The VXR-1000 is a mobile repeater meant to be used with a mobile radio in a vehicle. Since these 5W output analog radios are designed for interfacing with other equipment via a single dsub connector and are fairly compact, they’re good candidates to use as an embedded radio in various industrial applications. In this post I document what I needed to do to get one up and running.

Programming

The programming software for these radios from Vertex Standard is called CE22. The software can be found online for purchase. Experimentally, v1.06 was needed to successfully program my radio with firmware v2.10. Newer versions of the software were able to read from but not write to the radio.

The programming cable this radio needs is the Vertex Standard VPL-1. Rather than buying a cable, I made one using an ethernet cable. This post from LA2YUA discusses the pinout and how to connect the “CLONE” signal to standard 5V UART TX and RX signals. These can be connected to a generic USB/UART adapter.

Usage Notes

There are some minor details about the radio settings and CE22 software UI that took a moment to understand. Here are some pointers on using the UI and configuring the radio’s settings. The radio settings are what I found work well for treating the VXR-1000 as a generic radio rather than a repeater system.

• Note that the “Upload” function reads the data from the radio and “Download” function writes the data to the radio.
• Channels are activated/deactivated using the space bar. Click on the channel number on the left and then hit spacebar to make it editable or not.
• “MOD In” should be set as “Mix”.
• “MBL. Moni” should be enabled so that the 3.5mm audio jack on the rear of the unit plays the audio both being transmitted and received by the unit. This assumes that you’re getting your functional TX and RX audio signals from the dsub connector and that the 3.5mm would be used for debugging the system so hearing both feeds is desired.
• “MIC Ctrl” should be “Int”.
• “EXT.R Ctrl” should be “On” to use the unit for both TX and RX.
• Everything else can basically be left off.

Pinout

The 9-pin male dsub connector on the back of the VXR-1000 provides connections for power, audio, and control signals. The description of the pin functionalities takes some deciphering for using this unit as a standalone radio. Here is the basic pinout for use as a generic radio.

1. GND
2. RX Audio Output
3. Power Control
4. Unused
5. VCC
6. TX Audio Input
7. PTT Input (Active High)
8. Unused
9. Unused

The “PTT Input” is meant to be connected to the mobile radio’s carrier operated relay (COR) for repeater use. This is an active high input that seems to activate at around 3V by default. The threshold can be adjusted via VR1003 if necessary.

Internal Jumpers

Generally these can be left as stock. One modification I would recommend depending on your particular application would be configuring the radio to power on by default, rather than needing an explicit power control input via dsub pin 3. By default, the input power is internally switched using this signal. When the control signal off, the unit consumes essentially no current (<1uA). This feature isn’t really useful for me, so it can be disabled by setting JP1001/JP1002/JP1003 as CLOSED/open/CLOSED. The photo below shows the location on the assembly drawing from the service manual with solder blobs in blue.

Input Power

The current consumption of a single VXR-1000 operating at ~460MHz was measured for 12V input.

| RF    | Current |
| ----- | ------- |
| Idle  | 0.21A   |
| RX    | 0.22A   |
| 0.5W  | 0.66A   |
| 1.0W  | 0.88A   |
| 2.5W  | 1.28A   |
| 5.0W  | 2.13A   |

Limitations

One thing to note which may outright discount this unit for use in some applications is the way that the VXR-1000 transmit control and receive CTCSS/DCS decode. The unit does not have a direct PTT input, but rather a carrier operated relay (COR) input from the mobile radio it’s supposed to be paired with. If the VXR-1000 is receiving and the COR input signal goes high (which typically triggers the VXR-1000 to retransmit), it will not transmit until both the mobile COR and VXR-1000 receiver COR both go low. Unfortunately, the VXR-1000 COR activates even without valid CTCSS/DCS decode. This means that background noise could effectively lock out the VXR-1000’s ability to transmit.

There is a workaround which may work depending on your application. Each channel has a “Sql Ofst” field which allows adjustment of the squelch. A value from 0 to 100 allows you to set the squelch higher without realigning the unit. A value from 101-255 appears to completely deafen the receiver. This means you’ll never have to worry about the VXR-1000 COR locking out your ability to trigger the unit to transmit. This works fine for my application, but it’s a pretty serious limitation for use in a typical commercial radio environment.

Resources

These websites have extremely useful information about the VXR-1000. Many thanks to the authors!

• Service Manual (UHF) - Kevin Custer W3KKC, repeater-builder
• Service Manual (VHF) - Kevin Custer W3KKC, repeater-builder
• Connecting a VXR-1000V/U Extender to a System Fusion DR-1X - Scott Lichtsinn KBØNLY, repeater-builder