projects up and running can be a bit overwhelming for anyone who hasn’t played around with this before. [Balint] is tackling this problem head on with a series of YouTube tutorials to get SDR noobs up and running with GNU Radio and the Realtec USB TV tuner.

To demonstrate the power of software-defined radio, [Balint] is using GNU Radio and the USB TV tuner that started it all, the Ezcap EZTV668 (conveniently back in stock at DealExtreme, but other options exist). Because software-defined radio is a touch confusing for a beginner to wrap their head around, [Balint] is beginning his tutorial series by explaining radio sources, sinks, and the GNU Radio interface.

Already, [Balint] has put up 5 tutorials and made the flowgraph files available in his gr-baz project. He’s doing a wonderful job opening up the software-defined radio scene to beginners, but he’s still looking for some feedback. If you have a suggestion on what [Balint] should cover next, leave a note in the YouTube comments and we’re sure [Balint] will get around to that eventually.

Improving a software defined radio with a few bits of wire

Impressed by the recent advances in the software defined radio scene, [Jason] picked up a $20 USB TV tuner dongle to check out his local airwaves. Unfortunately, the antenna included with the little USB dongle is terrible at receiving any signal other than broadcast TV. [Jason] wanted to improve his reception, so he got some wire and made his own discone antenna.

The discone antenna is ideally suited for [Jason]‘s setup – properly constructed, it’s able to receive over the entire 64 to 1700 MHz band the RTL-SDR dongle is able to read. To construct his antenna, [Jason] checked out [VE3SQB]‘s list of antenna design programs, got the dimensions of his antenna, and set to work attaching wire to PVC pipe.

The antenna is a massive improvement over the stock antenna included with the TV tuner dongle. After mounting his discone at the far end of his back yard, [Jason] started picking up a few blips from the transponders of passing aircraft.

Putting a software defined radio on a mac

A few months ago [Antti Palosaari] discovered cheap USB TV tuners could be used as a software-defined radio. Since then, we’ve seen these TV tuners receive signals from GPS satellites and even the signals between air traffic control and passenger aircraft. Like everything cool, Mac support for these drivers is slightly terrible so [hpux735] wrote his own Cocoa app to support these amazing dongles.

[hpux735]‘s driver is a port of the osmocom driver, repackaged as a native Cocoa app so the terribly fickle libusb and other dependencies aren’t needed. All the code is up on GitHub, ready for you to start playing around with SDR.

As far as tutorials for those wading into the deep waters of software-defined radio, a number of how-to guides have popped up over the last month to get SDR noobs up and running quickly. Here’s a few of the best ones we’ve seen:

[braingram] put up an Instructable for Ubuntu users.

For people who have a Windows box lying around [balint] put up a getting started guide.

There’s a slightly more thorough Windows guide here.

Most of the development in the TV tuner SDR community is happening on the RTLSDR subreddit, and there’s more than enough info there to do just about anything with these TV tuner dongles. If you come up with a novel use for one of these dongles, send it in on the tip line.

Playing air traffic controller with software defined radio

Being an air traffic controller is a very cool career path – you get to see planes flying around on computer screens and orchestrate their flight paths like a modern-day magician. [Balint] sent in a DIY aviation mapper so anyone can see the flight paths of all the planes in the air, with the added bonus of not increasing your risk of heart attack or stroke.

[Balint]‘s Aviation Mapper uses software defined radio to overlay RADAR and ACARS messages from aircraft and control towers in an instance of Google Earth running in a web browser. After grabbing all the radio data from a software defined radio, [Balint]‘s server parses everything and chucks it into the Google Earth framework. There’s a ton of info, pictures, and explanations of the inner machinations of the hardware on [Balint]‘s official project page.

Right now, Aviation Mapper only displays planes within 500 km of Sydney airspace, but [Balint] is working on expanding the coverage with the help of other plane spotters. If you’re willing to help [Balint] expand his coverage, be sure to drop him a line.

Of course, [Balint] is the guy who gave us a software radio source block for those cheap USB TV tuner dongles. Just a few days ago we saw these dongles receiving GPS data, so we’re very impressed with what these little boxes can do in the right hands. [Balint] says his Aviation Mapper application will work with any GNU Radio receiver, so it’s entirely possible to copy his work with a handful of TV tuner dongles.

After the break, there’s two videos of [Balint] sitting at the end of the runway near the Sydney airport watching arrivials come in right above his head and on his laptop. It’s very cool, but we’d be interested in an enterprising hacker in the New York City area copy [Balint]‘s work.

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Working software-defined radio with a TV tuner card.

[Balint Seeber] just sent in a small yet timely project he’s been working on: a software radio source block for the Realtek RTL2832U. Now with a cheap USB TV tuner card, you can jump right into the world of software-defined radio.

[Balint]‘s code comes just a week after hackaday and other outlets posted stories about using a $20 USB TV capture dongle for software defined radio. At the time, these capture cards could only write data directly to a file. With [Balint]‘s work, anyone can use a cheap tv tuner dongle with HDSDR, Winrad, or GNU Radio. If you’ve ever thought about trying out software-defined radio, now might be the time.

Elsewhere on the Internet, a surprisingly active RTL-SDR subreddit popped up dedicated to using the Realtek RTL2832U tuner for software defined radio. There’s an awesome compatibility chart listing compatible USB dongles. The cheapest (so far, and subject to change) is the Unikoo UK001T available for $11 on eBay.

With his source block, [Balint] can listen to anything on the radio between 64-1700 MHz. The sample depth is 8 bits and the sample rate can be anything up to 3.2 MHz. You can watch [Balint] testing out his $20 GNU Radio rig after the break.

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Software defined radio from a USB TV capture card

With a simple digital TV USB capture card, you can build your own software defined radio or spectrum analyzer. While it may not be as cool as [Jeri Ellsworth]‘s SDR, it’s still very useful and only requires $20 in hardware.

The only piece of hardware required for this build is a USB FM/DTV capture device with the Realtek RTL2832U chipset. So far, two USB sticks have been tested and the unit with the largest frequency range (64 – 1700 MHz) is available direct from China for $20.

Turning these cheap capture cards into software defined radios and spectrum analyzers was discovered by [Antti Palosaari] after sniffing the device. These cards demodulate the frequency and send all the data to the computer and is decoded via software. If you have one of these capture cards lying around, you can grab the software and load it up on your *nix box. Right now, the software only writes directly to a file, and may drop a few samples if writing to a hard disk instead of ram. Small problems, but we’re sure this project will pick up steam in the very near future.

via reddit

Scratch-built Software-Defined Radio

[Ben] is showing off some results from his Software-Define Radio project. The board seen above, which he designed from the ground up, is receiving a WWV radio broadcast. This is the atomic clock signal from Fort Collins, Colorado. The audio heard in the clip after the break is a bit noisy, but since he’s about 2000 miles from the origin of the signal we think he’s done really well!

The seed for this build was planted in [Ben's] head back in July when he saw [Jeri Ellsworth's] SDR project. He’s posted some of the build details up in a forum post. The approach is similar to [Jeri's] but there are several key differences. He’s using a DS1085 programmable oscillator where she chose an FPGA for that purpose. Once his hardware demodulates and filters the incoming signal, a PIC32 does the rest of the work and outputs a PWM signal to an Op-Amp to generate audio.

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