The field regulators, outlined in red in the notional high voltage generating circuit diagram below, are shown with the handles in the positions found in the wreck. The settings show that an extra amount of field resistance was applied to increase the speed of the motor, while the alternator had a bit less resistance than normal applied to help bring the alternator voltage back up. Basically, it appears that the Marconi operators were trying to wring more power for the transmitted spark from the decreasing power supplied by the ship’s generating sets.