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Tune Around! Topics For Technicians!
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A "one man" method of raising a support mast for many ham antennas. by Rich Morgan - KF9F Before building, read all directions thoroughly. Use good quality hardware, workmanship, & materials Use common sense in ALL phases of project. Never forget the strength of a Powerline; --- It won't! Remember it this way; 1 ampere of current contains 6,250,000,000,000,000,000 electrons, 1 uA = 6,250,000,000 of the little beggars! You don't want them. So! Always Look First When You Erect An Aerial !!! This Gadget has lasted 28 yrs. With the addition of two more, -The first had no handle, washers around spike holes to prevent wear, etc. Make one for yourself and see what you do/don't like. Materials: 1 3/8" clevis pin (This is used to prevent the mast from sliding down inside the muffler pipe) 3 - 4 Bolts (to accommodate hinge req.) I used carriage bolts w/ heads thru from bottom with nuts/washers on top. 3 - 3/8" X 2" or 2 1/2" muffler clamps 1 - 12" - 14" X 2" or 2 1/2" 1 - pc. min. 18" X 24"X 3/4" marine plywood 1 - pc. 2" x 10" or 2" x 12" x 12" pressure treated or equiv. 4 -60d spikes w/ fender washers (mine were what have you,12" long, scrounged from barn.) Note: I did build one for another ham, being reimbursed for parts from a farm supply store, about 10 yrs ago, at a cost of about $20.for hdw. I don't remember lumber cost. Guy ropes are cut after you find out where your stakes can be driven. To Use: 1. Locate "Gadget" & Measure distance to guy stakes; driving two of them securely at your selected points. 2. Decide how high up your guy point will be eg; almost to the top of a 30 ft push-up pole, let's say 25'. 3. Use the Pythagorean theorem to approximate length, allowing a little for knots, & adjustment. Below is the formula. C squared = A squared + B squared = a number from which the square root is taken to give you the unknown guy wire length. C squared in the drawing below is your unknown guy wire length. Then the square root of the answer in your formula above is taken...you have your answer for the length of the guy.
Refer to the drawing above. For example if guy stake is 40 ft away (A squared) & guy is at 25 ft (B squared), then guy rope will need to be 1600 + 625, = 2225. Now take the square root of 2225 = 47.16 feet. Don't forget to add a foot or two for securing the guy rope. Another example. 4. Lay out 2 of the ropes from the guy point on the mast backwards to the guy stakes & tie. As you walk the pole up into place, the slack will come out of the two back ropes. If done correctly, you may go past vertical a little, but the ropes should hold until you can get an "eyeball" on it. Otherwise, just have another person watching for "plumb". 5. Once you're happy with the vertical position, (OR WORN OUT & ON BREAK), tie off the 3rd guy rope. A bit of touch up with the tension of the guys may be needed. In the drawing below, the "Aerial Gadget" is nothing more than a method to hold a hinge point for the bottom of the mast very secure to the earth when raising the mast that is attached to the "Gadget".
Notes: All the guys in our ham club liked this gadget because of the safety afforded as well as easier aerial erection. Editor note: Rich, KF9F, has been gracious enough to share this idea with you and me. Use the plans in this article as they are, or in hopes of giving you more ideas of doing the same thing with your own materials and ham engineering! Above all, be safe and plan ahead! N4UJW
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