Found in a 303 Circuits from the 90s, this circuit converts signals from the 10 kHz to 150 kHz band to the 4.01 to 4.15 MHz band.
This preamp with a transistor for turntables with crystal capsules was found in a Japanese...
This variable frequency oscillator generates signals that have a recurrence frequency determined by...
This circuit with neon lamp and unijunction was found in the September 1970 Radio Electronics...