SignalsEverywhere: SDR Bias-Tee’s and Enabling the V3 Bias Tee

Today's video from Corrosive on the SignalsEverywhere YouTube channel discusses Bias Tee's. He explains what they're used for, and how to enable them on various SDRs. In particular he shows how to use the software to enable the bias tee on our RTL-SDR Blog V3 dongles. A bias tee allows you to power antenna side devices like low noise amplifiers by putting DC voltage on the coaxial cable.

The RTL-SDR Blog V3 dongle has a built in software selectable bias tee. By default it is turned off, and can easily be turned on by running some simple software. Instructions are available on the V3 users guide at

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Where can I find the script to turn on the bias T on V3 please? Can’t seem to locate this?


How can I tell if the bias-tee is working on my rtl-sdr v3? I’m trying to enable the bias-tee to work with an MLA-30+ loop antenna and a Spyverter v2 but it doesn’t seem to be working for either or both of these.

I’m using the rtl_biast utility on OS X per the instructions at The command seems to execute properly, but it’s as though the bias-tee power isn’t ‘turned on’. The MLA-30+ and Spyverter v2 both work using their respective USB power options.


V3 has a tiny green LED at base of jack. Can only see in low light.


Sorry, not V3, the RTL-SDR Blog Wideband Low Noise Amplifier has a tiny green LED at base of jack. If you are not using that then I have no idea.


Anyone know if this would work for powering the Direct TV sup-2400 up/down converter hack?


Thanks for video. For RTLSDR-V3 is use CATV 5 Volt bias-T power inserter. RTLSDR-V3 in SDR# set the gain low. Some other tip like sharing, CATV have many antenna splitters and antenna couplers up to 2400MHz and those are usable for RTLSDR