.SUBCKT EL84 A S G K
*
* Calculate contribution to cathode current
*
Eat             at              0               VALUE={0.636*ATAN(V(A,K)/15)}
Egs             gs              0               VALUE={LIMIT(V(S,K)/19+V(G,K)+V(A,K)/1400,0,1E6)}
Egs2            gs2             0               VALUE={PWRS(V(gs),1.5)}
Ecath           cc              0               VALUE={V(gs2)*V(at)}
*
* Calculate anode current
*
Ga              A               K               VALUE={3.2E-3*V(cc)}
*
* Calculate screen current
*
Escrn           sc              0               VALUE={V(gs2)*(1.1-V(at))}
Gs              S               K               VALUE={2.0E-3*V(sc)*LIMIT(V(S,K),0,10)/10}
*
* Grid current (approximation - does not model low va/vs)
*
Gg              G               K               VALUE={PWR(LIMIT(V(G,K)+1,0,1E6),1.5)*50E-6}
*
* Capacitances
*
Cg1             G               K               10.8p
Cak             A               K               6.5p
Cg1a            G               A               0.5p
 
.ENDS