This circuit uses two diodes in a doubling configuration to receive medium-wave range signals. The phone is crystal. We found it in a 1968 American documentation.
This traditional high sensitivity voltmeter circuit using a FET can employ the MPF102 or BF245 in its...
This noise limiter for low intensity signals was found in a 73 magazine for radio amateurs from the...
This circuit is from a 1976 documentation. It provides a pulsating DC voltage that can be varied...