Greetings,
I have never used a schematic capture program before and I am just getting back into electronics after many years, so I'm a bit rusty. Please bear with me.
I am trying to simulate a low-power transmitter in the 3.5 MHz range in LTSpice. I would like to look at a plot of the emissions at ANT to see what my frequency output looks Like. Effectively, a frequency spectrum plot. I understand I should use an FFT plot after running a transient simulation, but I seem to be having no luck.
I'm at a loss as to whether my schematic is faulty, I don't understand how to properly use LTSpice or both. In particular, I wonder if I have configured the crystal properly (a colorburst crystal) and whether I need a 50 Ohm load instead of the ANT output?
Any insight would be appreciated, and I thank you in advance.
My LTSpice circuit follows:
----- snip 3.5MHZ xmtr.asc -----
Version 4 SHEET 1 892 680 WIRE 96 144 48 144 WIRE -16 144 -16 208 WIRE -80 272 -80 288 WIRE -80 288 -16 288 WIRE -80 208 -16 208 WIRE -16 288 -16 336 WIRE 48 224 48 144 WIRE 48 144 -16 144 WIRE 48 304 48 400 WIRE 48 400 336 400 WIRE 112 240 112 224 WIRE 112 224 160 224 WIRE 160 192 160 224 WIRE 160 224 192 224 WIRE 192 288 192 320 WIRE 192 320 112 320 WIRE 112 320 112 336 WIRE 48 144 48 32 WIRE 112 32 144 32 WIRE 160 96 208 96 WIRE 432 400 464 400 WIRE 464 400 464 416 WIRE 256 128 256 96 WIRE 256 96 336 96 WIRE 432 96 464 96 WIRE 336 128 336 96 WIRE 336 96 368 96 WIRE 336 208 336 400 WIRE 336 400 368 400 WIRE 336 400 336 448 WIRE 256 192 256 336 WIRE 288 448 336 448 WIRE 208 448 160 448 WIRE 160 448 160 464 WIRE 208 32 208 96 WIRE 208 96 256 96 WIRE 464 96 464 16 WIRE 464 16 560 16 FLAG -16 336 0 FLAG 112 336 0 FLAG 464 416 0 FLAG 256 336 0 FLAG 160 464 0 FLAG 560 16 ANT IOPIN 560 16 Out SYMBOL polcap -96 208 R0 WINDOW 3 24 64 Left 0 SYMATTR Value 33µ SYMATTR InstName C1 SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=10 Irms=60m Rser=2.3 MTBF=1000 Lser=0 mfg="Nichicon" pn="UPR1A330MAH" type="Al electrolytic" ppPkg=1 SYMBOL res -32 192 R0 SYMATTR InstName R1 SYMATTR Value 5.6k SYMBOL res 32 208 R0 SYMATTR InstName R2 SYMATTR Value 15k SYMBOL res 96 224 R0 SYMATTR InstName R3 SYMATTR Value 470 SYMBOL npn 96 96 R0 SYMATTR InstName Q1 SYMATTR Value 2N2222 SYMBOL Misc\xtal 112 16 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C3 SYMATTR Value 3.56169600e-014 SYMATTR SpiceLine Rser=3.56169600e-014 Lser=0.0555779237 Cpar=8.90424001e-012 SYMBOL ind 320 112 R0 SYMATTR InstName L1 SYMATTR Value 2.5µh SYMATTR SpiceLine Ipk=1 SYMBOL voltage 304 448 R90 WINDOW 0 -32 56 VBottom 0 WINDOW 3 32 56 VTop 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 9 SYMBOL polcap 144 48 R270 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C4 SYMATTR Value 0.01µ SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=10 Irms=60m Rser=2.3 MTBF=1000 Lser=0 ppPkg=1 SYMBOL polcap 176 224 R0 WINDOW 3 24 64 Left 0 SYMATTR Value 0.01µ SYMATTR InstName C2 SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=10 Irms=60m Rser=2.3 MTBF=1000 Lser=0 ppPkg=1 SYMBOL polcap 240 128 R0 WINDOW 3 24 64 Left 0 SYMATTR Value 100µ SYMATTR InstName C5 SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=10 Irms=60m Rser=2.3 MTBF=1000 Lser=0 ppPkg=1 SYMBOL polcap 368 112 R270 WINDOW 3 24 64 Left 0 SYMATTR Value 100µ SYMATTR InstName C6 SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=10 Irms=60m Rser=2.3 MTBF=1000 Lser=0 ppPkg=1 SYMBOL polcap 368 416 R270 WINDOW 3 24 64 Left 0 SYMATTR Value 0.01µ SYMATTR InstName C7 SYMATTR Description Capacitor SYMATTR Type cap SYMATTR SpiceLine V=10 Irms=60m Rser=2.3 MTBF=1000 Lser=0 ppPkg=1 TEXT -98 514 Left 0 !.tran 0 10m 0 startup TEXT -128 464 Left 0 !.option plotwinsize=0
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