User's Manual

vii
Before each use, verify that the antenna (and antenna cable, if used)
is securely attached and in good condition. A loose antenna or cable
may severely reduce the operating range of the system.
When installing the FDL01TU modem in a mobile unit such as an
Automated Guided Vehicle (AGV), Futaba recommends to use the
diversity reception feature as a remedy for multipath fading problems.
For diversity reception, install the two antennas as far apart as
possible in order to gain maximum benefit (6 cm minimum).
The FDL01TU operates at frequencies in the 2.4 GHz band. These
frequencies are more directional than lower frequencies and are
easily reflected. If there are metal structures nearby, the effective
range may be shortened or the directional properties may be further
narrowed. To help avoid this, mount the antenna as far away as
possible from surrounding metallic structures.
Multipath problems occur easily at frequencies in the 2.4 GHz band.
When multipath problems are present, moving the antenna as little as
10 cm may result in improved communication or, conversely,
worsened or complete loss of communication. Futaba recommends
that the mounting position of the antenna be determined after testing
and verifying optimal communication conditions. Negative multipath
effects can also be overcome with antenna diversity.
See p.8
D IVERSITY A NTENNA S ETUP and the related register settings for
more details regarding antenna diversity function.
When installing multiple FDL01TU modem systems that will use
different frequency groups in the same area, modem’s antennas of
different frequency groups must be mounted at least 6 feet (2 meters)
apart. Failure to do so may severely reduce the modem operating
range.
Please contact Futaba for information about antenna separation when
using the FDL01TU and other wireless products in the same area.