Using an integrated circuit from the time, this circuit was found in Radio Electronics from the 90s. The ZNA234E is an unusual component today.
This simple expandable circuit was obtained from a Popular Electronics from the 80's. The supply...
The frequency of the LC resonant circuit must be the same as that of the crystal and the JFET...
This circuit was obtained in a Popular Electronics of 1991. The magazine no longer exists, but the...