This is the Sylvania UHF varactor tuner that had an active (bipolar) mixer. As best I can work out, it arrived for the 1971 model year range:
And here was its companion VHF varactor tuner:
That had a dual-gate mosfet RF amplifier and a cascode bipolar mixer. UHF IF input was to the VHF mixer.
I think that the dual-gate mosfet RF amplifier plus cascode bipolar mixer combination was also used by Heathkit for its early 1970s VHF tuners.
Cheers,