A 40 dB attenuator project by Hartmut DK5LH.
Hartmut uses the attenuator to measure the power of his transmitter (2 watts) with a power meter for -80 dBm to -10 dBm
The attenuator is used to reduce the output power of the set to a value that is less than 0.1 milliwatt. (-10 dBm)
More details at PA1B’s QRPp blog.