This FM receiver tuning step circuit was found in a 1960 documentation. No information about the coils is given, but the FI used at the time was 10.8 MHz.
The circuit shown below is from the National Semiconductor's 1994 Linear Applications Handbook. The...
This metronome was found in a 1979 publication, but it can be assembled more easily with the BC548...
This circuit for a maximum current of 1 A is the most common version that uses the 78 and 7905...