This is one of the other great DHTs I received from Vegard Winge for tracing.
Here are the curves and the SPICE model: 864 DHT Composite
The SPICE composite model based on Dmitry’s:
**** 864 VT-24 DHT Composite ******************************************
* Created on 03/16/2013 19:30 using paint_kit.jar
* www.bartola.co.uk/valves
* Curves image file: 864 SMALL.jpg
* Data source link: 864 SMALL.jpg
* Created by Ale Moglia valves@bartola.co.uk
*----------------------------------------------------------------------------------
.SUBCKT TRIODE_864-Composite 1 2 3 4 ; Plate Grid K1 K2
+ PARAMS: CCG=2.3P CGP=5.3P CCP=1.3P
+ MU=7.14 KG1=13560 KP=98
+ KVB=1.88 VCT=-0.07 EX=1.41 RGI=2000
* Vp_MAX=200 Ip_MAX=0.008
* Vg_step=2 Vg_start=0 Vg_count=11
* END PARAMS -----------------------------------------------------------------------
* cathode resistor is 4.4 ohm, the pins K1 and K2 are 1.1 ohms from the ends of it
RFIL_LEFT 3 31 1.1
RFIL_RIGHT 4 41 1.1
RFIL_MIDDLE 31 41 2.2
E11 32 0 VALUE={V(1,31)/KP*LOG(1+EXP(KP*(1/MU+V(2,31)/SQRT(KVB+V(1,31)*V(1,31)))))}
E12 42 0 VALUE={V(1,41)/KP*LOG(1+EXP(KP*(1/MU+V(2,41)/SQRT(KVB+V(1,41)*V(1,41)))))}
RE11 32 0 1G
RE12 42 0 1G
G11 1 31 VALUE={(PWR(V(32),EX)+PWRS(V(32),EX))/(2*KG1)}
G12 1 41 VALUE={(PWR(V(42),EX)+PWRS(V(42),EX))/(2*KG1)}
RCP1 1 3 1G
RCP2 1 4 1G
C1 2 3 {CCG} ; CATHODE-GRID
C2 2 1 {CGP} ; GRID=PLATE
C3 1 3 {CCP} ; CATHODE-PLATE
D3 5 3 DX ; FOR GRID CURRENT
D4 6 4 DX ; FOR GRID CURRENT
RG1 2 5 {RGI} ; FOR GRID CURRENT
RG2 2 6 {RGI} ; FOR GRID CURRENT
.MODEL DX D(IS=1N RS=1 CJO=10PF TT=1N)
.ENDS
*$
Hope this is useful…
Ale