SDR Software — Choosing and Installing Your Tools
Learning goal: by the end you will be able to pick the right SDR application for your device and goal, and install it on Linux or Windows. Audience: beginner to intermediate ｜ Prerequisites: one working SDRLAB device (see Quickstart).
Concept: the software stack
Your SDR hardware digitizes radio spectrum, but something has to turn those raw samples into waterfalls, audio, or decoded packets. That "something" is the SDR application:
Each stage has its own ecosystem. A common beginner trap: the hardware is fine and the app is fine, but the driver layer between them is outdated — the RTL-SDR Blog V4 is the classic example, since older drivers simply don't understand its tuner.
Which app should I use?
Quick pick table
| Tool | Platform | Devices | Best for |
|---|---|---|---|
| GQRX | Linux / macOS / Windows | RTL-SDR V4, H4M (as HackRF) | General RX, spectrum, FM/AM demod, SDR newcomers on Linux |
| SDR# (SDRSharp) | Windows | RTL-SDR V4 | The classic beginner Windows app; huge plugin ecosystem |
| SDR++ | Windows / Linux / macOS | RTL-SDR V4, HackRF | Cross-platform modern GUI, server mode, great waterfall |
| SDR Console V3 | Windows | RTL-SDR V4, TRX-duo | Serious receiver features, ham radio, remote operation |
| HDSDR | Windows | TRX-duo, RTL-SDR V4 | HF transceiver-style control, IF panadapters, TRX-duo support |
| CubicSDR | Windows / Linux / macOS | RTL-SDR V4, HackRF | Simple cross-platform waterfall |
| SatDump | Windows / Linux | RTL-SDR V4 | Satellite decoding (NOAA, MetOp, LRPT, Meteor) |
rtl_* command-line tools | Linux / Windows / macOS | RTL-SDR V4 | Testing (rtl_test), raw IQ capture, scripts |
hackrf_* tools | Linux / Windows / macOS | H4M (as HackRF) | Firmware flashing, raw IQ TX/RX, spectrum (hackrf_transfer) |
Linux: install GQRX (recommended starting point)
GQRX is the friendliest Linux GUI and pairs perfectly with the RTL-SDR V4.
Step 1 — Install GQRX
# Debian / Ubuntu / Kali
sudo apt update
sudo apt install gqrx-sdr
Expected output (last lines):
Setting up gqrx-sdr (2.17-1) ...
Processing triggers for desktop-file-utils ...
Step 2 — Install the RTL-SDR command-line tools (used for driver checks)
sudo apt install rtl-sdr
rtl_test -t
Expected output when the V4 is plugged in and drivers are current:
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001
Using device 0: Generic RTL2832U OEM
...
Supported sample rates: 225001-300000, 900001-3200000, ...
Found 1 device(s)is the moment to cheer. If it printsNo devices found, see Troubleshooting → RTL-SDR not detected.
Step 3 — Open GQRX and find a signal
- Launch
gqrx(orgqrx-sdr). - On first run, the Device configuration dialog appears — pick your dongle, leave the I/Q settings at defaults, and click OK.
- Click the ▶ (play) button. The waterfall starts streaming.
- Enter 97.3 MHz in the frequency box (any strong FM station works — check your local one).
- Click the FM mode button, then press the mute icon off. You should hear the station.
Windows: install SDR# (recommended starting point)
- Download the SDR# zip from the Airspy download page.
- Extract the zip to a folder (e.g.
C:\SDRSharp). - Run
sdrsharp.exe. It needs .NET — Windows will offer to install it if missing. - In the top-left Source dropdown, select RTL-SDR (RTL2832U) and click the play icon.
- Tune to a local FM station (88–108 MHz), select WFM demodulation, and you're listening.
TRX-duo software notes
The TRX-duo is not a plug-and-play USB device — it is a networked instrument running its own embedded software (see the TRX-duo page for the official firmware image). On the PC side, the ecosystem that works with it is the Red Pitaya SDR software family:
- HDSDR — connect via the Red Pitaya network interface (ExtIO / network interface as documented by the vendor).
- SDR Console V3 — supports Red Pitaya-compatible devices over the network.
- Red Pitaya web apps — the board itself serves browser-based applications (spectrum analyzer, SDR receiver, VNA) straight from its own web UI.
Because the Red Pitaya ecosystem is driven by Pavel Demin's red-pitaya-notes project, most Red Pitaya-compatible applications run on the TRX-duo with the matching SD image.
H4M software notes
The H4M is a standalone device: it runs Mayhem firmware on the PortaPack itself, so no PC software is needed for basic operation. To use it as a plain HackRF from a computer, install the HackRF tools:
# Debian / Ubuntu / Kali
sudo apt install hackrf
hackrf_info
Expected output:
Found HackRF board.
Board ID Number: 2 (HackRF One)
Firmware Version: git-... (API:1.02)
See the H4M page for firmware installation and the firmware guide for update steps.
Command-line essentials worth learning
| Command | What it does | Typical use |
|---|---|---|
rtl_test | Self-test an RTL-SDR dongle | Verify driver + hardware |
rtl_fm -f 97.3M -M wbfm -s 200k | play -t raw | Stream FM audio to speaker | Quick "is my dongle alive" test |
rtl_sdr -f 1090M -s 2M - | Dump raw IQ samples to stdout | Feed ADS-B decoders |
hackrf_transfer -r out.iq -f 433M -s 2M | Record raw samples from HackRF | Capture bursts for replay analysis |
hackrf_info | Show HackRF version info | Verify H4M as HackRF |
Where to go next
- Firmware & drivers — keep the layers under the software healthy.
- Troubleshooting — "the app opens but there's no signal" and friends.
- Product pages: RTL-SDR V4, TRX-duo, H4M.