A Review of the SpyVerter R2

The SpyVerter is a high performance upconverter that enables HF reception on SDR’s that aren’t able to tune directly to HF frequencies. Like any upconverter it works by converting those lower HF frequencies ‘up’ into a higher frequency range that is actually receivable by the SDR.

Back in December 2015 when the SpyVerter first came out we reviewed the unit and found that it was probably the best and highest value upconverter on the market. It was priced at a similar or cheaper price to competitors, came in a metal enclosure and had excellent performance. The main reason for its high performance is due to the architecture. While most upconverters on the market like the ham-it-up use an ADE-1 double balanced mixer component, the SpyVerter instead uses an H-mode mixer design. This design is harder to engineer, but it provides better dynamic range meaning that strong signals are less likely to overload the upconverter.

The SpyVerter was recently given a refresh, and the SpyVerter R2 is now available. The changes are small and are mostly centered around the clock. The oscillator is now a 24 MHz 0.5 PPM TCXO, run through a SI5351 clock generator to produce the 120 MHz upconversion frequency. A new onboard microcontroller programs the SI5351 on power up.

This change in clock design also now allows you to connect a 10 MHz reference frequency if ultra stable, or phase coherent frequency operation is required. A u.FL connector is provided next to the output SMA connector on the PCB for connecting a 10 MHz reference. Unfortunately there is no breakout hole in the metal enclosure, meaning that you’ll need to drill your own hole in the enclosure to get the u.FL clock cable out. Few people will need this feature however, as thanks to the 0.5 PPM TCXO stock frequency stability is now excellent.

The new design also uses less power, only drawing 10 mA of current compared to 47 mA in the SpyVerter R1. It also has 12 dB lower local oscillator leakage meaning that the gains might be able to be pushed slightly higher without overload. Once again, just like with the SpyVerter R1 the R2 is also powered via the bias tee on the Airspy, and so is compatible with the bias tee on our RTL-SDR V3 dongles.

There’s also an interesting mod that can be performed with the SpyVerter R2. The LO frequency can be modded to run at 58 MHz instead of 120 MHz. 58 MHz is just low enough to avoid the broadcast FM band, and the lower frequency allows the switches used in the H-mode design to run at a lower frequency. This results in an insertion loss better by about 3 dB’s and less LO leakage meaning that the RF gains can be pushed higher. The main disadvantage to this mod is that the lowest input frequency will only be 28 MHz.  The mod details don’t seem to be published yet, but we’ll update this post once they are.

The cost of the SpyVerter R2 remains the same as before at $49 USD. Compared to the Ham-It-Up v1.3 which costs $41.95 USD and does not come with an enclosure or TCXO, the SpyVerter still seems to be the best value. Currently you can buy one internationally from iTead who ship from China, at Airspy.us for US customers, and there are several European distributors linked on the Airspy website.

Disclaimer: The SpyVerter R2 was sent by the Airspy team to us for free in exchange for an honest review.

DAB/DAB+ Decoder Software “Welle.io” Now Available on Android

Back in March of this year we posted about “Welle.io”, a DAB/DAB+ decoder that supports the RTL-SDR and other SDRs like the Airspy. It was available for Windows, Linux and Raspberry Pi 2/3.

Albrecht Lohöfener, the author of Welle.io has recently written in to announce that Welle.io is now available for Android as well. The app appears to be free, but is currently marked as beta, so there may still be a few bugs.

The only other app that we’ve seen which is capable of decoding DAB/DAB+ on Android is Wavesink. Wavesink costs $14.90 USD on the Google Play store, but there is a free trial version available with runtime limitations and no DAB+ support.

Albrecht notes that the app is fairly computationally intensive and will require an Android device with at least 4 cores and a clock speed of 1.3 GHz to run the app. He also mentions that they are also looking for any interested developers and translators to help with development of the app.

Welle.io on Android
Welle.io on Android


RTL-SDR.com Presentation Slides from Hamvention

During this years 2017 Hamvention convention I was invented by TAPR to present three talks about the RTL-SDR. Several people who watched the talks have requested the slides, so they are uploaded here in PDF format.

The World Of Low Cost Software Defined Radio – Presented at the TAPR Banquet. An introduction to the RTL-SDR and many of the interesting applications that it has been used for.

An Introduction to RTL-SDR – Presented at the TAPR Digital Forum. A brief introduction to the RTL-SDR and a selection of some of the most popular applications.

Introduction to Cheap SDRs for Radio Monitoring – Presented at the Digital Modes Now and In the Future Forum. A brief introduction to the RTL-SDR and a selection of some interesting digital modes that can be monitored.

The talks may be on YouTube in the future. If and when they are they will be posted here too.

A big thanks to all that came to the talks, and all the people who I met at Hamvention. It was a great event and really nice to meet everyone interested in RTL-SDRs and SDRs in general.

Radio For Everyone: An Easy ADS-B Antenna, ADS-B Advice, and Long Term Results

Over on his blog Akos has uploaded several new posts all relating to ADS-B reception. His first post shows how to build a very simple yet effective “Coketenna” ADS-B antenna which can be built with an empty coke can and some coax cable. This antenna is essentially a 1/4 wave ground plane antenna with the ground plane being a coke can cut in half and mounted upside down. The whip sticking up is simply the coax inner wire. In his post Akos shows exactly how to construct one.

Cantenna and Coketenna
Cantenna and Coketenna

In his second post Akos offers some advice on mounting and positioning ADS-B antennas, discusses the ‘range myth’, talks a bit about LNA’s and filters and shows the differences between a stock RTL-SDR dongle, and one optimized for ADS-B reception like a FlightAware Protstick.

In his third post Akos shows his results from long term ADS-B reception comparisons between a generic RTL-SDR dongle, an RTL-SDR.com V3 dongle with 1090 MHz LNA powered by bias tee, a FlightAware Prostick and a FlightAware Prostick Plus. The V3 dongle with bias tee powered LNA is used as the benchmark receiver and the results show that it received the most signals. The next best was the Prostick Plus, followed by the Prostick and finally the generic dongle.

ADS-B Comparisons between 4 different RTL-SDR setups.
ADS-B Comparisons between 4 different RTL-SDR setups.

HackRF Receives Negative Press in the UK’s ‘DailyMail’ Newspaper

The HackRF is a $300 USD RX/TX capable software defined radio which has a wide tuning range from almost DC – 6 GHz, and wide bandwidths of up to 20 MHz. It uses an 8-bit ADC so reception quality is not great, but most people buy it for its TX and wide frequency/bandwidth capabilities.

Recently the HackRF received some negative press in the ‘Daily Mail’, a British tabloid newspaper famous for sensationalist articles. In the article the Daily Mail show that the HackRF can be used to break into £100,000 Range Rover car in less than two minutes. The exact method of attack isn’t revealed, but we assume they did some sort of simple replay attack. What they probably did is take the car key far away out of reception range from the car, record a key press using the HackRF, and then replay that key press close to the car with the HackRF’s TX function. Taking the key out of reception range of the car prevents the car from invalidating the rolling code when the key is pressed. 

Of course in real life an attacker would need to be more sophisticated as they most likely wouldn’t have access to the keyfob, and in that case they would most likely perform a jam-record-replay attack as we’ve seen with cheap homemade devices like RollJam. The HackRF cannot do this by itself because it is only half-duplex and so cannot TX and RX at the same time.

We should also mention that the HackRF is not the only device that can be used for replay attacks – potentially any radio that can transmit at the keyfob frequency could be used. Even a very cheap Arduino with ISM band RF module can be used for the same purpose.

Mike’s SDRuno Tutorial Series

Mike Ladd, one of the top volunteer contributors of the SDRplay community was recently hired by SDRplay officially and has now been working on a fairly comprehensive SDRuno tutorial series over on the SDRplay YouTube channel. SDRuno is the official software for the SDRplay line of SDRs and is a slightly modified version of the ‘Studio1’ software which was previously acquired by SDRplay. SDRuno also supports the RTL-SDR.

SDRuno is a complex piece of software with many features and settings, so it’s great to see a comprehensive video tutorial like this. Mike’s tutorial series currently has 10 episodes, and discusses things like the basic layout and settings of SDRuno, using Virtual Audio Cable (VAC), noise reduction, memories, calibration, DSD, notch filters and FM broadcast with RDS. More videos are probably still on the way.


XRIT Decoder for GOES Satellites: Supports Airspy R2/Mini and SDRplay RSP2

Over on his blog USA-Satcom has released his XRIT (LRIT/HRIT) decoder for GOES satellites. The software requires a licence and costs $100 USD. GOES-13 (East), GOES-15 (West) and the new GOES-16 are geosynchronous orbiting satellites that broadcast very nice high resolution weather images of the entire visible disk of the earth. The transmit their LRIT/HRIT signals at about 1.7 GHz at fairly weak power, which means that a good LNA and dish set up is critical to be able to receive them. A dish size of about 1 meter, or an equivalent grid or Yagi is recommended as the lowest starting point.

GOES Full Disk Image of the Earth
GOES Full Disk Image of the Earth

USA-Satcom’s decoder is Windows based and comes with a nice GUI. Some portions of the code are based on the Open Satellite Project created by Lucas Teske. It currently supports the Airspy R2/Mini and the SDRplay RSP2 software defined radios.

The software is not free, it costs $100 USD for the licence. To help curb illegal distribution of his software which has been rampant in the past, USA-Satcom also requests that you show some proof of a working setup which is capable of receiving the GOES signal before inquiring about the software.

If you are also interested, USA-Satcom did an interesting talk at Cyberspectrum a few months ago, and he has also recently uploaded his slides.

Screenshot of USA-Satcoms GOES XRIT decoder.
Screenshot of USA-Satcoms GOES XRIT decoder.

QIRX SDR: A New MultiMode RTL-SDR Program with Built-In DAB+ Decoder

Recently Clem from softsyst.com wrote in and let us know about their new SDR software called ‘QIRX SDR’. This is a multimode receiver currently capable of receiving AM/NFM/WFM and also DAB Plus. It supports the RTL-SDR via an rtl_tcp connection, so it can be used on a local machine, or a remote networked one. The main differentiating features that QIRX has against other multimode receivers like SDR#, HDSDR and SDR-Console etc is:

  • Dual Receiver, within the bandwidth of the frontend. This is most useful e.g. for watching two stations simultaneously in busy airband regions.
  • DAB+ Demodulator, to our knowledge the first one written in C#, allowing for recordings in very good quality (some samples provided for download).

The full list of features are quoted below:

QIRX is an Open Source Software Defined Radio, written in C#, downloadable on this site as a Visual Studio 2013 Solution, offering the following features:

  • TCP/IP Based: QIRX accepts 8-bit I/Q-Data either from TCP/IP sources or from pre-recorded files containing the I/Q-data. It is designed to cooperate with RTL-SDR dongles and the widely available rtl-tcp.exe as I/Q-data server. Both QIRX and rtl-tcp may run on the same machine or on separate ones. The rtl-tcp.exe might be started automatically without additional user actions, also when used remote via a LAN.
  • Dual Receiver: Within the selected bandwidth, e.g. 2.56MHz QIRX is able to operate two independent receivers simultaneously.
  • Squelch: For each receiver, QIRX provides a digital squelch, enabling to monitor the selected stations – when not transmitting – without annoying background noise.
  • Simplest Operating Principle: QIRX – using its AM, NFM or WFM demodulators – is purely FFT-based, with a NF lowpass filter only. This might change in a future version.
  • Scanner: QIRX provides for Receiver 1 a simple scanner, being able to scan large frequency areas. This is still in an experimental state.
  • HF and NF Spectrum: For each receiver, QIRX provides a spectrum viewer being able to show the HF and the NF spectrum. No waterfall spectrum yet. For DAB+, it shows the constellation.
  • DAB+ Receiver: QIRX provides a comfortable DAB+ receiver ( Transmission Mode I ). It is -to the best of our knowledge- the first C# based SDR providing this facility. Some standard libraries like the Viterbi decoder are used as C/C++ packages, accessed via P/Invoke.
  • File Recorder: For all demodulators, the audio output can be saved to .wav files, independently for each of the both receivers. For DAB+ this allows for high-quality audio recordings.

    Additionally, the I/Q raw data can be saved to a file. It is possible to replay recorded I/Q-data files.

QIRX SDR: A new multimode receiver with DAB+ decoding
QIRX SDR: A new multimode receiver with DAB+ decoding