Well, here you go!
Unfortunately I don't quite have all the bits available to do this properly, but I did the following:
HP 8922S in CW (signal generator) mode.
Rigol DS1102E with 10x probe and ground spring, stuck in the 8922S IF output port. Equivalent time was used, though there seems to be a bug in my Rigol where stopping acquisition (to save the waveform image) reverts to normal acquisition mode. This completely messed up the 433 MHz reading, so I took a photograph instead.
Signal generator set to -10 dBm at 100, 200, 300, and 433 MHz.
So yes! You should be able to see something, even with some pretty horrible mismatches, and as long as you use equivalent time sampling and your signal has a CW carrier.