Found in a 90’s Popular Electronics, this circuit uses two CMOS inverters to generate a signal of a few hundred hertz determined by C1 and the R3 setting.
This 1956 direct amplification radio circuit was found in a documentation from Sylvania that...
This conventional oscillator with the 741 can be precisely adjusted to produce a 400 Hz signal. The...
This circuit uses two diodes in a doubling configuration to receive medium-wave range signals. The...