DRAKE DD860 Manuale
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DD860 DIGITAL DEMODULATOR
TM
12 POSITION RACK MOUNT
DIGITAL DEMODULATOR
DD806
DD806
SNR
LOCK
CHANNEL
SNR
LOCK
40 dB
40 dB
0
4
1
ERROR
ERROR
15 dB
15 dB
DD860 SATELLITE DEMODULATOR
The R.L. Drake model DD860 Digital
Demodulator is a professional quality modular
digital headend component designed to provide
optimum performance for VSB or QAM
demodulation. The DD860 receives an 8 VSB,
16 VSB, 64 QAM, or 256 QAM signal from a
terrestrial broadcast or CATV feed in the 54 to
858 MHz range, and demodulates the signal
providing an MPEG-2 digital transport stream
output.
The DD860 normally provides two 75 Ohm,
serial ASI outputs. A parallel SPI output is
available on special order.
Front panel signal to noise ratio and staus
indicators are provided.
R.L. DRAKE COMPANY
230 INDUSTRIAL DRIVE
FRANKLIN, OHIO 45005 U.S.A.
CUSTOMER SERVICE AND PARTS TELEPHONE: +1 (937) 746-6990
TELEFAX: +1 (937) 743-4576
WORLD WIDE WEB SITE: http://www.rldrake.com
is a trademark of the R.L. Drake Company
TM
is a registered trademark of the R.L. Drake Company
®
© Copyright 2003 R.L. Drake Company
POWER SUPPLY
DIGITAL DEMODULATOR
DIGITAL DEMODULATOR
DD806
PS8
CHANNEL
SNR
LOCK
CHANNEL
40 dB
0
4
1
0
4
1
ERROR
15 dB
A low phase noise tuner design provides
reliable operation with dense signal constella-
tions such as 256 QAM or 16 VSB.
An NTSC co-channel rejection filter for VSB
modes is incorporated.
A wide range equalizer eliminates multipath
effects.
QAM modes incorporate auto selection of ITU
A (DVB) or ITU B (DigiCipher II)
FEC.
IRC and HRC channel plans are selectable by
moving an internal jumper.
The DD860 is designed to mount in the
DRMM12 rack mounting cage.
P/N: 3852380A-1-2003
Printed in the U.S.A.
FRONT PANEL CONTROLS AND
POWER SUPPLY
DD806
F2
SNR
40 dB
15 dB
F1 - LOCK
This indicator shows that the demodulator is
receiving a valid digital signal and has locked
to it.
F2 - LED Signal-to-Noise Ratio Meter
Indicates the signal-to-noise ratio of the
received signal. The range is between 15 dB
and 40 dB. Threshold levels are nominally
15 dB for 8VSB, 29 db for 16VSB, 23 db for
64 QAM, and 28dB for for 256QAM. These are
minimum levels required for lock. Normal
operating levels must exceed threshold by
several dB to ensure reliable operation.
F3 - CHANNEL Selector Switch
This switch is used to enter the two or three
digit channel number. The range of numbers is
also used to determine the mode of operation.
F4 - ERROR
This indicator shows that the FEC is not able to
correct all errors in the received signal. Check
for a low signal-to-noise ratio or improper
antenna aiming if errors occur.
CONTROLS, INDICATORS AND CONNECTIONS
INDICATORS
F1
R1
DIGITAL DEMODULATOR
LOCK
CHANNEL
R2
F3
0
4
1
ERROR
F4
Figure 1
R1
R2
Figure 3 (SPI)
R1 - RF INPUT
This "F" type connector is the input for the
tuner. The DD860 will tune to all U.S.A. off air
broadcast frequencies or to standard EIA CATV
channels up to 858 MHz (channel 134).
R2 - DC Power Connector
This is the power input connector. Connect to a
Drake PS8 or equivalent power supply.
R3 - BNC Connectors (ASI output model)
These are the MPEG2 transport stream
outputs. The ASI (Asynchronous Serial
Interface) Output Impedance is 75 Ohms.
R4 - 25 Pin SPI LVDS OUTPUT Connector
(SPI output model)
This is the MPEG2 transport stream output.
The DVB Synchronous Parallel Interface levels
comply with low voltage differential signalling
specifications.
2
REAR PANEL CONNECTIONS
RF INPUT
13
25
ASI TRANSPORT
STREAM OUTPUT
14
POWER
1
+12 V GND +5 V
+12V GND +5
R3
Figure 2 (ASI)
RF INPUT
13
25
ASI TRANSPORT
STREAM OUTPUT
14
POWER
1
+12 V GND +5 V
R4