T21 Installation Guide
© 2006 Tramigo Ltd. All rights reserved. Under the copyright laws, this manual cannot be reproduced in any form without
the prior written permission of Tramigo. Page
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In general, you can expect that a mounting situation on the dashboard of a vehicle will be
satisfactory.
Specifically, the GPS antenna is in the top of the T21 housing, and the top must therefore be
uppermost and reasonably level and have a view of the sky that is not screened by the vehicle
structure. If you have the external GPS antenna option, you can locate the T21 unit anywhere in
the vehicle and place the GPS antenna in place with a view of the sky and not covered by metal –
under the dashboard usually works.
Additionally, because the cellular communications antenna is in the base of the T21 unit, the
base must not be closer than 5 cm to metal parts of the vehicle. It is not necessary to have a
direct path for the cellular communications signals – a reflected path is sufficient. If you have
the external GSM antenna option, then follow the above guideline for the external antenna.
The backup battery option can be attached to the bottom of the T21 unit as shown in the picture
above or located beside the unit. C shaped Velcro is provided for this purpose. The battery
should be charged for 3.5 hours prior to use and will power the unit for 48 hours under normal
conditions. The battery will not charge at temperatures below 0˚c or higher than 45˚c.
The ideal location in most cars is in the centre top of the dashboard.
Check your windscreen: Should the windscreen be provided with heating that uses a metal
film or fine wires built into the windscreen, or features a special heat reflecting athermic layer,
then the GPS signal from the orbiting satellites will be screened from the T21.
The T21 should then be mounted at the side of the windscreen where there is sometimes a
special zone free of the metallization.
If this does not work, then another location must be tried, or a commercial GPS Re-Radiator must
be used.
Window Tinting
GPS signals are blocked by metal surfaces which can include some brands of window film that
contain metal particles. To ensure that GPS, cell phone, and radio reception is not impacted
either:
1. Use a non-metallic tint
2. Avoid tinting the front windshield where the T21 unit is located (World wide legislative
trend is to ban windshield tinting due to increased risk of accidents)
3. Leave a 15 cm gap at the bottom of the windshield and place the T21 by this opening.
This still provides security for vehicle occupants.
4. Use the External Antenna option and locate the GPS antenna under the front bumper or
under the windshield wipers – as long as the antenna is not covered by metal.
The list of good quality non-metallic film includes the 3M film, Madico CharcOOl (not Madico
CharcOAl), Huper Optik Ceramic (Stark), and FormulaOne Pinnacle (ceramic film). Costs for good
quality metallic film is similar to non-metallic film.
Suitable fixings must be used – such as double-sided foam adhesive tape or Velcro.
WARNINGS:
•Your T21 must be securely mounted in a location where it cannot interfere
with the normal operation of the vehicle. It must not be located in a
position where the cables or the T21 Unit may become a hazard to the
driver or any passengers.
