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 page shows a crystal oscillator for 2 MHz. Other frequencies can be produced depending on the...
This circuit is from a 1970 publication. The time constant is given by 1.3R x C where R is the...
The supply voltage range of this circuit ranges from 4 to 20 V and the power depends on the chosen...