---
name: "rtl_biast"
section: "1"
platform: "linux"
package: "rtl-sdr"
version: "1:2.0.3-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/rtl_biast"
---

# rtl\_biast(1)

a tool for turning the bias tee or any GPIO on and off

## NAME

rtl\_biast - a tool for turning the bias tee or any GPIO on and off

## SYNOPSIS

**rtl\_biast \[OPTIONS\]**

## DESCRIPTION

Switch the bias tee power supply of an RTL2832 based receiver on or off. Many receivers provide a bias tee to feed DC power out over the antenna connector, for example to supply an external low noise amplifier or an active antenna.

The bias tee is driven by GPIO 0 of the RTL2832. Receivers that wire it to a different pin, or that expose further GPIOs, can be controlled with the -g option.

The setting is not reset when rtl\_biast exits. The bias tee stays in the state it was left in until it is switched off again, either by another call to rtl\_biast or by a client program that disables it explicitly.

## OPTIONS

- \-d device\_index or serial (default: 0)

  - \-b bias\_on (default: 0)

  - \-g GPIO select (default: 0)

  ## EXAMPLES

- To turn the bias tee of the first device on, call

   rtl\_biast -d 0 -b 1

- To turn it off again, call

   rtl\_biast -d 0 -b 0

- To switch GPIO 1 instead of the bias tee, call

   rtl\_biast -d 0 -g 1 -b 1

## SEE ALSO

RTL-SDR wiki documentation: **http://sdr.osmocom.org/trac/wiki/rtl-sdr**

Other rtl-sdr programs:

[rtl\_adsb(1)](/rtl_adsb/1.md), [rtl\_eeprom(1)](/rtl_eeprom/1.md), [rtl\_fm(1)](/rtl_fm/1.md), [rtl\_power(1)](/rtl_power/1.md), [rtl\_sdr(1)](/rtl_sdr/1.md), [rtl\_tcp(1)](/rtl_tcp/1.md), [rtl\_test(1)](/rtl_test/1.md)

## AUTHOR

This manual page was written for the osmocom rtl-sdr project.

## COPYRIGHT

Copyright (c) 2012 Steve Markgraf \<steve@steve-m.de\>

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.