The radar's Coupling Data Units (CDU), which provided the interface between the radar's hardware and the LM's onboard guidance computer, were powered by a 28-volt 800 Hz power supply, and a separate 28-volt 800 Hz power supply sent energy to the radar's Attitude, Translation, and Control assembly (ATCA) (which physically oriented the Lunar Module). The two power supplies were supposed to operate in phase lock with each other. However, likely due to inexact language in the LM's design documentation, the system was constructed such that while the two power supplies would always operate at the same "frequency" and in a fixed phase relationship, no provision was made to ensure the two supplies were aligned and putting out the "same phase" at the same time.