This circuit from the 1980s uses an operational amplifier that is uncommon today. The circuit can be designed with modern operators. The gain is 40 dB.
This circuit for monitoring telegraphy transmissions was found in a 1975 CQ magazine. Transistors may be...
The integrated circuit used in this application is like the 555. The components depend on the...
The circuit presented is a simple MW tuner that can be plugged into the input of any audio...