This circuit for medium and short wave range was found in an American documentation from 1992. The circuit can use general purpose transistors and the antenna can be external or telescopic.
In this circuit of a 1968 publication the unijunction may be 2N2646 and the transistor BC548. The...
The purpose of this circuit is to improve a trigger circuit using a zener diode. The circuit was...
This interesting circuit of the American publication Electronics Handbook Volume XIII 1993 shows a...