This circuit for signals up to 30 MHz can improve your reception in the medium and short-wave band. We found it in the Radio Electronics magazine of February 1989.
This power source, obtained in a 1973 publication, suggests the use of partially burned germanium...
This circuit was obtained from an Electronic Design from 1964. Transistors admit modern...
The circuit is from the 1994 National Semiconductor Linear Applications Handbook but can be...