The DGS-65 contains an air-erected directional gyro and the compass electronics required to provide both digital and analog (synchro) heading data for either electromechanical or electronic horizontal situation indicators (HSI), radio magnetic indicators (RMI), course indicators, and digital autopilots. The DGS-65 can be used in the Collins MCS-65 Magnetic Compass System. The directional gyro provides the compass electronics with incremental heading angle data. The gyro assembly is enclosed in a pressure sealed container that is secured, through vibration isolators, to the gyro base. The gyro is a 2-gimbal gyro with a 2-phase induction spin motor. Air-erection is used to maintain inner and outer gimbals in a mutually perpendicular position.

The gyro spin motor operates on a 400-Hz, 2-phase, ±26.5 V, tristate motor drive signal. The spin motor drive signal is generated in the compass electronics, enters the gyro assembly at connector J302/P302, passes through the encoder card, and is applied to the spin motor. The spin motor has a runup time between 1.5 to 2.5 minutes. The rundown time is between 3.8 to 9.5 minutes. The gyro flex card contains connector J302 which interfaces the compass electronics to the gyro assembly. The encoder contains two phototransistors and two LED's. The compass electronic supply 12 VDC to the LED's and 5 VDC to the phototransistors. The LED's and phototransistors are separated by a slotted disk attached to the gyro. As the slotted disk rotates, the LED light beams are broken, causing the phototransistors to switch on and off. The phase between the phototransistors determines the direction of rotation. The number of pulses from the phototransistors determines the angular change.

The compass electronics control the slaving between the directional gyro assembly and Collins FDU-70 Flux Detector Unit, then output synchro and serial digital heading signals. The compass electronics consist of five circuit cards which are enclosed within the gyro base. The DGS-65 is mounted on a surface perpendicular to aircraft yaw axis within 1 degree. The DGS-65 is convection cooled with a height of 5.410 in., width of 6.026 in., length of 9.500 in. and weighs 5.6 pounds. The DGS-65 has ±2 degrees of local magnetic heading accuracy with a max altitude of 55,000 feet. The DGS-65 allows for 6G operational shock and 15G crash safety shock.