Category: News

RTL-SDR Now Supported by MATLAB

The Communications System Toolbox in MATLAB 2013b now supports the RTL-SDR dongle. MATLAB is a scientific computing software product which scientists and engineers use for complex technical computations and simulations.

The RTL-SDR radio support package enables you to design wireless receivers using real world signals. Using Communications System Toolbox™ in conjunction with an RTL-SDR USB radio, you can design and prototype systems that process real-time wireless signals in MATLAB® and Simulink®.

Wireless engineers, students, and hobbyists can learn to receive and decode real-world radio signals using this low cost RTL-SDR hardware connected to your computer.

Key Features:

  • RTL-SDR radio as an I/O peripheral to receive streaming RF signals
  • Configurable center frequency and sample rate
  • NooElec™ NESDR Mini USB Stick (R820T) and NooElec NESDR Nano USB Stick (R820T) SDR devices with frequency range 30MHz – 1.8GHz
  • Compatible with other RTL-SDR USB radios (eg., Terratec T-Stick E4000)
  • Several application examples for getting started:
    • FM Mono / Stereo with RTL-SDR
    • FRS Receiver with RTL-SDR
    • Spectral Analysis with RTL-SDR radio
    • Frequency offset calibration with RTL-SDR

KN0CK and KF7LZE Custom HF RTL-SDR Receiver Revision 5

Previously on this blog we’ve seen KN0CK release his custom modified RTL-SDR tuners which have built in upconverters for accessing the HF bands. Revision 5 of the KN0CK receiver is now almost ready for sale, and will be sold over at KF7LZE’s webstore

Revision 5 promises to be lower priced as it will run using the direct sampling mod instead of using an upconverter which would require more components. It will also use a Mini-Circuits MAR 8 wideband amplifier to improve weak signal performance.

Kn0CK and KF7LZE RTL-SDR HF Receiver Rev. 5
Kn0CK and KF7LZE RTL-SDR HF Receiver Rev. 5

TCXO RTL-SDR Soon Available Internationally

Andy, programmer of the RTL1090 ADSB decoder software, and owner of the 1090Mhz webstore has notified us that he will soon be selling to international buyers the TCXO RTL-SDR dongle modified by Nobu Saitou. We recently featured a story about the TCXO RTL-SDR and also gave it a review on this blog. From the review we concluded that the TCXO RTL-SDR is a good product and will be useful for applications that need good frequency accuracy and stability.

Interested buyers can look for the contact us link on the 1090MHz shop TCXO page description to contact Andy for a reservation and notification on when the TCXO RTL-SDR becomes available for sale. Andy expects the first batch of TCXO RTL-SDRs to arrive in January.

Nooelec RTL-SDR Giveaway on has teamed up with to give away RTL-SDR packages to 10 hams. To be eligible to enter the competition, you must be a registered amateur radio operator, and you must comment on the competition page. The prizes are

Two (2)
Complete HF sets including:
NESDR Mini receiver
Ham It Up upconverter
SMA to MCX cable
SMA to BNC adapter
SMA to PL259 adapter
SMA to F adapter

Two (2)
Complete Touch SDR sets including:
NESDR Nano receiver
SDR Touch license (for Android tablets)
USB OTG micro & mini cables

Three (3)
NESDR Mini receivers

Three (3)
NESDR Nano receivers

The competition runs until the 11th of December.

Nooelec Giveaway Prize
Nooelec Giveaway Prize

AirSpy – A New 12Bit, 20Msps SDR Dongle Prototype by the Author of SDRSHarp

AirSpy is a new SDR Dongle currently being prototyped by the author of the popular SDRSharp software receiver platform. The technical specifications are as follows

- 24 – 1750 MHz range
- 12bit ADC @ 20msps
- Cortex M4F @ 204 MHz
- 10 MHz panoramic spectrum view
- Highly programmable / customizable

AirSpy also uses the R820T tuner, which is commonly used in the RTL-SDR as well.

Compared to the RTL-SDRs 8bit ADC@3.2msps, this is a large improvement, but we hope it will not cost much more than the RTL-SDR or FunCube.

Currently, if you want more information on the dongle there is only an AirSpy Yahoo Group available.

AirSpy Prototype Front

LNA4HF: Interest Check

Adam, the manufacturer of the LNA4ALL low noise amplifier designed for use with the RTL-SDR, and similar software radios is putting out an interest check for an LNA4HF product. The LNA4HF will be a low noise amplifier with low pass filter designed to work with an existing RTL-SDR upconverter. It will amplify signals between 2 Mhz – 30 Mhz by 16.5dB.

Adam will make a batch once there is interest for at least 50.

LNA4HF block diagram
LNA4HF block diagram

ShinySDR: A new SDR software package that supports RTL-SDR

ShinySDR is a new still in development SDR software package which supports the RTL-SDR. It is built on GNU Radio and has a web based user interface and a plugin system.

One of the main differentiating features of ShinySDR is that it has a persistent waterfall display. This means that as you browse through the frequency spectrum and zoom in and out on the waterfall, the displayed history will not be lost like on other SDR programs. Some other features are

  • Browser-based UI: The receiver can be listened to and remotely controlled over a network or the Internet, as well as from the same machine the actual hardware is connected to. (Required bandwidth: 3 Mb/s to 11 Mb/s, depending on selected spectrum frame rate. This may be improved in future versions by using more compact data formats.)
  • Modularity: plugin system allows adding support for new modes (types of modulation) and hardware devices.
  • “Hackability”: All server code is Python, and has no mandatory build or install step. Demodulators prototyped in GNU Radio Companion can be turned into plugins with very little additional code. Control UI can be automatically generated or customized and is based on a generic networking layer.
  • Frequency database: Jump to favorite stations; catalog signals you hear; import published tables of band, channel, and station info; take notes. (Note: Writing changes to disk is not yet implemented, unfortunately.)

The software also comes with an included VOR demodulator plugin.

New RTL-SDR Tuner Chip R828D

A new tuner known as the Rafeal R828D has become officially supported by the main software branch of RTL-SDR. Comments on the initial testing from this thread on the Reddit RTL-SDR forum show that there is no real improvement over the cheaper R820T tuner, and that a hardware mod is required to get acceptable results from the tuner.

On the Reddit thread user metropolis_pt2, the developer of the driver for this tuner writes

Internally it seems to be almost identical with the R820T, the only real difference is that it has 3 inputs instead of only one (Air-In, Cable1, Cable2), of which two are connected on the Astrometa DVB-T2 stick. Air-In is connected to an external (probably LC-)highpass which seems to have a cutoff-frequency around 320 MHz, and Cable1 to a low-pass with a similar cutoff-frequency. The driver I’ve added will switch automatically to Air-In if you tune > 345 MHz. The filters are not sharp at all though (not surprising given their low order, I only see a few capacitors and inductors in the input path), and their added benefit is a bit questionable. You might get a bit less WFM interference at, say, 900 MHz, but that’s about it…

In Antti’s LinuxTV blog, Antti talks about the internals of the device and shows many pictures of the insides.

Dongle containing the new R828D

HDSDR Updated to Version 2.70. Now with Autocorrelation Feature for Signal Identification

HDSDR, a popular SDR program used with the RTL-SDR dongle has been updated to version 2.70. The new features include

- better CPU utilization
- added Automatic Notch Filter
- added AFC for AM and FM. AFC can be deactivated in ECSS mode
- smoothed S-Meter display
- enhanced parameters for ‘SDR on IF output’
- new keyboard shortcuts for Lo/HiCut and WAV files
- ‘spectrum’ switchable to Autocorrelation/Cepstrum display (Click on ‘Spectrum’ label)
- TX-Button for HRD(DDE) / CAT to HDSDR
- added ‘Double Size’ option in Frequency Input Dialog
- Frequency Manager now provides 5 User Banks

The new autocorrelation feature is particularly useful for signal identification. The authors of HDSDR have created a webpage showing what the autocorrelation feature can be used for, and how to use it.

HDSDR Autocorrelation Feature
HDSDR Autocorrelation Feature

SDRSharp Frequency Manager Plugin updated to Version 1.4

The commonly used frequency manager and scanner plugin for SDRSharp has been updated to version 1.4. The new features include:

Frequency Manager

  • Frequency Presets - there are now 10 frequency presets you may use to store and recall favorite frequencies.


  • A new Signal Strength Indicator displays a real-time measure of a frequency’s signal strength compared to the Minimum Signal Strength that you set. The indicator shows the signal strength as it bounces below and above your minimum, and also shows when the “Seconds wait for transmission” and “Watchdog” timers have been triggered.
  • The Scanner Configuration window now has two tabs which organize scanner behavior into Rules settings and Performance settings.
  • Snap to next Step Size: a new checkbox lets you force the scanner to tune a scanned frequency to the SDR# step size, or instead allow it to tune to the actual detected peak signal strength of a frequency.
  • Update a frequency’s Date when monitored: a new checkbox that causes the scanner to record the current date for a frequency that is already in your database, when the scanner lands on that frequency.
  • Adjacent Frequency Rejection: a new setting that lets you define the width of the area around a tuned frequency that is used to monitor signal strength after tuning to a frequency. This reduces the influence of adjacent strong frequencies that “splatter” into the tuned frequency’s step size or bandwidth size.
  • Faster scanning speed: Scanning speed has been improved yet again, and is now faster than the improvements in version 1.31. On my equipment I now average 1.6 GHz scanning speed as measured with the built-in benchmark tool on a range scan.
  • Improvements to the busy-frequency detection process.

The updated plugin can be downloaded from