Chapter 2: Installation and Start-Up

Site Preparation

extend mast height to prevent multipath cancellation. The antenna should be at least 3.28 ft (1.0 m) from a reflecting surface. The figure at the right shows the recommended mounting of the antenna to the mast.

2.1.5GPS Window-Mounted Antenna (140-619) Installation

The GPS Window-Mounted Antenna is intended for use with products featuring ‘single satellite timing,’ (available with firmware version 8 and above). Customers with units running earlier firmware versions should upgrade to the current version. Information on upgrading is available at www.truetime.net/downloads.html.

Window mounted antennas have a restricted view of the sky, yielding intermittent satellite coverage.

With single satellite timing, a network time server can synchronize with individual GPS satellites as they pass through the antenna’s field of view.

Placing the Window Antenna

Select the window with the best unobstructed view of the sky. For equivalent views, select the window with the best orientation. The orientations, in order of preference, are as follows:

1.Equator-facing (e.g., South, for users in the Northern hemisphere.)

2.East/West-facing

3.Polar-facing (e.g., North, for users in the Northern hemisphere.)

Note: Regardless of orientation, use the window with the best view of the sky.

Mount the antenna on the lower part of the window, where it has the best upward visibility, by pressing the suction cup onto the window. Make sure the window and suction cup surfaces are clean. Note that some windows have metallic glazing that blocks GPS signals: this prevents GPS receivers from tracking satellites and determining the time.

B est W indow

12:00 NOON

2-14

TimeVault™ User’s Manual

6000-100Ch2.fm Rev. D

Page 28
Image 28
Symmetricom Time Server user manual GPS Window-Mounted Antenna 140-619 Installation