Rice Lake MSI-9850 CellScale RF Digital Indicator - Operator Manual - Manual (Page 19)

MSI CellScale ® System • 9850 User Guide Page 19
MEASUREMENT SYSTEMS INTERNATIONAL
Firmware Version 5-XX for 2450 Modems
ANTENNAS
To meet FCC licensing rules, you must use only antennas supplied or recommended by MSI. MSI offers the 9850
with six antenna choices: 1) Standard Antenna – This is a small 1/2 wave antenna that mounts directly on the
9000 CellScale enclosure and is suitable for most short to medium range applications. 2) Long Range Antenna
– A high gain antenna that is remotely mounted from the 9850 with a low loss coaxial cable. This omnidirectional
antenna increases the range up to 4 times. The 10' cable allows placement of the antenna above the 9850 for
ease of clearing possible obstacles to data transmission. 3) Vehicle Mount Whip Antenna – This antenna mounts
directly to the roof of mobile vehicles and is weatherproof. 4) For maximum range, a 15dBi Gain Yagi Antenna
is available by special order. Please contact MSI for details. 5) Corner Reflector – Often the best choice for a
wall mounted antenna. MSI offers a 14dBi and a 9dBi Corner Reflector. 6) Patch Antenna – For applications
where the standard antenna is vulnerable to physical use or outdoor applications. The Patch antenna is mildly
directional which requires more care in antenna placement for long range applications. Patch Antennas are avail-
able by special order only.
Antenna placement is critical to problem free use of your CellScale system.
1) Be sure a relatively clear transmission path exists between the 9850 and associated CellScale master devices.
The radio signals travel primarily by line of sight (LOS), and obstructions between stations will degrade the
system performance. LOS is less important as distances decrease.
2) When using the long range antenna, mount the antenna on a tower or other elevated structure to ensure that
you have a clear LOS transmission path. This will raise the antenna to a level sufficient to clear surrounding
terrain and other obstructions. It is not necessary or desirable to provide a ground plane for the antenna.
3) Never use a directional antenna (e.g. a Yagi, or a corner reflector) on a mobile system. However, fixed station
locations can often benefit from directional antennas when the location of the other components of the RF
network are always in the same general direction.
4) If using the meter mounted standard antenna, ensure that the antenna is not blocked by any metal. Transmission
is good through most kinds of glass so mounting a meter next to a window should work fine. If there is no
clear line of sight place to mount the 9850, consider switching to a coax connected antenna so the antenna can
be remoted. MSI offers bulkhead Coax kits for extending the antenna cable through a wall or enclosure.
5) The standard and long range antennas are vertical plane devices. Do not mount them sideways. They should
always point up (mounted vertically). It also works to point them down, when high off the ground (such as
on the underside of a large bridge crane). The long range 9dBi Antenna is particularly sensitive to off axis
mounting. Use a carpenters level to ensure the antenna is exactly 90° perpendicular to the earth.
6) Do not mount an omnidirectional Antenna next to a metallic or concrete surface. This can result in reflections
and undesired RF characteristics. For this application, use a Corner Reflector.
7) After installation, you must seal the Antenna connection with an Adhesive Heat Shrink Boot. Failure to seal
the Antenna may result in liquid destroying the Antenna, or the 9850.
MSI does not recommend extending the coaxial cable beyond 3 meters. At 2.4GHz more loss will result from coax losses than
are gained by raising the antenna. If you must extend the antenna, use a very low loss 50Ω coax such as RG-214, RF-195, or
other low loss varieties. For very short extensions (<1m), cables made with RG-316 are suitable.
Go to Index