The circuit shown in the figure below is from the 1993 Linear Technology Applications. The operational ones used are uncommon and the use of equivalents can be analyzed.
We find this vibrato configuration with transistors in a 1987 documentation. The components are still...
One 4018 is used to divide the frequency of a digital signal by ten as shown here. The maximum...
This filter for receiving audio in telegraphy was found in a magazine 73 for radio amateurs, in an...