Version 4
SHEET 1 880 680
WIRE -144 128 -144 96
WIRE -144 304 -144 208
WIRE -64 208 -64 192
WIRE -64 304 -144 304
WIRE -64 304 -64 288
WIRE -16 304 -64 304
WIRE -16 304 -16 160
WIRE 0 160 -16 160
WIRE 0 192 -64 192
WIRE 16 304 -16 304
WIRE 16 304 16 240
WIRE 16 320 16 304
WIRE 48 96 -144 96
WIRE 48 112 48 96
WIRE 144 176 96 176
WIRE 144 192 144 176
WIRE 144 304 16 304
WIRE 144 304 144 272
FLAG 16 320 0
SYMBOL voltage -144 112 R0
WINDOW 0 -16 57 Left 0
SYMATTR InstName Vp
SYMATTR Value 250
SYMBOL voltage -64 192 R0
WINDOW 0 -18 61 Left 0
SYMATTR InstName Vg1
SYMATTR Value 0
SYMBOL voltage 144 176 R0
WINDOW 0 -19 60 Left 0
SYMATTR InstName Vg2
SYMATTR Value 0
SYMBOL Misc\\pentode 48 176 R0
SYMATTR InstName U1
SYMATTR SpiceModel EL34Pent
TEXT -160 360 Left 0 !.dc Vg1 0 -50 10 Vg2 250 400 50