Broadcastify Calls: Radio Call Archiving + Incentives for SDR Software Developers

Broadcastify is a large scanner audio streaming site which provides live audio streams of Fire, Police, EMS, Aircraft and Rail communications across the USA and in many other countries. These streams are all provided by volunteers running scanners and software defined radios like RTL-SDRs in their local areas.

Recently Broadcastify have announced the beta of their "Calls" platform. This allows them to provide not only live streams of audio, but also an archived history of every radio call received. We believe that this is a technology similar to Radiocapture. The service advertises 30-day call retention, duplicate call handling, live call playback, playlists playback, tight integration with the RadioReference database and detailed statistics of the call and source.

Currently you can contribute received calls to Broadcastify via the Trunk Recorder software. However, Broadcastify recently wrote in and wanted our readers to know that they are providing incentives to SDR software developers to adapt their software in order to allow calls to be ingested into the Broadcastify Calls platform. 

We're announcing developer incentives for the Broadcastify Calls Platform.

If developers adapt their SDR based application to function as a call ingest platform for Broadcastify Calls, Broadcastify will pay them up to $2,500 for their efforts. Here are the details:

  • To qualify for incentives, developers must apply and have an approved agreement with RadioReference.com/Broadcastify. Developers can request to be part of the incentive program by contact us at [email protected]
  • When first system comes online in production on Broadcastify Calls, developer receives a $500 USD check
  • When 5 systems come online in production on Broadcastify Calls, developer receives an additional $2,000 USD check

Documentation for the API can be found here:

https://wiki.radioreference.com/index.php/Broadcastify-Calls-API

Broadcastify Calls
Broadcastify Calls

TechMinds: Hands on with the Elektor SDR Arduino Shield Learning Kit

The Elektor SDR Hands-On-Kit is a low cost (€49.46) SDR learning package that makes use of the Elektor SDR Arduino shield which turns an Arduino microcontroller board into a 150 kHz to 30 MHz capable SDR receiver. It also comes with a book that teaches several basic SDR concepts.

Over on YouTube TechMinds has recently uploaded a video where he unboxes, constructs, and tests the kit using the free G8JCFSDR SDR software. TechMinds also notes that this SDR Shield can also transmit with 10mW of power, and that there is a tutorial included in the book that shows how to use the shield as a simple WSPR transmitter.

Elektor SDRShield - Hands-on Software Defined Radio Kit

YouTube Series on Inmarsat Decoding with Scytale-C

Paul (microp11) is the programmer behind the Scytale-C Inmarsat decoder which has become very popular with RTL-SDR owners. With Scytale-C, and RTL-SDR and an appropriate L-band antenna and amplifier it is possible to receive STD-C NCS data from Inmarsat satellites. This is a public broadcast which contains information like search and rescue (SAR) and coast guard messages as well as news, weather, pirate activity and other incident reports. If you're interested, we have a tutorial available here which uses different software.

Paul has recently created a 6-part video series explaining Scytale-C and all it's features. As well as showing how to setup a Scytale-C decoder with the SDR# plugin in order to receive the STD-C text data via the UI, Paul's series goes into more depth showing how to review and inspect the raw data packets, how to monitor multiple Inmarsat channels at once using SDR# Spyservers and how to use the map feature for plotting coordinate and region data.

Building a 1-Bit Oversampling SDR with not much more than a low cost FPGA

Thank you to Alberto Garlassi for submitting information about his super low parts home made FPGA software defined radio which is capable of medium wave and shortwave AM reception. What makes this design interesting is that is is created with nothing more than 3 resistors, 1 capacitor, and a low cost 30€ Lattice MachXO2 FPGA dev board.

The design makes use of the FPGA's LVDS buffer input to implement a direct sampling 1-bit ADC to which a wire antenna is directly connected to. This 1-bit resolution is increased by using an SDR trick that involves superimposing random RF noise onto the desired signal, and oversampling at 80 MHz then decimating down to a 6 kHz bandwidth. This results in an effective ADC resolution of 6-bits, from 1-bit hardware.

Synthesized on the FPGA is the ADC, Mixer, two CIC filters, an AM demodulator and a PWM circuit for audio output. The synthesis allows for medium wave and shortwave AM reception where the frequency can be tuned via PC control.

The FPGA Verilog synthesis files are available on the projects' GitHub page, and a more in depth explanation of the SDRs operation is available on its hackaday.io page. Alberto has also created a short demonstration video which is shown below.

FPGA + 3 R + 1 C = Medium and Long Wave SDR Receiver.

Gorizont-rtlsdr: Another Linux OS Distro with Built in RTL-SDR Support & Software

A few days ago we posted about DragonOS, which is a Linux ISO file with several built in SDR programs that the creator Aaron has been working on during his COVID-19 lockdown period. We've now got a second lockdown inspired Linux distribution called "gorizont-rtlsdr" which was submitted by Steve Cox. The distro is based on Xubuntu 18.04 and focuses only on software for RTL-SDRs. Steve writes:

gorizont linux 1.0 is a live, USB bootable or VM .iso image, and my first attempt at sharing a project like this. It's built specifically for rtl_sdr/ RTL2832U family dongles, no other devices will be supported in the future (although drivers can be installed if required). It's meant for the cheapest, most available hardware out there.

I think there's a useful niche for this distro, Skywave Linux is getting a bit long-in-the-tooth and un-updated, and the recently reviewed DragonOS, whilst good, is a little complicated for beginners to use. gorizont concentrates on purely terrestrial HF/VHF/UHF analogue and digital signal exploration and decoding, hence the name. It also provides instant DAB+ and FM radio reception for emergency information using RTL V3 stock antennae.

It's built for customisation and compilation of evolving software, hence it's rather portly size. A pretty full suite of dev libraries and repos come as included. Users can also create a bootable USB image or .iso of an updated system using Systemback if gorizont is run as a VM.

We didn't see a list of programs preinstalled, but from the Readme it appears to have at least GNU Radio, GQRX, multimon-ng, DSD+, welle.io, PyBOMBs, wine32, sox, as well as a preset Virtual Audio sync set up through pulseaudio for piping audio between programs. We expect that many more programs will also have been preinstalled.

Easily Streaming SDR Output Audio through a Network to an Android Phone

Thank you to M Khanfar for submitting another video where he demonstrates and explains how to easily send audio from your Linux PC over to an Android phone. This can be used to monitor the audio output of SDR programs like OP25 and GQRX remotely. The main piece of software used in his setup is the SoundWire Server and SoundWire Android App. SoundWire is described below:

Turn your Android device into wireless headphones / wireless speaker. Stream any music or audio from your PC to your Android phone, tablet, or other PCs. SoundWire does audio mirroring (audio cast). You can use any music player on your PC or laptop like Spotify, YouTube, or iTunes and stream low-latency live sound over WiFi directly to your Android device. Also works over 3G/4G cell networks or WAN.

M Khanfar's full tutorial on how to setup SoundWire can be found in the description of the video.

Piping Op25-GQRX Audio Through LAN to Android Phone

AFEDRI LAN-IQ: Standalone 12-bit 30 kHz to 1.7 GHz SDR with LCD Screen for $339

AFEDRI have recently begun shipping their new software defined radio called the "LAN-IQ". The LAN-IQ is a full standalone SDR with good advertised specifications and a very decent price of only US$339. The advertised specs from the Afedri LAN-IQ website are pasted below:

  • 30 kHz to 1700.00MHz continuous frequency range
  • Direct sampling
  • DDC - Digital Down-Conversion
  • 12- bit 76.8 MSPS A/D conversion
  • Stand Alone mode (AM, CW, SSB, NFM, WFM stereo, BPSK, QPSK demodulators)
  • Up to 2.2MHz recording and processing bandwidth
  • Waterfall display functions, when used with appropriate software
  • Recording and playback, when used with appropriate software
  • Sensitivity -  MDS -136 dBm at 500Hz bandwidth (0.03MHz-35MHz)
  • Sensitivity -  MDS -143.5 dBm at 500Hz bandwidth (50MHz-435Mhz)
  • USB 2.0 (Full Speed) interface
  • LAN interface for remote access
  • Compatible with: Linrad, Winrad, HDSDR, Studio1,  SDR Console (SDR-radio), CuteSDR, SdrDX, Quisk, PowerSDR_mrx
  • Powered from USB or external power supply 7-10VDC
  • Dimensions 120mm deep x 78mm wide x 27mm high
  • Unit cost - $339
The Afredi LAN-IQ SDR
The Afredi LAN-IQ SDR

They go on to elaborate on the specs:

LAN-IQ SDR is stand-alone, direct sampling Software Defined Receiver (see picture above)  it has ability to send it's received I/Q stream in three different modes:

  • Stand-Alone (Digital processing, filtering , decoding is implemented inside SDR)
  • Network (LAN)
  • USB

LAN-IQ SDR has the following specification:

  • Frequency Coverage: 0.03MHz-35MHz & 35MHz-1700MHz
  • Noise Figure: ~11dB (for 1MHz-35Mhz range and maximum RF gain 35dB)*
    *input VGA (Variable Gain Amplifier) has variable Gain from -10dB up to +35dB
  • Noise Figure: ~3.5dB (for 50MHz-435Mhz range and maximum LNA/MIX gain )
  • MDS: -136 dBm at 500Hz bandwidth (0.03MHz-35MHz)
  • MDS: -143.5 dBm at 500Hz bandwidth (50MHz-435Mhz)

Output data format: two 16-bit I/Q channels (audio stereo stream emulation)

Maximum Receiving Bandwidth:

  • BW = up to 2200kHz (for 2400kHz sample rate) -  using Network connection
  • BW = up to 706kHz (for 768kHz sample rate) -  instand-alone mode
  • BW = up to 230kHz (for 250k samples/s sample rate) -  using USB connection

RF ADC sampling rate: 76.800 MHz

Power Supply Voltage Requirements:

  • 5V (supplied from the PC's USB bus or from external) or  from external power supply able to provide 5VDC +/-0.2V).
  • 7.0-10V DC to the DC power connector.

Power Supply Current Requirements:

  • up to 850mA (max. LCD brightness, network cable connected, VHF/SHF band)

The LAN-IQ SDR is designed to be used in stand-alone mode , i.e. without need to use  any additional computer and software.

In same time the SDR can be connected and used with  Personal Computer (PC) by two interfaces:

1. Ethernet Network connection.

This can now provide up to 2400 kHz sample rate

2. Full Speed USB

From PC point of view, the SDR-Net can be used alternatively as:

1. Network device using two IP protocols: TCP and UDP.

  • TCP protocol is used to control the SDR parameters.
  • UDP protocol is used to send received I/Q stream from SDR to PC

2. Or exactly like the  AFEDRI SDR-Net -USB Composite Device, that contains two USB functions:

From the Afedri Groups.io forum we've learned that by default the unit will come without the tuning knob, but a knob can be requested if preferred, although it comes with some limitations.

Ordering of the LAN-IQ is done via email only, and the email address can be obtained at the end of their ordering page. They accept PayPal, and shipping costs anywhere from $18 - $32 depending on the country. Also regarding shipping they note that deliveries may be delayed due to COVID-19 which is of course the case for every global delivery right now.

From the SWLing Post blog post we've also learned of a short demonstration video created by Fenu-Radio which is shown below. We are also awaiting his full review which will be posted on fenu-radio.ch.

Afedri LAN-IQ in Action

In a second video Fenu-Radio compares the LAN-IQ against the Malahit-DSP which is another similar low cost standalone SDR which we posted about back in November 2019.

Malahit-DSP & Afedri LAN-IQ "Head to Head"

More videos of the LAN-IQ in action can be found on the Afredi-SDR YouTube channel.

DragonOS Updated: Now with OP25 Installed and many new YouTube Tutorials

Last month we posted about Aaron's "DragonOS" project, which is a ready to install Linux ISO aimed to make getting started with SDR software easy by providing several programs preinstalled, as well as providing multiple video tutorials. Recently he's updated the build, this time basing it on Lubuntu 18.04 allowing for Legacy and UEFI support, along with disk encryption. The OS supports RTL-SDRs as well as the HackRF and bladeRF and probably supports most other SDRs via the SoapySDR interface.

In terms of software he's also added OP25 and bladeRF support. Other programs pre-installed include rtl_433, Universal Radio Hacker, GNU Radio, Aircrack-ng, GQRX, Kalibrate, hackrf, wireshare, gr-gsm, rtl-sdr, HackRF, IMSI-catcher, Zenmap, inspectrum, qspectrumanalyzer, LTE-Cell-Scanner, CubicSDR, Limesuite, ShinySDR, SDRAngel, SDRTrunk, Kismet, BladeRF.

His DragonOS YouTube tutorial channel is also growing fast, with several tutorials showing you how to use DragonOS to perform tasks like listen to trunked mobile radios, use QSpectrumAnalyzer with a HackRF, receive NOAA APT weather satellite images, retrieve cellular network information via a rooted Samsung Galaxy S5, create a ShinySDR server with rtl_433 and how to capture and replay with a HackRF.

DragonOS running CubicSDR
DragonOS running CubicSDR