RE: [Discuss-gnuradio] Values of gain differ with Python and C++

[De Lima Julian]

> Hello,
> 
> I have seen in the file usrp_basic.h that the minimum value of the
gain
> is -20 and the maximum is 0. And in the user guide of the USRP, it is
> written that the PGA has a maximum gain of 20 dB.

> Yes, this is true, for the PGA in the AD9862.

But the AD9862 is only used for the transmit path. For the receive path
is the PGA implemented with the FPGA?

Why on the usrp_basic.h there are 2 functions for set_pga(), pga_min(),
pga_max()? The maximum gain for 1 is 0dB and for the other it is 20dB
and the minimum gain is -20db and 0db?


> But with Python when you call subdev.gain_range(), the minimum value
is
> 0 and the maximum value is 90. Is it the same? With Python it is just
a
> different representation?

> There's additional gain available on the daughterboard.  We give you a
> single knob that adjusts both values.

What is the unit?

Thank you