HAM APRS Tracker – Byonics to the Rescue – sort of

APRS Tracker Issues – an Amusing Response.

APRS Trackers are used by HABworx for our non commercial payloads. We have experienced a few issue with degrading of the transmitted signals over time. This story is a pat on the back for HABworx, but a costly pat on the back.

In Australia to use an APRS tracker you will need a “full call sign” for an amateur radio operator. A foundation or other license is not good enough. We use these trackers by always ensuring that we are not putting it on to a commercial payload, or that the commercial payload agrees to space in their payload for community experiments. We always use 2 trackers and they simply may be a pair of SpOT trackers or a spot tracker and APRS. At times we have even used 2 APRS trackers with different SSIDs (identifying codes)

My High Altitude Balloon (HAB) work just got made a little easier. My old trackers were all starting to fail. I just took delivery from Byonics of one of their MT2000 HAM radio APRS trackers. This is only for licensed Ham Radio operators and it is a sweet device for its size. It can output over 2W of power and has a full transceiver on board. It is easily configurable and runs off 5v to 12v. I think power output is a bit less than 500mw at 5V. It is as light at anything and easily programmable as I also bought the USB cable – a 9 pin D connector for RS232 slips over the end and I will solder it in place. I usually slip a VHF antenna right on the end (red cover cap) and I will solder the special GPS receiver in place on the board. There is still a connector on the GPS unit. It should be noted that these GPS units are configured to work above 60,000 ft as most GPS stop there. Don’t try using the GPS in your phone for tracking on a balloon!

Hey, before I go too far with the Tracker, here is a video from one of our flights. Made for MYOB, it shows the quality of our work. This payload was extreme and we built it on the spot from a wooden frame prepared the night before:

I suggest that you click full screen to get the real impact of this video! In fact go to YouTube and it is really HD


The payload had 8 cameras 3 power banks, 6 voltage regulators, 1 actuator and 2 trackers. One camera was a Fly360 x 240 camera.

Back to the tracker:


Here is what they say:

The Micro­Trak 2000 (MT2K) is a frequency agile, 2 Watt, programmable miniature APRS (Automatic Position Reporting System) transmitter utilizing a TinyTrak3 controller chip and is capable of operating from 144 to 148 MHz.

Just plug in a GPS receiver, such as the Byonics GPS5, add a SMA antenna, and start tracking!

  • No need to tie up an expensive radio for APRS tracking
  • Simple 2 wire GPS connection
  • Supports all the latest Byonics TinyTrak3 features.

Note the special GPS block in the picture below. That is what to look for:

Byonics MT2000 APRS Tracker

APRS Tracker Failures – Why?

We could not get an answer to this question because we are simply too good at recovering the units.

We insulate them with bubble wrap, but the super low temperatures in the jet stream (-50ish C) seem to affect the devices over time. Several have died. When I asked Byonics the question as to why, it appears no one can answer me. It seems customers always loses their trackers and we seem to only notice this problem because we have never lost a payload and keep using them. It looks like they only last about 10 flights with super low temperatures and super low pressure. If this works as expected, then I will have to order more. Everyone else loses them by this time. I expect it is a temperature issue and we will try and compensate of update our units after about 7 flights.

Configuring your APRS Tracker

The important parameters to specify for preconfiguration when ordering from Australia for a MT2000 balloon tracker are:

Your HAM radio Call Sign with the appropriate SSID. Mine is VK2URB-11

The Digi Repeater parameters:  WIDE 1-1

The Australian APRS frequency:  145.175MHz

Transmit interval:  every 20 seconds – no receiver check

Symbol:  /o balloon

Any appropriate text:  mine is “UpLift Balloon”. Keep it short as it makes the transmit packet bigger.

Watch out – other countries use different frequencies