Can i make some conclusions by looking at IV dynamic locus shape?
I can not understand what you want to mean at all.
but oscillator have very "distorted huge circle" IV curve...
What analysis do you use ?
If you use Transient Analysis, (Vload, Iload) include higher harmonics. Here you can not use constant value reactance such as Zload=70+j*4.
See
https://www.edaboard.com/threads/202948/#4
On the other hand, you can plot (Vload, Iload) locus regarding single frequency, if you use Large Signal Steady State Analsis.
Here you can use constant value reactance such as Zload=70+j*4.
Show me your (Vload, Iload) locus.
If someone interested in drawing AC load line, i tried it in SpeqMath and superimposed on Transient analysis curve (biasing as in S53MV's bfp420 VCO, but AC is blocked for biasing resistors):
........................................................
f2(x) is AC load line. x is vce. Curve is almost exact match to transient simulation!
I think it is correct, but not sure.
What simulator do you use ?
You can plot (Vload, Iload) locus very easily, if you use Keysight ADS, Keysight GoldenGate, Synopsys HspiceRF, Mentor eldoRF, AWR MicrowaveOffice, Ansoft Designer, Nexxim, Cadence Spectre, etc.