DAVIS Wireless Repeaters for VP2 Bedienungsanleitung PDF herunterladen (Seite 9)

Rev A 7/28/06 25 - 9

Overcoming Major Obstructions

Whether you go over or around an obstruction, you should choose whichever is the shortest

distance. To determine the distance when going around, if possible, select a location to place a

repeater where you can visually see repeaters on either side of the obstruction. If you cannot,

you will need to place one or more repeaters around the obstruction until you achieve this

criterion. When going over an obstruction, if possible, place a repeater at the top of the

obstruction where the repeaters on either side can be seen. For long range repeaters with Yagi

antennas, the angle between the ground and the straight line up to the repeater on the

obstruction cannot exceed 25°, for standard repeaters, this angle is 30°.

DETERMINING DISTANCE

Next, determine what type of repeater(s) you need.

Standard Repeaters

Most antennas sacrifice performance in certain directions in order to gain performance in other

directions. This makes the relative orientation of two antennas important. Most antennas do

not perform equally well in all directions.

All Davis transmitters, receivers and Standard Repeaters come with a Dipole antenna, which is

omni-directional. This means that (with the antenna pointing straight up), the antenna performs

best and equally well in all directions around the side of the antenna (perpendicular to the

antenna). It does not do as well above or below the antenna. For a vertically oriented dipole

antenna, another antenna can be 30° above or below its horizontal plane before the

performance starts to seriously degrade. If two dipole antennas need to communicate, but have

more than this 30° angle between them (say due to an elevation change), the antennas can be

rotated so that this perpendicular direction of best performance can be pointing at each other.

With sufficient height, optimal antenna orientation, and no obstacles or interference, a Davis

Vantage Pro2 transmitter/receiver pair with dipole antennas can achieve a range of 1000 feet

(300 m). Obstacles or interference will reduce this range.

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DAVIS Wireless Repeaters for VP2 Bedienungsanleitung Seite 9