Microsemi SyncSystem 4380A - Page 5

12
100
)(
_
*)
100/(_
)
(_
−=
ft
LengthCable
ftdBLossCable
dBGain
MIN
The MIN_Gain value shown in equation above serves as the minimum gain required from the
line amplifier being used. It is possible to use amplifiers with a slightly higher gain than the
minimum value but it will not improve the performance of the system. Using amplifiers with
significantly higher gain values can also cause degradation of the GNSS signal because it
overdrives the input of the GNSS receiver.
Placement of the line amplifier is also a concern in a properly designed system. Placing the
amplifier too far from the antenna may cause unexpected degradation in the GNSS signal and
the performance will remain poor. The best place for the amplifier is typically half way
between the antenna and the 4380A. This allows the line amplifier to benefit from any surge
protection that may be installed near the antenna, but is still close enough to the antenna so as
not to degrade the signal significantly. Another consideration when installing the line amplifier
is how it will receive power. Some amplifiers are powered using a DC bias on the antenna cable
and others are powered from AC adapters directly. Please contact Microsemi if you require
assistance in selecting the right amplifier for your application.
Q10: How do I know if the GNSS signals are good?
A10: To determine if the carrier to noise ratios (C/N
o
) of the GNSS signals that are being
received by the unit are within their normal operating range, initiate a Telnet communication
session with port 1700 of the 4380A via the Ethernet connection on the rear panel of the unit.
Once at the “4380A>” command prompt, enter status gps as shown in the example below:
4380A>status gps
[auto_positioning]
[time_remaining] 0 seconds
[mode]
[tracking]
[value] 4
[model]
[hw_version] OEM628-2.01
[name] G2SB0GTTN
[serial number] FBN15160339
[sw_version] OEM060220RN0000
[position]
[alt] 1.590260000000000e+03
[fixed] true
[lat] 4.001941930600000e+01
[lon] -1.052390921940000e+02
[satellite]
[number] 10
© 2016 Microsemi Corporation. All rights reserved. SyncSystem 4380A FAQs Version 1.0 (22 Feb 2016)
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