[robert casey]

* 7719 triode Spice 3F4 model mu=25, Gm = 3500, Rp = 7100 pinout looks
like a twin triode (like a 12AU7) except with both cathodes, grids, and
plates shorted together, respectively.
..SUBCKT X7719 P G K

Bp P K
I=(0.02155032103/1.0e3)*uramp(V(P,K)*ln(1.0+(-0.02409617047)+exp((4.11077476)+(4.11077476)*((29. 68431589)+(-226.3229273/1.0e3)*V(G,K))*V(G,K)/sqrt((4.564710556e-006)^
2+(V(P,K)-(5.978004682))^ 2)))/(4.11077476))^ (1.625508506)

Cgk G K 1.1P
Cgp G P 5.5P
Cpk P K 0.8P

..ends X7719


More at
http://home.netcom.com/~wb2jia/tubes/spice4.txt