RADAR DATA DISTRIBUTION Table 3-1.—The MODE SELECTOR Switch Functions SWITCHBOARD (RDDS)

the sweep counters in the display console at the same rate. The output of the sweep counters is continuously fed to the deflection circuitry, and the beam will be deflected at 45 degrees. Figure 3-3 shows the front panel of a typical RAC. The RACs installed on your ship may not look exactly like this one. On this particular RAC panel, internal testing is accomplished by using the MODE SELECTOR switch. Most RACs have a similar MODE SELECTOR switch that operates in the same basic manner. When the MODE SELECTOR switch is in the OPERATE position, the RAC operates with its radar. The other switch positions of the front panel are used for maintenance and troubleshooting as shown in table 3-1. The RACs are combined together into a cabinet or cabinets called the radar azimuth converter group. The cabinets provide a common power supply and mountings for several RACs. The output of the RACs are fed to the radar data distribution switchboards (RDDSs). RADAR DATA DISTRIBUTION Table 3-1.—The MODE SELECTOR Switch Functions SWITCHBOARD (RDDS) signals (video levels) directly from each sensor. The radar data distribution switchboard (RDDS) The RDDS provides the display consoles access to routes radar and sonar antenna position data and all the sensors connected to the switchboard. The timing signals from the sensor RACs to the display RDDS can accept inputs from 11 radar or sonar consoles. It also receives up to four separate video sensors and provide outputs to display consoles on 10 output channels, one standard display console per Figure 3-3.—A typical RAC front panel. 3-4