This signal injector and tracer (follower) was found in an old American documentation. The transistors can be general use and power is made with one or two common cells.
This configuration is from a 1964 US documentation valid for any FET. The range of power voltages...
The operational amplifier used in this circuit from a 1970s publication is no longer easily found...
This circuit was found in an old American documentation. It can operate with signals from 40 Hz to...