Installation Instruction - SW3-159
Introduction
A.
This document is a guide for the installation of L[G]V range of low profile VHF antennas onto a vehicle roof and should be utilized as advice in the
context of a planned installation .
It should be noted that the requirements of any particular installation may differ from those envisaged in this document, which is not a substitute for
advice from installation experts or the vehicle manufacturer, whose advice should be sought if required.
The antenna can be fitted to panels of a maximum 12mm (1/2”) thickness using the standard M14 mounting bush.
The L[G]V range of antennas is supplied pre-tuned to the required freq. range and installation condition (groundplane of advised size/no-
groundplane) – please check that the antenna specification is suitable for the installation condition.
Select A Suitable Mounting Location
B.
The mounting location should be flat– the antenna enclosure may be stressed and damaged if an attempt is made to fix it to conform to excessive
curvature. Select a suitable mounting location which is spaced away from other structures (e.g. air conditioner, battery packs) on the mounting panel
and check for clearance below the mounting panel. The appropriate spacing distance will depend on height of the structure, but the minimum
recommended spacing is 1/2 wavelength at the lowest operating frequency of the antenna. To calculate this, see below:
150 / frequency in MHz = ½ Wave length (m) As an example for 150MHz - 150/150 = 1m (3’ 3”).
Measure to check for central position, if applicable.
When fitting on a ground plane, the securing washer and nut must make a low resistance electrical contact with the metal panel.
C.
Make a 14mm (1”) clearance hole for the main cable entry mounting bush.
The antenna enclosure also has 12x 6 mm (0.24”) mounting holes around the periphery of the antenna housing. It is recommended that
M6 fasteners of appropriate length, preferably with environmentally stable rubber sealing washers, are used to secure the antenna to the mounting
panel. The antenna cover can be used as a drilling template. Clean the area around the holes, removing all swarf & burrs. Consider applying an
appropriate conductive corrosion resistant coating or spray to bare metal surfaces to prevent corrosion.
D.
The antenna enclosure is supplied assembled and sealed to the base plate. The installer should ensure effective seal of the antenna to the mounting
panel, as part of the installation process. It is important to consider the curvature of any mounting surface when determining how to seal the antenna
to the panel. For most types of installation it is recommended to apply a suitable environmentally stable, neutral cure sealant in at least 3 areas:
1. In a ring around the cable entry mounting bush on the base of the antenna
2. Around the entire circumference of the antenna
3. On the underside of the antenna - it may be best to apply 2 or 3 concentric circles of sealant to the base of the antenna
Ensure that the mounting panel is clean within the antenna baseplate “footprint” area. Place the antenna in position, check that mounting holes are
correctly aligned and that connector(s) is/are accessible from the underside. Fit the antenna using the selected mounting method. Check the sealing
of the installation and apply any extra sealing to the antenna as required. Once the antenna is fixed in place, seal the perimeter fastener heads, (if
applicable).
Fitting and Sealing the Antenna
E.
Routing and Terminating Coaxial Cable(s)
Route the coaxial cable(s) to the equipment, taking care to avoid running adjacent to existing wiring or fouling any moving controls or components.
Fit
connectors to the cable if required. Consider securing connectors in place to prevent them coming loose during service. When planning the cable
routing, consider minimum cable bend radius (25mm / 1” for CS23 and 13mm / 1/2” for RG174) and ensure that no undue stress is placed on
connector joints.
Prepare and Make Holes
Electrical Safety Note
The LG versions of this product contain an ac ve GPS antenna.
Rated voltage: 3-5VDC Rated current: 20mA maximum
The supply to this device must be provided with overcurrent protec on of 1A maximum.
F.
Test and Commission
The comms antenna is d.c. grounded and will present a short circuit across the connector. In versions with GNSS function, this will present a high
resistance (~70-85kΩ) across the GNSS connector. It is recommended to carry out a VSWR check on the comms antenna, the VSWR should be as
specified in the product datasheet or agreed VSWR plot.
Waiver:
This document represents information compiled to the best of our present knowledge. It is not intended as a representation or warranty of fi tness of the products described for
any particular purpose. This document details guidelines for general information purposes only. Always seek specialist advice when planning installations and ensure that antennas are
always installed by a properly qualifi ed installer in compliance with local laws and regulations.
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