Xylem H-4271 - Manual (Page 12)

2.4 Power Mode Jumper
The end-plate has a 2-position power mode jumper
marked Auto and Always On. For most applications
install the jumper in the “Always On” position. See
Chapter 1.
2.5 Connecting The Antenna
Warning: When operating at a 1-Watt power output, observe a minimum separation of 2-feet
(0.6m) between radio modules. Transmitting in close proximity of other modules can the
damage the front end circuitry of the modules.
RF Exposure Warning: This equipment is approved only for mobile and base station
transmitting devices. It is not tested for “portable” applications. Antenna(s) used for this
transmitter must be installed to provide a separation distance of at least 30cm from all persons.
The power output is emitted at the antenna terminal and can be adjusted from 1 milliwatt to 1
Watt. This is an RF module approved for limited modular use operating as a mobile transmitting
device with respect to Section 2.1091 and is limited to integrator installation for mobile and fixed
applications only (it is not approved for portable applications). Professional installation
adjustment is required for setting module power and antenna gain to meet EIRP compliance for
high gain antenna(s).
FCC regulations stipulate a maximum 36 dBm EIRP power limitation. Users implementing
antenna gain greater than 6.0 dB must compensate for the added gain with cable loss. When
operating at 1-Watt power output, the sum (in dB) of cable loss and antenna gain shall not exceed
6.0 dB.
The H-4271 must be used with a 50-ohm, 900 MHz antenna. The antenna connector is a
RPSMA (Reverse-polarity SMA) connector which is required to meet FCC regulations.
A simple vertical whip antenna will work up to 2 or 3 miles. Longer distances require a
directional antenna with gain. A 6dB YAGI will work fine, do not use a 12dB model. Please
refer to the Antennal Options section of the Digi 9XStream product manual for approved
antennas for use with this module.
At 900 MHz, RG58 type coaxial antenna feed lines have excessive loss (1.8dB/10 feet).
Consider using newer low loss RF cable such as Times Microwave LMR-400 or similar
(0.8dB/10 feet). The LMR-400 requires special RG8 connectors.
2-2 Installation And Maintenance
H-4271