Computer Automation Technology

Interfacing a CAT-250 to M/A COM Master III

This CAT Note describes the wiring between a (GE) M/A-COM MASTER-III and the CAT-250 Controller. Connection is made between the CAT-250 and the 2/4-wire 600 ohm balance line ports that would normally be used to connect a remote console via D.C. or tone remote control over telephone lines. The MASTER-III Control Shelf Personality was setup as 4-wire D.C. Remote Control. The digital pots were optimized for audio Input/Output levels of -10 dBm at the 4-wire line terminals with full system deviation. Please note that User Output #1 was configured in this example to control the MASTER-III CG Monitor (PL Disable) function from the CAT-250 controller but any of the available User Outputs may be selected.

M/A-COM MASTR-III

CAT-250 Repeater Controller

P2-1

A+

J3-CNTR

+ 12 VDC INPUT

P2-2

DGND

J3-RING

GROUND

P2-14

RMT REPEATER PTT IN

J2-10

PTT #1

P3-5

COR

J2-6

COR #1

P3-8

CG MON

J2-14

USER OUTPUT #1

P3-16

RUS

J2-4

CTCSS #1

J109-2

DUPLEX AUDIO (+)

J2-11

TX AUDIO #1

J109-5

DUPLEX AUDIO (-)

J2-17

GROUND

J109-3

LINE AUDIO (+)

J2-13

RX AUDIO #1

J109-4

LINE AUDIO (-)

J2-18

GROUND

Install a 680 ohm resistor across RX AUDIO #1 to ground as this is needed to provide a proper termination for the Master-III Line Output. Remove the jumper block from J8 of the CAT-250 to option the input stage for de-emphasized audio as supplied by the Mastr-III. Strap J-104 (2-3) and J-105 (2-3) on the Mastr-III T/R Board.

 

Channel Data

Ch

1

Rpt

N

Tx Freq

XXX.XXXX

Rf Sim

No

Tx Cg

XXX.X

CCT

0

BW

25

DODT

0.0

Rx Freq

XXX.XXXX

Tx Pot

250

Rx Cg

XXX.X

Cg Pot

95

Cg Lvl

Low

Pa Pwr

95

Ste

Y

 

 


Control Shelf Options

Battery Alarm

Disabled

Voting System

Disabled

Logic Standby

Disabled

Control Line

4 Wire

Intercom

No

Sidetone

No

Reference Freq

Internal

Rx Option

None

Circulator

Disabled

DTMF

Disabled

Synth. Part No

New

Digital Pager

Disabled


Morse Code Options

Mores Code

Disabled

Wait

5

Ch

1

Tx Required

Yes

MCID Enabled

Yes

ID With Keys

No

ID Text

EGEMASTER

Tx Pot

No

Interval

30

ID On Ch Change

No


PTT Options

Repeat

CCT, DODT, CG ENCODE

Remote

CG ENCODE  

Local

CCT, CG ENCODE  

External

CG ENCODE  

Morse Code ID

None


Potentiometer Settings

Line Out

14

Dsp Line In

48

Repeater Gain

816

Dsp Compressor

1190

Line In

0

Dsp Comp Level

3157

Dsp Line Cancel

0

Squelch Pot

Manual


Information courtesy of WA8WG