Motorola SG 2000 operation manual DS SG2 DRT/A Digital Return Transmitter, DS-SG2-DRT/A

5 - 2 0 O p e r a t i o n

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

RF TP	Optical
	TP

Return

band RF 5-42 MHz

Anti-

aliasing

LPF

CATV

gain block

Serial bit	Digital
stream	lightwave to
@1.6 Gbps	SG2 output

		Transmit
RF	A/D	signal	Serializer
XFMR	converter	processing
		logic

Optical transmitter module

XO XO

Figure 5-22 illustrates the DS-SG2-DRT/A and attached cable:

Figure 5-22

DS-SG2-DRT/A

Digital Transmitter

STATUS 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).

SG 2000 Installation and O peration Manual