The purpose of this circuit is to measure the resistance of an antenna at the resonant frequency. The circuit is from an old American documentation for hams.
This VFO (Variable Frequency Oscillator ) has the output frequency controlled by a potentiometer....
This well-crafted speed game setup for two competitors was found in a 1998 Poptronics. The circuit...
To obtain more output power from an operational amplifier, we can use a transistor, as shown in...