[op25-dev] rx.py Airspy MASTER GAIN Setting option?????

op25 at zellners.com op25 at zellners.com
Sat Sep 5 11:23:04 UTC 2020

Quoting Graham Norbury <gnorbury at bondcar.com>:

> 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..


More information about the op25-dev mailing list