Microhard Systems MHX-910A, Operating Manual

Page: 20 / 26

10 MHX 910A Operating Manual: Chapter3 Installation
WARNING
To satisfy FCC RF exposure
requirements for mobile
transmitting devices, a
separation distance of 23 cm
or more should be
maintained between the
antenna of this device and
persons during device
operation. To ensure
compliance, operations at
closer than this distance is
not recommended. The
antenna used for this
transmitter must not be co-
located in conjunction with
any other antenna or
transmitter
WARNING
Direct human contact with
the antenna is potentially
unhealthy when a MHX-
910A is generating RF
energy. Always ensure that
the MHX-910A equipment
is powered down during
installation.
WARNING
Never work on an antenna
system when there is
lightning in the area.
3.3 Installing External Cables, Antennas and
Lightning Arrestors
The installation, removal or maintenance of all antenna components must be
carried out by qualified and experienced personnel.
Never work on an antenna system when there is lightning in the area.
Direct human contact with the antenna is potentially unhealthy when the
MHX-910A is generating RF energy. Always ensure that the MHX-910A
equipment is powered down during installation. At all time, a distance of 23
cm must be maintained between the antenna and any person when the device
is in operation.
Surge Arrestors
The most effective protection against lightning is to install two lightning
(surge) arrestors, one at the antenna, the other one at the interface with the
equipment. The surge arrestor grounding system should be fully
interconnected with the transmission tower and power grounding systems to
form a single, fully integrated ground circuit. Typically, both ports on surge
arrestors are N-female.
External Filter
Although the MHX-910A is capable of filtering out RF noise in most
environments, there are circumstances that require external filtering. Paging
towers, and cellular base stations in close proximity to the MHX-910A
antenna can desensitize the receiver. Microhard Systems’ external cavity
filter eliminates this problem. The filter has two N-female ports and should
be connected in line at the interface to the RF equipment.
Weatherproofing
Type N and RTNC connectors are not weatherproof. All connectors should
be taped with rubber splicing tape (weatherproofing tape), and then coated
with a sealant.
Cabling
The following coax cables are recommended:
Table 2 Cable Loss
Cable Loss (dB/100ft)
LMR 195 10.7
LMR 400 3.9
LMR 600 2.5