Version 4 SHEET 1 3088 1688 WIRE 1888 896 1792 896 WIRE 2000 896 1888 896 WIRE 1792 912 1792 896 WIRE 2000 912 2000 896 WIRE 1888 928 1888 896 WIRE 2000 1008 2000 992 WIRE 2064 1008 2000 1008 WIRE 2160 1008 2128 1008 WIRE 2240 1008 2160 1008 WIRE 1792 1024 1792 992 WIRE 2160 1024 2160 1008 WIRE 2000 1056 2000 1008 WIRE 1632 1104 1568 1104 WIRE 1808 1104 1712 1104 WIRE 1888 1104 1888 1008 WIRE 1888 1104 1872 1104 WIRE 1936 1104 1888 1104 WIRE 1568 1136 1568 1104 WIRE 2160 1136 2160 1104 WIRE 1888 1168 1888 1104 WIRE 2000 1184 2000 1152 WIRE 2096 1184 2000 1184 WIRE 2000 1200 2000 1184 WIRE 2096 1216 2096 1184 WIRE 1568 1248 1568 1216 WIRE 1888 1312 1888 1248 WIRE 2000 1312 2000 1280 WIRE 2096 1312 2096 1280 FLAG 1792 1024 0 FLAG 1568 1248 0 FLAG 2240 1008 OUT FLAG 2000 1312 0 FLAG 1888 1312 0 FLAG 2096 1312 0 FLAG 2160 1136 0 SYMBOL voltage 1792 896 R0 SYMATTR InstName V2 SYMATTR Value 15 SYMBOL voltage 1568 1120 R0 WINDOW 3 37 57 Left 2 WINDOW 123 24 104 Left 2 SYMATTR Value 0 SYMATTR Value2 AC 1 SYMATTR InstName V1 SYMBOL npn 1936 1056 R0 SYMATTR InstName Q1 SYMATTR Value 2N2222 SYMBOL res 1984 896 R0 SYMATTR InstName R3 SYMATTR Value 1K SYMBOL res 1984 1184 R0 SYMATTR InstName R5 SYMATTR Value 100 SYMBOL res 1872 912 R0 SYMATTR InstName R1 SYMATTR Value 75K SYMBOL res 1872 1152 R0 SYMATTR InstName R2 SYMATTR Value 10K SYMBOL cap 1872 1088 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value .1µ SYMBOL cap 2080 1216 R0 SYMATTR InstName C2 SYMATTR Value 10µ SYMBOL res 2144 1008 R0 SYMATTR InstName R4 SYMATTR Value 100K SYMBOL cap 2128 992 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 1µ SYMBOL res 1728 1088 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R6 SYMATTR Value 1K TEXT 1880 1360 Left 2 !.noise V(out) V1 oct 10 1K 100K TEXT 1536 1376 Left 2 ;To plot NF vs. Frequency:\n10*log10(V(inoise)*V(inoise)/(4*k*300.15*1K))\nNote that the units are dB but will be labeled V/sqrt(Hz)\nIf you add the line\n.func NF(R) 10*log10(V(inoise)*V(inoise)/(4*k*300.15*R))\nto your plot.defs file, then you can conveniently plot the quantity NF(1K) TEXT 1640 1272 Top 2 ;1K Source Impedance TEXT 1936 1544 Top 1 ;This example schematic is supplied for informational/educational purposes only. RECTANGLE Normal 1792 1328 1488 1056 2