Cooper Bussmann Wireless Ethernet & Device Server BU-945U-E 802.11 DSSS User Manual

The net gain of the antenna/cable configuration is determined by adding the antenna gain and the cable loss.

For example, an 8dBi antenna (5.8dBd) with 10 meters of Cellfoil (3dBd) has a net gain of 2.8dB (5.8dB – 3dB).

Installation tips

Connections between the antenna and coaxial cable should be carefully taped to prevent ingress of moisture. Moisture ingress in the coaxial cable is a common cause for problems with radio systems, as it greatly increases the radio losses. We recommend that the connection be taped, firstly with a layer of PVC Tape, then with a vulcanizing tape such as “3M 23 tape”, and finally with another layer of PVC UV Stabilized insulating tape. The first layer of tape allows the joint to be easily inspected when trouble shooting as the vulcanizing seal can be easily removed.

Where antennas are mounted on elevated masts, the masts should be effectively earthed to avoid lightning surges. For high lightning risk areas, approved Cooper Bussmann surge suppression devices such as the “BU-CSD-SMA-2500” or “BU-CSD-N-6000” should be fitted between the module and the antenna. If using non Cooper Bussmann surge suppression devices then the devices must have a 'TURN ON' voltage of less than 90V If the antenna is not already shielded from lightning strike by an adjacent earthed structure, a lightning rod may be installed above the antenna to provide shielding.

Omni-directional Antennas

An omni-directional antenna transmits radio power in all directions and is easy to install and use. The Dipole antenna with its integral 15ft (5m) of coax cable and does not require any additional hardware, however a coax cable and mounting kit is required with the Collinear antenna.

All omni-directional antennas should be mounted vertically, preferably 1 wavelength away (see drawing below for distances) from a wall or mast and at least 3ft (1m) from the radio module to obtain maximum range.

3A1582Rev1.6

www.cooperbussmann.com/BussmannWirelessResources

11

Page 11
Image 11
Cooper Bussmann BU-945U-E 802.11 DSSS user manual Installation tips, Omni-directional Antennas