This symmetric 30 mA x 15 V power supply was found in the Ferranti transistor manual from 1974. Transistors are common types at the time.
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...