I can see that the XCVR2450 allows to set a TX gain from 0dB to 30dB.
I see in the XCVR2450 schematics that in the TX path path there is a MAXIM2829 chip (which has a programmable TX gain register from 0 to 64 value) and then a power amplifier which amplifies 25-30dB (depending on the frequency band). I also see in the firmware of the UHD that the value set in software (from 0 to 30 dB) is not split between the MAX chip gain and a IRM046U7 Power amplifier.
However I can see Ettus website that the XCVR2450 board in the transmit path has a gain of: VGA: 0-30 dB range BB: 0-5 dB range
Is VGA gain the gain of the power amplifier and BB gain is the gain of the MAXIM chip? How are these two values set from the overall gain set in software (0 - 30 dB) ? It is not detailed in the firmware code. I need to understand where the 0 to 30 dB gain is psychically placed in the XCVR2450 (MAXIM or power amplifier)