Black Friday Sales on Airspy and SDRplay Products

Black Friday is upon us again. This year we were not expecting any major sales as the component supply chain crisis has meant that many electronic products, including SDRs are very low in stock. However, there are two great sales that we have found:


Airspy is holding a 25% off sale for this years Black Friday event. Discounts should track across most of their distributors and their main direct sales platform on iTead. On our own store we resell the YouLoop and have also discounted it there, however stock may be backordered by a few days (discount only available via direct sales, or via Aliexpress).

Airspy HF+ Discovery: $169 $126.75
Airspy Mini: $99 $74.25
Airspy R2: $169 $126.75
SpyVerter: $49 $36.75
YouLoop: $34.95 $26.21

Airspy are also holding a #Freebie promo via Twitter.

Airspy Sale Banner


Direct sales from the SDRplay website appear to have no discount and the RSP1A is backordered until Jan.Feb, but Ham Radio Outlet are holding a site-wide sale including their SDRplay stock.

SDRplay RSP1A: $119.95 $99.95
SDRplay RSPdx: $239.95 $199.95
SDRplay DUO: $279.95 $239.95

Did you find any other great Black Friday sales? Please let us know in the comments. Unfortunately this year due to low stock we will not be holding our own sale for our products, but over the next year as the situation hopefully improves we hope to drop prices naturally.

CaribouLite Crowd Funding Launched: A $119 30-6000 MHz 13-bit 2.5 MHz Bandwidth TX/RX SDR Hat for the Raspberry Pi

Back in June of this year we first posted about the upcoming CaribouLite product which is a software defined radio HAT for the Raspberry Pi. The project has just launched on Crowd Supply with a price tag of $119 for the CaribouLite, and $69 for a CaribouLite ISM only band version. The product is expected to ship in May 2022. CaribouLabs write:

CaribouLite is an affordable, open-source, dual-channel software-defined radio (SDR) platform—and an SDR-focused FPGA development framework—implemented as a Raspberry Pi (RPi) HAT. CaribouLite turns your Raspberry Pi single-board computer (SBC) into a self-contained, dual-channel radio Tx/Rx that spans a wide tunable frequency spectrum up to 6 GHz.

The CaribouLite RPi HAT

The CaribouLite is entirely open source and designed for makers, hackers, educators, and researchers. It comes in two versions, the full and ISM band only versions. For most people the full version will be most desirable as it covers the full 30 MHz - 6 GHz range. However, certain projects may want to make use of the ISM band only version as they note that it may easier to obtain regulation compliance.

The full version comes with two TX/RX half-duplex channels, with channel one covering 30 MHz to 6 GHz, and channel two covering sub 1 GHz only. Both channels use a 13-bit ADC, capable of a bandwidth of up to 2.5 MHz maximum. The unit is capable of up to 14 dBm of transmit power.

The libcariboulite drivers support Soapy API, meaning that many SDR programs including SDR++, GQRX, CubicSDR and GNU Radio will be able to support the CaribouLite. 

One interesting design feature is that the CaribouLite does not interface with the Raspberry Pi via USB or Ethernet which is how most SDRs interface. Instead they make use of the SMI (Secondary Memory Interface) connector, which is a high bandwidth interface available on Raspberry Pi's. This is a very fast interface allowing the IQ samples to stream back and forth, however the disadvantage is that the CaribouLite will only work on Raspberry Pi devices. Although it should be possible to use the Raspberry Pi as a host device if you wanted to use the SDR on a PC.

One problem is that we note that most Raspberry Pi resellers are out of stock and the component supply crisis appears to have slowed Raspberry Pi production. So this may be an issue for purchasers who do not already have their own Raspberry Pi. However, given that the CaribouLite ships in May 2022, there may still be time to obtain a Pi.

Given the low cost, specs and features, this appears to be quite an interesting SDR that we are excited to get our hands on. Combined with a Raspberry Pi Zero we can imagine multiple portable use cases and projects that will come from this product.

Frugal Radio: Choosing a “Step Up” Software Defined Radio

In this weeks Frugal Radio episode Rob explores some low cost "Step Up" radios that for a moderately higher price, can give improved receiver performance when compared to RTL-SDRs .

In the video Rob overviews and compares the Airspy Mini ($99), SDRplay RSP1A ($119), Airspy R2 ($169) and the Airspy HF+ Discovery ($169). He discusses their differences such as the tuning ranges, bandwidths and ADC bit depths and why these parameters matter.

Choosing a "Step Up" Software Defined Radio (SDR)

LeanHRPT – A set of tools for the manipulation of HRPT data

Over on Reddit u/Xerbot has posted about the release of his new software called "LeanHRPT". When combined with a software defined radio, this software can be used to decode and view HRPT weather satellite images received from satellites such as NOAA, Meteor, MetOp and FengYun. We note that unlike APT and LRPT weather satellite signals which transmit in the VHF bands, HRPT signals are generally at ~1.70 GHz and require a motorized or hand tracked satellite dish to receive. u/Xerbot writes:

LeanHRPT is a flexible, easy to use and powerful set of tools for the manipulation of HRPT data (maybe I could be convinced to add LRPT support).

When used properly LeanHRPT Decode can generate (almost) L1B data usable in actual land/weather observation, or just pretty images :)

You can get it here:

The LeanHRPT project also contains LeanHRPT Demod, as you probably guessed, a HRPT demodulator. It features an incredibly high sensitivity as well as being able to do both realtime (through SoapySDR) and offline demodulation (baseband).

You can get it here:

LeanHRPT Applying a map overlay on FengYun

GNU Radio Conference 2021 Talks Now Available on YouTube

The GNU Radio YouTube channel has recently finished uploading the talks from GRCon21, this years annual GNU Radio Conference. GNU Radio is an open source development toolkit for signals processing and is commonly used to build software demodulators and decoders for Software Defined Radios.

The GNU Radio conference talks are generally about cutting edge SDR research topics and the YouTube playlist contains 67 videos covering a gambit between what changes have been made in new releases of GNU Radio to presentations and demonstrations focusing on topics such as reverse engineering smart power meters and 5G cell detection among many others.

Some of the talks from this years conference that we found most interesting include:

GRCon21 - Keynote: Joe Gibbs Racing Team

Receiving Starlink Beacons with a HackRF Supercluster

Over on Reddit member u/OlegKutkov has recently posted about his success at receiving Starlink beacons at 11.325 GHz with his HackRF "supercluster". Starlink is an Elon Musk / SpaceX venture that aims to provide fast global satellite internet access for low cost. The venture is advanced enough that in most locations the service is now operational, and there will be Starlink satellites in the local sky at any given time.

Oleg's setup to receive the satellite beacons consists of a small hand tracked satellite dish with LNB feed connected to his HackRF "supercluster". The supercluster is 8 HackRFs connected to the same antenna via a splitter, resulting in 160 MHz of bandwidth. Oleg's blog post from last year appears to contain a bit more information about the start of the supercluster. The 11.325 GHz beacon frequency is out of range for the HackRF which covers up to 6 GHz, so a standard satellite TV LNB is used to downconvert the frequency. The LNB had to first be converted to circular polarization, and is fed via an 'invacom' feedhorn.

Update Notes: Thank you to @dereksgc for pointing out that the HackRF supercluster and modified LNBs aren't actually required to receive Starlink beacons. Derek notes that the Starlink beacons are actually very easy to receive. All you need is an RTL-SDR V3 and a stock "astra" LNB (or the Bullseye LNB) which will convert the 11325 MHz beacon frequency to 1575 MHz which is in the range of the RTL-SDR. The bandwidth of the beacons including doppler shift is also small enough for the RTL-SDR. The beacons are circularly polarized, but strong enough to be received with an unmodified linear LNB and small offset TV dish. So receiving the beacons is possible with modest hardware, provided you have a way to power the LNB. Oleg's setup appears to be gearing up to receive the actual wideband data from Starlink, or some other wideband satellite signals.

In the spectrum waterfall image, the doppler shift of the beacons is clearly visible due to the speed at which the satellites orbit.

More information about his setup is available from his followup Reddit comment and the Twitter links he provides there. You can also visit his Twitter directly at @olegkutkov where he shows more images of his HackRF supercluster and the hardware he' using.

In the past we've posted about how IU2EFA and Jan de Jong were able to track the Starlink satellites via an alternative means involving reception of the European GRAVES space radar being reflected off the satellite body.

Oleg's HackRF Supercluster
Starlink Beacons Received. Doppler shift clearly visible.

Lightweight Windows Software uSDR Updated to Version 1.4.0

Back in July we posted about the release of Viol Tailor's "uSDR" software, which is a lightweight general purpose multimode program for Windows which supports the RTL-SDR, Airspy, BladeRF, HackRF and LimeSDR radios. Recently Viol has updated the software to V1.4.0. The new release brings SDRplay support, and various performance and GUI improvements listed below.

The software can be downloaded from SourceForce.

  • customizable tool panel behavior (fixed, floating, undocked)
  • SDRPlay frontend support (API v.2.13)
  • RTL-TCP streaming interface support, presets quick switch (server, port, description)
  • high precision Wav IQ file play back
  • support RIFF 8, 16, 24 and 32 bits integer, 32 bits float, FR64 file formats for playback
  • recognize Wav IQ file central frequency for play back
  • frequency offset (shift) for x-verters
  • swap IQ (invert spectrum) option
  • improved FFT spectrum calculation and visualization
  • waterfall color map range may be changed manually on the spectrum window as well as on tool panel, also included the auto scale option
  • color map palette can be customized and fast switched, palette presets are included
  • FIFO buffer size (IQ history time) may be changed on the fly, all memory allocations are under hood, no losses of previously stored history 
  • pass band may be attachment to global frequency as well as to local baseband frequency or to screen position
  • squelched threshold control and level indicator for demodulation (in addition to adjustable spectrum threshold detector)
  • stereo FM demodulator
  • low latency audio
  • frequency manager, groups and interactive markers, visualize, edit, navigate, tune the pass band
  • spectrum and waterfall popup menus
  • improved GUI controls
  • "fine tune" option: set pass band to rounded frequency (spectrum right click)
  • statistics visualization window
uSDR aka microSDR. A lightweight SDR receiver program from Windows.

SignalsEverywhere: Setting up the Retrogram Terminal Spectrum Analyzer for the PlutoSDR

This week on the SignalsEverywhere YouTube channel Sarah shows how to install the "Retrogram" software. This is a command line 'retro' styled spectrum analyzer designed to be used with the PlutoSDR. The software makes use of ASCII art to display the spectrum, meaning that a spectrum can be viewed directly in an SSH terminal, without any GUI. 

In the video Sarah goes through the steps to install the software before demonstrating it in action.

Retrogram - A Command Line Spectrum Analyzer For The PlutoSDR