This completes your study of the antenna system of the AN/GRC-103. During this lesson
you learned how to lay out an antenna site by pacing 12, 6, 10 and 10. This procedure will locate
where the guy stakes should be positioned. The next task was the assembly of the launcher and
antenna during which the launcher was positioned and the reflector installed. The third task was
raising the mast to a height of 35 or 50 feet. During this task, mast sections were inserted,
locked, and jacked into position. Also the guy wires were tensioned and the mast was oriented
with the strap wrench. The fourth task involved lowering the mast once it's no longer needed.
During this operation the upper guy wires were loosened and the mast sections were jacked
down and removed. During the fifth task the launcher and antenna were disassembled. This
included removing the lowest set of guy wires, removing the spikes from the base plate, and
removing and folding the reflector. The sixth task consisted of packing the mast sections in the
launcher and the seventh task involved packing the mast accessories kit and the mast extension
There were also two safety warnings brought out during this lesson. One was that if a
strong wind is blowing while raising or lowering the mast, you should station at least one man to
maintain adequate tension on the windward upper guy wire to keep the mast vertical. The other
warning is never to place hands or feet between the lowest mast section and the azimuth plate.
You have now completed everything in this lesson. Before you continue to the next
lesson, read the lesson objectives at the beginning of this lesson. If you have any doubt about
being able to meet the objectives, study the portion of the lesson in which you feel weak.