A:Answer The antennas are each about 3.25 inches or 8.26 CM when extended. The actual device is about 2 inches or 5.08 CM
How high does the unit measure with the antennas extended?
ANSWER: When the antennas are fully extended the unit is about 5.25 inches or 13.34 CM
Is it necessary to fully extend the antennas for operation in a 2200 square ft home?
ANSWER: IT may not be necessary but ideal if you need the most optimal service from your device. You just have to have to try place your device in a central location to propagate throughout the house. Then you would have to keep adjusting both the location of the device as well as the angles of the antennas to see what gives you the best tolerated level of service that would be most satisfactory to your needs. The manual under WiFi Range only gives a generic response:
Homes come in all shapes and sizes and the Nighthawk X6 Tri-Band WiFi Router with 6 powerful high performance external antennas provides WiFi coverage no matter where you connect in your home.
Ultimate range—WiFi coverage throughout very large homes
Antennas—High-powered amplifiers and 6 high-performance external antennas
Of course, you may never get total WiFi coverage from every area of your home because factors such as layout and the materials used to construct house, among other factors may create "dead zone" for reception. Your alternative, then would be to purchase a good WiFi extender to extend your signal range.
Have a happy adventure in the placement and optimizing your new device; if you so still decide to purchase it of course.
