Sea Tel COASTAL 18, Инструкция по установке и эксплуатации

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Basic System Information Coastal 18 Ku-Band TVRO
3-4
3.2.4. Stabilization
Your antenna is a “stabilized” antenna. Stabilization is the process of de-coupling the ships’ motion from
the antenna. Simply put, this allows the antenna to remain pointed at the satellite while the boat turns,
rolls or pitches under it. To accomplish this, the
P edestal C ontrol U nit (PCU) on the antenna pedestal
assembly senses the motion and applies drive to the appropriate motor(s) in opposition to the sensed
motion. Azimuth (AZ), Elevation (EL) and Polarization (POL) are actively
stabilized automatically by the
PCU as part of its normal operation.
3.2.5. Search Pattern
When the power is turned on, the system will calculate the Elevation & Polarization of the selected
satellite, drive the antenna to the calculated Elevation and adjust the Polarization to the calculated
polarization. It will then drive the antenna in a 400 degree Azimuth sweep at the calculated Elevation.
The Elevation will be increased and decreased in 4 degree increments after each Azimuth sweep until the
selected satellite is found and tracking begins or the system has completed Azimuth sweeps through
several Elevations. If the selected satellite is NOT found, the system will re-target and repeat the search.
Once the selected satellite is found tracking begins.
If you want to change satellites, press the NEXT key until the desired satellite is displayed. The system
will calculate the Elevation, Relative Azimuth and Polarization of the selected satellite and drive the dish
directly to the Azimuth and Elevation, and adjust the Polarization, for the new satellite. The new satellite
should be acquired and tracking begins. If the satellite is not found a search will begin, as described
above.
3.2.6. Satellite Identification Receiver
The Satellite Identification Receiver (Tracking Receiver) located in the Pedestal Control Unit (PCU) is
used to acquire, identify and track a specific satellite. To do this the receiver is set-up to a specific
Frequency , Baud rate, FEC rate and a unique Network ID hexadecimal code ( NID ) setting for each
saved satellite.
During search, if a signal is found, this receiver compares the programmed settings to the present
satellite signal values being received. The system will track the satellite while the comparison is being
done, If they do NOT match, the search pattern will be continued. If they DO match, Tracking will begin.
Up to six different satellites may be saved for use.
The system should only be set-up for satellites that are going to be used so that you don’t have to
go through so many choices when switching satellites. Unused satellite setups should be left
blank to skip over those choices.
3.2.7. Tracking
The antenna actively optimizes the pointing of the dish for maximum signal reception using a receiver
which is built into the Pedestal Control Unit (PCU). This process is called
tracking and is accomplished
by making small trial movements of the dish while monitoring the level of the received signal. Evaluation
of this information is used to continuously make minor pointing corrections to keep the signal level
“peaked” as part of normal operation.
3.2.8. Unwrap
Mechanical stops limit the azimuth rotation to 680 degrees. When the azimuth rotation is within 5
degrees of either mechanical stop, the antenna will be driven 360 degrees away from that stop. This
“unwinds” the cables that are routed through the pedestal assembly and repositions the antenna to a mid-
point between the two stops. By rotating 360 degrees the azimuth position of the antenna will have
returned to the previous position and will resume normal satellite tracking. Unwrap will occur when the
boat continues turning far enough in one direction for it to be required. It is normal for the television
picture to “freeze frame” until the antenna completes unwrap and resumes tracking the satellite.