*>>>Please humor me. How are you determining that the gain is not being
set?*
See my previous message with Baudline captures:
~$ rtl_fm -f 89000000 -R -s 1000000 -g 0 - | baudline -stdin -samplerate
1000000 -quadrature -flipcomplex -channels 2 -format le16
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000013
Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Oversampling input by: 2x.
Oversampling output by: 1x.
Buffer size: 4.10ms
Tuned to 89500000 Hz.
Sampling at 2000000 Hz.
Output at 1000000 Hz.
Exact sample rate is: 2000000.052982 Hz
Tuner gain set to 0.00 dB.
Result:
https://dl.dropboxusercontent.com/u/102802145/baudline0dB.jpg
~$ rtl_fm -f 89000000 -R -s 1000000 -g 30 - | baudline -stdin -samplerate
1000000 -quadrature -flipcomplex -channels 2 -format le16
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000013
Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Oversampling input by: 2x.
Oversampling output by: 1x.
Buffer size: 4.10ms
Tuned to 89500000 Hz.
Sampling at 2000000 Hz.
Output at 1000000 Hz.
Exact sample rate is: 2000000.052982 Hz
Tuner gain set to 29.70 dB.
Result:
https://dl.dropboxusercontent.com/u/102802145/baudline30dB.jpg
GQRX, LNA gain = 0dB
Result:
https://dl.dropboxusercontent.com/u/102802145/gqrx0dB.jpg
GQRX, LNA gain=30dB
Result:
https://dl.dropboxusercontent.com/u/102802145/gqrx30dB.jpg
I know its very strange but I lost two days trying to make work a project
here before I realized rtl_fm was outputting only noise.