Sea Tel 5012-33, Руководство по установке

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Site Survey 5012-33 Installation Manual
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foot rung should be added. Additional rungs should be added for every 0.3 meter (12 inches) of
pedestal height above the ship’s structure.
9. For an ADE mounted greater than 3 meters (9 feet) above the ship’s structure, a fully enclosing cage
should be included in way of the access ladder, starting 2.3 meters (7 feet) above the ship’s
structure.
2.4. Mounting Height
The higher up you mount the antenna above the pivot point of the ship the higher the tangential acceleration (g-
force) exerted on the antenna will be (see chart below).
When the g-force exerted on the antenna is light, antenna stabilization and overall performance will not be affected.
If the g-force exerted on the antenna is high enough (> 1 G), antenna stabilization and overall performance will be
affected.
If the g-force exerted on the antenna is excessive (1-2 Gs), the antenna will not maintain stabilization and may even
be physically damaged by the g-force.
2.5. Mast Configurations
Sea Tel recommends the ADE be mounted on the ship in a location which has both a clear line-of-sight to the target
satellites in all potential azimuth/elevation ranges and sufficient support against vibration excitement. If possible,
mounting the ADE pedestal directly to ship deckhouse structures or other box stiffened structures is preferred.
However, in many cases, this imposes limits on the clear line-of-sight the antenna system has.
Often the solution for providing the full azimuth/elevation range the antenna needs is to mount the ADE on the ship’s
mast. Unfortunately, masts do not consider equipment masses in design and often have harmonic frequencies of their
own.
There are many designs of masts used on ships – masts are nearly as unique in design as the ship is – but the designs
often fall into just a few categories. These categories can be addressed in terms of typical responses and problems
with regards to vibration and mounting of ADE. The most common categories of masts are: