About PocketTracker

Pocket Tracker is a 2-meter FM transmitter combined with a TinyTrak3 that provides an easy and inexpensive way to build an APRS tracker. Just plug in a GPS receiver and Track!

  • No need to tie up an expensive radio for APRS tracking

  • No complicated radio cabling

  • Simple 2 wire GPS connection

  • Extremely long battery life ( > 100 hours when properly configured) - Keep on trackin'!TM

  • PIC controlled, PLL-Stabilized, FM APRS Transmitter

  • Simple kit (All SMT parts are pre-assembled)

  • Simple RF alignment (one variable inductor)

  • Supports all the latest Byonics TinyTrak3 features.

Pocket Tracker Kits are normally shipped pre-programmed to operate on either 144.390 MHz or 144.340 MHz. Also European Version pre-programmed to operate on either 144.800 MHz or 144.850 MHz are available.

For detailed  information and ordering visit the Byonics homepage.

My version of the PocketTracker (DK7XE-6) with integrated GPS

The completly assemled PocketTracker PCB. I needed ~4hour for this. The size of the PCB is ~4x6cm.
Backside view with the wires that need to be assembled.
The 3x7x10cm metal housing for my PT with the already mounted GPS (BR-305 from Navilock). Also the SMA socket for the antenna, PWR on/off and setting select switch are already in place. The setting select switch changes frequency and TT3 settings primary/secondary. At the bottom i placed a 9pin female SUB-D for programming.
Detailed view of the GPS antenna, the SMA socket and the switches.
Pockettracker mounted in the housing before first test & calibration. I used 8mm metal spacers to hold the PCB. That gives enough room for the GPS below the PocketTracker.
During Calibration (adjustment of L3). The adjustment is really simple if you follow the instructions in the manual.  
The completly assemled device. The extra PCB in the middle of the picture is the jumper-board where i can select which device is connected to the SUB-D for programming (GPS or PocketTracker).
At all i needed 2 days for the complete assembly including mounting of the GPS.
Size comparison with TH-D7.
After some tests i observed that the 9V / 150mAh rechargeble battery is not good enough to power the device. Power consumption of GPS-RX and TT3 is ~90mA. During data TX power consumption goes up to ~180mA.
So i put 6 size AAA NiMH cells together as accupack. They have 650mAh.
Operation time for my pocket tracker will be ~6hr. Weight with 650mAh accupack and antenna is ~280g.
The 1450mAh NiMH accupack i built. It consits of 6 prismatic 1,2V cells from GP.
Weight with this accu and antenna in ~340g.
So that's still lightweight compared to other APRS devices.
Operation time with this configuration is now ~12hr. That's fantastic :-)

My conclusion

The PocketTracker is a kit easy to built (with some soldering experience). And it's really a small, lightweight and cheap device.
So it's perfect for portable operation within a radius of 5-10km within the next DIGI/a receiving station. Or for air operation (balloon/kite) on a special QRG.
For normal APRS i propose the use of a common handheld in combination with a TinyTrack or similar tracker unit with busy channel detection.
Why? In the "urban jungle" where APRS traffic is very high or far away from the next digi the missing "anti collision" is a problem. Since PocketTracker is a transmitter only
it does not know when the APRS channel is free to use.
So you will have collisions with packets from other stations. If you are far away from the next digi or in an area with heavy loaded APRS channel the signal of pockettracker is too weak compared to other stations. So you will loose.

But anyway it's a great device for beginners or persons who like building kit's.
Have fun with it!

Owner: DK7XE

PocketTracker - DK7XE/OE6DLD

Update: 15.05.2006