The subject: "How fast does that jet fly?" is well known and not only kids are asking that, the internet-offers models with astonishing "Vmax more than 100 mph".....

The solution I found for verifying real speed is this:

Take a "3 in 1 GPS" oder "iblue 747" [ebay-search] datalogger for 40 bis 50,-€. Besides 16MB memory it comes with LI-Ion battery, USB-charge-cable and software for data-downloading and even works as bluetooth mouse for your notebook or PDA.

The case will be opened carefully with your thumbnail and put away to save the 20g weight.
The battery will be fixed with thin tape in the correct position over the board.
Finally cover the complete unit with heat shrink tubing and make openings for usb-jack and main-switch and you've got your
42 gramm lightweight standalone datalogger.

In case you are operating your model by lipo-battery you can save the loggers-lipo and connect it to the balancing-port of your lipo-battery (at the port for one cell) which reduces overall-weight down to 20g.

Detailed dexcription of the logger will be found at Transsystem

Further Tweaks and Hints here GPSPASSION

A better and faster Software for downloading data is on Sourceforge to find, among other things you can set logging to 5HZ.

The logger works on MTK-Chip, which is even better than Sirf3, interruptions during normal flights were not detected.
Because of speed-detecting by Doppler effect the accuracy is in the +/- 0,1 kmh range.

See pictures on right and than "Happy Logging"....

These are some readings to Vmax on my jets:

Interceptor Standard 110kmH
Phase 3 Fantom Standard 136 kmH
Twister Standard 156 kmH
Phase 3 F16 Standard 156 kmH
Phase 3 F16 "Tuning" 193 kmH

The subject: "How fast does that jet fly?" is well known and not only kids are asking that, the internet-offers models with astonishing "Vmax more than 100 mph".....

The solution I found for verifying real speed is this:

Take a "3 in 1 GPS" oder "iblue 747" [ebay-search] datalogger for 40 bis 50,-€. Besides 16MB memory it comes with LI-Ion battery, USB-charge-cable and software for data-downloading and even works as bluetooth mouse for your notebook or PDA.

The case will be opened carefully with your thumbnail and put away to save the 20g weight.
The battery will be fixed with thin tape in the correct position over the board.
Finally cover the complete unit with heat shrink tubing and make openings for usb-jack and main-switch and you've got your
42 gramm lightweight standalone datalogger.

In case you are operating your model by lipo-battery you can save the loggers-lipo and connect it to the balancing-port of your lipo-battery (at the port for one cell) which reduces overall-weight down to 20g.

Detailed dexcription of the logger will be found at Transsystem

Further Tweaks and Hints here GPSPASSION

A better and faster Software for downloading data is on Sourceforge to find, among other things you can set logging to 5HZ.

The logger works on MTK-Chip, which is even better than Sirf3, interruptions during normal flights were not detected.
Because of speed-detecting by Doppler effect the accuracy is in the +/- 0,1 kmh range.

See pictures on right and than "Happy Logging"....

These are some readings to Vmax on my jets:

Interceptor Standard 110kmH
Phase 3 Fantom Standard 136 kmH
Twister Standard 156 kmH
Phase 3 F16 Standard 156 kmH
Phase 3 F16 "Tuning" 193 kmH