The continuous maximum input power of the 20 dB attenuator is 1.5 W and 1.7 W for the 10 dB attenuator, with resistors or ½ watt. This power will be doubled with 1 W resistors.
Because the attenuator of 10 dB and 20 dB can be switched independently, they are both designed for about the same maximum input power. Each attenuator must have a switch, so the attenuators can be switched ”on” or ”off” at any moment, for instance for tuning.
The power attenuators are asymmetrical. The input of the attenuator is connected to the set and the output to the tuner. Input and output of asymmetrical attenuators, should not be reversed.