The digital data amplifiers (DDA's) were located on level 3 of the MSCB. There were four rows of DDA's, one for each antenna face. Each row contained 5,000 drive-amplifier cards, one for each antenna element (phase shifter).
The drive-amplifier cards processed the 4 bit words computed by the BSC to generate the forward and reverse bias for the phase shifter diodes to provide electronic beam steering.