This circuit was found in a documentation of the 80s, having didactic purpose. For R1 values between 10k to 1M can be used. Transistors are general purpose types.
This circuit is from a 1992 Electronics Handbook. The circuit generates a special tone effect for...
This FM receiver tuning step circuit was found in a 1960 documentation. No information about the...
This circuit was obtained in an English magazine from 1979, but it can be easily assembled with...