This circuit has visual and audible status indication using an oscillator. The circuit is from a Radio Electronics magazine from June 1991.
The frequency of this transmitter depends on the coil. For 100 turns the operation is in medium...
This circuit was found in an Argentine Radio Escuela Gráfica magazine published in the 1970s. The...
This circuit generates low-frequency sinusoidal signals. The variable capacitor is dual and the...