Installation Guide

Date : October 18th 2019
DM3G Low-band
Ref : Installation Guide
Edition 1.2.0
Page
16/27
7 Installation
Before setting any piece in the vehicle TPL Systèmes advises you to assemble all pieces
together and find best place for each, in order to avoid overstretched cables.
7.1 Antennae
7.1.1 RF Antenna
For US market :
The antenna gain used with this device should be 0 dBi or less and all persons should maintain
a minimum separation distance of 141.05 cm for general uncontrolled exposure and general
controlled exposure.
Antenna characteristics must be :
- 50 impedance
- ¼ or 5/8 wavelength
Antenna must be set on a good ground plane.
- Install antenna in the middle of vehicle roof, if possible
o Or at least in the middle of a horizontal metallic wide enough surface
Use coaxial double-braided cable (RG223 type).
Antenna must be cut (tuned) at TX mobile frequency. In order to work on several channels
choice will be made to cut antenna at frequency band middle.
Please refer to antenna manufacturer chart to get the correspondence between wire lengths
and tuning frequency.
A VSWR measurement is necessary to validate installation.
VSWR must be below 1.5 in TX band, and below 2 in RX band.
7.1.2 GPS antenna
GPS antenna must have following characteristics :
- 50 impedance
- 5VDC supply voltage
- SMA male connector
Antenna must be placed, in or out of the vehicle, so it can receive GPS satellites signals
properly.