The results you are measuring are certainly within the range of the
MFJ 259. As an example: a 493 ft dipole, 50 ft above an average
ground shows anti-resonance, at 1.9 MHz, and is 15,000 ohms.

Frank

Frank, that is twice that you have mentioned dipoleas a comparison.
May I remind you again that for equilibrium purposes the radiator
must be a wavelength or multiple there of, assuming ofcourse we are
considering a single radiator
To talk of a "dipole" when considering my design is totally
unreasonable.
Regards
Art

But that is the typical input impedance of a one wavelength long
antenna (15,000 ohms).

Frank