This high impedance step suggested by an English publication can operate up to 1 MHz with 1 V rms output. Input impedance is 1 M ohm.
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...