GlobalTime NTP Products
User manual of GTT-030
5
Antenna installation should be lower than the lightning rod or other constructions that can attract
thunderstroke and the installation location should better be 10-15 meters away from them. GPS antenna
itself is rarely struck by thunderblot but is often damaged by the stong induced electric field resulted from
the stuck buildings (the lightning rod, tower, etc) around. In this circumstance, we should install the
arrester in the cable. Normally the arrester
will be installed near the equipment. To make sure that the
arrester can be well earthed, the arrester should be installed between the feeder and the equipment.
Then lead the grounding wire from the arrester and connect it to the earth. The earth resistance should
be under 4 ohm and must be firmly connected to ensure the reliable discharge by lightning.
Sometimes the antenna can be installed outside the window, but the building must be located in the
open fields with no corner. In this way, it can receive at least half of the satellite signal. But as a
long-term using equipment , it is recommended that the antenna is installed in high places, while the
outside installation can be only adopted as a temporary test.
The high-power microwave transmitting of the same band can not be around where the GPS antenna is
installed. In addition, we should try to avoid the GPS antenna from the direct irradiation of high-power
electromagnetic radiation.
If the length of the feeder is less than 100 meters, the antenna and equipment can be directly connected;
between 100 meters to 200 meters, one more line amplifier is needed; ranging from 200 meters to 300
meters, two more amplifiers are needed. If you need longer feeder links, please contact us, GlobalTime
Electronic Co., Ltd. We will provide the special program to you. The feeder usually adopt 1 / 2 inch RF
cable whose loss is 12.8dB/100m from the United States Andrew's.
The primary considerations when setting up the feeder:
1. Do not bend too much, because it will result in a broken feeder conductor.
2. When we connect the feeder into the interior, it should be bent into U-shape to prevent
In the
feeder should be bent into the interior U-, to prevent water from flowing backward.
You can use GPS signal transponder to lead the signal to the interior. Generally speaking, GPS signals
can be well received within 5 m of the transponder antenna. Because of the way of forwarding, it is much
effective for the prevention of lightning and the protection of the host. Problems caused by the lightning
is the transponder damaged. Due to a certain transmitting power, it is suitable for some occasions.
