Usage cautions

The LNA of HackRF is extremely sensitive, thus you need to notice the following things:

SMA port

• DO NOT change/ swap/ take off/ put on antennas while power is on IN ANY CASE.
• If you use an antenna that expose the literal metal part (for example a telescopic antenna), DO NOT physically touch the antenna with you hands/ body/ or any physical things that is conductive, since the static elec is dangerous to LNA. (It's not like it's definitely would damage it, but a thing that you may should prevent. Antennas which have plastic protection however won't be influenced.)

Monitoring range

• The LNA of hackrf is physically between SMA port and radio front end
• Thus, you shouldn't receive near high power transmitters, even if it's not in the range that you are monitoring.
• For example: You are receiving FM radio at 100.00MHz, and there's a high power transmitter at 2.5GHz around you, the transmitter will still blow your LNA, if you set LNA/AMP too high and/or too near the transmitters, even if 2.5GHz is not in the freq range that you are monitoring.

I suspect I damaged the LNA, how do i check?

• Try listen local radio. Try with AMP on and off both.
• Try capture and replay a non-rolling code _{(to prevent break the rolling sync)} fob. Try with AMP on and off both.