This third-order filter was found in a 1975 publication. The circuit must be powered by a symmetrical source. The components can be changed for operation on other frequencies.
The purpose of this simple stabilized source, obtained in a documentation from the 70s, is to...
This simple receiver for listening on a crystal phone tunes the range of medium waves. The circuit...
This medium- or short-wave receiver circuit was found in documentation from the 1980s. The circuit...