We found this circuit in a Radio Electronics from December 1963. The circuit combines valves and transistors and has a high input resistance. The circuit is powered by two batteries.
In the figure we have the typical configuration of a sinusoidal audio oscillator with twin-T. The...
This circuit was found in a 1969 US documentation. It provides a signal that can be externally...
We found this adapter in a 1970s American documentation on instrumentation. It is suitable for analog...