The Improved Limited Motion (ILM) Antenna installation started with site location and preparations.  Due to wind loading, weight requirements and stress analysis these antennas must be secured to a solid base. In this case the antenna was being installed on the roof of a new 2 floor addition to the facility. Extensive engineering and analysis was done during the design of this addition to insure that the antenna could be added safely.

Four pads were prepared for the installation to secure the antenna structures to the roof. The mounting bolts were secured in high strength concrete based on the antenna manufactures specification and the structural analysis.

ILM Antenna location for installation

When the antenna arrived, the install team unpacked and inventoried the shipment, placing the components in the defined assembly area. The assembly started by placing the hub on a stable fixture. The back frame that holds the dish panels in place was assembled. Each support strut and mounting bracket had to be aligned and torqued down in place to ensure the stability of the completed surface. The panels were installed and aligned with openings left to accommodate access and simplify attachment of the completed dish structure to the pedestal.

A crane was used to lifted the pedestal of the antenna into position on the roof  where it was aligned and secured. With the pedestal securely in place the crane lifted the dish and it was guided into place.

After verifying the alignment of the panels, the support structure and sub-reflector assembly could be installed. Final panels were then installed in place to complete the dish.

The antenna control interface, motors, RF equipment, cabling and waveguide were installed. Mechanical and communications testing followed to commission the antenna for service.

The completed antenna shown in this final picture.  Exterior panels were added to inclose the support structure of the antenna. This was part of a de-icing system that used propane heaters to warm the dish surface and feed assembly preventing snow or ice from  accumulation during the winter season.  As with all antennas of this type lightning rods were installed and grounded to protect against damage from lightning strikes.