If you're using rx.py try setting "--gain-mode 0" on the command line. That parameter is not implemented in multi_rx.py but if you change it in one app (e.g. gqrx), it will persist in other apps until you power cycle the airspy dongle.
Graham On 9/5/20 8:25 AM, Graham Norbury wrote: > This happens when the agc is turned on. Bill Becks and I experimented > with it a while back and found a way to enable/disable, but at this > moment I don't recall the magic incantation. > > Graham > > On Sat, Sep 5, 2020, 7:23 AM <[email protected] > <mailto:[email protected]>> wrote: > > > Quoting Graham Norbury <[email protected] > <mailto:[email protected]>>: > > > I'm not aware of a master gain parameter. LNA, MIX, IF are the > three gain > > controls. All take value between 0-15. > > > >> > >> ./rx.py --args 'airspy' -N 'IF:10,MIX:5,LNA:15' -S 2500000 -f > >> 774.55625e6 -v 7 -T P25PC.tsv -q 2 -V -2 -U -x 2 2>> airspy.log > > > I reran my tests on this again, using -N 'IF:,MIX:,LNA:' like above > with 0-15 values. > > The spike for the CC, as a test, didn't budge at all, all 15, or > anything in between, no changes. > > It is significantly lower to start -20 to -40db lower v. other > programs and depending on antenna. > > Its almost like the gains are set to 0 or something and never > change??? ? ? ? ? > > Even using a duck direct to the Airspy with another program > results in > much higher signals on its spectrum, and gains will adjust > accordingly. > > Changes will occur in another program with adjustments to all 3 > (outside its faked single slider mode, using just the REAL GAINS), > gains shows changes in the signals and noise floor. > > In op25, not a bit of change at all in any thing. noise or signal. > Like these are not being sent? Or not taking affect?? ? ? 15 for > all, > combos of values, even things like 50 for all three, no changes. > > > I am not sure what to even try at this point? Other than missing lib > when it was compiled??? I didn't have the airspy then or airspy > pacakges installed when compiled.. does that change anything??? It > seems to work regardless of that, it tunes, it will trunk, voice > etc., > just the gains don't seem to do a thing at all. IF there was > something > missing in this, I would expect it to fail to tune, audio etc.. > > Ideas????? > > >
