There's not a darned thing wrong with using a 7B53A in a 7704 or
7704A. It's the 7B92/A that you can't easily use on lower bandwidth
scopes only because they can't handle the faster sweeps. And 7B53A's
are so plentiful that they should be cheap. Having to come up with
and pay for a pair of 7B7x or 7B8x is a lot more difficult and
expensive -- and you'll need two service manuals instead of one. And
the 7B53A leaves a horizontal compartment free for a counter or DMM.
