This is the receiver for the previous circuit found in the November 1991 Radio Electronics magazine. The frequency is 2.2 MHz determined by the coils.
This configuration was obtained in a 1977 FET Databook. The circuit can be practically any JFET...
The integrated circuit used in this regulator is not very common today. The circuit is from old...
The operational used is uncommon today, but equivalents can be used. Unlike the previous one, this...