This receiver was found in a Japanese publication in 1967. The circuit uses germanium transistors and details of the coils are not given. Power is supplied by a 9 V battery.
Found in a documentation from the 90s, this circuit has a typical accuracy of 2% with 20 V signals at...
This circuit was obtained from an English publication from 1977. The integrated circuit is a...
The configuration shown was found in an old American manual. The circuit can be made with modern...