Also posted to LTSpice Yahoo Group:
This oscillator is "inter-modulated" by SINE voltage V2, even though the latter is not connected! Is this due to rounding errors in the solver? Is there any way to reduce the effect?
TIA
Version 4 SHEET 1 2732 740 WIRE 528 -320 352 -320 WIRE 608 -320 528 -320 WIRE 800 -320 688 -320 WIRE 992 -320 896 -320 WIRE 1168 -320 1072 -320 WIRE 352 -288 352 -320 WIRE 800 -288 736 -288 WIRE 960 -288 896 -288 WIRE 1168 -272 1168 -320 WIRE 528 -256 528 -320 WIRE 304 -224 240 -224 WIRE 240 -176 240 -224 WIRE 736 -160 736 -288 WIRE 960 -160 960 -288 WIRE 1168 -160 1168 -192 WIRE 352 -144 352 -192 WIRE 528 -144 528 -192 WIRE 528 -144 352 -144 WIRE 528 -96 528 -144 WIRE 528 0 528 -32 WIRE 624 0 528 0 WIRE 752 0 704 0 WIRE 1072 0 816 0 WIRE 352 16 352 -144 WIRE 1072 32 1072 0 WIRE 528 48 528 0 WIRE 752 64 752 0 WIRE 352 160 352 96 WIRE 528 160 528 112 WIRE 1072 160 1072 112 FLAG 1168 -160 0 FLAG 352 160 0 FLAG 240 -176 0 FLAG 736 -160 0 FLAG 960 -160 0 FLAG 528 160 0 FLAG 1072 160 0 FLAG 752 64 0 SYMBOL voltage 1168 -288 M0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 10 SYMBOL res 720 -16 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R2 SYMATTR Value 50 SYMBOL tline 848 -304 M0 SYMATTR InstName T1 SYMATTR Value Td=2n Z0=50 SYMBOL cap 544 -256 M0 SYMATTR InstName C1 SYMATTR Value 10p SYMBOL cap 544 -96 M0 SYMATTR InstName C2 SYMATTR Value 33p SYMBOL cap 544 48 M0 SYMATTR InstName C3 SYMATTR Value 33p SYMBOL res 368 0 M0 SYMATTR InstName R4 SYMATTR Value 220 SYMBOL voltage 1072 16 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value SINE(0 1e-6 105e6) SYMBOL njf 304 -288 R0 SYMATTR InstName J1 SYMATTR Value 2N3819 SYMBOL res 704 -336 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R1 SYMATTR Value 0.1 SYMBOL res 1088 -336 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R3 SYMATTR Value 0.1 TEXT 784 -88 Left 0 !.tran 30u