This circuit was found in documentation for radio amateurs of the 1980s. This is the so-called roger-beep, which is the beep that is transmitted when the talk-listen function is changed.
Found in American documentation from the 1990s, this circuit generates signals in the 350 to 500...
This instrument was obtained in a documentation for radio amateurs of 1976. The circuit measures...
This circuit was suggested by Motorola in 1980s documentation. The circuit employs an operational of...