Repairs and Calibrations
I (Paul Remde of Cumulus Soaring, Inc.) can replace logger backup batteries, re-seal the electronic security seal in GPS-NAV units (not 302 units), and calibrate the logger altimeters for all Cambridge GPS-NAV and 302 products. You can see details here: Services.

Photos Click on the images below to view larger versions. GPS-NAV Model 20 GPS-NAV Model 25 LCD Navigation Display The Model 20's small package features a built in antenna, allowing easy installation and removal. Using the same 1/4"-20 mounting screw as a camera allows simple attachment to a standard camera mount. The small size also permits installation on or just under the instrument panel cover. For more difficult installations the Model 25 features an external antenna, rather than a built-in antenna. This allows the GPS antenna to be located remotely and connected to the flight recorder via a coaxial cable. The optional LCD Navigation Display offers a very simple user interface and can be used to edit tasks and make electronic flight declarations.

Background
Cambridge pioneered Secure GPS Flight Recording and Navigation with the introduction of the Model 10. This was the first GPS based Flight Recorder to score a World Championship. It was first to receive FAI approval. The Model 10 set the standard for all to follow.  The Model 20 and 25 used the latest technology and eliminate the Model 10's internal battery. This reduces both size and cost. All GPS-NAV models have the same functionality and are approved for validation of FAI Badge and Record flights (but not World Record flights).

Better by Design
Cambridge systems are designed by glider pilots for glider pilots. The FAI approved GPS-NAV replaces both cameras and barographs. Ease of use and attention to detail make Cambridge the best GPS system for soaring.

Features

• The optional LCD display is very easy-to-use in flight - perfect for use in gliders owned by clubs or syndicates.
• Small size
• Wind speed and direction calculated while circling. Helps you locates wind shear and blue streets.
• IGC approved GPS position recorder, pressure altitude recorder (barogram), and motorglider engine run sensor, approved for badge and record flights (but not World Record flights)
• Automatice motion based recording - It notices when you start flying and uses a buffer to record the two minutes preceding the flight.
• 9900 GPS/Altitude fixes are logged - 11 hours of logging at 4 second intervals.
• Works great with an L-NAV.  The GPS-NAV sends destination elevation data to the L-NAV so that the L-NAV can display differential final glide data.  No other logger offers that feature with the L-NAV. 
• Works great with Glide Navigator II software for Pocket PC.  Glide Navigator can download flight logs from the GPS-NAV and send flight declarations to the GPS-NAV.  The GPS-NAV also relays data from the L-NAV to Glide Navigator.  No other logger can do that.
• The GPS-NAV can provide 5V power for a Compaq Aero 1550 Pocket PC.  It may, or may not have enough current to power an iPAQ.  It may work as long as the iPAQ is fully charged, but most pilots invest in a 12V to 5V converter like the Goddard PS-5a to be on the safe side.

Need to Know Items
I am very up-front about the limitations of the products I sell.  I want to be sure that you feel I have helped you select the best system for your needs.  This section points out some items that may not be obvious when comparing products.

• The GPS-NAV is somewhat expensive when compared with similar competitive products.  The 302A is also a much lower cost solution.  However, the optional LCD display offer the best user interface by far.  Also, the GPS-NAV works better with the L-NAV than competitive products.
• Memory for only 250 waypoints.  The 302 and CFR hold 2000 waypoints.
• Memory for only 11 hours of flight recording at 4 second intervals.  The 302 and CFR hold up to 100 hours at 4 second intervals.
• Flight logs files downloaded from the GPS-NAV are stored in ".cai" files and must be converted to ".igc" files using PC software.  Most flight analysis software programs prefer ".igc" files.  It is very easy to convert the files, but a little bit of a pain.