User Manual

AS4000 Wireless Local Loop

System Overview

GSI 002

605-0000-430

Issue 1.2 Date 7/4/99

Page 9 of 8

• a Low Noise Amplifier (LNA) module, which amplifies the low-level receive signal, after

filtering but before splitting.

• a Shelf Monitor Card, which collects information from the PAs, LNA and PSUs, and

passes it to the Shelf Controller Cards.

Lamp

Test

Test Trunks

Green

White

Red

Receiving

Attention

Power OK

Prompt/

Deferred

Instation/

Clear

DC SUPPLY

OFF

RF1 RF2 RF3 RF4 Mon1 Mon2

Diplexer and

Low Noise

Amplifier

DIP/LNA 1

TX Filter

DIP/LNA2

Alm55B

PSU1 PSU2 PSU3

PA1

PA2

1+ 1- 2+ 2-

Figure 18. RF Combiner Shelf

• Three PSUs to provide the interface between the local DC power source and the

equipment of the AS4000 CT Rack. The shelf contains two circuit breakers, to give

protection by using two independent DC supplies, and three PSUs which supply a

nominal 13.5V DC. The input to the PSU can be in the nominal range of −24 V to −

60 V.

• Power for the RF cards is provided from a PSU contained in the combiner monitor card

and a redundant monitor card containing only a PSU is used to provide power backup in

the event of failure of the monitor card PSU.