commercial   practices. For example, there are safety interlocks   on   the   antenna   pedestal,   the receiver/transmitter (R/T) unit, and the azimuth range indicator. All the other units include ON/OFF switches and indicator lights. Maintenance The  AN/SPS-64(V)9  was  purchased  as  the  single, commercially  available,  off-the-shelf  radar  for  the Navy’s Class B1 radar program. Maintenance support, including   documentation,   spares,   and   levels   of maintenance is also an off-the-shelf concept. Maintenance responsibilities are assigned to an existing   billet   and   performed   by   an   Electronics Technician  (no  specific  NEC  assigned).  Organizational level  maintenance  consists  of  preventive  maintenance (PM) and corrective maintenance (CM). PM is done according   to   the   maintenance   requirement   cards (MRCs). CM consists of (1) adjustments, alignments, and tests, as described in the technical manual and (2) replacement  of  the  lowest  replaceable  unit  (LRU) required  to  correct  radar  discrepancies. The  Miniature/Microminiature  (2-M)  Electronic Repair Program and the Support and Test Equipment Engineering Program (STEEP) are not used for the AN/SPS-64(V)9 radar, since the Navy has no data rights for  the  equipment. Major   overhaul   and   restoration   of   the AN/SPS-64(V)9  radar  and  LRU  repair  are  performed  at the  depot  level,  in  the  prime  contractor’s  facility. Technical  Repair  Standards  (TRSs)  are  not  available since the Navy does not make depot-level repairs. AN/SPS-55 The AN/SPS-55 is a solid-state, Class A surface search and navigation radar. It is used to detect small surface targets and for navigation and pilotage. The AN/SPS-55 radar detects targets from as close as 50 yards to as far as 50 nautical miles. It was specifically designed   for   installation   in   the   following new-construction ship classes: AO-177 CGN-38   DDG-993   MCM-1 CG-47 DD-963 FFG-7 PBC-1 A radar video converter (RVC) modification was developed for AN/SPS-55s used on the FFG-61 class. The AN/SPS-55 radar supports several mission areas   including   Antisurface   Warfare   (ASUW), Antisubmarine  Warfare  (ASW),  Amphibious  Warfare (AMW),  Special  Warfare  (SPW),  Mobility  (MOB),  and Command  and  Control  (CAC). General  Theory  of  Operation The radar set operates from 9.05 GHz to 10 GHz, and  can  tune  over  the  entire  bandwidth  within  60 seconds.  Tuning  can  be  controlled  from  either  the remote radar set control (RSC) or the receiver-transmitter (R/T) unit. The transmitter uses a magnetron with a minimum peak power of 130 KW. The receiver can operate in a long-pulse mode (1.0 %sec) or short-pulse mode (.12 %sec) with minimum ranges of 200 yards and 50 yards respectively. The antenna  consists  of  two  back-to-back  end-fed,  slotted waveguide arrays with a scan rate of 16 rotations per minute  (rpm). Some special operating features of the AN/SPS-55 radar set include: Squint   compensation Variable  sensitivity  time  control Fast  time  constant  (FTC) Log/linear-log   intermediate   frequency   (IF) amplifier Video blanking circuit Sector  radiate  capability Automatic  and  manual  frequency  control (AFC/MFC) The RVC modification provides these additional features: Analog/digital   (A/D)   conversion Digital integration with beam time interval Noncoherent  DMTI Moving   window   constant   false   alarm   rate (CFAR)  thresholding Segmented  CFAR Configuration As shown in figure 2-4, the major components of the  AN/SPS-55  radar  include  the  antenna,  the 2-6