Plan view display modifications for the 9020 replacement system

The modifications that were made to a plan view display (PVD) which allowed it to be switched between the present National Airspace System and a future 9020 Replacement (9020R) System are described. A second PVD was also modified and used to simulate the outputs of the 9020R System. The outputs of the simulated 9020R System were analog X and Y deflection signals, video unblanking, and brightness control bits. The PVD switch was controlled by a spare switch located on the front panel. The PVD was driven either in the normal manner by the present system or by the remote signals brought in from the 9020R simulator PVD. The R-controls were also switched between two different radar keyboard multiplexer output connectors by means of an external relay box controlled by the front panel switch of the PVD. The switched PVD was driven over cable lengths of 20, 50, 70, and 100 feet. Line width and brightness measurements were taken and display patterns were observed at each of these lengths. Results were very good up to 70 feet and satisfactory up to 100 feet.