Found on a 1969 EDN this circuit switches a current from a digital control signal. The impedance of the circuit ON is approximately 10 ohms. Modern equivalent transistors may be used.
This circuit was found in an American 80's documentation. The transistor is of germanium of the...
This circuit produces a signal in the range corresponding the the VHH channels between 2 and 6....
Using a general-purpose transistor this AC amplifier was found in the November 1993 issue of...