Category: Other

ARTEMIS: Free Signal Identification Software

Marco, a reader of RTL-SDR.com and user of our sister site sigidwiki.com has been developing some Windows software to display the sigidwiki.com database in an easier to access format. The software is called Artemis and can be downloaded from http://markslab.tk/project-artemis/.

Artemis allows for various example signals to be quickly viewed with the corresponding example waterfall image, frequency, bandwidth and other information. There is also a filtering function that allows you to search by frequency and type of signal.

Marco writes that he would love to hear any user requests for new features such as more filters, improvements, or anything else as well as any bug reports. We also note that data such as frequencies and bandwidths provided in the sigidwiki.com database may not yet be 100% correct since the wiki is relatively new and is yet to mature.

Screenshot of Artemis
Screenshot of Artemis

New Notch Filter Plugin for SDR#

SDR# plugins programmer Vasili Beliakov has recently published a new notch filter plugin for SDR#. A notch filter will allow you to remove interfering signals that appear on top of a signal of interest. An example is shown in the image below first posted on Twitter by Youssef, the main developer of SDR#. In this image there is an interfering signal within the AM signal of interest. The notch filter removes the interferer without the need to remove the entire sideband.

The plugin also has VFO tracking which allows you to save preset notch filters for particular frequencies.

The plugin can be downloaded from https://t.co/dkEaWaQSmT. New Link: https://dl.dropboxusercontent.com/u/43061070/ifnotch.zip

Notch Filter Plugin Example
Notch Filter Plugin Example

Updates to the Power Line Noise Detector “Driveby” System

A few days ago we posted about Tim Havens “driveby” project, which is a RTL-SDR based system he developed to help create heatmaps of power line noise in his neighborhood. Upon doing further research, Tim discovered that the main source of power line interference was appearing at a frequency of 44.252 MHz. Then by using his driveby system to create a heatmap of his area at this frequency and also by using a hand held radio he was able to pinpoint a massive source of power line noise.

The noise appears to be coming from a faulty and unsafe power pole near a local school. He writes that the power poles primary ground line has been severed and that a wire from the AC line is simply dangling in the air, ready to be grabbed by school children.

Heatmap showing sources of powerline interference
Heatmap showing sources of powerline interference
The faulty power pole
The faulty power pole with dangling AC line
Severed grounding line
Severed grounding line

PortableSDR now on Kickstarter

Back in November, 2014 we posted about the PortableSDR, a 0 – 35 MHz portable software defined radio transceiver that was the third place winner in the Hackaday Prize competition. The PortableSDR project is gaining traction and now has a Kickstarter campaign. They write:

The Portable Software Defined Radio, or PSDR, is an Open Source, Fully stand-alone HF/Shortwave Software Defined Transceiver. It includes a Vector Network Analyzer and Antenna Analyzer as well as GPS. It’s built for rugged portable use. It is designed to be a flexible platform for development, a learning aid, and and a useful instrument for electronics enthusiasts.

Features:

  • Coverage from 0 to 35MHz
  • Waterfall display that lets you see radio signals
  • Receives AM, USB (Upper Side Band), LSB (Lower Side Band), and Morse code (CW)
  • Modulates USB and LSB signals
  • Variable bandpass filter

The campaign hopes to raise $60,000 USD to aid in the development of the hardware and software and with the manufacturing process. The kickstarter is offering kits at various stages of completion from $250 to $475 and a fully assembled kit at $499. They note that the current PSDR2 that you will receive from the Kickstarter is still a development version, not the final product. The PSDR2 is missing some key features that will be in the final version like filters and output amplifiers.

The PSDR v.1
The PSDR v.1
PortableSDR - 2014 Hackaday Prize Judge Recap

Receiving VLF with a PC sound card, Miniwhip Antenna and SAQrx

Over on YouTube user Mile Kokotov has uploaded a video showing how he is able to receive Very Low Frequency (VLF) signals between 300 Hz to 30 kHz using just his PC, a Miniwhip antenna connected to his sound card input port and a program called SAQrx Panoramic VLF Receiver. This allows reception of signals between 0-48 kHz with a sound card that can sample at 96 kHz.

Using this set up he is able to receive the Alpha navigation system beacons which are at around 10-12 kHz and some other Navy navigation system beacons between 18 and 48 kHz from his home in Macedonia.

Receiving VLF with PC and software only

Roundup of Software Defined Radios

New software defined radio (SDRs) products are popping up every few months these days so we thought we'd compile a big list of available SDRs as there are a few people who were bitten by the RTL-SDR bug and are now looking to upgrade.

For each SDR we compare the cost, frequency range, ADC resolution, maximum instantaneous bandwidth, whether or not it can TX and if it has any pre selectors built in. Here is a quick guide to what some of these metrics mean.

Frequency Range: The range of frequencies the SDR can tune to.
ADC Resolution: Higher is better. More resolution means more dynamic range, less signal imaging, a lower noise floor, more sensitivity when strong signals are present and better ability to discern weak signals. Some SDR's give their resolution in ENOB which stands for effective number of bits.
Instantaneous Bandwidth: The size of the real time RF chunk available.
RX/TX: Can the radio receive and/or transmit.
Preselectors: Analogue filters on the front end to help reduce out of band interference and imaging.

* - Denotes top choice for high value

General Use Software Defined Radios

We define general use SDRs as ones with a wide frequency range and with no focus on any specific frequency band.

R820T RTL2832U a.k.a RTL-SDR*

RTLSDR_PCB

Cost: $10 - 22 USD
Frequency Range: approx. 24 MHz - 1766 MHz (below 24 MHz available on RTL-SDR.com V3 dongles)
ADC Resolution: 8 Bits
Max Bandwidth: 3.2 MHz / 2.4 or 2.8 MHz max stable.
TX/RX: RX Only
Preselectors: Uses tracking RF filters on the R820T2 chip.
Release Date: August 2016

The RTL-SDR is still the best 'bang for your buck' software defined radio out there. While it was never designed to be used as a general purpose SDR in the first place, its performance is still surprisingly good. If you're on a budget or are just starting out with SDR or radio this is the one to get. (Link)

Continue reading →

New Signal Identification Guide Wiki: sigidwiki.com

We’ve recently created a new radio signal identification guide over a www.sigidwiki.com. This is a wikipedia styled site which is editable by anyone. We hope that some readers will make a contribution by adding new reference signals, fixing mistakes or identifying unknown signals. Any comments or requests about the page are also welcome.

You can still contribute known or unknown signals to rtlsdrblog__AT__gmail__dot__com and I will add them to the sigidwiki myself.

SoftRock Lite II Build and Test Tutorial Video

The SoftRock Lite II is a (now fairly old) soundcard based software defined radio kitset that is capable of receiving on the HF bands. Over on YouTube user w2aew has uploaded a video showing the entire kitset build process for the SoftRock Lite II SDR radio. He also goes over the circuit blocks explaining their function and how they work.

This is an excellent video if you are interested in learning more about the components and circuits used in some SDRs.

#148: Software Defined Radio kit | Tutorial | Build | Test | Softrock Lite II