Using the 7B92 in a 7704 is akin to stuffing a Ferrari engine in a Chevy
pickup. Looks and runs nice, but ...
Whereas it is true that the 7B92A is good to 500ps/div and the 7704A is only
specced at 2ns/div, there is absolutely no reason that the combination
should not work just fine. I find the 7704A is still pretty darned good to
1ns/div.
And yes - I generally use the 7B92A in either my 7904 or 7834, but the
question was asked about whether it would work in the 7704A - and the answer
is yes it does.
Cheers
Craig