Motorola Starline SG 2000 Installation And Operation Manual page 84

5 - 2 0 O p e r a t i o n
D S - S G 2 - D R T / A D i g i t a l R e t u r n T r a n s m i t t e r
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:
F i g u r e 5- 21
DS -S G2- DRT / A
Return
band RF
5-42 MHz
Anti-
aliasing
LPF
CATV
gain block
Figure 5-22 illustrates the DS-SG2-DRT/A and attached cable:
F i g u r e 5- 22
DS -S G2- DRT / A
You can gain access to test point A through the transmitter test cable MCX-F (DS-SG2-DRT-TC,
P/N 476803-001).
S G 2 0 0 0 I n s t a l l a t i o n a n d O p e r a t i o n M a n u a l
RF TP
RF A/D
XFMR converter
XO
Test
Point
A
Serial bit
stream
@1.6 Gbps
Transmit
signal
Serializer
processing
logic
XO
SG2000 Digital Transmitter
INPUT
STATUS DS-SG2-DRT/A
A
1310 DFB
Optical
TP
Digital
lightwave to
SG2 output
Optical transmitter module