I was poring over a HW-9 schematic already.

Very cool, cept it's anything but broad range: doubler/tripler, mixers,
LOs, all sorts of acrobatics that cut down the number of components but
make the whole more inflexible.

Right now I am thinking about using:

- a signal generator

- 1 driver and 2 or 3 massively derated finals in parallel, all AB
class or so, with broadband RF transformers, i/o at 50 ohm or so

- perhaps a bit of negative feedback

- putting all the filtering at the end, such as 3 tank circuits with
3-section VC + pi network; doing so would possibly simplify the
mechanics of providing effective shielding.