Initially after having made the DSB transverter, I tried to measure output power with my HP432 power meter, which has a 10 GHz termistor mount with a N-connector. Results was very dissapointing, very little read-out. Not even enough for making a relative optimiztion.
When the need to measure increased after I had built the waveguide filter, so did my innovative spirit. I tried all sorts of SMA/N adapters, and indeed there was some difference in the still very mearger read-out. Until I tried a random BNC T-joint - whoops ! loads of readout. By turning the BNC joint around read-out could be optimized to at least aound -3 dB of what I believe to be the true reading.
I tried another BNC T-joint, with a different dielectricum, but no succes. Only this very cheap one will match the termistors at 24 GHz. Here is a photo of the setup. My morale: Never give up on old faithfull measuring equipment :-)