SDR– is software-defined radio built around a visual signal path: connect a receiver to a channel, then route the channel to an output such as a speaker, map, log, or recording. The project describes its approach as: “Nothing happens behind your back.” Its current site lists version 2.0.0, dated October 1, 2026; release details and supported modes can change.
How SDR–’s patch-based setup works
Think of the interface as a modular-synth-style diagram, not as a radio that works without configuration. Blocks represent devices, channels, processing and outputs; virtual cables show how signal data moves between them. A receiver can supply IQ data to a channel, a demodulator can turn that signal into audio or messages, and output blocks can send the result to a speaker, map, logger or recorder. The project’s site presents this visible routing as its defining idea: SDR–.
The benefit is that the intended flow is visible and editable. You still need a compatible radio, an antenna appropriate to the signal, and a configuration suited to the mode and output you want. The block layout is an interface metaphor; it does not establish that SDR is simple for every user.
What you can do with it
The project lists support for a broad range of signal types, including broadcast FM with RDS, AM, NFM and SSB audio; ADS-B and AIS position data; POCSAG messages; FT8; SSTV and ATV images; and recording and replay. It also lists direction-finding and passive-radar tools. The project README and decoder catalog distinguish modes by maturity: support ranges from tested on air to experimental, so a listed mode is not a guarantee that every workflow is equally mature or suitable for every receiver.
#1 Best Overall
- Turn your computer, phone or tablet into a radio scanner/ham radio receiver that can receive nearly all RF signals! Compatible with Windows, Mac OS, Linux, and Android
- NESDR SMArt RTL-SDR v5 can be used for the reception of broadcast AM radio, broadcast FM radio, shortwave radio, CB radio, public security radio, trunked radio, air traffic control, ACARS (plane-ground communications), ADS-B (plane tracking), AIS (ship tracking), POCSAG (pagers), NOAA and GOES weather satellites (weather images), weather balloons, radiosondes, DAB radio, DVB-T video, Inmarsat, Iridium, and so much more!
- The best-performing low-cost RTL-SDR available anywhere! Compared with RTL-SDR v3, HF SNR is improved by up to 15dB, VHF & UHF SNR is improved by up to 6dB, tuning accuracy is improved by an average of 4x, and the frequency range is expanded all the way down to 100kHz
- v5 has a frequency capability of 100kHz to 1.75GHz and up to 3.2MHz of instantaneous bandwidth. HF reception below 25MHz is accomplished with direct sampling and requires a suitable antenna. We recommend using a Balun One Nine to make a DIY long wire or dipole antenna (sold separately, product ID B08HGSYB7R or B00R09WHT6)
- Though the direct sampling implementation of NESDR SMArt v5 is much better than any other RTL-SDR, we still recommend using an upconverter like the Ham It Up for a more fulfilling HF experience (sold separately, product ID B076CYK8XZ)
Hackaday’s overview also describes ready-to-use decoder examples such as ADS-B, POCSAG, SSTV, DAB and RDS, along with passive radar and direction-finding tools. See Hackaday’s October 1, 2026 article for that feature overview.
A documented first-receiver example
The official README’s starter walkthrough uses an RTL-SDR USB receiver. Its settings and wiring are an example for that walkthrough—not universal defaults for every signal or device.
Rank #2
- Turn your computer, phone or tablet into a radio scanner/ham radio receiver that can receive nearly all RF signals! Compatible with Windows, Mac OS, Linux, and Android
- NESDR SMArt RTL-SDR v5 can be used for the reception of broadcast AM radio, broadcast FM radio, shortwave radio, CB radio, public security radio, trunked radio, air traffic control, ACARS (plane-ground communications), ADS-B (plane tracking), AIS (ship tracking), POCSAG (pagers), NOAA and GOES weather satellites (weather images), weather balloons, radiosondes, DAB radio, DVB-T video, Inmarsat, Iridium, and so much more!
- The best-performing low-cost RTL-SDR available anywhere! Compared with RTL-SDR v3, HF SNR is improved by up to 15dB, VHF & UHF SNR is improved by up to 6dB, tuning accuracy is improved by an average of 4x, and the frequency range is expanded all the way down to 100kHz
- v5 has a frequency capability of 100kHz to 1.75GHz and up to 3.2MHz of instantaneous bandwidth. HF reception below 25MHz is accomplished with direct sampling and requires a suitable antenna. We recommend using a Balun One Nine to make a DIY long wire or dipole antenna (sold separately, product ID B08HGSYB7R or B00R09WHT6)
- Though the direct sampling implementation of NESDR SMArt v5 is much better than any other RTL-SDR, we still recommend using an upconverter like the Ham It Up for a more fulfilling HF experience (sold separately, product ID B076CYK8XZ)
- Connect an RTL-SDR and add its receiver block in SDR–.
- Set the receiver sample rate to 2.4 MS/s, as specified in this walkthrough.
- Add a wide-FM channel and tune it to a local broadcast station.
- Connect the receiver’s IQ output to the channel input, then connect the channel’s audio output to a speaker.
- Start reception and check that the selected station produces audio. If it does not, verify the device connection, frequency, antenna and routing links.
The walkthrough is in the official SDR– README. If you need hardware, “RTL-SDR USB receiver” is the grounded starting point—not a claim that a particular model is best or compatible with every setup. Compare candidate receivers against the frequency range and bandwidth needed for your signals, the antenna connection, and your intended operating arrangement. The README’s 2.4 MS/s setting applies to its FM example only.
Desktop or server: where to run it
The project lists macOS, Windows and Linux support. Its README describes two broad arrangements: run the desktop application locally with an SDR, or put a server near the antenna and connect through a browser. The latter can separate the radio hardware from the computer you use to operate the interface. The right choice depends on where the antenna and receiver will be, whether you need access from another device, and which operating system and hardware you plan to use. See the project site and README for current setup details.
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Rank #3
- Includes 1x RTL-SDR Blog brand R860 RTL2832U 1PPM TCXO HF Bias Tee SMA Dongle (V3) (Dongle Only)
- Several improvements over other brands including use of the R860 tuner, improved component tolerances, a 1 PPM temperature compensated oscillator (TCXO), SMA F connector, aluminum shielded case with thermal pad for passive cooling, and an activatable bias tee circuit.
- Can tune from 500 kHz to 1.7 GHz and has up to 3.2 MHz of instantaneous bandwidth (2.4 MHz stable). (HF reception below 24 MHz in direct sampling mode with reduced performance). Please note RTL-SDR dongles are RX only.
- Please follow the quickstart guide linked in the included the manual for installation of the drivers and free software. Please feel free to contact us via Amazon messaging for technical support - we're happy to help
Software cost and optional remote access
As listed on the project site on October 3, 2026, SDR– is free and open source under AGPL-3.0-or-later. The project also offers app-based remote access as an optional service, listed from €3 per month on that date. The service is not required to use the core software, and its price may change. Check the official site for current terms.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How to assess performance claims
SDR– publishes comparative benchmark results on its site. These are the project’s own results, not independent tests; the project labels them same machine, same input and release builds, and cautions that compared applications may not include equivalent components—for example, SDR– is headless while another program may include a graphical interface or audio output.
Rank #4
- A full, wide-band RF solution for those interested in getting started with software defined radio and with a keen interest in HF bands
- The NESDR SMArt HF Bundle utilizes a well-designed upconverter--the Ham It Up--to receive HF, NOT direct sampling hacks. This results in a vastly different HF experience--much better performance, and no loss of gain controls
- Included is a Ham It Up v1.3 upconverter, installed in a custom black aluminum enclosure; an NESDR SMArt RTL-SDR, 3 antennas, an impedance matching balun for longwire and dipole antennas, and interconnect adapters
- Proudly manufactured by NooElec in the USA and Canada, with a full 2 year product warranty on all bundle components and 24/7 technical support availability. Please contact our support team any time if you have questions!
- Amazon-exclusive bundle! Only available for a limited time
| Project-published comparison | Reported result |
|---|---|
| FM demodulation throughput, SDR– | 1,176 Msps (SDR– project, 2026) |
| FM demodulation throughput, liquid-dsp | 328 Msps (SDR– project, 2026) |
| FM demodulation throughput, GNU Radio | 238 Msps (SDR– project, 2026) |
| DMR speed, SDR– | 367× realtime (SDR– project, 2026) |
| DMR speed, dsd-fme | 35.1× realtime (SDR– project, 2026) |
| Memory with 16 NFM receivers, SDR– | 129 MiB (SDR– project, 2026) |
| Memory with 16 NFM receivers, SDR++ | 387 MiB (SDR– project, 2026) |
These figures describe the project’s stated test conditions and workloads, not a prediction for a different computer, receiver, configuration or application build. They are most useful as a record of the project’s own comparisons; they do not establish an independent ranking.
Quick Recap
Best Value
- Included: Nooelec USB dongle & antenna
- RTL2832U interface IC & R820T tuner IC on USB dongle
- These are custom USB devices tuned for SDR and include much better components than generics
- Full 1-year warranty & installation support available!
What to check before building a setup
- Signal: Identify the broadcast, data or image mode you want to receive before choosing hardware or wiring.
- Receiver: Check frequency coverage, bandwidth and antenna connector against that use case; the starter RTL-SDR example does not establish universal compatibility.
- Mode maturity: Consult the project’s decoder catalog to distinguish modes tested on air from experimental ones.
- Placement: Decide whether the receiver and application will run together or whether a server near the antenna and browser-based access better fit your location.
- Access: Determine whether local use is enough or whether the optional app-based remote-access service is relevant.
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