This circuit from a 1967 documentation generates 2.5 Hz signals depending on the capacitors used, in this case 160 uF. For 4 6700 pF the signal will be 20 kHz.
This receiver was obtained in a documentation from the 90's and is of the super-regenerative type....
This circuit couples 600-ohm signals to a line of the same impedance consisting of an amplifier stage....
The circuit presented is from an old magazine having been translated and published in a national...