These circuits were found in the February 1995 issue of Electronics Now magazine. The circuits have normal response in (a), boost in (b), cut in (c), and plate response in (d).
This 1992 circuit operates in the range of cordless phones used at the time. The circuit is based...
This different circuit uses a relay as an oscillator, whose frequency is determined by C1, and to...
This antenna or booster amplifier operates with signals from the midband (MW) range up to the VHF...