User's Manual

3. Pre-Installation Procedures 3-3

o Antenna direction

7) Measure the Link Distance: The two ways to measure link distance are as follows:

o GPS: record the latitude and longitude for the near and far installation sites and

calculate the link distance. Record the mapping datum used by the GPS unit and

ensure the same mapping datum is used for all site evaluations in a given

network.

o Range finder: measure the link distance (imperial or metric units may be used).

Once the link distance has been measured, verify that the link distance meets the

availability requirements of the link.

8) Select the Grounding Location: The EVENT 5800 must be properly grounded in order

to protect it and the structure it is installed on from lightning damage.

9) Determine the Length of Interconnect Cable from IDU to the ODU. For a stand-alone

EVENT 5800, this cable is included and is normally 8” long. For a EVENT 5800 with a

secondary RF ODU unit the following applies. The primary consideration for the

IDU/ODU interconnect cable is the distance and route between the primary EVENT

5800 and the secondary RF ODU unit. This cable should not exceed 330 feet using

Times Microwave LMR-200 cable. Guidelines are provided in Table 3-1.

Table 3-1. Maximum IDU/ODU Cable Lengths

Loss at (dB/100 m)*

Cable Type 140 MHz 350 MHz

Maximum

Length*

LMR-200 12.6 20.1 100 m

LMR-300 7.6 12.1 165 m

LMR-400 4.9 7.8 256 m

RG-214 8 13.1 153 m

Belden 7808 8.6 14 143 m

*Does not account for connector loss.

10) Determine the optimum transmission line between the EVENT 5800 and the Antenna.

This is normally part of the link analysis calculations.

11) Confirm the availability of Power for the EVENT 5800.

12) Ensure Building Aesthetics: For building-mounted units, ensure that the Antenna can

be mounted so that it is aesthetically pleasing to the environment and to the

property owner. Aesthetics must be approved by the property owner and the

network engineer.

13) Take Site Photographs

14) Sketch the Site

3.2 Critical System Calculations

3.2.1 Received Signal Level (RSL) and Link Budget

The received signal level (RSL) can be estimated using the following formula: