% Author: Stephan Kregel, DG1HXJ
% Year: 2022
\begin{circuitikz}
    \ctikzset{
        resistors/scale=\getDarcImageFactor,
        capacitors/scale=\getDarcImageFactor,
        inductors/scale=\getDarcImageFactor,
        transistors/scale=\getDarcImageFactor
    }
    \coordinate(init) at (0,0);
    \draw (init)++(3,0)
        node[npn, name=T1, tr circle] {};
    \draw (init) ++(7,-1.5)
        node[npn, name=T2, tr circle] {};
    \draw (init) 
        node[ocirc, name=b]{} 
        to [PZ, o-] ++(0,-2) coordinate(c1a)
        to [vC, tunable end arrow={Bar},invert, o-] ++(0,-2) -- ++(1.5,0) coordinate(c2a) 
        to [C, *-*] ++(0,2) coordinate(c2b)
        to [C, -*] ++(0,2) coordinate(c3b)
        to [R, -*] ++(0,3) coordinate(r1b) -- ++(-1.5,0)
        to [C] ++(0,-1) to node[rground]{} ++(0,0);
    \draw (b)
        -- (c3b)
        -- (T1.B);
    \draw (c2a)
        -- ++(1.5,0) coordinate(r2a)
        to [R, *-*] ++(0,2) coordinate(r2b) -- ++(0,0.5) 
        node[ocirc, name=c4a]{}
        to [C, o-*] ++(2,0) coordinate(c4b);
    \draw (c4b)
        -- ++(0,-0.5)
        to [R, -*] ++(0,-2) coordinate(r3b);
    \draw (c2b) -- (r2b);
    \draw (r2a)
        node[rground]{};
    \draw (r2a) -- ++(2,0);
    \draw (c4a) -- (T1.E);
    \draw (r1b) -- ++(1.5,0) coordinate(l1a);

    \draw (T1.C) to [short,-*] (l1a);
    \draw (c4b)
        -- ++(0,1.5)
        to [R, -*] ++(2,0) coordinate(r4b)
        -- (T2.C);
    \draw (c4b) -- (T2.B);
    \draw (r3b)
        -- ++(1,0) coordinate(c5a)
        to [C, *-] ++(0,1.5) coordinate(c5b);
    \draw (c5a)
        -- ++(1,0) coordinate(r5a)
        to [R, *-*] ++(0,1.5) coordinate(r5b) -- (T2.E);
    \draw (c5b) -- (r5b);
   
    \draw (r4b) 
    to [C] ++(2,0) coordinate(c5b)
    to node[ocirc, name=out]{} ++(0,0);
    
    \draw (r5a) -- ++(2,0)
    to node[ocirc, name=gnd]{} ++(0,0);

    \draw (r4b) 
        to [R] ++(0,3) coordinate(r5b)
        to [american inductor, *-, name={myL}] ++(2,0) coordinate(l1b)
        to node[ocirc, name=vcc]{} ++(0,0);
    \draw [dashed] (myL.core west) -- (myL.core east);
    \draw (l1a) -- (r5b);
    
    \draw (gnd) node[anchor=north]{--};
    \draw (vcc) node[anchor=south]{+};
    
    \draw (out) node[anchor=south]{\textbf{4}};
    \draw (c4a) node[anchor=east]{\textbf{3}};
    \draw (b)   node[anchor=east]{\textbf{2}};
    \draw (c1a) node[anchor=east]{\textbf{1}};
\end{circuitikz}