Prof R. Jennison wrote:

Go for the biggest loop with the highest Q that you can get
73.
Roger G2AJV

Agreed.  The fundamental parameter is APERTURE.  The number of turns is
really a sort of impedance matching arrangement, especially if a high
impedance tuned load is used.  But in the end it is SQUARE METRES of
loop area that does the basic receiving.

In ZL we have found that the minimum sized loop that can still receive
with external QRN as the dominant noise source is for a loop with about
1.5 metres per side i.e. just over 2 square metres area.  That is for
180 kHz.  Smaller area than that gets dominated by noise in the
receiving pre-amplifier.

Bob ZL2CA