Computer Automation Technology

Connecting a CAT to a Kenwood TKR-720 or TKR-820.

Connecting a CAT controller to a Kenwood TKR-720 or TKR-820 Repeater can be accomplished easily by following these steps.

Build a interconnect cable with a DB-25 male connector on one end and a 15 pin Molex connector on the other end. (Note: a pre-built cable can be special ordered from CAT).

 

TKR720 TKR820

 

Note: Install a 2200 ohm pull-up resistor on the controller board at the COR #1 position. Set dip-switch #1 to the ON position for an active low COR.

Connector is a male Molex catalog #1625-15PRT (.062 inch pin spacing)

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

USB to RS-232 Converter Cables

Computers today do not have a RS-232 port. Since CAT products communicate using RS-232 this presents a problem. The solution is to purchase a USB to RS-232 Converter Cable and install its accompanying software on your computer. When the cable is plugged in, a “VIRTUAL COM PORT” will be created. All of the CAT editor programs can only be assigned to COM1, through COM4. Sometimes the software will create a COM5 or higher. In this case you must reassign the COM port’s number to work with the CAT editors.

 

To reassign the COM port follow the procedure described below:

1. Click START.
2. Click CONTROL PANEL.
3. Click SYSTEM.
4. Click the HARDWARE tab.
5. Click DEVICE MANAGER.
6. From the list of devices click the [+] box next to Ports (COM & LPT) to display: “Your Converter Cable Name” USB-to-Serial Comm Port (COM?).
 
If (COM?) is COM5 or above it must be changed to a COM port between COM1 and COM4 to operate with the CAT Editor programs.

7. RIGHT CLICK on “Your Converter Cable Name” USB-to-Serial Comm Port (COM?).
8. From the drop down box click PROPERTIES.
9. CLICK on the PORT SETTINGS tab.
10. CLICK on ADVANCED.
11. CLICK on the COM PORT NUMBER cell.
12. From the drop down box select an unused COM port below COM5 CLICK OK and return to the DESKTOP.
13 Repeat steps 1 through 6 to verify “Your Converter Cable Name” USB-to-Serial Comm Port (COM?) has been changed to the new COM port setting.

 

CAT products only require three connections to the RS-232 port. They are pins 2, 3 and 5 of the standard 9 pin “D” connector. When connected to a CAT product, pin 7 is connected to pin 8 and pins 1, 4 and 6 are connected to each other. This is a standard connection when these pins are not being used. This does not cause a problem with a standard RS-232 port. However two of the cables tested show excessive jitter and the CAT products were unable to decode the signal properly.

It was determined that when pin 6 was disconnected from pins 1 and 4 the signal from the computer was stable, jitter free and easily decoded by the various CAT products.

In summary make sure the virtual COM port that is created can be found by the CAT software and if you encounter jitter of the RS-232 signal from the USB to Serial Converter cable remove pin 6 from the 9 pin “D” connector.

Computer Automation Technology recommends the EasySink Model ES-U-1001-C100 Premier USB-RS232 Adapter cable. This cable can be purchased from the EasySink USA web store at http://www.easysync-ltd.com/

Computer Automation Technology tested the Digitus Model PL-2303 Adapter cable. This cable can be purchased from the Digi-Key web store at http://www.digikey.com/. The Digi-Key part number is AE1488-ND. This adapter exhibited the jitter problem. It was necessary to remove pin 6 from the 9 pin “D” connector.

 



Repeater “Death-Ray”

The Repeater Death-Ray provides a simple method of connecting a control receiver to your repeater system without having to use port #2 of the CAT controller. When a signal with the proper CTCSS tone is received by the control receiver, relay K1 will activate disconnecting the repeater’s receiver from the input of the controller. This will instantly stop the interfering signal on the repeater’s input. The control receiver will now temporally become the repeater’s receiver. The control operator can enter commands to turn the repeater off without having to fight to over power the interference.

 

DeathRay

 

 



Connecting a CAT to the Motorola Maxtrac
and Radius line of mobile transceivers.

Connecting a CAT controller to a Motorola Maxtrac and Radius series transceiver radios can be accomplished by following the interconnections below.

 

Build a cable with a Male DB25 connector on one end of a 5-wire conductor cable (Plugs into the CAT controller). The other end of the cable will be soldered to the accessory connector that plugs into the Motorola radio. Wire the cable as follows:

FUNCTION
CAT controller
Accessory Connector.
Signal Function
 Signal and Logic Grounds  Pin 17  Pin 7  Ground
 Receiver COR #1  Pin 6  Pin 8  COR
 Receiver Audio  Pin 13  Pin 11  Discriminator Audio
 Transmitter Audio  Pin 11  Pin 2  TX Microphone Audio
 PTT #1  Pin 10  Pin 3  Transmitter PTT

 

GM300

 

 

Notes:
1) A jumper connection on the accessory connector between pin 15 and pin 16 will activate the internal speaker.

2) Since the transmit audio input to the Motorola radio is microphone audio, it's advisable to attenuate the TX audio output of the CAT controller. Some CAT controllers have a 100 ohm resistor from the TX audio output to ground that can be inserted with a jumper plug. If your controller does not have the 100 ohm resistor jumper option, solder a 100 ohm resistor between the TX audio output and ground.

3) The Accessory connector (16 pins) carry the following part numbers:
    A) Connector housing AMP 104422-1
    B) Connector pins (Tin Crimp) AMP 1-87309-3