GTRANS Kenwood TH-D72A

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Connection and Setup of the Kenwood TH-D72A and Garmin Nuvi 350 using the Argent Data Systems GTRANS cable:

What Will This Do?

Connecting your Kenwood D72A to the Garmin Nuvi 350 with the Argent GTRANS cable will give you a tactical display of your current position on the color moving map of the Nuvi. This will show the position, call sign and symbol of other nearby APRS stations relative to your position. The favorites display will list the call signs of nearby APRS stations in order from closest to furthest with their bearing and distance shown from your current position. Both the map and favorites display will refresh, replacing old data with new as new packets are received. The display may be of use to emcomm operators or other APRS hobbyists who wish to have a tactical display. An internet connection is not required. This set up lacks some of the features of the AVMap GeoSat 6 here and has a much smaller screen, but it is considerably less expensive and may be of considerable practical use as a tactical display for many Kenwood APRS users. The Garmin Nuvi 350 is no longer in active production but many can be found on EBay or Craigslist for well under $100. The Argent GTRANS cable takes advantage of the Fleet Management Interface within the Nuvi 350 that allows it to track multiple vehicles and show their positions in real time. The instructions below walk you through the setup of these components.

Components Needed:

Kenwood TH-D72A settings:

Under the | APRS menu:

  • Baud rate [330] = 4800bps
  • Input [331] = GPS
  • Output [332] = Waypoint
  • Format [340] = Kenwood (will make the Nüvi 350 display GPS/"APRS"-like icons).
  • Length [341] = 9-Char (otherwise call signs will be truncated).
  • Output [342] = All (or local or filtered, user's choice).

The above can also be configured using the MCP-4A software from Kenwood.


  • Connect the male 2.5mm mini-jack of the Argent GTRANS cable to the Kenwood TH-D72 female 2.5mm mini jack located under the weather flap labeled "COM" on the right side of the D72.
  • Connect the GTRANS Mini-USB connector to the Garmin Nüvi 350's mini-USB port located on the right side of the Garmin.
  • Connect the Garmin Nüvi 350 to the external 12V dc at the Nüvi's cradle.

(Note: You cannot use the Argent cable to transfer data from the TH-D72 to the Garmin under battery power. The Garmin must be connected to an external power source for this to work).

Power Up:

  • Power on the Nüvi 350, when the battery symbol in the upper right screen corner shows a

lightning bolt, it is operating and communication through the GTRANS cable is started.

  • Power up your TH-D72A
  • Make sure your TNC is on and set for APRS on your Kenwood by pressing TNC. It should show "APRS 12" on the display
  • Make sure that your GPS has a position fix. The icon "GPS" should blink in the upper right corner of the Kenwood display when position is fixed.

To Display the Waypoints and Packet data on the display of the Garmin Nuvi:

  • On the Garmin Nuvi, Select the option "Where to?"
  • Select "My Locations"
  • Select "Favorites." At first this list will be blank. As your radio receives each APRS packet with station position information, it will populate this screen with the call sign received and an arrow showing the distance and bearing to the GPS coordinates received. Stations are listed nearest to furthest from your current position. Stations will refresh their positions with updated positions and the out of date positions will be erased automatically as fresh packets are received.
  • You may either navigate to a listed station or display all stations on the map
    • To navigate to a listed station: select it from the list and hit "Go"
    • To view all stations on the map: return to the main menu by selecting "Back" until you are at the main menu, then hit "View Map." The call sign and Kenwood symbol for the APRS station should be displayed on the map. The station will update its position and erase the old position each time a new packet is received from that station.

To clear the list of favorites and delete all of the received station call signs and position waypoints on the Garmin Nuvi:

After use of the device, before powering down for an extended period, you may wish to delete all favorites you have been tracking in order to clear the list. This allows your next use with fresh position information that will continually update as new information is received. If you don't delete the old waypoints and these stations are no longer sending fresh packets, the next time you power up, these old waypoints will clutter the display with information that is out of date from your last use. If you forget to do this before powering down, you can always do it at the beginning of your next session or at any point during use of the device to "wipe the slate clean."

  • Select "My Locations"
  • Select "Favorites"
  • Select "Delete all"

To clear the list of received station call signs and position waypoints on the Kenwood D72A:

While in list mode, a single press of the A/B button will ask you if you want to clear that single listing. Press the right toggle on the 4-way control and that listing will be deleted. If you press and hold the A/B button for one second, the question changes to "Clear All?". Press the right toggle on the 4-way control and the radio will ask you "Sure?". Press the right toggle of the 4-way control again and the entire list will be deleted.

Preserving Points of Interest you Wish to Retain on the Garmin Nuvi 350:

In order to prevent loss of points of interest that you wish to retain when deleting the old APRS packets you will need to load these other waypoints as "Points of Interest." The procedure to do this is listed here:


Serial communication will not start before the Nüvi 350 has external 12V dc connected and the TH-D72 has detected a valid external GPS signal in on the COM-port (GPS blinks on TH-D72 display).

TH-D72 - Format [340] = NMEA will only make the Nüvi 350 display small black squares for APRS stations.

Use care and discretion while using APRS in a moving vehicle, it only takes a moment for a tragedy to occur.

Sending and receiving text messages, showing the status or QSY frequency or any information other than GPS position and call sign received in an APRS packet does not appear to be supported with this device. Please see Bob Bruninga's site and the Kenwood manual for information on configuring your D72 for "voice alert" to enable an audible "Ham Radar" alert to notify you of other APRS stations in simplex range by configuring your CTCSS at this link . You do not need, nor should you turn your APRS volume off on the D72 to eliminate packet noise. See the link above for why and how to do this. If you configure your Kenwood properly to show your active QSY phone frequency in your APRS packets you enable one button QSY to you from other Kenwood radios on the Kenwood display. The more the APRS community adopts this practice the more we take advantage of the full features of APRS as a system of increasing connectivity.

This instructional wiki has been written based upon my experience in getting this set up for my own personal use pooling the resources I found on this Argent Wiki website for the GTRANS Kenwood D700 to Garmin Nuvi 350 wiki page as well as the references below. I hope it is of assistance to you. I am an end user only and am not a representative of Argent Data Systems, nor am I an expert on this device or its connection. I have found the above setup to work for me. I have run the above with the most recent Garmin Nuvi 350 ROM update as of 9/28/2011 and the latest firmware update on the D72 as of the same date. Feel free to edit this page as you discover errors or additional features. I did have one Garmin Nuvi 350 which suddenly failed to display APRS position data in either the favorites list or the map after working for several weeks with the above set up. This does not appear to be the result of a malfunctioning Argent GTRANS cable or the settings on the D72 as I connected the cable and D72 to another Garmin Nuvi 350 and it worked without difficulty. I cannot explain why the first Nuvi suddenly failed and have sent this to Garmin for repair and have had no subsequent problems. Please post additional troubleshooting on this site for other users. Anthony Mascola KJ6OKV


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