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How to Use the BigRedBee APRS Tracker


    The BigRedBee 2m APRS tracker is a telemetry device which emits a radio pulse containing its current location.  These pulses are picked up by digipeaters, special receiving devices placed on top of mountains and other high places specifically to listen for these APRS packets and then put them online.  Consequentially, the BigRedBee's path can be viewed online at websites such as Google Aprs.  

Image from


One Time Cost: $260

Re-use Cost: 4 lithium AA batteries


         Extremely dependable

         Extremely durable

         Easy to use


         higher one-time cost

         requires ham license 

How to get a Ham License:

            Ham Radio, short of Amateur Radio, is a hobby/service which users of radio equipment on ham-specific bands can practice, perform, and help others in radio related activities.  Emergency communications, geo-caching, and tracking are among them.

            Getting a license is not too difficult.  The best place to start is by finding a Ham club near you.  They will provide you will all the information and assistance you need to get licensed.  If you do not know of any groups in your area, simply learn by taking the practice exam here:  By testing yourself you can determine what you do not know, and pursue that knowledge through the internet, books readily available at a local library or to purchase, or other hams. 

            Once you are ready you will have to find an exam session (  These are offered multiple times a year in various locations across the United States.  You will only need to take the test for the lowest license class: Technician.  This 35 question multiple choice test and a nominal fee (~$10) will get you your license and a call sign.


Your Call Sign:

            The ham radio call sign is an ID number which identifies you or your device.  Make sure you write it down and keep it handy, as you will need it to track your balloon.

Purchasing the 2m BigRedBee:

            Simply place an order at the BigRedBee website:  You want the 2m version.  Do not get a mag-mount antenna. 

Using the APRS:

            The BigRedBee comes nearly ready for a trip to near space.  All you need to do is:

  1. Download the programming software here:
  2. Add your callsign to the ID string Box, you can leave all other settings at their default for your first launch and refine them as need be
  3. Power the transmitter with 4 AA batteries (normal ones work fine on the ground, but use lithium batteries for near space)
  4. Attach and antenna and flip the power switch to on (NEVER DO THIS WITHOUT THE ANTENNA!)

The BigRedBee will automatically track satellites and acquire a GPS signal assuming it is outside and can see the sky.  It will transmit an APRS packet at either a specified interval or at a rate based on how fast it's moving, which will all be received by digipeaters and placed online.  To track its progress:

  1. Go to
  2. Enter your callsign or callsign-SSID
  3. Select the time period (Show last: 1 hour, 24 hours ....)
  4. Hit search
Your search should give you something like this:

You can easily zoom in, click on data points, and view your path.


Balloon Launch:

            Place the BigRedBee at the top of your payload box, preferably not under anything metal and with the GPS antenna facing upwards.  Make sure to test that the beacon works in the box with everything turned on before sending it to space.


            At the launch site:

  1. Turn your BigRedBee on following the instructions (make sure the antenna is attached!)
  2. If you have an I-phone, check online to see if packets are getting through
  3. If you can't, call someone with internet
  4. If it still doesn't show up, you may not be reaching a local digipeter and can check with a handheld transceiver capable of packet operation
  5. Package it up with your balloon stuff and launch


            Following the flight:

  1. Calmly get somewhere with internet
  2. will automatically track your balloon.
  3. You can download your flight data from the BigRedBee's flash memory (using the programming software) or the data viewer
  4. Export your data from google aprs by hitting "Google Earth KML."
  5. Open it up in Google Earth, and see a nice 3D plot of your balloon's travels



Jul 26, 2010, 11:06 AM