Aluminum tape is wrapped around fiberglass rod to make the reflectors for my GH10n3 SNAP antenna. This is easier work than what appears in my previous antenna reflector rod Instructable. The computer model for this antenna may be found at http://clients.teksavvy.com/~nickm/gh_n3_uV/gh10n3_9V7_15u0.html, but this method can be used to make reflectors for any model of Gray-Hoverman.
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Step 1: Tools and Equipment
Wrapping metallic aluminum tape (home center) around 5/16" dia fiberglass rod (sold at home centers as driveway marker in 6 foot lengths) takes little equipment and is easy. The fiberglass is cut to length specified for a set of reflector rods plus the center gap separating them, plus 5mm added to each end. The 5mm points are marked on the ends of the rod. A length of tape is cut a couple inches longer than the rod and taped sticky face up, about half the rod's diameter from a straight edge attached to the edge of the bench. A little of the peel-off strip is removed from each end, and the ends of the foil strip are taped to the bench. The rod is pressed onto the near long edge of the tape, then the tape is cut crosswise at the rod's 5mm points, except for a small tab that is stuck under the rod. The rod is rolled onto the tape a little at a time, and a small roller is repeatedly run the length of the rod to press it onto the tape underneath. Once all the tape is on the rod, the small tape tabs left on the ends are cut and peeled away, and the innner gap is marked. The tape is cut around and peeled out of the gap. The roller, sold for sealing wallpaper seams, is used to thoroughly press the tape onto the rod all over, especially the cut edges.
Step 2: Rod Gap
The rod is completely covered with aluminum tape, except for 5mm at each end, then the gap is created by cutting around with a sharp knife and peeling off the foil.
Step 3: Rod End Caps
The inner ends of the foil rolls will be protected inside a sealed adapter tube, the outer ends by a cap glued with outdoor adhesive. These caps are sold at home centers for use with white wire shelving. The lengthwise end edge of the foil roll will be positioned in the antenna so that water will shed from it.
Step 4: Complete Set of Reflector Rods for GH10n3
A complete set of reflector rods for a GH10n3 antenna.
Step 5: Complete Set of Reflector Assemblies for GH10n3 SNAP
A complete set of reflector assemblies for GH10n3 SNAP antenna.
Step 6: Tape the Tape
Tape a strip of aluminum tape, a few inches longer than the rod, with backer strip (adhesive) up, to workbench, spaced off of straightedge about an eighth of an inch.
Step 7: Peel Off Backer
Peel off the backer strip, untape one end and pull the Al tape taut, stick the end back down.
Step 8: Cut Off Ends
Press down on one end of the rod to secure the Al tape, and cut at the mark, but do not try to remove the cutoff tape yet. Next, do the same at the other end of the rod, making sure to press down on the rod. Then, while pressing down on the rod end, cut along the end of the rod then across the end of the rod. Repeat at the other end of the rod, making sure to press down on the end of the rod while cutting the Al tape. Carefully remove the cutoff tape.
Step 9: Lets Roll
Lift and move the rod and tape away from the straight edge, roll the rod back while pressing down on it to secure the small strip of tape stuck to the bottom of the rod, working along the length of the rod with the fingers of both hands. Lift and move the rod back against the straight edge. Press the rod against the straight edge, then roll the rod about one-eighth of a turn to roll more Al tape onto the bottom of the rod. Lift and move the rod and tape away from the straight edge. Without pressing down on the rod, roll the rod back to place the new tape under the rod. Press down and roll the rod forward until just before the flap of tape hits the work surface. Repeat this action working along the length of the rod. Lift and move the rod back to the straightedge and repeat this process until all the tape is on the rod. When the first long edge of the tape appears on top of the rod, use a roller to press the edge tightly against the rod. When the final section of tape has been thusly pressed onto the under side of the rod, use the roller to press the final edge of the tape tight. Use the roller to press all the tape to the rod. Measure, mark and cut the gap for the reflector rod pair, carefully pick and peel off the tape from the gap. Cut and remove the tape tabs from the ends of the rod.
Step 10: Rod Holder for SNAP Antenna
A length of 1/2" CPVC pipe, two caps and two rubber grommets grip and support each reflector, aluminum tape wrapped over 5/16" dia fiberglass rod. The pipe assemblies snap into the GH10n3 SNAP antenna frame. The pipe is 3-1/2" long; the grommet I.D. is 5/16", and O.D. is 5/8". Marks made on the rod at 2-1/4" each side of center fall just outside the caps as an aid in centering the rod within the assembly as the caps are being cemented in place. One cap is glued in place at a time, but moderate pressure is applied at both ends during each glueing and maintained until the cement has completely set. Squeezing the grommets between the cap and the end of the pipe causes the grommet to create a very tight grip on the rod. It also creates a watertight seal between the grommet and the rod and between the grommet and the inner face of the cap.
Step 11: Glue Reflector
One cap is glued on at a time, but both caps/grommets are squeezed with clamps as the glue is setting on the first.
Step 12: Squeeze Reflector
Clamps squeeze the second cap/grommet as the glue sets on the second cap.
Step 13: Set of Reflectors for GH10n3 SNAP Antenna, Preassembled Sealed Modules
Modular reflector assemblies snap into the antenna plastic spine assebly temporarily for testing or permanently for glueing in place.
Step 14: How to Center-Drill Caps
CPVC caps can be center-drilled by mounting them onto a short piece of 1/2" CPVC pipe held in drill press vise. The pipe should protrude enough to center the cap but not jam in it. A drill bit that will just fit inside the pipe is used to center the pipe under the drill press quill, then the vise is locked in place, and the drill bit changed to the size of the desired hole. The lip of the cap should rest on the vise jaws, to keep it vertical. The cap is held with pliers to keep it from spinning while the hole is drilled.