A report on Radio masts and towers and Electrical length

During the first 20 years of radio, long distance radio stations used long wavelengths in the very low frequency band, so even the tallest antennas were electrically short and had very low radiation resistance of 5-25 Ohms, causing excessive power losses in the ground system.

Because those radio waves are several hundred meters to many kilometers long, mast radiators of the necessary height cannot be realised economically.