Paging system operation – Codan Radio MT-3 User Manual

Page 25

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MT-3 ANALOG RADIO SYSTEMS | USER GUIDE

Chapter 3: Analog Radio System Confi gurations Page 17

PAGING SYSTEM OPERATION

The MT-3 modules may be confi gured to operate in digital and/or analog paging confi gurations, such
as base station paging, remote paging or simulcast paging using the CI-PM-3 paging modulator. The
CI-PM-3 is confi gured via the front panel switches and internal jumper settings.

The CI-PM-3 paging modulator supports both analog and digital paging formats, and can transmit
POCSAG and other 2-level modulation schemes at transfer rates of 512, 1200 and 2400 baud. It can
also be confi gured for use as a data repeater, whereby 2-level paging data is recovered, re-shaped and
then re-transmitted to an additional repeater/paging transmitter.

The CI-PM-3 supports 4-level modulation formats at data transfer rates up to 6400 bps. Each of the
four modulation deviation levels can be independently set, making the CI-PM-3 suitable for use in such
pager signaling schemes as Motorola’s FLEX™ paging protocol.

The receiver, transmitter and CI-PM-3 paging modulator are shown in Figure 3-5.

Figure 3-5: MT-3 Analog / Digital Paging system shown with one pair of transceivers

The CI-PM-3 uses an on-board frequency reference source consisting of a 10 MHz OCXO with
a frequency stability of +/- 0.35 ppm from -30 C to +60 C. For high stability applications (such as
Simulcast), the CI-PM-3 paging modulator may be confi gured to use an external high stability reference
source (i.e. rubidium, GPS or WWV) with a standard stability greater than or equal to 0.002 ppm, to
discipline the on-board phase-locked loop OCXO oscillator.

The CI-PM-3 has a current draw of less than 250 mA.

SET

DEV

4 LEVEL

SETUP

MODE

DATA

MODE

A

D

2 LEVEL

SET

MOD

NORM

REF IN

REF OUT

PAGING

MODULATOR

DATA

INT

FREQ

REF

EXT

DATA / CTRL

PORT

PULL DOWN
TO REMOVE

T X

REFERENCE

INPUT

OFF

KEY TX

MIC

RF OUT

NORM

TRANSMITTER

FREQUENCY (MHz)

MADE IN CANADA

MODEL # CODE

SQ . DI SA B L E

N

O

RM

O

F F

RF N

I

REFERENCE

INPUT

RECEIVER

FREQUENCY (MHz)

MADE IN CANADA

MODEL # CODE

VOL

SYSTEM REGULATOR

METER

+

-

MADE IN CANADA

ON
OFF

SPKR

INT

EXT

EXT

SPKR

OFF

POWER

ON

2

1

5

4

3

6

7

8

11

10

9

FUNCTION

12

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