using the Tektronix 7934 pretty much showed me the same thing, NOTHING when i switched to FM mode.
video here
https://www.youtube.com/watch?v=v2Esh0rI8SY
started in AM , tuned up and down, then changed to FM, then set scope to what SHOULD be able to see it on the screen, then switched back and forth from AM/FM and phono.
it's just not working at FM frequency for some reason will have to see what a new tube does.
AND, just to prove that the scope CAN see that high, i grabbed my eico 324 rf signal generator and set it to 95 MHz, and fed it in.
https://i.imgur.com/5aVnrpy.jpg
in the meantime I may try feeding the output from the Eico into it to see what happens.