Found in the CQ radio amateur magazine, this circuit generates a standard 100 kHz signal. The circuit is from 1965 and can be made with modern equivalent transistors.
This circuit was found in a 1986 publication. The speed of the effect is determined by the 555,...
This preamp version uses BC109 transistors that are older versions of the current BC549 in plastic...
This simple voltage-controlled oscillator generates signals from 300 Hz to 1,500 Hz with voltages from...