Purchased "broken-down" (for part) at the Ham-Expo 2022 show.

Failure observed: the 2 SD1407 power transistors are burnt out (SWR, input power or temperature too high?).

Improvements made: replacement with 2 MRF422s + optimization of the ventilation system.

Addition of a "minimum filtering" solution (but serious): EMI mains filter + HF low-pass filter.

These types of "wideband" transistor amplifiers are not equipped with band-pass filters.

Followed by a small matte black varnish finish.