The home of VK3MGR-VK6MRG

  • Increase font size
  • Default font size
  • Decrease font size


Some information on the tracker VK6MRG-7 

I have installed APRS tracking equipment to my Ute.

My Ute is a Nissan Navara D22 2010 dual cab with the worst motor in history under the bonnet (2.5 common rail). I have a love hate relationship with this Ute and it with me. It's my daily driver and I have installed the following radio gear: 1x MOTOROLA GM339 UHF with a remote head mounted in the roof console and the main unit mounted on the rear of the cab behind the back seat. I have an ICOM 7000 with the remote head mounted on the dash with a Codan mobile auto tuning HF antenna and a 2m/70cm dual band antenna and the Puxing 777 hand held radio with an Argent Data Open Tracker.

 ute arps

The box on the lower centre of the photo is an off delay timer, so the APRS tracker will stay on for about 5 minutes before it automatically switches off. The Argent Data Open Tracker which uses the Puxing 777 hand held radio can be seen under the Motorola speaker. I'm planning on changing the Puxing 777 for an ICOM IC208H so that I can have more power if required. The Puxing is a 5 watt radio and does an outstanding job, but with all the country driving that I do, 5 watts limits the range of the tracker a great deal.


The Radio and tracker are operated via the APO3.

The APO3 is a black box designed to prevent a vehicle battery from being discharged and damaged by a DC load. Typically it is used to switch a radio transceiver off 10 minutes after the vehicle is shut off.

The APO3 is designed for 12 volt vehicle electrical systems with negative ground. It can switch up to 20 amps and carry up to 30 amps. The shutdown voltage can be set to one of four pre-programmed voltages (11.8, 12.1, 12.7, 13.05 volts) using two DIP switches; the shutdown delay can be set to one of four pre-programmed times (0, 5, 10, 20 minutes). The device is housed in a sturdy ABS plastic case.


Puxing PX-777 PLUS VHF Handheld Radio

The PX-777 is an unbeatable value for basic VHF communications, and better than any other radio we've seen demonstrates that Chinese radio manufacturers have finally achieved the level of quality and sophistication that western consumers demand. This radio is easily a match for any of the current generation of entry-level Japanese models, and at a lower price.

The PLUS version adds ANI and scrambler functions. While the scrambler isn't exactly military-grade encryption, it's sufficient to prevent casual eavesdropping and ensure a reasonable degree of privacy.

These radios are FCC Part 90 certified, shipped straight from the factory to our California warehouse, not gray market imports like most you're likely to find online.

The radio ships with a 1200 mAh Li-ion battery, but at a total of 8 ounces (227 grams) it weighs 1/3 less than the comparably-sized VX-150 despite having 70% more battery capacity.

A drop-in charger is included. The provided wall adapter is the standard US two prong type, and functions on 110 or 220 volts. The charger can also be used with any 12-volt, 1 amp source connected to its 2.1 x 5.5mm DC jack.

The speaker/mic connection is identical to the type used by most Kenwood handhelds.

Features include:

  • 5 Watt output power
  • 136 - 174 MHz frequency range
  • 1200 mAh Li-ion battery
  • 128 Memory channels
  • Wide (25 kHz) or narrow (12.5 kHz) operation
  • 3-color display back-light and back-lit keypad
  • PC-programmable  


Warranty: 1 year

This product is for use by licensed operators only.

The OpenTracker+ is the second generation of OpenTracker that Argent Data produced. It is a single through-hole board with two DB9 ports on it, one for programming and GPS data in, and the other port for radio connection.

Features include: - 1200,300, and PSK31 transmit of APRS protocol data. - Encode and transmit data from several supported weather stations. - Report temperature and voltage from on-board sensors - Outputs way-point data for display on various external devices

The firmware is programmable via the OTWINCFG program. The unit does not print all received packets, although it does decode it for efficient channel usage.

The OpenTracker+ has a single port for computer or GPS connection. The OpenTracker2 has two ports for GPS/computer.

open tracker

I have changed the radio in the Ute. I had an ICOM IC 208H dual band radio in the wagon and as I don't use the wagon as much any more I thought I'd use the radio as my tracker radio.

So, I made up the cable for the tracker to connect to the radio and did some testing. After a short drive and checking APRS.FI everything is working as it should. I've mounted the head on the dash next to the IC7000 head so that all the radios are in a central place.

I made a change to the APO3 so that the radio could be switched with the tracker. I added a relay in line with the radio power cable so the APO3 doesn't take the full load current from the radio.

I'm looking at making a delay so the the APO3 will turn off the tracker first and then a few seconds later will turn off the radio. This few seconds will give the tracker time to power down, this will then give the radio time to stop transmitting before the radio turns off.

Just an update on the APRS tracker in the Ute.

I've swapped out the icom ic208h for a Motorola Solutions SMP908 VHF radio. This is not a MOTOROLA Japan radio but a chinese radio from eBay. It cost about $200 delivered at the time (I've had it for a few years now)  and it has been easy to use and intergrate with APRS equipment.

used the microphone cable to make a patch lead to connect the radio to the tracker and though this was easy enough, I couldn’t get anything out of the tracker. I mean, it worked and I had audio when the tracker transmitted but nothing showing on

It turns out the audio processing done in the radio was over driving the audio, so after some time playing with the tracker audio output setting I managed to get the audio level low enough to compensate for this issue. 

Now that I have tested the setup and i'm happy the the results, I will will use the same equipment and settings in the Prado using VK6MRG-8 which was originally used for my wagon.

Radio info is below.

 2016-11-09 10.57.03
 smp-908-spec-vhf s-l300


Last Updated on Wednesday, 09 November 2016 16:53