One may expect as low as 30 ohms for the Low Zcm case and as high as
some thousand ohms for the High Zcm one. The first figure (32 ohms) presents
in Ted's "Instructions for building an L Tee Network Dipole" as a radiation
resistance. The second figure (2368 ohms) is used by Lloyd Butler in his
theory. Both figures are right, each for its case. In a practical installation
where there is no true ground connection, almost any impedance can be observed.
However a high-Q circuits formed by a top half of the EH dipole and a coil
usually has a high characteristic resistance (Rho=SQRT(L/C)). As a result,
only a relatively small frequency detuning (where VSWR=1) is measured when
an antenna connected to its feeder.
Some more feeder layouts are summarized on the next picture.
It seems like the main reason of lack of repeatibility and the main unknown in EH antennas is their common mode feeder impedance.