When planning a radio system the distance or hop between a radio transmitter and the
receiver that is receiving its signals should be about 25 to 30 miles. This distance is
figured with a 35-foot antenna over smooth earth. For more detailed information
concerning systems planning refer to "Radio Propagation and System Planning" in TM
11-5820-540-12.
f.
Guy Anchors. The antenna system of the AN/GRC-103 will not stand on its own. Guy
wires are required to support the antenna mast. Guy anchors provide a solid base for the
guy wires. There are several types of guy anchors that may be used depending on the
type of soil at the antenna site and height of the antenna.
(1)
Stake Anchor. Three 24-inch guy stakes are provided as part of the accessories
kit. These stakes are used as guy anchors in normal soil to secure a 35-foot
antenna system. The 24-inch guy stakes may also be used to secure a 50-foot
antenna system if the surface is shale, sandstone, ice, or permafrost. To install a
guy stake, hammer it into the ground at a 60 degree angle, slanted away from the
mast. Open Fold-Out 1, at the rear of this booklet, and refer to View A which
shows a properly installed 24-inch guy stake.
(2)
Screw-type Anchor. The 50-foot antenna requires the use of screw-type anchors.
Three of these anchors are supplied with the MK-1009/GRC-103 mast extension
kit. To install a screw-type guy anchor, screw it into the ground at a 45 degree
angle, slanted towards the mast. Insert the universal tool thru the anchor eye to
provide leverage while screwing the anchor into the ground. View B of Fold-Out
1 shows a properly installed screw-type guy anchor.
(3)
Other Anchors. Some ground may be too soft or too hard to permit proper
installation of the guy anchors supplied. A tree or rock may be used as an anchor
by wrapping a 1/2-inch thick rope or cable around it and then connecting the guy
wire. This is shown in View C of Fold-Out 1. When a tree is used as an anchor
be sure to connect the anchor at the base of the trunk.
27