Rocketry Planet

You have to admire any company that is comfortable with calling itself "BigRedBee." Not BeeTrex. Not BeeCom. Just BigRedBee.

This is a small business with a small, clever product: the BeeLine GPS Tracker. The BeeLine is a tiny (1-1/4 x 3 inch) module that contains a GPS receiver and GPS patch antenna, a Lithium-Poly battery and a 70-cm FM transmitter. The whole package weighs about 2 ounces.

The BeeLine is designed to be a go-anywhere APRS tracker. In case you're unfamiliar with the term, APRS stands for the Automatic Position Reporting System. An APRS tracker takes position information supplied by a Global Positioning System (GPS) receiver, reformats it as packet radio data, converts the data to a modulated audio signal and passes the signal to a transmitter (typically a VHF FM radio). At the receiving end, a packet radio Terminal Node Controller (TNC) decodes the transmission and feeds the information to a computer running APRS software. The result is a computer-generated map that displays the location of the tracker (and the object being tracked). This is similar to fleet tracking systems where the GPS information from the receiver is sent via a cellular data signal to the software application, which in turn allows the receiver's position to be displayed on a map.

BigRedBee's BeeLine GPS Tracker is a small, compact unit that includes everything in one tiny package.

Unlike some bulky APRS tracking setups comprised of separate GPS receivers, TNCs and radios, the BeeLine integrates everything, including the battery, into a single compact unit. The only downside is that the BeeLine operates on 70 cm, whereas most APRS activity takes place on 2 meters (144.39 MHz). For specialized applications where you’re not concerned with making the position information available to the traditional APRS network, this probably isn’t an issue.

The BeeLine Package
For this review I purchased the complete BeeLine GPS package, which includes a battery charger, serial adapter (to communicate with your computer) and a 70-cm antenna.

The battery charger is an imported device originally intended to charge cell phone batteries. The BigRedBee Web site suggests modifying the charger to make it easier to interconnect with the BeeLine module. That’s the approach I took, modifying the charger by adding a cable with a small three-terminal connector (DigiKey part number WM4201-ND) so that I could easily plug in the BeeLine for recharging.

The serial adapter is something you’ll use only occasionally to program the BeeLine with your call sign and other parameters. The BeeLine Communicator software for Windows is downloadable from the BigRedBee Web site. You simply plug the BeeLine into the serial adapter, plug the serial adapter into a convenient COM port on your computer and then read and write your settings to the BeeLine. It is interesting to note that you can also set the transmit frequency and output power in this fashion. The BeeLine will transmit anywhere in the 70-cm band. I set my unit on 433.920 MHz with full output power (about 16 mW).

The antenna is a quarter wavelength flexible wire terminated in an SMA connector.

Firgure 1: Plot of cat tracking, beacon set to transmit once every 60 seconds.

Kitty Tracker!
My first impulse was to launch the BeeLine in a model rocket, but the odds of it finding a new home in a treetop placed that notion well outside my comfort zone. So, I grabbed the nearest moving object at hand — my cat. I attached the BeeLine to her harness and turned her loose for a neighborhood patrol. I set the BeeLine to transmit a position beacon once every 60 seconds.

The BeeLine’s GPS receiver quickly acquired enough satellite signals to determine her position and apparently maintained GPS lock throughout most of her journey. Back at home, I had no difficulty receiving the BeeLine’s reports. You can see the result in Figure 1.

Serious Applications
The minimal size and weight of the BeeLine makes it ideal for a variety of tracking applications such as model rockets, high-altitude Amateur Radio balloons, radio-controlled airplanes, search and rescue, etc. The BeeLine also features onboard memory that will record about 10 minutes worth of position data. This is particularly useful for model rocket and R/C airplane activity.

Manufacturer: BigRedBee, 5752 Bay Point Dr, Lake Oswego, OR 97035; http://www.bigredbee.com/. $299

Copyright © 2007, The American Radio Relay League.

Reader comments:

#1 two hobbies

I have to admit this is the first time I have seen an article on one of my two hobbies in a magazine for my other hobby!

k3td on 08-11-2007 07:02 PM

#2

One of the guys in our local club got one of their GPS units last year. I had the honour of trying it out in my CAR L4 flight. Flight went to about 7,300' or so, and landed out of sight. It was nice to be able to just walk right out to the exact location, rather than wandering around while the local wildlife laugh at the silly human waving the funny tree branch (yagi antenna) around.

GPS tracking is *definitely* THE way to go.

CF-105 on 08-12-2007 05:42 PM

#3

Quote:

I have to admit this is the first time I have seen an article on one of my two hobbies in a magazine for my other hobby!

QST ran an article probably two years ago, now, that showed how to build modular telemetry transmitters and sensors (don't remember if the xmtr was for 2m or 440, though, and haven't been able to find that issue of the mag). Was one of the things that piqued my re-interest in rocketry!

Gotta admit... I'm seriously thinking of trading my Icom W32 in for a Kenwood D7 HT!

Ya know, honey.. if I spent just a little bit more, I could get this real nifty transmitter that would guarantee that I wouldn't lose my rocket! I mean, I've already got the HT, the Arrow (antenna)... and I know the phone number for H-R-O!

n5wd on 08-12-2007 06:03 PM

#4

Quote:

Ya know, honey.. if I spent just a little bit more, I could get this real nifty transmitter that would guarantee that I wouldn't lose my rocket! I mean, I've already got the HT, the Arrow (antenna)... and I know the phone number for H-R-O!

Let us know how that works out... Anything we should do if we don't hear back from ya?

ddmobley on 08-12-2007 06:16 PM

#5

Already have my Kenwood TH-D7A(G)! Just need one of these little babies!

Hmmm....I even like the idea of tracking the cat....

JohnK3 on 08-13-2007 11:19 AM

#6 Article in QST about modular telemetry....

Quote:

QST ran an article probably two years ago, now, that showed how to build modular telemetry transmitters and sensors (don't remember if the xmtr was for 2m or 440, though, and haven't been able to find that issue of the mag). Was one of the things that piqued my re-interest in rocketry!

There was an article in the February 2006 QST by a guy named Jerry Baumeister, KD5ZUG, titled "Morse Code Telemetry for Small Rockets and Aircraft". He describes two modular sensors and the radio unit to which they can connect. Fairly simple 2-meter FM tech - the transmitter is a two-transistor rig. I couldn't find my copy of that month's QST, but I got a reprint from the ARRL for $3.

The BeeLine unit sounds nice - may have to save my pennies for one.

73,

Jon K4ISP

P.S. BigRedBee has enhanced the BeeLine already! See this message...

http://www.rocketryplanet.com/content/view/2002/28/

JonKerfoot on 08-13-2007 07:18 PM

#7 QST article

Got my QST today... very cool!

n5wd on 08-15-2007 01:10 AM

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