Motorola Starline SG 2000 - Page 84

5-20 Operation
SG 2000 Installation and Operation Manual
DS-SG2-DRT/A Digital Return Transmitter
The DS-SG2-DRT/A is an SG2 return transmitter that digitizes a single analog 5 MHz-42 MHz
return-path signal to produce a 1.6 Gbps data stream. This data stream is then routed to a digital laser
for transmission to a corresponding digital return receiver.
The transmitter can be configured with a digital laser wavelength that is applicable to the required
link length. An automatic power control (APC) system regulates the optical output power from the
laser. User-accessible input level-control adjustments enable you to adjust the transmitter +2 to
−13 dB from an input level of 15 dBmV. All transmitter status-monitor information is available at
the digital return receiver.
To facilitate easy upgrades, the DS-SG2-DRT/A fits the same footprint and has the same set-up
levels as the analog return transmitters.
Figure 5-21 illustrates a block diagram of the DS-SG2-DRT/A:
Figure 5-21
DS-SG2-DRT/A
Serializer
Transmit
signal
processing
logic
A/D
converter
RF
XFMR
XO
Anti-
aliasing
LPF
Return
band RF
5-42 MHz
CATV
gain block
Digital
lightwave to
SG2 output
Optical transmitter module
Serial bit
stream
@1.6 Gbps
Optical
TP
RF TP
XO
Figure 5-22 illustrates the DS-SG2-DRT/A and attached cable:
Figure 5-22
DS-SG2-DRT/A
INPUT
A
STATUS
SG2000
Digital Transmitter
DANGER
DS-SG2-DRT/A
1310 DFB
Test
Point
A
You can gain access to test point A through the transmitter test cable MCX-F (DS-SG2-DRT-TC,
P/N 476803-001).