This simple receiver of two transistors for the 80-meter range was found in an American documentation from the 1980s. The transistors admit equivalents and the antenna must be long.
With this circuit it is possible to divide the frequency of a rectangular signal by values between 2...
This circuit, which we find in a documentation from the 70s, filters out the Ru [occurring in...
This circuit simulates the call tone of a telephone. The transducer is a high impedance capsule, and...