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.
In the figure we give a simple divisor by 2. The complementary output (Q /) is connected to input...
This circuit is from a Modern Electronics from April 1990. The circuit can be assembled with BC558...
This configuration found in GE documentation from the 90s, can also be seen elsewhere in this...