CalAmp Wireless Networks GPDB Gemini/PD User Manual revised pages 7 and 8 for preliminary ver1 11

CALAMP WIRELESS NETWORKS INC. Gemini/PD revised pages 7 and 8 for preliminary ver1 11

revised pages 7 and 8 for preliminary ver1 11

120 20111-100 preliminary 7 Gemini/PD Installation Guide
2.5 Antenna
To meet the FCC’s RF Exposure Guidelines,
the main transmitter antenna should:
- be installed to ensure a 7.9 in/20cm
minimum distance between the body of the
user or nearby persons and the antenna.
-have the antenna gain less cable loss which
does not exceed 2.7dBi.
2.5.1 Recommended tools and
supplies
• circle cutter
• hole saw or
• socket punch for antenna
• Mini-UHF Crimp tool
2.5.2 Planning
GeminiPD commonly uses three separate
antennas:
• Main transceiver – constraints are MPE
limits and omni-directional factors
• Auxiliary receiver – constraints are diversity
spacing and omni-directional requirements
• GPS – constraints are TX spacing and clear
sky view.
For ground-plane dependent antennas –
the center of metal surface is preferable for best
omni-directional pattern.
For ground-plane independent antennas –
installation may be close to the edges of the
surface.
Follow spacing for TX antenna. Install the
antennas in one of the following positions:
- Most preferred for all antennas: centerline of
roof. For transmitter antenna, it is the ONLY
acceptable position.
- Less preferred for receiver antenna: trunk
lid, providing distance to transmitting
antenna is respected whether lid is opened or
closed.
- Much less preferred, but permissible for
receiver antenna: left or right rear
fenders, just in back of rear window
- Least preferred, but permissible for
receiver antenna: left or right front
fenders, ahead of windshield
Note: Proximity to other vehicle-mounted
antennas may cause mutual
interference especially at higher
frequencies.
The auxiliary receiver antenna must be
installed at least 5/8 λ distant from the
transceiver antenna.
The GPS antenna placement requires a fairly
unobstructed view of the sky. It must also be
at least two feet distant from the transceiver
antenna but it may be close to the auxiliary
RX antenna.
For the optimum antenna spacing at the
frequency you are using, consult system
engineering.
2.5.3 Antenna Installation
1. Route good quality 50-ohm coaxial
cables (e.g. RG-223) from each of the
selected antenna positions to the
position where the GeminiPD unit is
mounted.
2. Terminate the end at each of the antenna
positions with the appropriate connector for
the antenna used and make the connection.
3. At the GeminiPD position, cut the three
cables to length and terminate with the
appropriate plug. For the transceiver and the
auxiliary cables, use a Mini-UHF crimp plug
using an appropriate crimping tool. For the
GPS, use a SMA connector.
4. Positively identify the transceiver mini-UHF
plug and connect to the left rear of
GeminiPD.
5. Positively identify the auxiliary receiver
mini-UHF plug and connect to the front left
of GeminiPD to the RX position.
6. Connect the SMA connector to the GPS
position below the auxiliary connector
position.
7. Do not skip this last step, trust us; it is an
important one. To complete the installation,
tie-wrap together the auxiliary and the GPS
antenna cables at a point about two inches in
120 20111-100 preliminary 8 Gemini/PD Installation Guide
front of the unit. It will be much easier
hereafter to correctly identify which mini-
UHF plug goes where. You DO NOT want
to cross the auxiliary plug with the
transceiver plug.
2.6. Completing the physical
Installation.
To complete the physical installation and
prior to testing GeminiPD:
• Connect DC Power cable’s connector to
GeminiPD’s until you hear a click as the
two parts snap together.
• Re-check that all other connections are
secure (antennas, PC, etc.)
• Switch vehicle ignition ON.
You are now ready to check for normal operation
and to run the Radio Installation Software (RIS)
program for testing or trouble-shooting.
2.7. Checking out Normal
operation
Check that the vehicle ignition is ON.
1- Check for proper operation of the
GeminiPD’s LEDs as per Table 1 in
section 3.1
2- Using the RIS program (described in
section 4) and an in-line wattmeter,
check forward & reverse power to
confirm main antenna installation.
3- Using the RIS, check the RF link with a
base station that can be heard by using
the RIS “Ping” feature.
See paragraph 4.4.4.4
or
If user application and its base station
are available, test the installation by
going through a normal sequence of
transmitting and receiving messages.

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