This variable frequency oscillator for radio transmission covers the range from 1.6 MHz to 20 MHz, depending only on the coil used. The circuit is very stable and can be used in amateur equipment.
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...