**** GU-72 ******************************************
* Created on 07/24/2022 12:21 using paint_kip.jar
* www.dmitrynizh.com/tubeparams_image.htm
* Plate Curves image file: gu72-p.png
* Data source link: <plate curves URL>
*----------------------------------------------------------------------------------
.SUBCKT GU-72 P G2 G K ; LTSpice tetrode.asy pinout
* .SUBCKT GU-72 P G K G2 ; Koren Pentode Pspice pinout
+ PARAMS: MU=10.04 KG1=23352.68 KP=24.31 KVB=0.648 VCT=15.39 EX=2.229 KG2=69520 KNEE=2.469 KVC=1.617
+ KLAM=8.778E-10 KLAMG=2.33E-6 KNEE2=19.61 KNEX=2654.21 KNK=0.1399 KNG=1.934E-6 KNPL=0.2261 KNSL=0.3432 KNPR=154.24 KNSR=173.04
+ CCG=37P CGP=0.1P CCP=10P VGOFF=-44 IGA=9.03 IGB=0.005243 IGC=542.36 IGEX=0.6588
* Vp_MAX=1500 Ip_MAX=1500 Vg_step=20 Vg_start=15 Vg_count=12
* X_MIN=93 Y_MIN=32 X_SIZE=719 Y_SIZE=544 FSZ_X=1296 FSZ_Y=736 XYGrid=true
* Rp=1400 Vg_ac=20 P_max=84 Vg_qui=-95 Vp_qui=300
* showLoadLine=n showIp=y isDHP=n isPP=n isAsymPP=n isUL=n showDissipLimit=y
* showIg1=y isInputSnapped=y addLocalNFB=n
* XYProjections=n harmonicPlot=y dissipPlot=n
* UL=0.43 EG2=300 gridLevel2=y addKink=y isTanhKnee=y advSigmoid=n
*----------------------------------------------------------------------------------
RE1 7 0 1G ; DUMMY SO NODE 7 HAS 2 CONNECTIONS
E1 7 0 VALUE= ; E1 BREAKS UP LONG EQUATION FOR G1.
+{V(G2,K)/KP*LOG(1+EXP((1/MU+(VCT+V(G,K))/SQRT(KVB+V(G2,K)*V(G2,K)))*KP))}
RE2 6 0 1G ; DUMMY SO NODE 6 HAS 2 CONNECTIONS
E2 6 0 VALUE={(PWR(V(7),EX)+PWRS(V(7),EX))} ; Kg1 times KIT current
RE21 21 0 1
E21 21 0 VALUE={V(6)/KG1*ATAN((V(P,K)+KNEX)/KNEE)*TANH(V(P,K)/KNEE2)} ; Ip with knee but no slope and no kink
RE22 22 0 1 ; E22: kink curr deviation for plate
E22 22 0 VALUE={V(21)*LIMIT(KNK-V(G,K)*KNG,0,0.3)*(-ATAN((V(P,K)-KNPL)/KNSL)+ATAN((V(P,K)-KNPR)/KNSR))}
G1 P K VALUE={V(21)*(1+KLAMG*V(P,K))+KLAM*V(P,K) + V(22)}
* Alexander Gurskii screen current, see audioXpress 2/2011, with slope and kink added
RE43 43 K 1G ; Dummy
E43 43 G2 VALUE={0} ; Dummy
G2 43 K VALUE={V(6)/KG2*(KVC-ATAN((V(P,K)+KNEX)/KNEE)*TANH(V(P,K)/KNEE2))/(1+KLAMG*V(P,K))-V(22)}
RCP P K 1G ; FOR CONVERGENCE
C1 K G {CCG} ; CATHODE-GRID 1
C2 G P {CGP} ; GRID 1-PLATE
C3 K P {CCP} ; CATHODE-PLATE
RE23 G 0 1G
GG G K VALUE={(IGA+IGB/(IGC+V(P,K)))*(MU/KG1)*
+(PWR(V(G,K)-VGOFF,IGEX)+PWRS(V(G,K)-VGOFF,IGEX))}
.ENDS
*$