User's Manual

SBS-900 Shore Based Radar Systems
Chapter 10: Corrective maintenance
KH-1602-2 issue 1: Standard SBS900 Systems Operator & Maintenance Handbook
Page 154 of 240
PCA failure: If a failure of the Switch control and BITE PCA should occur then the default
transceiver (Tx A) will still be able to operate. Manual control of the waveguide switch,
and therefore Tx B, is still available.
Start-up: During start up, the waveguide switch is to be set to Tx A, and the polarisation switch
to horizontal. Once the communication between the PCA and the RDU has been
established and start-up checks are complete, then the processor takes over the
control of the waveguide and polarisation switches as commanded by the RDU.
Power: The PCA is powered by the 15VDC output of the power supply. When either PSU A
(single transceiver systems) or PSU B (dual transceiver systems) is powered, the
PCA is powered and operational.
On board DC-DC conversion provides all the power requirements of the PCA.
+15V
PSU A
+15V
PSU B
Control and BITE PCA
CHL Antenna
Encoder Power
Waveguide
Switch Driver
+15V
+15V
Board Power
Requirements
+5V
+28V (+0/-3V)
KH Antenna
Encoder Power
+15V
CHL Polarisation
Switch Driver
5V Stepdown
5V Stepdown
+28V DC-DC
Converter
Polarisation
Switch
Waveguide
Switch
SBS-A126 PCA DC power schematic
10.7.8.2 Encoder DC power selection
Encoder power: The SBS-A126 PCA provides a DC power source for the ACP/ ARP encoder in the
antenna sub-assembly.
Link 8: Depending on the system installed, link 8 must be set to select the appropriate DC
output voltage.
SBS-A126 DC output
Standard
antenna sub-systems
Advanced
antenna sub-systems
Encoder power
SBS-A126: PL4 Pins 11 and 12
+15VDC +5VDC
Link 8 setting R_n ni •A jimcncih R_n ni •B position