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  Make a Vertex VXR7000 Work
With a CAT300DX Controller

By Billy Singleton K4ACT
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Modify the Repeater:

Verify you have the correct model for the frequency of your repeater: VXR7000 VHF: 136-150 (a), 150-174 (c).

The VXR7000 does not have a "COR with PL Output" on the rear DB25 accessory jack. However, you can easily add that capability. See the COR Mod courtesy of Scott Lintsinn KB0NLY here.

Program the Repeater:

With the radio and computer power OFF, hook up the programming cable to the serial port on the PC and plug the 8-pin mic plug into the radio.

Turn on the PC and install the CE27.EXE and CE27.HLP files on your PC.

On the PC, right click on "My Computer" then "Device Manager" then scroll down and right click on "COM Port" then click on "Settings". Port settings need to be 4800 Baud, 8 Data Bits, No Parity, 1 Stop Bit, Flow Control=Hardware.

Start CE27.EXE then click on "Read from Radio" on the task bar. The software should load the current configuration of the radio. After loading the information, edit the following data on the screen. Scroll right to see the rest of the fields on the screen. Consult the VXR-7000 CE27 Programming Manual for more information.

Field NameSet To
Ch 01Choose this row
Rx Freq.Your Frequency
Decoders: CTCSS/DCSYour Tone/Code
W/NWIDE
Clk SftNO
NSQ: Mode/LvPRPGM
Court BlipOFF
Rev BstON
DCS TypA
DDec TypeFIXED
Multi ToneNo
CWID ANI/ENIOFF
Action ModeDUPLEX
TX Freq.Your Frequency
Encoders: CTCSS/DCSYour Tone/Code
Base TOTNO
Base GuardOFF
LOUTBTLO
TX PwrHI
TOT MuteOFF
RPT TOT UseNO
RPT TOT BeepNO
RPT HTNO
RPT GTNO

Click in each setting to set. Set your RX and TX freqs. Set your CTCSS/DCS tones. Set all the other fields as posted above.

All timers must be off for external (CAT300DX) control. LOUT must be set to BTLO to allow tone only access to the repeater's receiver. If you wish to have the repeater open (no tone) set LOUT to "OFF".

On the CE27 software tool bar click "Save File" and give it a name. I named mine the repeater's call sign. Then on the CE27 tool bar click "Send to Radio". A screen will pop up showing data sent. Programming is complete!

Make the Interface Cable:

Here is the CAT300DX to VXR7000 DB25 cable configuration. Consult the CAT300DX Manual or the VXR7000 Repeater Operating Manual for connector details.

SignalCAT PinConnect WithVXR7000 Pin
COR62.2K resistor10
PTT10Wire12
TX Audio11Wire3
RX Audio13Wire6
Ground17Wire7
Power PlugTIPWire2
Power PlugSHIELDWire1

Bring the DC power wires outside the DB25 hood and attach to the 2.5mm power plug. The VXR7000 can supply up to 1A to an external controller, therefore it can power the CAT300DX, which only draws 80mA, through the DB25 accessory plug as seen above.

The 2,200 ohm resistor is needed in series with the COR line. I soldered mine to the DB25 pin 6 of the CAT300DX then soldered the wire to the resistor inside the DB25 hood and insulated the joint.

Configure the Repeater:

Set VXR7000 front panel switches as follows:

Configure the CAT300DX:

You will need to set the COR Input DIPswitch for active-low. See the CAT300DX manual for its programming.

This is all you will need to interface the CAT300DX to the VXR7000 Repeater with Tone Control.

Contact information:

The author can be contacted at: k4act [ at ] yahoo [ dot ] com.

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This page originally conceived on Monday 22-Sep-2014



Article text © Copyright 2014 by Billy Singleton K4ACT.
Article layout and HTML conversion © Copyright 2014 by Robert W. Meister WA1MIK.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.