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.
This circuit was found in the November 1993 issue of Electronics Now magazine. The two-stage...
This circuit acts on a relay disconnecting the load when the input voltage exceeds the set limit....
This circuit is from a Radio Electronics from March 1970. The integrated circuit used is one of...