Complex sentence: One was that by varying the turns ratio, the impedance of the antenna could be matched to the impedance of the receiver, to transfer maximum RF power to the receiver, vitally important to achieve adequate receiving range in the unamplified receivers of this era.
Split into simpler sentences: One was that by varying the turns ratio, the impedance of the antenna could be matched to the impedance of the receiver, to transfer maximum RF power to the receiver. This was vitally important to achieve maximum receiving range in the unamplified receivers of this era.