We found this circuit in a 1957 Raytheon transistor publication. The circuit can be assembled with more modern transistors with minor changes. The handset must be high impedance magnetic.
Using two of the 4 NAND gates of the integrated 4001, the circuit in the figure activates the...
This traditional 3-channel mixer configuration with FET appears elsewhere on this site. The FET...
This circuit was obtained in an old American manual. The circuit is valid for any operational. The...