TeleGPS by Altus Metrum is a GPS-based position tracker and logger. Its signal is received by the TeleBT receiver as other Altus Metrum flight computers and the ground station program specifically for use with TeleGPS can be downloaded from Altus Metrum.
It is so small that can be mounted inside a 29 mm tube coupler, and can be used not only to find rockets, but also on kites, balloons, airplanes and any other valuable object that can go out of sight.

Telemetry transmitter (70cm ham band transceiver) allows all the flight data to be seen real-time during the mission. The telemetry system sends flight data 10 times per second during ascent, and once per second after apogee. It also transmits an audio tone once every five seconds that is used for tracking purposes on the ground with a directional rocket locator. The range is over 30 kilometers (Line-of-sight distance. Of course, this depends on the antenna you connect to the receiver).

The TeleGPS requires a 1S LiPo battery (3.7 v) with appropriate JST connector for operation. To ensure proper voltage and polarity, we strongly suggest you buy an Altus Metrum battery for use with this device. The manual for TeleGPS is available in pdf format and can be dowloaded from the Attachments tab above.

The photo is of production version 1.0, which is substantially similar visually to the current production version.

RANGE
The maximum range of the telemetry system is determined by the power output, the transmit antenna gain, the receive antenna gain, and the receiver sensitivity. Improving any one of these will give a greater range. The easiest one to make better is the receive antenna gain.

The theoretical maximum range of the system with a 3-element yagi antenna on the ground is about 50km. However, there are a number of reasons why the actual range is less than the theoretical range. Tests performed at Altus Metrum have shown that a 3-element yagi antenna yields good telemetry from rockets to 20 Km altitude, and that an 11-element yagi antenna can receive telemetry from the TeleMetrum (which uses the same telemetry system as the TeleGPS) to around 100 Km.
Finally, the software reports the signal strength, so it's pretty easy ground test the range of the system in a given airframe before flying it.

Specs:

• Custom digital telemetry, APRS and direction beacons
• 70cm ham-band transceiver for telemetry downlink
• High-dynamics GPS receiver for accurate tracking
• Uses 3.7V Lithium Polymer battery.
• 38 mm x 25 mm board designed to fit inside 29mm airframe coupler tube
• 2MB on-board data logging flash
• Built-in USB connection for configuration, data download and battery charging
• 12.3g flight weight (including antenna, excluding any battery)
• Output power: 16 mW