Version 4.1
SHEET 1 3068 2660
WIRE 2208 1952 2064 1952
WIRE 2064 1968 2064 1952
WIRE 2208 1968 2208 1952
WIRE 2064 2064 2064 2048
WIRE 2208 2064 2208 2048
WIRE 2304 2064 2208 2064
WIRE 1424 2080 1392 2080
WIRE 912 2128 880 2128
WIRE 1296 2128 912 2128
WIRE 1392 2128 1392 2080
WIRE 1392 2128 1376 2128
WIRE 1456 2128 1392 2128
WIRE 1520 2128 1456 2128
WIRE 1712 2128 1584 2128
WIRE 1920 2128 1712 2128
WIRE 2032 2128 1920 2128
WIRE 2080 2128 2032 2128
WIRE 2160 2128 2080 2128
WIRE 2032 2144 2032 2128
WIRE 1712 2160 1712 2128
WIRE 1920 2160 1920 2128
WIRE 1456 2176 1456 2128
WIRE 880 2208 880 2128
WIRE 2208 2208 2208 2160
WIRE 2304 2208 2208 2208
WIRE 2032 2224 2032 2208
WIRE 2096 2224 2032 2224
WIRE 2112 2224 2096 2224
WIRE 2208 2224 2208 2208
WIRE 2208 2224 2176 2224
WIRE 2032 2240 2032 2224
WIRE 2208 2240 2208 2224
WIRE 1456 2272 1456 2240
WIRE 1712 2272 1712 2224
WIRE 1920 2272 1920 2240
WIRE 880 2336 880 2288
WIRE 2032 2336 2032 2304
WIRE 2208 2336 2208 2320
WIRE 880 2464 880 2416
WIRE 880 2592 880 2544
FLAG 1920 2272 0
FLAG 2032 2336 0
FLAG 2208 2336 0
FLAG 2064 2064 0
FLAG 1712 2272 0
FLAG 2304 2064 drain
FLAG 2304 2208 source
FLAG 2080 2128 gate
FLAG 2096 2224 fb
FLAG 1456 2272 0
FLAG 880 2592 0
FLAG 1424 2080 varactor_bias
FLAG 912 2128 staircase_voltage
SYMBOL NJF 2160 2064 R0
SYMATTR InstName Q1
SYMATTR Value 2N5484
SYMBOL RES 2192 1952 R0
SYMATTR InstName R1
SYMATTR Value 500
SYMBOL res 2192 2224 R0
SYMATTR InstName R2
SYMATTR Value 1K
SYMBOL ind 1936 2256 R180
WINDOW 0 3 79 Right 2
WINDOW 3 1 40 Right 2
SYMATTR InstName L1
SYMATTR Value 100µ
SYMBOL cap 2016 2144 R0
SYMATTR InstName C1
SYMATTR Value 500p
SYMBOL cap 2016 2240 R0
SYMATTR InstName C2
SYMATTR Value 500p
SYMBOL cap 2176 2208 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C3
SYMATTR Value 200p
SYMBOL VOLTAGE 2064 1952 R0
SYMATTR InstName V1
SYMATTR Value 7.
SYMBOL diode 1696 2224 M180
WINDOW 0 24 72 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL varactor 1472 2240 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D2
SYMATTR Value KV1471
SYMBOL cap 1584 2112 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C4
SYMATTR Value 1.5n
SYMBOL voltage 880 2448 R0
SYMATTR InstName V2
SYMATTR Value 2V
SYMBOL res 1392 2112 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 60k
SYMBOL voltage 880 2320 R0
WINDOW 3 -109 107 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PULSE(0 1 20m 1u 1u 1 2)
SYMATTR InstName V3
SYMBOL voltage 880 2192 R0
WINDOW 3 -120 116 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PULSE(0 1 40m 1u 1u 1 2)
SYMATTR InstName V4
TEXT 1840 2456 Left 2 !.tran 0 60m 1m 10n startup
TEXT 1840 2488 Left 2 !.options method=trap
TEXT 1208 1944 Left 2 ;using a KV1471 varactor diode\n35pF at 1V dc bias\n6.5pf at 5V dc bias
TEXT 768 1952 Left 2 ;this block creates\na staircase voltage\nat 2V, 3V, and 4V.
TEXT 736 1184 Left 2 ;click on run\nthen click on "staircase_voltage" to plot it.\nthen click on the plot window then on plot settings / add plot pane\nthen click on "varactor_bias" to plot it\nthen click on the plot window and plot settings/add plot pane\nthen click on "source" to plot it\nlet the sim finish before taking the FFTs specified below.\n \nthen click on the plot window, then on View/FFT\nthen click on "source" , then specify a time range as 12ms to 18ms, and click OK.\nin the FFT window that opens zoom in on the peak and measure its freq. should be about 0.997Mhz\nif you click on the "Vsource" text title in the FFT window it opens a measurement curser.\n \nthen click on the plot window, then on View/FFT\nthen click on "source" , then specify a time range as 30ms to 36ms, and click OK.\nin the FFT window that opens zoom in on the peak and measure its freq. should be about 1.009Mhz\n \n \nthen click on the plot window, then on View/FFT\nthen click on "source" , then specify a time range as 52ms to 58ms, and click OK.\nin the FFT window that opens zoom in on the peak and measure its freq. should be about 1.016Mhz
TEXT 1128 1832 Left 2 ;R3 and C4 are neccessary to bias the varactor diode\nhowever the values of R3 and C4 form a low pass filter\nand must be chosen to allow audio frequencies through.\nAlso too low a value of R3 stops the oscillation.
TEXT 1152 1800 Left 4 ;Varactor diode circuit
TEXT 768 1888 Left 4 ;Staircase circuit
TEXT 1992 1848 Left 4 ;Colpits oscillator
TEXT 936 1088 Left 5 ;Colpits osc FM, staircase voltage input.
RECTANGLE Normal 1024 2656 688 1920 2
RECTANGLE Normal 1776 2368 1104 1824 2
RECTANGLE Normal 2464 2384 1872 1872 2