APRS: how popular are Kenwood trackers

APRS has evolved to be all things to all men.

It inventor, Bob Bruniga, generalised the original meaning Amateur Position Reporting System to Amateur Packet Reporting System as he extended APRS to include all manner of generalised broadcast and point to point messages.

Perhaps in doing that,it was recognition of the inability for many reasons of APRS to provide reliably good position reporting performance in practice.

Any thinking person understands that there is conflict between use for timely reporting of position and loading the radio channel up with generalised message traffic, or even extending the RF coverage of a position report by repeating it many times into adjacent precincts. But simple minds muttering “use it or lose it” ruin APRS for position reporting by sending repeating traffic without a demonstrated demand.

Attempts to emphasise position reporting performance tend to be opposed in my experience mostly by owners of Kenwood trackers (eg DM-710), and the weather propagators. Many Kenwood owners like to see position reports from a very wide area repeated into the local area so that they can be displayed on their radio. There are other features that generate traffic that appeal to Kenwood owners.

This article looks at how significant the Kenwood users are in terms of unique packets reaching APRS-IS, the basis of mapping for most users these days.

The answer is revealed by analysing an APRS-IS feed to count the packets from Kenwood trackers. The following analysis does just that, 5000 records filtered on source VK1 or VK2 were analysed and summarised in the following graph,

Clip 048

Above, the results of the analysis.

In this sample, Kenwood trackers accounted for just 2.5% of the VK1/VK2 packet sample.

Being so small, that percentage might vary widely if one or two more or less stations were active during the measurement period (which was almost three hours to midday on a Saturday morning in this case).

Though some Kenwood owners are vocal about maximising their utility from the radio, thinking owners recognise that do so at the expense of good position reporting is not in their interest, nor any one elses in the long run.


  • On this occasion, Kenwoods contributed just 2.5% of the sample of 5,000 unique packets from VK1 and VK2.
  • Operating networks to suit Kenwood owners is catering to a very small minority.
  • Kenwood owners are disadvantaged by network performance that is degraded by ill considered design decisions and usage that drives high channel utilisation.