switcher wrote:

The loop is 2 x 3 meter of PVC tube, bended in a circle.
There are now 3 turns. Guess ... how many turns to have the LW
153-279khz ???

If 3 turns resonated with about 11000 pF (your 10 nF plus about 1 nF
from the tuning capacitor) produces a resonance within that band, then
raising the turns to about 9 (3 times as much for about 3^2 times as
much inductance) would resonate at the same frequency with about 1/9th
as much capacitance (same L*C product). Of course, those extra turns
will also add quite a bit of stray capacitance between turns, so you
may not be able to reach the top of the band at minimum tuning
capacitance.

What kind of insulation is on the wire in the big loop? Its thickness
and dielectric constant have a big effect on the total stray
capacitance each turn will add.