Very approximately -

To compare one loop with another, at a given frequency, the receiving
sensitivity of small loops is very simply proportional to the area enclosed
and tends to decrease as the number of turns.

Best to use very thick wire with a single turn loop (as with magloops) and a
tuning capacitor to suit. Multi-turn loops are used ONLY because of
availability of paractical sizes of tuning capacitors.

With a multi-turn ferrite rod antenna of given dimensions, sensitivity
increases roughy proportional to the permeability of the core material but
decreases according to loss in the core. Permeabilty increases the
effective area enclosed. So use an HF core material - not one intended for
VLF power transformers.

Ferrite rod receiving antennas appear to do very well ONLY because medium
and long-wave broadcast transmitters are generally high power. They are high
power because of the poor sensitivity of very small (in comparison with a
wavelength) receiving antennas.
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Reg.