Version 4
SHEET 1 880 680
WIRE 320 0 176 0
WIRE 448 0 320 0
WIRE 320 16 320 0
WIRE 176 96 176 80
WIRE 176 96 112 96
WIRE 176 112 176 96
WIRE 320 128 320 96
WIRE 320 128 256 128
WIRE 320 144 320 128
WIRE 48 160 48 96
WIRE 80 160 48 160
WIRE 128 160 112 160
WIRE 256 176 256 128
WIRE 256 176 224 176
WIRE -16 192 -64 192
WIRE 80 192 80 160
WIRE 80 192 64 192
WIRE 128 192 80 192
WIRE -64 208 -64 192
WIRE 448 208 448 0
WIRE 320 240 320 208
WIRE 320 240 272 240
WIRE 320 256 320 240
WIRE 112 288 112 160
WIRE 272 288 272 240
WIRE 272 288 112 288
WIRE -64 336 -64 288
WIRE 144 336 144 240
WIRE 144 336 -64 336
WIRE 320 336 144 336
WIRE 448 336 448 288
WIRE 448 336 320 336
SYMBOL res 80 176 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R1
SYMATTR Value 470k
SYMBOL res 192 96 R180
WINDOW 0 36 76 Left 0
WINDOW 3 36 40 Left 0
SYMATTR InstName R2
SYMATTR Value 82k
SYMBOL res 336 112 R180
WINDOW 0 36 76 Left 0
WINDOW 3 36 40 Left 0
SYMATTR InstName R3
SYMATTR Value 47k
SYMBOL res 336 352 R180
WINDOW 0 36 76 Left 0
WINDOW 3 36 40 Left 0
SYMATTR InstName R4
SYMATTR Value 180k
SYMBOL Misc\\pentode 176 176 R0
SYMATTR InstName U1
SYMATTR Value Pentode
SYMBOL voltage -64 192 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 50
SYMBOL voltage 448 192 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 300
SYMBOL cap 304 144 R0
SYMATTR InstName C1
SYMATTR Value 10nF
SYMBOL cap 112 80 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C2
SYMATTR Value 47nF
TEXT -98 346 Left 0 !.tran 0.1