The commercial monitor scopes expect something fairly close to 50-75 ohms with reasonable reactance for the sampling port so I would put it before and not after the tuner. If you are running high power into a heavy mismatch the scope sampling network could easily see far more voltage than it can handle.
Rodger WQ9E
I also say BEFORE the tuna as well. On the output side, you will get the benefit (if you want to call it that) of the tuna's flywheel.... Might miss something you'd see on the input.
--Shane
