This zero-crossing switch circuit was found in documentation from the 1990s. GE's PA424 is the main element of the circuit, uncommon today.
Found in a 90s Popular Electronics, this circuit is intended for amplifying analog video signals....
This antenna amplifier or booster for receivers from 100 kHz to 30 MHz was published in a...
This somewhat complex circuit was found in the May 1984 issue of Radio Electronics magazine. The...