With this circuit, signals in the range of 10 kHz to 150 kHz can be received at close to 4 MHz from a shortwave receiver. The circuit is from a 303 Circuits from the 90s.
We found this circuit in a 1960 Sylvania transistor manual. The relay can be 12 V and C1...
The basic siren configuration shown in figure 1 activates a piezoelectric transducer and can be...
One flip-flop of the 4018 can be used as a frequency divider or counter as shown here. Frequency...