Sea Tel 6012-33, Nstallation Manual

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6012-33 Installation Manual Installation
3-4
3.3.3. Preparing and Installing the Single Piece 81” Radome Assembly
The antenna pedestal is shipped completely assembled in its 81” single piece radome.
1. Remove the shipping hold-down bolts which mount the ADE to its’ pallet.
2. Install four lifting eye bolts, provided in the radome installation kit, in holes around the perimeter of
the baseframe.
3. Attach a four-part lifting sling to the four lifting eyes in the
base of the radome and lift the radome assembly free of
its shipping pallet. Place the radome assembly on
temporary support blocks at least 22 inches high.
4. Loosely assemble the radome base frame's eight legs and
eleven braces as shown in the Radome Base Frame
Assembly drawing using the hardware provided. Insure
that a split washer is used under each nut. When
assembled, apply Loctite and tighten all hardware.
5. Using the four-part lifting sling, and with a tag line
attached to the radome base frame, hoist the antenna
assembly to its assigned location aboard ship by means of
a suitably-sized crane or derrick.
6. The radome assembly should be positioned with the BOW
marker aligned as close as possible to the ship centerline.
Any variation from actual alignment can be compensated with the Home Flag Offset and AZIMUTH
TRIM adjustment, so precise alignment is not required.
7. Bolt or weld the legs of the radome base frame directly to the ship's deck or suitable mounting
surface. If the deck is uneven or not level, weld clips to the deck and attach them to the legs of the
radome base frame. When completed the radome should be as near to level as is practical.
8. Disconnect the lifting sling from the four lifting eyes in the base of the radome.
9. Remove the four lifting eye bolts. Save the lifting eye hardware in case lifting of the ADE is required
in the future.
10. Route AC Power and IF coax cables through the strain reliefs installed in the basepan of the radome.
Allow enough service loop to terminate these cables to the circuit breaker assembly and connector
bracket respectively (see cable termination information below).
3.4. Grounding the Pedestal
The antenna pedestal must be grounded to the hull of the ship. A grounding point is provided on the upper base plate
to ground the pedestal. A ground wire, of appropriate gauge for it’s length, must be provided to ground the pedestal to
the mounting platform that it will be bolted to (this is usually on or near the mounting surface). This mounting must
also be electrically common with the hull of the vessel.
If a longer ground connection is required to reach a common metal connection to the hull, you must provide that
longer cable/strap that is of sufficient gauge and length to ground the pedestal to the nearest grounding point of the
hull.
Solid strap
is the conductor of choice for low impedance RF ground connections because the RF currents tend to
flow along the outer surface and the strap has a large smooth surface area to take full advantage of this effect.
Braid
is the conductor of choice where flexibility is required. Sea Tel uses braid to cross axes of the antenna pedestal
and to connect various subassemblies together.
Wire
is the easiest to install and connect and is readily available with a weather protective jacket. 4 awg and 6 awg
bare solid copper wire is commonly used as safety grounds and very basic lightning protection grounds. 2 awg
stranded wire is often used for lightning grounding and bonding and it much more flexible.