MRC DRS4000, Руководство пользователя и техническое руководство

Страница: 68 / 88

Installation 4-6 DRS4000 Receiver User and Technical Manual
use and record them for use with the receiver:
- RF Band: 2 or 7 GHz
- Channel
- Modulation mode: DVB-T or LMS-T
- Modulation type: QPSK, 16QAM, or 32QAM
- Bandwidth: 6, 7, or 8 MHz
- Guard interval: 1/32, 1/16, 1/8, or 1/4
- Video line standard
- Audio: Analog or Digital
6. Power up the receiver and use the Setup menu to
configure it to the same settings as for the transmitter.
Refer to the
“Routine Operation” Chapter on page 2-1
for details.
7. For the receiver, also verify the Factory Setup menu.
Make sure that the Number of Inputs and BCD Type
are correctly set for your configuration.
8. Set the transmitter to Low Power Transmit mode.
9. Verify that the control screen on the receiver displays
a receive carrier level (RCL), signal-to-noise ratio
(SNR), and Link Quality reading for each antenna.
This indicates that each antenna is feeding its
corresponding signal to the receiver.
10. At the end of testing, power down all equipment and
disconnect all cables in preparation for installation.
4.9 Installing Antennas and
Downconverters
To feed the incoming signal to the receiver, you need to properly
install the antennas, downconverters, and associated cabling.
4.9.1 Cabling Practices
To install cabling for optimum performance and ensure minimal
maintenance, MRC recommends the following general practices.
CAUTION Do not run cables where they can be walked on.
Protect cables against pinching and chafing,
especially at locations where the cables enter or
exit an enclosure or make a sharp bend.
CAUTION
Do not install near a UHF transmitter, as the
high signal level will be received by the UHF
cable as though it is an antenna and will cause
the DRS4000 receiver to operate improperly or
not at all.
• Secure the cabling at close intervals along its entire
length.
• Protect the cabling with added sheathing or padding if it
passes through a hole or lays against an obstruction.
• Provide flex relief at any location where the cable must
change direction sharply, to maintain a smooth bend and
prevent kinking.
• Provide strain relief at each connector to absorb any
pulling forces on the cable and prevent damage to the
connector.
4.9.2 Selecting Coaxial Cables
For applications where you must connect the downconverters via
coaxial cables, use high quality 75 ohm UHF cable and use the
shortest lengths possible to prevent UHF signal loss. If long
lengths of cable are required, a UHF amplifier or gain block may