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

op25 at zellners.com op25 at zellners.com
Fri Sep 4 10:34:52 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.

Ummm...mmm...hmmmmmm...

SDRTrunk exposes:

4 CONTROLS and 3 options in a drop down.

A guess is these "modes" are some sort of custom setup? As you can set  
CUSTOM MODE and you can then adjust IF,MIX,LNA separately... in  
SENSITIVITY or LINEARITY MODES it has a "MASTER" slider which I will  
take it that if there really are only 3 real gains must be a custom  
adjust to all 3 via that slider???? Which it doesn't reflect in the  
GUI that its adjusting them.... but thats not really relevant here.

I am trying to match performance from an RTL to the Airspy, and the  
plot on the spectrum is at least 20db down from the RTL (RTL Gain  
49)..unless the Airspys are significantly less sensitive which SDRT  
doesn't seem to show.

I get -20db power level with the RTL and and the airspy is at  
-40db...and playing with those gains didn't seem to budge it... hmmm..

I'll give another whack tonight using only the 3 controls and see what  
I get...

Thanks...







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