No, I realise that the output of the NRF24L01 itself is set to 0dBm/1mW when you use setPALevel(RF24_PA_MAX).
setPALevel(0) should be the same as setPALevel(RF24_PA_MIN), i.e. -18dBm.
Whats more confusing is what the RF24.h file says;
* Set Power Amplifier (PA) level to one of four levels:
* RF24_PA_MIN, RF24_PA_LOW, RF24_PA_HIGH and RF24_PA_MAX
* The power levels correspond to the following output levels respectively:
* NRF24L01: -18dBm, -12dBm,-6dBM, and 0dBm, lnaEnable affects modules with LNA
* SI24R1: -6dBm, 0dBm, 3dBm and 7dBm with lnaEnable = 1
* -12dBm,-4dBm, 1dBm and 4dBm with lnaEnable = 0
* @param level Desired PA level.
* @param lnaEnable En/Disable LNA Gain
But then my +PA+LNA devices dont use the SI24R1 but the AT2401C.
I would measure it, but I dont have a Spectrum anlyser or Power meter that is fast enough to pick up even the longest NRF24L01 packet.