5. CONSIDERATIONS FOR LONG CABLE
RUNS
5.1. Due to process variations in the
fabrication of the HP 58516A, the gain through
the device can vary from +3 dB to -3 dB.
Assume the worst case loss of the HP 58516A
when determining if line amplifiers are
necessary in your GPS antenna system.
5.2. The assumed worst case loss through the
HP 58516A is equal to:
•
18 meters (60 ft) of cable length when
using LMR 400 cable
•
8 meters (25 ft) of cable length when
using RG-213 cable.
5.3. Use this procedure to determine if line
amplifiers are required:
1. First, calculate the distance from the
antenna to the most distant receiver.
2. Add the assumed worst case loss
through the HP 58516A in terms of
cable length.
3. Compare the result to the requirements
for line amplifiers below. If line amplifiers
are required, they should be added as
close to the GPS antenna as possible
(within 10 meters/33 feet).
6. REQUIREMENTS FOR LINE AMPLIFIERS
6.1. This section provides information that will
help you determine if line amplifiers are required
for your GPS antenna system installation.
For LMR 400 cable:
6.2.
If the estimated cable length between the
antenna and the most distant GPS receiver is
(include the assumed worst case loss through
the HP 58516A):
•
Less than 115 meters (377 feet), no line
amplifier is necessary.
•
More than 115 meters (377 feet) and
less than 240 meters (787 feet), you
need 1 line amplifier.
•
More than 240 meters (787 feet) and
less than 360 meters (1181 feet), you
need 2 line amplifiers.
•
More than 360 meters (1181 feet),
contact HP for assistance.
For RG-213 cable:
6.3.
If the estimated cable length between the
antenna and the most distant GPS receiver is
(include the assumed worst case loss through
the HP 58516A):
•
Less than 53 meters (174 feet), no line
amplifier is necessary.
•
More than 53 meters (174 feet) and less
than 105 meters (345 feet), you need 1
line amplifier.
•
More than 105 meters (345 feet) and
less than 158 meters (518 feet), you
need 2 line amplifiers.
•
More than 158 meters (518 feet),
contact HP for assistance.
7. INSTALLATION
7.1. This section provides information on
installing the distribution amplifier.
1. Connect the cable from the GPS antenna to
the antenna input connector.
2. Connect the initial GPS receiver to the "Port
1" connector. The receiver at this port
provides dc power to the distribution
amplifier and the GPS antenna. Additional
receivers can be connected to any of the
other port connectors.
8. MAINTENANCE
8.1. There is no periodic maintenance
required for the distribution amplifier. However, it
is recommended that all components of the
antenna system be checked periodically and
replaced, if necessary, as specified in company
procedures.
HP 58516A Data Sheet.pdf
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