[Davidsteam]

I've not yet seen any Data sheets for these items, but as suggested, can work out the individual switch connections, I guess the 'C' and 'S' being the CW and SSB connections.

I'm guessing, if I feed white noise into a filter, and put an audio spectrum analyser on the output, I will get the typical graphical response curve?

Much easier to use a couple of smartphones instead of manually plotting spot frequencies and measuring levels with a dB meter and drawing a graph. I remember doing this in the telecommunications world almost 40 years ago to check audio responses in equipment.

David