241. The position of the PPI scope sweep must indicate the position of the antenna. The sweep and antenna positions are frequently kept in synchronization by the use of:

Synchro systems are specifically designed to transmit and repeat angular position, ensuring the PPI sweep aligns with the antenna bearing. This synchronization is crucial for accurate bearing readings on a PPI display, as synchro systems electrically transmit shaft angle/position between the antenna and the indicator. Other options, such as servo systems, DC motors, and differential amplifiers, lack the precise angular-position synchronization capability of synchro systems.