If you massage this old bus-terminator speeder-upper negative capacitance idea:
into a Clapp oscillator topology you get the Negative Cap Clapp which sounds like a very bad type of venereal disease to get.
It makes even low-Q coils ring just set the R looking into the negative C about equal to the ESR, make the positive parallel capacitance slightly larger than the equivalent negative and watch it rip.
It tends to be finicky with component choices though and likes to head for the rails or bounce around at low frequency if you pick "bad" ones due to the lack of a DC feedback path between points A, and B at the lower op-amp output; it's not obvious to me how to improve that and suggestions are appreciated
Version 4 SHEET 1 1940 2228 WIRE 1488 -320 1488 -368 WIRE 608 -304 608 -368 WIRE 608 -304 -176 -304 WIRE 992 -304 608 -304 WIRE 1456 -304 992 -304 WIRE 1712 -288 1520 -288 WIRE 1824 -288 1712 -288 WIRE 1456 -272 1328 -272 WIRE 1488 -208 1488 -256 WIRE 992 -144 992 -304 WIRE -176 -80 -176 -304 WIRE -704 -64 -704 -96 WIRE -496 -64 -496 -96 WIRE 608 0 608 -304 WIRE -704 64 -704 16 WIRE -496 64 -496 16 WIRE 992 112 992 -64 WIRE -176 176 -176 0 WIRE 608 320 608 64 WIRE 976 320 608 320 WIRE 1328 320 1328 -272 WIRE 1328 320 1056 320 WIRE 1712 320 1712 -288 WIRE 1712 320 1328 320 WIRE -176 432 -176 256 WIRE -176 432 -464 432 WIRE 48 432 -176 432 WIRE 304 432 112 432 WIRE 64 688 64 672 WIRE 608 688 608 320 WIRE -464 704 -464 432 WIRE -176 704 -176 432 WIRE 32 704 -176 704 WIRE 304 720 304 432 WIRE 304 720 96 720 WIRE 32 736 -176 736 WIRE 64 784 64 752 WIRE -176 960 -176 736 WIRE 32 960 -176 960 WIRE 304 960 304 720 WIRE 304 960 112 960 WIRE 416 960 304 960 WIRE -176 1104 -176 960 WIRE -464 1312 -464 768 WIRE -176 1312 -176 1184 WIRE 608 1328 608 752 FLAG -496 -96 VCC FLAG -496 64 0 FLAG -704 64 0 FLAG -704 -96 VEE FLAG 608 1328 0 FLAG 1488 -208 VCC FLAG 64 784 VCC FLAG 64 672 VEE FLAG 992 112 0 FLAG -176 1312 0 FLAG 1488 -368 VEE FLAG -464 1312 0 FLAG 608 -368 A FLAG 416 960 B FLAG 1824 -288 OUT IOPIN 1824 -288 Out SYMBOL voltage -496 -80 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value 5 SYMBOL voltage -704 -80 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value -5 SYMBOL res 128 944 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R7 SYMATTR Value 10k SYMBOL ind -160 16 R180 WINDOW 0 36 80 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName L2
SYMATTR SpiceLine Rser=25 SYMBOL cap 592 0 R0 SYMATTR InstName C5 SYMATTR Value 47n SYMBOL cap 592 688 R0 SYMATTR InstName C6 SYMATTR Value 47n SYMBOL res 1072 304 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 1k SYMBOL res 976 -160 R0 SYMATTR InstName R5 SYMATTR Value 100k SYMBOL res -192 1088 R0 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL cap 112 416 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value 10n SYMBOL Opamps\\AD8034 64 784 M180 SYMATTR InstName U7 SYMBOL Opamps\\AD8034 1488 -224 M180 SYMATTR InstName U3 SYMBOL cap -480 704 R0 SYMATTR InstName C7 SYMATTR Value 11n SYMBOL res -160 272 R180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R9 SYMATTR Value 25 TEXT -704 160 Left 2 !.tran 100m startup uic