Trackcom Limited DPU-4500 ユーザーズマニュアル

 

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Type of mounting arrangement. Determine the method of fixing the unit to the 
vehicle. If there is a plane surface, the unit can be bolted or screwed directly to 
this. 
 

3.9 Antenna 

position. 

 
The siting of the antenna is crucial to the satisfactory operation of the equipment. 
Most noise and interference that is fed to the DPU is picked up and amplified by 
the antenna. Little is picked up via the cable of the unit. The vehicle antenna must 
be fitted incorporating all the following points: 
 
- Adequate ground plane around the antenna. 
 
- Away from the vehicle's engine and other RFI sources. 
 
- High as possible away from sources of interference and Driver / Passengers. 
 
- Hidden or disguised. 
 
- Access to the underside of the antenna for routing cables. Cables should not be 
wound or bound together. 
 
- Where it will not get damaged in normal use. 
 
- There should be no metal objects obstructing the antennas view for example 
parts of the vehicle chassis or metal lined dashboard. 
 
- In vehicles with metallic window tinting, the GPS antenna should be mounted 
outside on the vehicle body, for example on the roof or inside the plastic fender. 

 

Note: To ensure perfect function please keep a distance of at least 10cm to metal 
parts like window frames. 
 
Ground plane. A ground plane is required for a good transmission and to help 
subdue RFI to the low frequency navigational signals. This is normally obtained 
from the chassis of the vehicle. In the case of a glass reinforced plastic (GRP) 
vehicle, a ground plane will need to be provided for the antenna. The size of the 
ground plane is to be 375mm by 375mm (15in by 15in) typically 24swg 
aluminium.  
 

3.10   Cable runs 

 
Ensure that cables are not routed close to RFI sources such as HT Leads. 
Ensure that cabling and equipment are well away from Engine Management 
units, ABS sensors and Airbags sensors.