PRODUCT OVERVIEW
001-9193-001 Version 1
Page 11 of 48
Sentry 4G 900
TM
User Manual
W
A
23.6"(60cm)
G
8"(20cm)
8"(20cm)
5/8
Hz: 8" (20cm)
T
Constraints are TX spacing of at least 60cm/23.62 inch from all transmitting antennas and a
clear view of the sky.
“W” – WiFi antenna
Constraints are TX spacing of at least 8 inches or 20 cm from all transmitting antennas
Note: For units utilizing diversity antennas, best overall operation is achieved utilizing antennas with
equal gains
WARNING: As per FCC rules, all Sentry 4G transmitting antennas should be at a minimum of
eight (8) inches (approximately 20 centimeters) from all persons.
T- Primary Antenna
A-Auxiliary Antenna
G-GPS Antenna
W-WiFi Antenna
Figure 3 - Antenna Spacing
1
For installation of ground-plane dependent antennas (main and WiFi antennas), the center of the
metal surface used for mounting is preferable for best omni-directional pattern. For ground-plane
independent antennas (diversity and GPS antennas), installation may be close to the edges of the
surface.
For vehicular installations CalAmp recommends the following antenna 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
1
The diagram is not drawn to scale
