The sensor used in this circuit is uncommon today, however equivalent types can be tried. The comparator also supports modern equivalents. The circuit is from 80's documentation.
Based on 4066 CMOS, we found this circuit in a Popular Electronics from 1992. The signal is...
This receiver of two transistors for the 3.5 MHz band was found in a circuit manual from the 80's....
This circuit uses an unusual Motorola integrated. The circuit is from Motorola's 1990 Linear...