Hardware and Drivers

Hardware and Drivers

Supported receiver paths

Receiver path	Typical capabilities
HackRF One / PortaPack in USB mode	Wide tuning range, selectable sample rate, LNA/VGA, RF amplifier, DC/IQ correction; half-duplex hardware used receive-only by GP-SDR
RTL-SDR family	Low-cost receive-only IQ source, gain control, model-dependent direct sampling and bias tee
SoapySDR	Other local SDRs supported by an installed Soapy module
rtl_tcp	Remote RTL-SDR stream with reduced hardware-control visibility

Multiple receivers can be connected simultaneously. GP-SDR assigns exactly one capture owner to a physical device at a time, preventing the tuner, Mapper, and P25 engine from fighting over the same USB receiver.

Hardware page status

Each card reports the detected name, driver readiness, serial where available, current owner/job, center frequency, sample rate, gains, amplifier/bias state, stream health, dropped blocks, and overload or noise-only notices. Press Refresh after connecting hardware or installing a component.

HackRF setup

On a PortaPack, enter HackRF USB mode before refreshing GP-SDR. Start with:

• RF amplifier off
• LNA around 16–24 dB
• VGA around 16–24 dB
• DC removal on
• antenna suited to the target band

The RF amplifier can overload the front end and make every frequency look active. Increase gain gradually while watching the noise floor and target SNR. Higher sample rates widen instantaneous coverage but increase USB and CPU load; they do not automatically improve a weak or overloaded signal.

RTL-SDR setup

Only one program can normally claim an RTL-SDR at a time. Close SDR++, SDRTrunk, rtl_tcp, or other SDR software before starting GP-SDR. On Linux, install the distribution's rtl-sdr package and udev rules. On Windows, follow the in-app WinUSB guide for the exact dongle interface.

Install and How-to actions

GP-SDR bundles its own interface and P25 stack. User-space host tools, vendor drivers, optional decoder programs, and large transcription models may remain separate for licensing and platform reasons. Missing cards provide:

• Install when GP-SDR can perform a reviewed, platform-specific install.
• How to when a driver must come from the OS or device vendor.
• Ignore to keep using the app without that optional capability.

Never replace a USB driver unless the selected interface is positively identified as the SDR.

Remote RTL-SDR

Open Hardware → Remote RTL-SDR, enter the rtl_tcp host and port, save it, and refresh. Remote gain, bias tee, calibration, and supported sample rates depend on the remote server. Use a VPN for untrusted networks; do not expose an unauthenticated rtl_tcp port to the public internet.