% Author: Dr. Matthias Jung
% Year: 2022
\begin{circuitikz}
    \draw(0,0) 
        to [american inductor] ++(0,2)
        to [short,-*] ++(1,0) node[antenna](){}
        to [short,-*] ++(1,0) coordinate(c2)
        to [variable capacitor,invert, tunable end arrow={Triangle},-*] ++(0,-2) coordinate(c3)
        to [short,-*] ++(-1,0)
        node[ground](gnd){}
        to [short] ++(-1,0);
    \draw(c2)
        to [stroke diode] ++(3,0)
        to [loudspeaker, l={\qty{2,7}{\kilo\ohm}}] ++(0,-2)
        to [short] (c3);
\end{circuitikz}