GPS Grandmaster Clock
34
RT430-TM-EN-5
2.9
GPS Antenna Terminal
A 3.3-Volt active GPS antena (100mA max) must be connected to the antenna terminal if GPS satellites are
used as time reference. See
Chapter 1
for additional information.
Figure 11: GPS antenna connector
If the GPS antenna is already connected and it is possible to receive signal from at least 4 GPS satellites the
L
OCKED
indicator will start to blink after a couple of seconds, indicating that the internal time-base is being
synchronized with the satellites. The L
OCKED
indicator will stop blinking and will remain lit as soon as
maximum accuracy is achieved. This process may take several minutes if the equipment was transported for
more than a few hundred kilometers or was unpowered for many weeks.
The antenna must be mounted outdoors, in a vertical position, with an unobstructed view of the sky, as
. The antenna should be placed above the height of the building as much as possible. A partially
obstructed sky view will compromise the unit's performance.
Figure 12: Recommended position for installing the GPS Antenna
The antenna should not be located under overhead power lines or other electric light or power circuits, or
from where it can fall onto such power lines or circuits.
