Communications Development LLC JNM032189 Benutzerhandbuch
Using a Different Antenna
In certain circumstances it may be desirable to extend the range of the ATR900 radio modem by
using an external antenna in place of the standard whip antenna. The radio modem is equipped
with a standard SMA external jack. This allows the use of one of the other certified antennas
provided by the manufacture – See the list on the previous page.
The use of a different antenna may radically improve the results obtained with ATR900 radio
modems. It is imperative to obtain line of sight with the antennas, and changes in placement height
of as few as a couple of feet may make the difference between no link and one that is solid and
reliable.
These antennas allow versatility in the ATR900’s deployment, extending its range and allowing it to
get around obstructions.
If external directional antennas are used, FCC regulations concerning effective radiated power
limitations must be followed.
using an external antenna in place of the standard whip antenna. The radio modem is equipped
with a standard SMA external jack. This allows the use of one of the other certified antennas
provided by the manufacture – See the list on the previous page.
The use of a different antenna may radically improve the results obtained with ATR900 radio
modems. It is imperative to obtain line of sight with the antennas, and changes in placement height
of as few as a couple of feet may make the difference between no link and one that is solid and
reliable.
These antennas allow versatility in the ATR900’s deployment, extending its range and allowing it to
get around obstructions.
If external directional antennas are used, FCC regulations concerning effective radiated power
limitations must be followed.
Caution:
Any antenna placed outdoors must be properly grounded. It is required by FCC
regulations that qualified personnel experienced in antenna installation and familiar with
local codes and regulations complete the antenna installation. It is also required by FCC
regulations that only approved antennas be used. Use extreme caution when installing
antennae and follow all instructions included with the antennas.
The use of external antennae subjects the radio modem to greater exposure to direct lightning
strikes. It is strongly recommended that a lightning arrestor be used on all outdoor antenna
installations.
Long RS232 cable runs should also be avoided in areas with increased lightning activity or static
electricity unless they are properly isolated from the radio modem. Nearby lightning strikes or
elevated levels of static electricity may lead to voltage spikes on the line, causing failure in the radio
modem’s RS232 interface. It is also recommended that the RS232 data cable not be located near
high voltage power lines as this can cause interference in data communications, damage the
ATR900 as well as an increase in risk of personal injury.
local codes and regulations complete the antenna installation. It is also required by FCC
regulations that only approved antennas be used. Use extreme caution when installing
antennae and follow all instructions included with the antennas.
The use of external antennae subjects the radio modem to greater exposure to direct lightning
strikes. It is strongly recommended that a lightning arrestor be used on all outdoor antenna
installations.
Long RS232 cable runs should also be avoided in areas with increased lightning activity or static
electricity unless they are properly isolated from the radio modem. Nearby lightning strikes or
elevated levels of static electricity may lead to voltage spikes on the line, causing failure in the radio
modem’s RS232 interface. It is also recommended that the RS232 data cable not be located near
high voltage power lines as this can cause interference in data communications, damage the
ATR900 as well as an increase in risk of personal injury.