This circuit was obtained in an English magazine of 1976 and can be assembled with equivalent transistors such as BF245 for FETs and BC557 for bipolar PNP. In the complete circuit, we have several scales selected by a key.

This circuit was obtained in an English magazine of 1976 and can be assembled with equivalent transistors such as BF245 for FETs and BC557 for bipolar PNP. In the complete circuit, we have several scales selected by a key.