In this video Maxtena will demonstrate how to use the GPS Helix Antenna Tuning Kit to select a high performing and truly optimized passive GPS antenna for your system.
http://www.maxtena.com/gps-tuning-kit.html
The tuning kit is an inexpensive, quick and effective way to determine the correct GPS antenna to use inside a device. The tuning kit contains five standard Helicore® samples optimized for a range of different loading conditions commonly encountered in devices requiring an embedded antenna configuration.