* SPICE netlist
M1 N007 N008 0 0 2N7002
Q1 N001 N004 N006 0 2N5087
R1 mosfet_output N007 60R
R2 N001 mosfet_output 180R
R3 N004 mosfet_output 150R
R4 N008 0 600R
R5 N006 video_output 150R
R6 video_output 0 150R
V1 N001 0 5
R7 mosfet_output 0 800R
V2 N002 0 SINE(0 5 3580000)
D1 N003 N008 D
R8 N003 N002 330R
D2 N005 N008 D
R9 N001 N005 1200R
M2 N009 N010 0 0 2N7002
R10 video_output N009 15R
R11 N010 0 600R
R12 N002 colorburst 2400R
R13 colorburst 0 800R
R16 video_output 0 75R
M3 N011 N012 0 0 2N7002
R17 N012 0 1K
R18 mosfet_output N011 150R
.tran 0 .000003s 0s .00000001s

* LTspice schematic (.asc)
Version 4.1
SHEET 1 1904 1632
WIRE 88 -816 -424 -816
WIRE 248 -816 88 -816
WIRE 248 -752 248 -816
WIRE 88 -640 88 -816
WIRE 88 -640 -248 -640
WIRE 248 -624 248 -672
WIRE -248 -576 -248 -640
WIRE -424 -560 -424 -816
WIRE -840 -480 -952 -480
WIRE -760 -480 -840 -480
WIRE -504 -480 -680 -480
WIRE 88 -480 88 -640
WIRE -248 -432 -248 -496
WIRE -152 -432 -248 -432
WIRE -120 -432 -152 -432
WIRE 24 -432 -40 -432
WIRE -424 -416 -424 -480
WIRE -840 -384 -840 -400
WIRE -248 -384 -248 -432
WIRE -504 -368 -504 -480
WIRE -840 -352 -840 -384
WIRE -152 -352 -152 -432
WIRE -120 -352 -152 -352
WIRE 88 -272 88 -384
WIRE -840 -256 -840 -272
WIRE -248 -256 -248 -304
WIRE 952 -224 408 -224
WIRE -952 -208 -952 -480
WIRE -504 -176 -504 -304
WIRE -424 -176 -424 -352
WIRE -424 -176 -504 -176
WIRE -296 -176 -424 -176
WIRE 88 -160 88 -192
WIRE 408 -160 408 -224
WIRE 408 -160 88 -160
WIRE -504 -112 -504 -176
WIRE 88 -112 88 -160
WIRE 952 -112 952 -224
WIRE -952 32 -952 -128
WIRE -504 80 -504 -32
WIRE -248 80 -248 -160
WIRE 88 80 88 -32
WIRE 408 80 408 -160
WIRE -120 240 -120 -352
WIRE -120 240 -328 240
WIRE 408 384 408 160
WIRE -328 448 -328 240
WIRE -120 448 -120 240
WIRE 360 464 264 464
WIRE 264 480 264 464
WIRE 408 560 408 480
WIRE -328 576 -328 528
WIRE 264 624 264 560
WIRE -376 656 -520 656
WIRE -520 688 -520 656
WIRE -328 752 -328 672
WIRE -120 752 -120 528
WIRE -520 816 -520 768
FLAG 248 -624 0
FLAG 88 80 0
FLAG -248 80 0
FLAG -504 80 0
FLAG -120 752 0
FLAG -952 32 0
FLAG 88 -160 video_output
FLAG -248 -432 mosfet_output
FLAG 408 560 0
FLAG 264 624 0
FLAG -840 -384 colorburst
FLAG -840 -256 0
FLAG 952 -32 0
FLAG -328 752 0
FLAG -520 816 0
SYMBOL nmos -296 -256 R0
SYMATTR InstName M1
SYMATTR Value 2N7002
SYMBOL pnp 24 -480 R0
SYMATTR InstName Q1
SYMATTR Value 2N5087
SYMBOL res -264 -400 R0
SYMATTR InstName R1
SYMATTR Value 60R
SYMBOL res -264 -592 R0
SYMATTR InstName R2
SYMATTR Value 180R
SYMBOL res -24 -448 R90
SYMATTR InstName R3
SYMATTR Value 150R
SYMBOL res -520 -128 R0
SYMATTR InstName R4
SYMATTR Value 600R
SYMBOL res 72 -288 R0
SYMATTR InstName R5
SYMATTR Value 150R
SYMBOL res 72 -128 R0
SYMATTR InstName R6
SYMATTR Value 150R
SYMBOL voltage 248 -768 R0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL res -136 432 R0
SYMATTR InstName R7
SYMATTR Value 800R
SYMBOL voltage -952 -224 R0
SYMATTR InstName V2
SYMATTR Value SINE(0 5 3580000)
SYMBOL diode -520 -368 R0
SYMATTR InstName D1
SYMBOL res -664 -496 R90
SYMATTR InstName R8
SYMATTR Value 330R
SYMBOL diode -440 -416 R0
SYMATTR InstName D2
SYMBOL res -440 -576 R0
SYMATTR InstName R9
SYMATTR Value 1200R
SYMBOL nmos 360 384 R0
SYMATTR InstName M2
SYMATTR Value 2N7002
SYMBOL res 392 64 R0
SYMATTR InstName R10
SYMATTR Value 15R
SYMBOL res 248 464 R0
SYMATTR InstName R11
SYMATTR Value 600R
SYMBOL res -856 -496 R0
SYMATTR InstName R12
SYMATTR Value 2400R
SYMBOL res -856 -368 R0
SYMATTR InstName R13
SYMATTR Value 800R
SYMBOL res 936 -128 R0
SYMATTR InstName R16
SYMATTR Value 75R
SYMBOL nmos -376 576 R0
SYMATTR InstName M3
SYMATTR Value 2N7002
SYMBOL res -536 672 R0
SYMATTR InstName R17
SYMATTR Value 1K
SYMBOL res -344 432 R0
SYMATTR InstName R18
SYMATTR Value 150R