Product specifications

GSP-1620 Modem Product Specification
80-99240-1 Rev. D 5-21
Calculating Antenna Cable Length
The maximum loss for an antenna cable of any length is 0.6
dB at 1.6 GHz for modem transmit and 3 dB at 2.5 GHz for
modem receive.
OEMs must take these losses into account when calculating
antenna lengths for a GSP-1620 modem installation. For
example, the GSP-1620 Modem Integrator’s Kit utilizes three
feet of LMR 195 cable, which has a loss of 0.6 dB at 1.6 GHz.
Mounting Antennas at the Field Site
When mounting an antenna on-site, OEMs must position it
properly to obtain Globalstar satellite signals. An antenna
can be mounted on a flat surface or on a pole. In either case,
the antenna connectors should be sealed against dirt and
moisture.
Caution
The ODU must be installed in a configuration that ensures a
minimum line-of-sight separation distance of 21.5 centimeters
(8.5 inches) is maintained at all times between the ODU and any
personnel.
Mounting and Sealing Antennas on Flat Surfaces
OEMs can mount the modem antenna (DRA) on a flat surface
with six M4 screws. Depending on whether the surface is
smooth or rough, different methods are recommended for
sealing out moisture and dirt from the antenna’s SMA
connectors, which are not sealing connectors.
If the surface is smooth, flat, and solid, an O-ring can protect
the antenna’s connectors. The O-ring should be 2.050 inches
in diameter by 0.103 inch wide, to fit within the groove on the
bottom of the antenna. Silicone or ethylene-propylene is the
preferred material.