24
StarBand
®
Field Service & Maintenance Bulletins
StarBand
®
Field Service & Maintenance Bulletins
©2004-2013,
Recommended Action
Unless sophisticated RF test equipment is available at the customer's
VSAT, such as an Agilent E4411B spectrum analyzer, the process of determining the
presence of interference from a radar detector is one of observation and testing.
Identifying an Outbound Reception Problem
First, the problem must be isolated to an outbound reception problem. The procedure to
follow to determine an outbound reception problem is provided in StarBand
®
Field
Service Bulletin SB-0016,
LNB Troubleshooting
. Also, SB-0020,
IFL Troubleshooting,
should be referenced, to determine if the receive IFL is functioning properly. If the
outbound problem has been determined to not be associated with the StarBand
®
antenna,
LNB, receive IFL, satellite modem or configuration parameters, the problem could be a
radar detector interference problem. Since radar detector problems are rare, it is
recommended that the StarBand
®
VSAT be checked thoroughly first. Outbound
problems due to faulty antenna peaking, LNB, IFL, satellite modem or parameters are
typically always present, while RF interference problems are usually intermittent.
Search for Active Radar Detectors
To cause interference, radar detectors must be powered on and near the VSAT antenna,
with a clear line-of-sight. At the VSAT antenna, look around in all directions to see if
there are vehicles present in the field of view of the VSAT antenna. Since most vehicles
are in-route when radar detectors are turned-on, continuous interference from radar
detectors is most often due to parked cars with radar detectors left on or a VSAT
installation near a busy traffic area.
Spectrum Analyzer Test Set-Up
This test should only be performed if a high quality spectrum analyzer, such as an
Agilent E4411B, and a trained RF technician are available. The receive L-Band IFL
spectrum can be observed, to determine if radar detector interference is present.
Connect the spectrum analyzer as shown in the figure on the previous page and observe
the 950-1,450 MHz spectrum, to see if interference is present.
Removing the Interference
Once a potential source of radar detector interference has been identified, the source
should be turned-off or blocked. Asking the owner of a parked vehicle to turn off their
radar detector should be attempted first. In some states, radar detectors are illegal. This
can potentially be a volatile issue among neighbors and should be handled with the
utmost diplomacy.
Temporary shielding is a more involved effort, as a physical barrier is required between
the source and the VSAT, to block the radar detector signals in the 11.7-12.2 GHz band.