User's Manual

14221-1200-4010, Rev. B
44
4. Obtain a hole saw specifically designed for drilling NMO mounting holes of the required diameter.
(e.g., Antenex/Laird Technologies model HS34 or equivalent for a ¾-inch hole; Antenex/Laird
Technologies model HS38 or equivalent for a ⅜-inch hole).
5. If the vehicle’s headliner panel, carpet, seats, or otherwise, is below the mounting location, move or
remove the headliner panel, etc. as necessary to protect it. Alternately, apply a heat-resistant mask
material (such as a fiberglass mat or thin sheet metal with masked edges) as required to “catch” the
metal shavings and the metal plug (if any) produced by the hole saw. The plug (if any) may be
relatively hot if/when it drops out of the saw upon completion of the hole drilling process. ⅜-inch
diameter hole saws generally produce only shavings, not plugs.
6. Using the hole saw and a drill, drill a hole at the marked hole center point. Position the drill square to
(i.e., 90 degrees from) the vehicle mounting surface so paint immediately outside of the perimeter of
the hole is evenly removed.
Excessive use of the hole saw and/or failure to position the drill square with (i.e., at a
90-degree angle from) the vehicle mounting surface may result in damage to the metal
mounting surface, in the area immediately outside of the perimeter of the hole.
7. Ensure the saw removed the paint immediately around the hole as the drilling operation completes. If
not, do so by reinserting the saw completely into the hole and spinning it as required. This allows
proper grounding via the mount’s lock nut on the top of the mounting surface. On the bottom of the
mounting surface, the “teeth” of the mount’s bushing assembly may not provide a good ground due to
thick vehicle undercoating, thick primer, oxidation/rust, etc.
8. For a ¾-inch hole, feed the unterminated end of the mount’s coax cable into the hole from the top
surface of the vehicle until the mount’s bushing assembly is in position to drop into the hole. The
bushing should be tilted at a slight angle and fed into the hole. The threaded shank of the mount’s
bushing assembly will not fall through a ¾-inch hole.
9. For a ⅜-inch hole, feed the threaded shank of the mount’s bushing assembly into the hole from the
underside of the mounting surface. Hold it into position until the lock nut is installed.
10. If installing a thick-roof antenna mount (⅜-inch shank) into a ¾-inch hole, place the alignment ring
onto the threaded shank of the mount. This ring has an approximate ¾-inch outside diameter.
11. A tube of synthetic lubricant is included with the antenna mount. Apply this lubricant to the mount’s
rubber O-ring. Do not get any lubricant on the center contact of the mount’s bushing assembly.
12. As illustrated in Figure 8-3 and Figure 8-4, add the O-ring (C) and lock nut (D) to the top of the
mount’s bushing assembly (A). With the O-ring in the groove in the underside of the lock nut, thread
the lock nut onto the bushing assembly. Be sure the O-ring remains in the groove before tightening
the lock nut.