---In op25-dev(a)yahoogroups.com, <verymetl@...> wrote:
Using device #0 Realtek RTL2838UHIDIR SN: 00000061
Found Rafael Micro R820T tuner
gain: name: LNA range: start 0 stop 0 step 0
supported sample rates 250000-2560000 step 24000
OK very interesting . First , try adding a new option when you run scope.py -S 250000
which should set the sample rate to 250K. Seems it's unhappy with the default 320K.
When you're running scope.py manually you can add the -c NNN option where NNN is the
offset in Hz. If you know the PPM (error offset) you can multiply that by the frequency
in MHz to get the offset NNN. For example say your PPM error is 2.5 then 2.5 * 851 = 2127
so you would have -c 2127..... You may need to fiddle with the sign (so, also try -c
-2127)
As far as adjustable gain - looks like you can't adjust the RF gain. Is it adjustable
when running osmocom_fft ? Also you can try adding an option -o 50000 if there's a
DC offset problem (usually shows up as a spectral line at the tuned frequency even when
the antenna is disconnected)
so to sum up try ./scope.py --args "rtl=0" -f 851.012e6 -S 250000 -o 50000 -c
2127
Best
Max