The AWUS036H connected to the R36 auto-adjusts output power by connection quality.
The R36 shows a number from 1 to 100 in the setup screens: This number does not refer to the AWUS036H power output – rather it is for the R36’s radio. This means that there is no way for the user to control power output from the AWUS036H — it is adjusted up and down by the firmware to suit conditions.
Therefore, a power amplifier could not safely be added to increase range. (However, an input amplifier could be added to increase receive sensitivity.)