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.
This circuit is an excellent shield for microcontrollers and was found in the October 1987 Radio...
We found this circuit in a 1981 publication, when it was still possible to find 22.5 V batteries (used...
This grid-dip meter was found in a 1956 documentation from Sylvania. It can be implemented with...