How to parametrisize the existing transformer for LTSpice (Simple approach)

What we can simply measure::

1. R₁ -- the resistance of the primary winding L₁
2. R₂ -- the resistance of the 2-ndary winding L₂
3. U₁ -- the voltage on input terminals (of the winding L₁ the same as R₁)
4. U₂ -- the voltage on output terminals (of the winding L₂(R₂))
5. I₁ -- the current through L₁

What we can compute is::

6. I₂ -- the current through L₂ the I₂ = I_RTEST = U₂ / R_TEST

7. the inductance of the winding L₁ is derived from::
Z₁ = U₁ / I₁ = ²√(X₁² + R₁²) , where Z₁ is impedance of L₁ , X₁ is X_L1
thus X₁ = ²√(Z₁² - R₁²)
and L₁ = X₁ / (2·Pi·f) , where Pi = Arg(-1) , f = grid's frequency (50Hz/60Hz)

8. the inductance of the winding L₂ is derived from::
η · P₁ = P₂ or η · U₁² / Z₁ = U₂² / Z₂ , where η is transformer's efficiency
so Z₂ = 1 / η · Z₁ · (U₂ / U₁)² we don't know the η so we assume η = 1
when we measured U₂ we can compute the L₂ 's value as we did for the L₁

What we can't estimate is::

9. η = ?::
by running the simulation in 'Spice that reproduces the experiment shown on the
above figure (assuming a set of R_TEST -s was used) we can statistically find the
best (statistically least erroneous) R_TEST instances and (by these) re-tune the
L₂ value for simulation

so the actual η = P₂ / P₁ or η = (U₂ / U₁)² · (Z₁ / Z₂) but we don'no' it unless we
measure the L₂ value in real

NB! as the title suggest we get the L₂'s value fo 'Spice simulation.
The value for real-life η (for that transformer) is not found nor used --- why?
B-coz  simulating with η = 1 ** is tremendously faster and less prone to
"Timestep too small" errors.

(((( i hope the 'bove article is readable ))))

note !
there are four x2 conceptually different L₂ values
L₂ -- generic (not strictly specified)
L₂ -- computable by measured U₂ value
L₂ -- the real life value (it's difficult to measure it with decent precision)
L₂ -- the value derived from re-produced 'Spice experiment

x2 -- the L is the name of the winding(coil) also the name of the variable
for it's inductance -- so in 1-st case the L.index points to L.L.index and R.L.index
in 2-nd case the L.index is L.L.index while R.index is assumed to be R.L.index
(clear as soapy water)

[End of the TEST post]

here's how to apply:: ((((~)%/~=)(&%="~)(&%"~=)?&%" V^^^V chchchch  - ok it works now))))

update 16 jan MMXIV 7:13