Motorola VSWR, Service Manual Supplement

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General description of the VSWR monitor
5th Feb 99 Service Manual Supplement: VSWR Monitor for M-Cell 6
68P02900W86-O
1–1
General description of the VSWR monitor
Introduction to
the VSWR
monitor
This supplement describes the features of the EGSM 900 VSWR Monitor (VM) and how
it can be configured to suit most application requirements.
Purpose of the
VSWR monitor
The VM is for use in M-Cell 6 Indoor (or equivalent) BTS systems. Each VM can monitor
the VSWR performance of a single BTS sector, assuming the sector has no more than
three antennas and there is only one Tx antenna in the sector. If duplexers are used then
additional VMs will be required.
The VM is designed to be installed in the Tx/Rx lines between the BTS and the antenna.
It monitors the RF signals by means of side-mounted dual directional couplers. An
integral mounting bracket is fitted to the base of the VM.
The VM requires an external –48 V dc power supply, which must be provided by the user.
Alarm outputs are provided to connect the VM to an external PIX alarm connector on the
BTS (refer to the appropriate section of the M-Cell
6 Service Manual for information on
wiring alarm sensors to the PIX connector).
Figure 1-1 shows the main features of the VSWR monitor:
DC POWER
CONNECTOR
ALARM
CONNECTOR
CABLE LOSS
COMPENSATION JUMPERS
ANTENNA RF COUPLERS
(RX)
ANTENNA RF COUPLER
(TX)
BTS RF COUPLERS (RX)
BTS RF COUPLER (TX)
MOUNTING
BRACKET
POWER
LED
ALARM
LEDs
Figure 1-1 VSWR Monitor