This circuit was found in an American documentation from the 1980s. The sensitivity ranges from 100 mV to 1 V. The supply must be done with an excellent filtering source.
This circuit was obtained in a Electronics World of 1968. The transistors can be equivalent as the BC558...
This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an...
This converter has coils according to the reception and converted frequency bands. We found it in...