Sea Tel ST144-21, Инструкция по установке и эксплуатации

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Maintenance and Troubleshooting ST144-21 C/Ku-Band TVRO
13-12
13.7.2.1. Channel 1 (White)
HORIZ C/Ku-low coax has +18 VDC Voltage supplied by Matrix Switch plus C-Band IF (950-
1450MHz) OR Ku-Band IF (950-1950MHz) “Band Selected” output from the C/Ku-low Switch.
Horizontal C/Ku-low band switched output passes through this channel of the 75 ohm coaxial rotary
joint, to the base of the radome, down the ADE-BDE coax to the C/Ku HORIZ LO input of the four
port Matrix Switch. The ACUs’ Tracking Receiver and each of the C or Ku-Band Satellite Receivers is
connected by coax cable to one of the available IF outputs of the Matrix Switch. Total signal loss of
this path is the accumulation of the coax cable losses from antenna to receiver, plus the loss in the
C/Ku Switch and the Matrix Switch.
13.7.2.2. Channel 2 (Blue)
VERT C/Ku-low coax has +13 VDC Voltage supplied by Matrix Switch plus C-Band IF (950-1450MHz)
OR Ku-Band IF (950-1950MHz) “Band Selected” output from the C/Ku-low Switch AND Antenna
Control RF (Pedestal TX at 1.1 & Base TX at 1.5 MHz) which is added onto this coax by the Pedestal
FSK Modem (connected to the PCU). Vertical C/Ku-low band switched output passes through this
channel of the 75 ohm coaxial rotary joint, to the base of the radome, down the ADE-BDE coax to
the Base FSK Modem (connected to the ACU) and then to the C/Ku VERT LO input of the four port
Matrix Switch. Total signal loss of this path is the accumulation of the coax cable losses from
antenna to receiver, plus the loss in the C/Ku Switch, Pedestal & Base Modems (1 dB max loss each)
and the Matrix Switch.
13.7.2.3. Channel 3 (Red)
HORIZ Ku-high coax has +18 VDC Voltage supplied by Matrix Switch plus Ku-Band IF (1100-
2150MHz). Horizontal Ku-high band un-switched output passes through this channel of the 75 ohm
coaxial rotary joint, to the base of the radome, down the ADE-BDE coax to the Ku HORIZ HI input of
the four port Matrix Switch. Total signal loss of this path is the accumulation of the coax cable
losses from antenna to receiver, plus the loss in the Matrix Switch.
13.7.2.4. Channel 4 (Green)
VERT Ku-high coax has +13 VDC Voltage supplied by Matrix Switch plus Ku-Band IF (1100-
2150MHz). Vertical Ku-high band un-switched output passes through this channel of the 75 ohm
coaxial rotary joint, to the base of the radome, down the ADE-BDE coax to the Ku VERT HI input of
the four port Matrix Switch. Total signal loss of this path is the accumulation of the coax cable
losses from antenna to receiver, plus the loss in the Matrix Switch.
13.7.3.
Turn the pedestal power supply ON. The brakes on the Elevation and Cross-Level motors will release. A brake
release power supply control circuit supplies 24 VDC to the brakes initially (5-10 seconds) and then reduces
the voltage to 12VDC. The PCU will initialize the stabilized portion of the mass to be level with the horizon
and at a prescribed Azimuth and Elevation angles in the specific sequence of steps listed below.
Antenna Initialization (ST-21 Series)
Initialization is completed in the following phases, each phase must complete properly for the antenna to
operate properly (post-initialization). Observe the Initialization of the antenna pedestal.
Step 1. Elevation and Cross-Level axes activate simultaneously - Input from the Elevation sensor is
used to drive the Elevation of the equipment frame to 45.0 degrees in elevation. Input from the
Cross-Level sensor is used to drive Cross-Level of the equipment frame to bring it to level (this
results in the tilt of the Cross-Level Beam being level).
Step 2. Azimuth axis activates - Antenna drives CW in azimuth until the “Home Flag” signal is
produced. This signal is produced by a Proximity sensor in close proximity to a metal tab. After a
short period of time (a total of approximately 1-2 Minutes after power is initially applied to the
antenna), the PCU will report its model setting and software version number to the Antenna Control
Unit (ACU).
This completes the phases of initialization. At this time the antenna elevation should 45.0 degrees and
Relative azimuth should be at home flag (home switch actuated).
If any of these steps fail, or the ACU reports model "
xx97B or xxx00B
", re-configure the PCU as described
in the Maintenance section of this manual. If initialization still fails, this indicates a drive or sensor problem.