Hi Zack,
Your description of the RPM of the SAQ Alexanderson
alternator rotation speed reflects a fundamental misunderstanding
of the principles of operation of the Alexanderson alternator.
The motor in the SAQ Alexanderson alternator operates at 720 RPM
which then feeds a speed increaser gearbox that increases the RPM
feeding to rotor to 2700 RPM. The operating frequency feeding the
antenna is the product of 2700 RPM rotator rotation speed and
the number of magnetic poles in the rotor.
The rotor has no conductive windings or electrical connections;
it consists of a solid disc of high tensile strength magnetic steel,
with narrow slots cut in its circumference to create a series of
narrow "teeth" that function as magnetic poles.
This is an excellent technical description of the Alexanderson
alternator.
https://www.navy-radio.com/xmtrs/vlf/alexanderson-mayes-1975.pdf
This is a superb video of the very complex process
of preparing the SAQ alternator for on the air transmission.
73
Frank
W3LPL