[Premium-Rx] What's in a WJ-8716 front end preselector?

[Tim Shoppa]

I've got a WJ-8716 that has a front end preselector in it. It's a big
metal box with obvious coax in, coax out, and some presumably digital
and power wiring going into it too.

I'm familiar with, say, the R-390A's front end preselection: a bunch
of octave-wide tunable LC narrow filters, with mechanical coupling
between the main tuning and the slugs that tune the L's. Pretty
nifty and perfectly obvious to me how iwoks.

Is this how a WJ-8716 preselector works too? Are there little motors
moving slugs up and down inside as I tune, and banks of slugs
for each octave? Or does it work on some entirely different mechanism?

Tim N3QE