HackRF One

A half-duplex TX/RX software radio, 1 MHz to 6 GHz. The step up from an RTL-SDR when a job needs to transmit.

320€ Radio & RF

What it does

The HackRF One is a wideband, half-duplex software-defined radio that both receives and transmits from 1 MHz to 6 GHz. Where an RTL-SDR only listens, the HackRF plays recorded IQ back on air, which is what replay and injection against sub-GHz remotes, wireless sensors, and custom protocols actually need. It works the same GNU Radio / Universal Radio Hacker toolchain as the RTL-SDR, just with the transmit half unlocked.

Use cases

Replay a captured sub-GHz signal

Record IQ off a remote or sensor with an RTL-SDR, then transmit the same samples back with the HackRF.

Reverse an unknown digital signal

Feed a capture into Universal Radio Hacker to detect the modulation and slice the bits before building an attack.

Build a custom TX/RX flowgraph

Assemble a GNU Radio chain block by block for a waveform no off-the-shelf decoder covers.

How you use it

Confirm the device is seen, then record and play back IQ at the same center frequency and sample rate:

hackrf_info
hackrf_transfer -r capture.iq -f 433920000 -s 8000000   # record IQ
hackrf_transfer -t capture.iq -f 433920000 -s 8000000   # play the same IQ back

Variants & pitfalls

Half-duplex. It cannot receive and transmit at the same time; a full-duplex job (or a live TX-while-listening setup) needs a different radio.

One antenna, huge range. No single antenna is efficient across 1 MHz to 6 GHz; swap to one tuned for the band you're actually working before trusting a weak signal.