Comtech EF Data LNB User Manual
Page 9
LNB Low-Noise Block Downconverter
Revision 0
Preface
MN-LNB
xi
4B4B
Installation Guidelines Regarding Power Line Quality
The LNB is reliant on a continuous DC power source and high stability 10MHz reference for
operation. These can be supplied by L Band modem with optional LNB supply and 10MHz reference
over outdoor coaxial cable or at the antenna from Comtech EF Data LPOD family of outdoor amplifier
BUCs with optional LNB supply feature. In the case where the LNB is mated with our LPOD product the
following cautions should apply.
IMPORTANT
Comtech EF Data has become familiar with the varying quality of the AC
power grid around the world. Observing the following installation guidelines
should help ensure a reliable installation.
•
Surge suppression: High voltage surges can cause failure of the power supply. These surges
are typically caused by circuit switching on the main AC power grid, erratic generator
operation, and also by lightning strikes. While the LPOD does have built in surge
suppression, if the unit is to be installed in a location with questionable power grid quality,
Comtech EF Data recommends installation of additional power conditioning/surge
suppression at the power junction box.
•
Grounding: The LPOD provides a grounding terminal. This is provided to allow the user to
ground the LPOD to the antenna’s grounding network. All components installed at the
antenna should be grounded to a common grounding point at the antenna.
•
Electrical welding: If welding needs to take place at the antenna, disconnect all cables from
the LPOD except for the ground wire. Cap all RF connections with terminations. This will
prevent damage to the input/output circuitry of the LPOD.
•
Lightning: Lightning strikes on or around the antenna will generate extremely high voltages
on all cables connected to the LPOD. Depending on the severity of the strike, the LPOD’s
internal surge protection combined with the recommended external suppression may protect
the LPOD’s power supply. However, if the installation will be in an area with a high
probability of lightning strikes, Comtech EF Data recommends the installation of surge
suppression on the RF and IF cables. One source of these suppressors is PolyPhaser
.