We found this circuit in a 1977 factory documentation. The operational amplifiers can be 741 and the symmetrical power supply. Capacitors can be changed for operation at other frequencies.
This highly-sensitive circuit causes a relay to be closed when the other is open or still...
The coil is formed by 70 + 5 turns of 6 to 30 AWG wire on a 1 cm to 10 cm ferrite core. The...
This mixer with amplification stage has two inputs, but it can be expanded. The input impedance is high...