\begin{circuitikz}
	\draw(0,0) node[njfet,yscale=-1] (fet) {};
	\draw(fet.gate) |- (fet.drain);
	\draw(fet.source) to [vR, l_=Decade Box, mirror] ++(0,2)
	to [short] ++(1,0)
	to [ammeter] ++(0,-2) node[] (end) {};
	\draw(fet.drain) to [short] ++(1,0)
	to [V, l_=\SI{16}{\volt}DC \& \SI{32}{\volt}DC] ++(0, 2)
	to [short] ($(end)$);
	\draw (fet.gate) node[anchor=north east] {2N5459};
\end{circuitikz}

\begin{circuitikz}
	\draw(0,0) node[njfet,yscale=-1] (fet) {};
	\draw(fet.gate) |- (fet.drain);
	\draw(fet.source) to [vR, l_=Param\{RD\}, mirror] ++(0,2)
	to [short] ++(1,0)
	to [ammeter] ++(0,-2) node[] (end) {};
	\draw(fet.drain) to [short] ++(1,0)
	to [V, l_=\SI{16}{\volt}DC \& \SI{32}{\volt}DC] ++(0, 2)
	to [short] ($(end)$);
	\draw (fet.gate) node[anchor=north east] {2N5459};
\end{circuitikz}

Change 'decade box' to 'Param{RD}' to match PSpice
Change 'decade box' to 'Param{RD}' to match PSpice
