SDR Gain

[SV1RVP]

Hello.

I have raspberry pi 3, last raspbian & dvbt usb , how to change sdr gain?

thx

[SV1RVP]

Thanks for the fast response

edit

sudo nano /etc/default/dump1090-mutability

the default is  GAIN="max"

i to change to "0" because i have a preamplifier

GAIN="0"

thx
73

[helios]

0 gain is probably too low, even with preamp. You can observe the signal strength for individual aircrafts on the web interface and there is an overall statistic in /var/log/dump1090-mutability.log.
The unit is dBFS (dB relative to full scale) and the dynamic range reaches from about -40dB (noise floor) to 0dB FS.
I have a 20dB preamp and my gain is at 28.0dB. But the optimum gain vastly depends on the individual components.