Here is the schematic for the power supply section on the PA Board of the Xiegu G90 transceiver.
The board is marked "G90-BASEBD-V2.0.7-GAI01" and contain:
-Power supply section with EMI filter, reverse voltage protection, electronic power switch, linear regulators for 9V (LM2940-9.0) and 5V (LM7805).
-Dir/Ref RF power bridge
-Antenna Matching Unit (ATU).
Here is the schematic for the power supply section (for high resolution click on image then right click and "save as"):
NOTE: There is an error in the diagram; will be corrected soon. The voltage divider R3/R4 is connected to the main V+ and not to the 9V rail.
Most probably, there is an error in the resistor values, the resistive divider most probably is connected to the ADC input of the main MCU for Battery voltage indicator. Thanks Jake G1YFF for this pertinent observation!