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 circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms...
Placed near a telegraphic transmitter (CW) and with a small antenna or pickup, it reproduces the...
We found this filter in the 1990 Motorola Linear Databook, but it can be implemented with other...