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The base impedance of a 3-meter x 1/4″ OD Part 15 AM antenna is about 0.12 -j2900 ohms at 1700 kHz, and about 0.01 -j9000 ohms at 540 kHz.
Antenna system radiation efficiency is a function of the radiation resistance of the antenna compared to the other resistances in the antenna system (mostly in the r-f ground plane and the loading coil). The 1700 kHz antenna has over 10X the radiation resistance of the 540 kHz antenna. Radiation resistance is the first number appearing in the base impedance values above (ie, 0.12 or 0.01 ohms). The coil loss needed to resonate the 1700 kHz radiator can be significantly less, also, because its input reactance is about 2/3 less than on 540 kHz.
The end result is that the radiation efficiency of these two systems at resonance will greatly favor the 1700 kHz system.