The cascode configuration boosts the main Colpitts BJT’s output resistance to present a higher QL to the resonator. Better quality oscillators often run higher QL to isolate the tank from transistor variations and/or to reduce phase noise and possibly some temperature (frequency) drift.
Above — RF board built with 100% Classic Ugly Construction.
Above — RF section prior to wiring up the pots plus switch. More bolts were added later.
