Tagged: rtl2832u

RTLSDR4Everyone: Review of the RTL-SDR V3 + Avoid Ripoff’s Part 4

Akos from the RTLSDR4Everyone blog has just released several new posts. The first three posts review our V3 dongle and the fourth post continues his series on helping users avoid bad deals when it comes to RTL-SDRs.

The first post compares the NooElec SMArt against the V3. Akos finds that the SMArt has a better enclosure for use with the Raspberry Pi, but the V3 has more features and a lower price. The second post is a general review of the V3 dongle, where Akos reviews the features of the V3, shows what comes in the package, shows visually the difference between V2 and V3 PCBs and demonstrates how the V3 has a cleaner waterfall with less spurs. Finally, the third post compares the V2, V3 and SMArt on ADS-B and concludes that there is little to no difference between the three.

The fourth post points out some rip off RTL-SDR related auctions found on eBay. As stated before we believe that the majority of these ripoff sellers are people who are using market arbitrage bots. These bots simply take a listing from Amazon or elsewhere and list it on eBay as their own with a price markup. Then when a buyer purchases from them, they simply order directly from the original seller and get them to ship to the customer. While this is unethical, it seems to be allowed by eBay.

ADS-B Shootout setup

TETRA Decoding on Windows with Telive

TETRA is a type of digital voice and trunked radio communications system that stands for “Terrestrial Trunked Radio”. It is used heavily in many parts of the world, except for the USA. Telive is a decoder for TETRA which is compatible with RTL-SDR dongles, and has been around and in use for almost 2 years now. If you have unencrypted TETRA signals available in your area it can be used to listen in on them.

Telive is dependent on GNU Radio, so it is normally installed and used on a Linux system. Previously we wrote a tutorial on it’s installation and use, and other users have also made bootable Linux images of telive available.

However, now a TETRA experimenter by the handle of “cURLy bOi” has released a new prototype of a telive modification that works on Windows systems. It makes use of the GNU Radio for Windows development. The telive Windows file can be downloaded from curly’s webserver. His reademe file shows how to install and use the software and it reads:

This has been put together as lowest-effort configuration
to run telive on Windows system. I have also optimized to process (for example adding the CQPSK block to GRC since the python code in the original telive package is IN FACT some unused part of GNU Radio)

Warning:
———
This package contains pre-compiled binaries that work on my 64-bit system. I have compiled them inside the M-SYS2 package. If you don’t trust me, you can follow the installation guide from telive docs, just be prepared you are going to need a lot of packages for the M-SYS2 (pacman -S gcc automake git wget, etc.)

Install:
———
1) Download GNU Radio for Windows from http://www.gcndevelopment.com/gnuradio/downloads.htm
and install
2) Copy contents of gnuradio_mod to c:\Program Files\GNURadio-3.7\
3) Download and install M-SYS2 from https://sourceforge.net/projects/msys2/ and install
4) Copy contents of msys_root to your M-SYS2 installation directory
5) Download FFmpeg for Windows (64-bit Shared) from https://ffmpeg.zeranoe.com/builds/
and extract everything from bin to usr\bin in your M-SYS2 installation directory
6) In M-SYS2 shell execute “pacman -S socat”
7) Get GNU Radio Companion (GRC) projects from original telive package at
https://github.com/sq5bpf/telive/tree/master/gnuradio-companion
(only udp or xmlrpc, pipes won’t work)
8) Open whatever GRC project you want to use and edit it:
– Delete the link between (all) Fractional Resampler and UDP Sink
– From the modules on the right (ctrl-f to search) drag CQPSK Demod to project
(If you don’t see CQPSK Demod then you have messed up #2)
– Connect Fractional Resampler -> CQPSK Demod -> UDP Sink
– Change UDP Sink Input Type to Float in its properties
– Save

Use:
——
1) Open GRC project of your choice (already with the CQPSK Demod box)
2) Use the Project/Execute to run the project from the GRC
– OR –
If you had headless (without GUI) project, use Project/Generate option
to generate top_block.py file in the GRC project directory.
Then open GNURadio Command Prompt from Start menu, the use this command
c:\Program Files\GNURadio-3.7\gr-python27\python.exe -u c:\path\to\grc\project\top_block.py
This will enhance performance.
3) Open new M-SYS2 shell for every channel in that project and execute
command “receiver1udp X” where X is the number of each channel in GRC project
4) Open new M-SYS2 shell, resize it to 203×60 and execute:
– cd /tetra/bin
– ./rxx OR ./rxx_xmlrpc (if you are using XMLRPC GRC project)
You can edit these files to match your preferences
5) That’s it, should work.

Note that we have not tested this out ourselves yet and can’t guarantee the file safety or that it works, but we have no reason to believe that it wouldn’t be safe or not work.

TETRA Decoding (with telive on Linux)
TETRA Decoding (with telive on Linux)

RTL-SDR.COM Broadcast FM Band-Stop Filter (88-108 MHz Reject) Now for Sale + RTL-SDR V3 Dongle Availability

In our store we have just released our new broadcast FM band-stop filter. The cost is $14.95 USD with free international air mail worldwide shipping. (Of course you may choose to upgrade to faster shipping if desired). This product is currently only shipping from our warehouse in China and is not available on Amazon for the time being.

The filter comes in a 2.8 cm x 2.8 cm x 1.3 cm aluminum enclosure and uses female SMA connectors on each end. Included in the package is also a SMA male to SMA male straight barrel adapter.

Click here to visit our store

Important Shipping Note: Please note that right now it is the long “Golden week” holidays in China (1 – 7 Oct), so this product will probably ship out next week and there may be some delays relating to heavy “catch-up” mail volumes around this time.

The filter attached to our RTL-SDR.COM V3 dongle.
The filter attached to our RTL-SDR.COM V3 dongle.

This filter rejects signals between 88 – 108 MHz with around 50 dB or more attenuation. A broadcast FM band-stop filter is very useful for use with SDRs as in some areas broadcast FM signals can be so strong that they overload the SDR, causing very poor performance in other bands. You can tell if this is the case for you if you see images of BCFM stations or interference that looks like a WFM signal at other frequencies when you turn up the gain.

The filter is based on a simple 7th order Chebyshev design. The 3 dB roll off is at 76 MHz and 122 MHz. 88 MHz is attenuated by almost 60 dB, and 108 MHz is attenuated by 45-50 dB. Outside of the pass band the insertion loss is practically zero below 500 MHz, less than 0.5 dB from 500 MHz – 1 GHz, and below 1.5 dB between 1 GHz – 2 GHz. Between 2 – 3 GHz performance degrades slightly, but insertion loss remains below 1.5 dB for most frequencies. The filter can also pass up to 80 mA of DC current (probably can do more) and has negligible DC resistance.

Active Area
RTL-SDR.COM BCFM Band-Stop Filter
BCFM Filter Disconnected
BCFM Filter Connected
Active Area RTL-SDR.COM BCFM Band-Stop Filter BCFM Filter Disconnected BCFM Filter Connected

Below we show a comparison of what a cheap $5 TV FM band-stop filter looks like on the network analyzer. You can see that the stop band is attenuated by significantly less, and the insertion losses on other frequencies are much much larger.

Cheap $5 TV BCFM Filter
RTL-SDR.COM BCFM Band-Stop Filter
Cheap $5 TV BCFM Filter RTL-SDR.COM BCFM Band-Stop Filter
The Cheap $5 TV BCFM Band-Stop Filter
The Cheap $5 TV BCFM Band-Stop Filter

RTL-SDR v3 Availability Note: Our next batch of RTL-SDR v3 dongle stock should be available in 1-2 weeks (there is a delay with restocking due to the Golden week holidays). Production has completed, and we are only waiting for delivery of this stock. Batch 2 includes minor enhancements including slightly tweaked capacitor values, an additional decoupling cap and a fuse on the bias tee.

RTLSDR4Everyone: Review of the RTL-SDR V3 + Avoid Ripoff’s Part 4

Akos from the RTLSDR4Everyone blog has just released several new posts. The first three posts review our V3 dongle and the fourth post continues his series on helping users avoid bad deals when it comes to RTL-SDRs.

The first post compares the NooElec SMArt against the V3. Akos finds that the SMArt has a better enclosure for use with the Raspberry Pi, but the V3 has more features and a lower price. The second post is a general review of the V3 dongle, where Akos reviews the features of the V3, shows what comes in the package, shows visually the difference between V2 and V3 PCBs and demonstrates how the V3 has a cleaner waterfall with less spurs. Finally, the third post compares the V2, V3 and SMArt on ADS-B and concludes that there is little to no difference between the three.

The fourth post points out some rip off RTL-SDR related auctions found on eBay. As stated before we believe that the majority of these ripoff sellers are people who are using market arbitrage bots. These bots simply take a listing from Amazon or elsewhere and list it on eBay as their own with a price markup. Then when a buyer purchases from them, they simply order directly from the original seller and get them to ship to the customer. While this is unethical, it seems to be allowed by eBay.

ADS-B Shootout setup

TETRA Decoding on Windows with Telive

TETRA is a type of digital voice and trunked radio communications system that stands for “Terrestrial Trunked Radio”. It is used heavily in many parts of the world, except for the USA. Telive is a decoder for TETRA which is compatible with RTL-SDR dongles, and has been around and in use for almost 2 years now. If you have unencrypted TETRA signals available in your area it can be used to listen in on them.

Telive is dependent on GNU Radio, so it is normally installed and used on a Linux system. Previously we wrote a tutorial on it’s installation and use, and other users have also made bootable Linux images of telive available.

However, now a TETRA experimenter by the handle of “cURLy bOi” has released a new prototype of a telive modification that works on Windows systems. It makes use of the GNU Radio for Windows development. The telive Windows file can be downloaded from curly’s webserver. His reademe file shows how to install and use the software and it reads:

This has been put together as lowest-effort configuration
to run telive on Windows system. I have also optimized to process (for example adding the CQPSK block to GRC since the python code in the original telive package is IN FACT some unused part of GNU Radio)

Warning:
———
This package contains pre-compiled binaries that work on my 64-bit system. I have compiled them inside the M-SYS2 package. If you don’t trust me, you can follow the installation guide from telive docs, just be prepared you are going to need a lot of packages for the M-SYS2 (pacman -S gcc automake git wget, etc.)

Install:
———
1) Download GNU Radio for Windows from http://www.gcndevelopment.com/gnuradio/downloads.htm
and install
2) Copy contents of gnuradio_mod to c:\Program Files\GNURadio-3.7\
3) Download and install M-SYS2 from https://sourceforge.net/projects/msys2/ and install
4) Copy contents of msys_root to your M-SYS2 installation directory
5) Download FFmpeg for Windows (64-bit Shared) from https://ffmpeg.zeranoe.com/builds/
and extract everything from bin to usr\bin in your M-SYS2 installation directory
6) In M-SYS2 shell execute “pacman -S socat”
7) Get GNU Radio Companion (GRC) projects from original telive package at
https://github.com/sq5bpf/telive/tree/master/gnuradio-companion
(only udp or xmlrpc, pipes won’t work)
8) Open whatever GRC project you want to use and edit it:
– Delete the link between (all) Fractional Resampler and UDP Sink
– From the modules on the right (ctrl-f to search) drag CQPSK Demod to project
(If you don’t see CQPSK Demod then you have messed up #2)
– Connect Fractional Resampler -> CQPSK Demod -> UDP Sink
– Change UDP Sink Input Type to Float in its properties
– Save

Use:
——
1) Open GRC project of your choice (already with the CQPSK Demod box)
2) Use the Project/Execute to run the project from the GRC
– OR –
If you had headless (without GUI) project, use Project/Generate option
to generate top_block.py file in the GRC project directory.
Then open GNURadio Command Prompt from Start menu, the use this command
c:\Program Files\GNURadio-3.7\gr-python27\python.exe -u c:\path\to\grc\project\top_block.py
This will enhance performance.
3) Open new M-SYS2 shell for every channel in that project and execute
command “receiver1udp X” where X is the number of each channel in GRC project
4) Open new M-SYS2 shell, resize it to 203×60 and execute:
– cd /tetra/bin
– ./rxx OR ./rxx_xmlrpc (if you are using XMLRPC GRC project)
You can edit these files to match your preferences
5) That’s it, should work.

Note that we have not tested this out ourselves yet and can’t guarantee the file safety or that it works, but we have no reason to believe that it wouldn’t be safe or not work.

TETRA Decoding (with telive on Linux)
TETRA Decoding (with telive on Linux)

RTL-SDR.COM Broadcast FM Band-Stop Filter (88-108 MHz Reject) Now for Sale + RTL-SDR V3 Dongle Availability

In our store we have just released our new broadcast FM band-stop filter. The cost is $14.95 USD with free international air mail worldwide shipping. (Of course you may choose to upgrade to faster shipping if desired). This product is currently only shipping from our warehouse in China and is not available on Amazon for the time being.

The filter comes in a 2.8 cm x 2.8 cm x 1.3 cm aluminum enclosure and uses female SMA connectors on each end. Included in the package is also a SMA male to SMA male straight barrel adapter.

Click here to visit our store

Important Shipping Note: Please note that right now it is the long “Golden week” holidays in China (1 – 7 Oct), so this product will probably ship out next week and there may be some delays relating to heavy “catch-up” mail volumes around this time.

The filter attached to our RTL-SDR.COM V3 dongle.
The filter attached to our RTL-SDR.COM V3 dongle.

This filter rejects signals between 88 – 108 MHz with around 50 dB or more attenuation. A broadcast FM band-stop filter is very useful for use with SDRs as in some areas broadcast FM signals can be so strong that they overload the SDR, causing very poor performance in other bands. You can tell if this is the case for you if you see images of BCFM stations or interference that looks like a WFM signal at other frequencies when you turn up the gain.

The filter is based on a simple 7th order Chebyshev design. The 3 dB roll off is at 76 MHz and 122 MHz. 88 MHz is attenuated by almost 60 dB, and 108 MHz is attenuated by 45-50 dB. Outside of the pass band the insertion loss is practically zero below 500 MHz, less than 0.5 dB from 500 MHz – 1 GHz, and below 1.5 dB between 1 GHz – 2 GHz. Between 2 – 3 GHz performance degrades slightly, but insertion loss remains below 1.5 dB for most frequencies. The filter can also pass up to 80 mA of DC current (probably can do more) and has negligible DC resistance.

Active Area
RTL-SDR.COM BCFM Band-Stop Filter
BCFM Filter Disconnected
BCFM Filter Connected
Active Area RTL-SDR.COM BCFM Band-Stop Filter BCFM Filter Disconnected BCFM Filter Connected

Below we show a comparison of what a cheap $5 TV FM band-stop filter looks like on the network analyzer. You can see that the stop band is attenuated by significantly less, and the insertion losses on other frequencies are much much larger.

Cheap $5 TV BCFM Filter
RTL-SDR.COM BCFM Band-Stop Filter
Cheap $5 TV BCFM Filter RTL-SDR.COM BCFM Band-Stop Filter
The Cheap $5 TV BCFM Band-Stop Filter
The Cheap $5 TV BCFM Band-Stop Filter

RTL-SDR v3 Availability Note: Our next batch of RTL-SDR v3 dongle stock should be available in 1-2 weeks (there is a delay with restocking due to the Golden week holidays). Production has completed, and we are only waiting for delivery of this stock. Batch 2 includes minor enhancements including slightly tweaked capacitor values, an additional decoupling cap and a fuse on the bias tee.

New SDR# Audio Waterfall Plugin

The old audio waterfall plugin for SDR# seems to be no longer available for download anywhere (it may have gone out of date and is no longer compatible with the latest versions of SDR#). Alan Duffy decided to write his own version of the audio waterfall plugin and make it available for download. An audio waterfall shows the demodulated audio in waterfall form, essentially creating an audio spectrum analyzer. This can be useful for understanding the demodulated frequency structure of a signal.

To install the plugin simply download the dll from his website and place it in the SDR# folder. Then open plugins.xml file with a text editor, and add the magicline specified on his page. Note that for us Chrome detected this file as malicious, but this is a false alarm as Chrome does this often with unknown .dll files. To recover the file we had to go to the Chrome menu -> Downloads, then select "Recover File" to download the file. (If you still have problems with the download then check out the comments as some users have kindly mirrored it). (File was moved to a trusted site so this problem shouldn't occur anymore)

Audio waterfall with the built in audio spectrum analyzer.
Alan's Audio waterfall shown together with the built in audio spectrum analyzer in SDR#.

A Good Quickstart Guide for RTL-SDR Linux Users

Recently we found this excellent quick start guide by Kenn Ranous which shows how to set up various RTL-SDR related software programs on (Debian) Linux. The guide shows how to install the drivers, how to install and set up GQRX, CubicSDR, dump1090, Virtual Radar Server, QSpectrum Analyzer and SDR Trunk.

If you are struggling with getting an RTL-SDR to work on a Linux system then this should be a very good starting point.

The guide can be found on Kenn’s blog at https://ranous.wordpress.com/rtl-sdr4linux.

rtlsdr_linux_qsg

RTLSDR4Everyone: Preliminary Review of the ThumbNet N3 Prototype

A few weeks ago we posted about ThumbNets announcement of their new N3 RTL-SDR dongles. The main theme of their new dongles is lower noise as can be seen by their decision to disable the on board switch mode power supply and add an external power port for powering the dongle from a clean power supply.

Akos from the RTLSDR4Everyone blog received a prototype sample of the N3 for an initial review. In his review he shows some close up shots of the N3 PCB, and does a quick test on receiving some signals. His screenshots show that the noise floor is indeed very low, and that many noisy spurs are eliminated or at least significantly reduced.

Once ThumbNet release their actual commercial units we intend to produce our own review as well.

ThumbSat is a company hoping to enable experimenters to get low cost mini satellites into orbit for about $20k. To support the need for global RX of these satellites they have the ThumbNet project which utilizes RTL-SDR dongles as the receiver. They aim to provide schools and eligible volunteers around the world with free RX hardware to receive and record the data coming from these satellites.

generic_vs_thumbnet
Generic RTL-SDR and the ThumbNet N3

 

FPGAs for DSP and Software-Defined Radio: Short Course at UCLA

The University of California, Los Angeles is hosting a 3-day hands on short course on using SDR’s like the RTL-SDR with FPGA hardware and MATLAB Simulink. This is a course with a high knowledge pre-requisite, so you will likely need qualifications and/or knowledge equivalent to a bachelors in Electrical/Computer Engineering to be able to understand the material. It is mainly intended for DSP and Communications Engineers, HDL designers, FPGAs engineers, RF engineers, and systems engineers. The course runs for 3 days between 10 – 12 October. The main blurb of the course is described below:

One of the main aims of this course is to demonstrate the workflow required to take floating point Simulink receivers (such as the ones presented in the book) and target them onto SDR hardware. This means converting to fixed point, generating HDL code, and then packaging it into something that can be deployed to ZynqSDR hardware.

In this short course we will present, review, simulate then implement real-time DSP enabled software defined radios (SDR) on laptops, Raspberry Pis, Xilinx (Zynq) SoC FPGAs with RF transceivers. The design, simulation and implementation will take the form of a complete model based design work-flow from within MathWork’s MATLAB and Simulink software tools. The course will ensure attendees are educated in key relevant multi-rate DSP algorithms and techniques, in communications modulation methods, quadrature/QAM transceiver designs, and timing and synchronisation. The first part of the course will educate on DSP and communications, followed by a second part on FPGA systems implementation (focussing on Xilinx Zynq SoC) and introduce MathWorks Embedded and HDL Coder methods for hardware targeting. In the third and final part of the course we will develop real-time ‘desktop’ implementations of SDR transceivers using a model based design flow. We will start with floating point designs, which will evolve to fixed point, and then undergo final code generation stages with the Embedded and HDL Coder packages prior to FPGA deployment..

All attendees on the course will use (and take home!) an RTL-SDR device (which tunes from 25MHz to 1.75GHz) and have access to a Raspberry Pi and Zynq SDR kits in class hosting the RTL-SDR device and a wideband FMComms RF card respectively. The class format will be 40% lecture, 20% live SDR demonstration and 40% hands-on ‘desptop SDR’ using software and SDR hardware. 

This course is related to the desktopsdr.com text book which was released September 2015. The physical copy of the book can be purchased on Amazon, or downloaded for free in pdf form on their desktopsdr.com website.

Download the book at desktopsdr.com
Download the book at desktopsdr.com

Introduction to Signal Analysis Baltimore-DC Course Live Stream and Recorded Videos

Earlier in the month we posted about the “Unallocated Space” free four week class on signal analysis taking place in the Baltimore-DC area. The course has now started and they are live streaming the lectures and saving them on YouTube. The first two classes have already passed, and two videos are uploaded.

The first class went over installing the RTL-SDR as well as showing a few examples of decoding some signals. The second class covers various modulation types and digital encoding schemes. They show how to learn how to identify various digital signals by listening to them and viewing them on the waterfall. The class slides are also available on links placed in the video description.

The third and fourth classes have not yet streamed. The third class will be live streamed on October 4, 7PM local time. Visit their YouTube channel for the videos. 

Introduction to Signal Analysis Week 1

Introduction to Signal Analysis Week 2