Section II. EQUIPMENT INSTALLATION AND OPERATION

TM 11-5985-335-15

Avoid locating the antenna near electrical interference sources such as radar sets and power transmission lines.

2-4.

Plotting Profiles

To determine that a line-of-sight path exists before attempting an installation, draw a profile map of the terrain between

the two sites (fig. 2-2). Nonlinear graph paper may be used for plotting profiles from terrain maps as follows:

a. Determine the scales to be used for the distances involved.

b. Draw a line between the two proposed sites (A or D, fig. 2-2). Convert the length of this line to distance.

Determine the total elevation of each site, including antenna height above ground (40 feet in the examples of fig.

2-2). Draw a straight line between two points. Note the lowest point along the line.

d. Draw a complete profile of the terrain between the two sites. Pick up the high and low points along the line. Plot

these points, then join them.

All points that are above the straight line on the graph (C or E, fig. 2-2) represent

intervening obstructions.

e. For best communications, use a path such as path 4 (F, fig. 2-2).

Section II. EQUIPMENT INSTALLATION AND OPERATION

2-5.

Tools and Test Equipment Required for Installation

Tool Kit, Electronic Equipment TK-101/G (NSN 5180-00-064-4178) and Multimeter AN/URM-105

(NSN 6625-00-581-

2036) are the only tools and test equipment required.

For additional tools, refer to the technical manual for the

associated radio set or mast assembly with which the AS-1425/GRC is to be used.

2-6.

Erection of Antenna

WARNING

During installation of this equipment, conform to all safety requirements set forth in TB SIG 291. Do not

install antenna at a distance of less than twice the height of the mast from power lines. Do not attempt

antenna installation if the windspeed exceeds 25 miles per hour (21.7 knots).

The AS-1425/GRC (configuration A) may be mounted on any adequate mast assembly by using a special mast adapter.

(The mast must be properly sited in accordance with paragraph 2-3.) Install each antenna using the procedure outlined in

a through m below.

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