Our wide line of fiberglass quad spreader arms allows our customers to select the ideal spreader arm for its intended role: lowest band desired, total number of bands, and the most severe weather conditions likely to be encountered in the customer’s location. You may design your quad with budget in mind, or to be “bulletproof”. In either case, our aim is to give you absolutely the most for your money.
MAX-GAIN SYSTEMS’ spreaders – unlike earlier types of sleeved spreaders using smaller diameter, less reliable materials-offer a number of advantages:
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Buying spreaders to repair a damaged Lightning Bolt quad?? Take a look at this VERY well done page by WB9DLC:
PLEASE NOTE: If you have not done so already, be certain to visit this additional page on our site, which contains even more useful information of interest to quad builders:
Wire Attachment Method for Quads – Does Not Require Drilling Spreaders
The following photos illustrate an easy method of making almost indestructible clamps to be used to attach element wires on quad antenna spreaders. This method does not require drilling through the spreaders. Allowing easy and infinite adjustment of the corners of the wire loops, for easy and precise loop centering on the element spreaders. This method cushions and protects the wire elements at the points of greatest stress . the loop corners, and prevents sharp bends which weaken the wire.
These clamps consist of an ALL STAINLESS hose screw-clamp.. (be certain the screw clamp says “All Stainless” or the screw itself will be plated, not stainless, and it will eventually rust), a short length of copper plumbing pipe, and a plastic tube. Very simple, but effective. For the plastic tube, it is best to use a very tough and UV resistant material such as truck air-brake hose (from auto parts store) instead of clear vinyl tube. It will last MUCH longer. Also, spray-paint the plastic tube with flat-black spray paint for additional UV protection.
DimensionsMinimum spreader lengths required for quad reflector loop at various frequencies*
*(calculated for bottom end of bands) |
Useful formula
In order to estimate how far out (measured from the center of the boom) a quad wire of a given length will intersect with a spreader, use this formula:
Take the total wire length of the quad loop in feet (for example, 70.79 ft for a driven element on the 20 meter band) and divide it by 4….(about 17.7 in our example). Then square the result…(about 313.3 in our example). Divide this figure by 2….(about 156.65 for the example) and then take the square root. For our example, this yields the result 12.51, so you know that the wire intersect point will be 12.51 feet out the spreader, measured from the center of the boom.
A far less complex method (with thanks to Ed Niemi, K6EDJ) is to simply take the cosine of one side of the quad loop, (.707 times the length of one side of the quad loop) and measure out the spreader (measure from the center of the boom) to determine the point of wire attachment! The measurement from corner to corner, measuring down one spreader, through the boom, and up the opposite spreader, (wire attachment point to wire attachment point) of each quad loop will be 1.414 times the length of one side of the quad loop.
FOR MORE USEFUL TIPS, VISIT THIS PAGE: