This circuit, based on a 555, was found in a Popular Electronics from the 90s. The circuit has the frequency determined by R1, R2 and C1.
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...