We found this circuit in the 1989 Radio Electronics Experimenter. The circuit uses common components, and the thermistor is supposed to determine the value of the trim potentiometer.
This circuit decodes a 1800 Hz tone used in communications. The circuit is from an American...
These two circuits were found in Radio Electronics magazine from February 1960. The transistor is a power...
With the development and availability of small LCD screens for automotive use, especially in...