Learn how to decode digital voice communications like APCO P25, DMR MotoTRBO, NXDN and D-STAR with DSD+ and an RTL-SDR dongle.
The RTL-SDR software defined radio can be told to run in a mode called “direct sampling mode”, which with a small hardware mod allows the dongle to tune to the HF frequencies where ham radio and many other interesting signals are found. This means that no upconverter circuit is required.
New software defined radio (SDR) products are popping up every few months these days so we thought we’d compile a big list of available SDRs.
With an RTL-SDR dongle, a cheap $10 modified GPS antenna or 1-2 LNA’s and a patch, dish or helix antenna you can listen to Inmarsat satellite signals, and decode the STD-C NCS channel which contains information such as search and rescue (SAR) and coast guard messages as well as news, weather and incident reports.
The Meteor-M N2 is a polar orbiting Russian weather satellite. With an RTL-SDR an appropriate antenna, you can receive and decode its image downlink and download LRPT weather satellite images.
Follow trunked radio conversations with your RTL-SDR and a program called Unitrunker. Also decode digital communications like P25 and DMR using the Digital Speech Decoder (DSD+) software.
Use your RTL-SDR to decode data from weather balloons (aka Radiosondes) that are launched twice daily by meteorological agencies all around the world.
There are a number of SDRSharp plugins that extend its functionality. Here is a collection of all the plugins and download links that we know of.
When people consider upgrading from the RTL-SDR, there are three mid priced software defined radios that come to most peoples minds: The Airspy, the SDRplay RSP and the HackRF. These three are all in the price range of $150 to $300 USD. In this post we will review the three units and compare them against each other on various tests.
By using an RTL-SDR dongle together with a low cost noise source it is possible to measure the response of an RF filter. Also, with an additional piece of hardware called a directional coupler the standing wave ratio (SWR) of antennas can also be measured.