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W2IK's NEW E.N.V.I.S. ANTENNA
PART 2: Building The Antenna
Designed and built by Bob Hejl - W2IK - NNN0KSI NAVMC MARS
all rights reserved 2007 (See part one here: E.N.V.I.S. part 1)
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Take the 1/2 inch PVC elbow, as shown on the left, and drill a 1/4 inch hole completely through the elbow at about 1/4 inch from the bottom. Drill another hole, this time 1/8 inch diameter, completely through the center of the elbow "joint". This will leave you with two holes as shown on the right. This elbow is the center insulator of the dipole configuration. The smaller hole will accommodate the wires (one run out of each side) and the larger hole will be used during deployment to secure the insulator to the center telescoping pole with the last 1/4 x 20 machine screw and nut. You may want to use a wing nut instead of a standard nut.
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Cut the 66 ft length of wire into two equal lengths. Insert them into the smaller holes of the elbow and pull them slightly out from the inside. Tie a knot in each about 3/4 inch from the ends and strip the insulation away about 1/8 inch on the ends. It should look like the picture on the left. (for MARS operation, use about 100 ft total length and adjust details accordingly)
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Take the "barrel" connector and epoxy it into the 1/2" PVC ring as shown. Make sure that it's done exactly as shown so that the lip of one end of the connector is exposed just above the PVC. Before you epoxy the unit, roughen up the inside of the PVC so the epoxy will adhere better. If you are lucky, the barrel will have to be "screwed" into the PVC as you apply the epoxy. Refer to the picture to the right. Let the epoxy cure (harden) before the next step
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Take a file and roughen the outer edge of the barrel connector on the end where it just protrudes beyond the PVC ring. Solder one wire to this edge and solder the other length of wire to the center of the barrel. Be careful not to apply excessive heat on the center connection or the solder will run down to the other side. Refer to the picture on the left for the proper result.
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When you are satisfied that you've made good solder connections, using PVC cement, glue the ring with the connector into the elbow. MAKE SURE TO DO THIS QUICKLY as the cement bonds in a matter of seconds. ALSO: make sure that the wires inside aren't twisted. You may wish to do a dry run before applying the cement. Press the PVC ring/connector in as far as it will go. The knots in the wires act as strain relief when the antenna is deployed. Refer to the picture on the right. One last step: Fill the void with epoxy or caulking just to the point where you don't see the wires, but no further.
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On the other ends of the two lengths of 33 ft. wire, attach 20 feet each of poly or nylon cord by tying and epoxying the knots so they don't become undone. Knot both the wire and the cord. See picture at left. It may be difficult to see from the picture, but the wire is knotted around the cord as well as the cord being knotted. Pull the knot tight, making sure it doesn't slip apart, before applying the epoxy. There is no need to add end insulators as the nylon cord is non-conductive and the wire itself has insulation. This completes the building of the antenna section. Now to show you how to deploy and use the system.
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part three (click below):
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