Spacing between elements are 34 and 1/2 inches.
The elements are 1/2 inch aluminum tubing of 1/16-inch wall thickness.(you can cut up an old TV antenna they work great).
The Boom length is 72 inches (6 feet).The boom is 1 and 1/4 inch tubing.
You can attach 50 ohm coax to this antenna after you add a gamma match.
To attach the gamma rod to the antenna you will need to mount an SO-239 chassis connector to the center of the driven element.
This can be made from a piece of sheet metal about 1 inche wide by 3 inches long.
Bend the long side of the sheet metal into and L-shape so that you now have a 2×1 inch surface and a 1×1 inch on a 90 degree angle.
Then center punch the 2×1 side and mount the SO-239 connector in the middle.
Next bend the 1×1 inch surface onto the center of the driven element and secure it with 2 sheet metal screws.
Gamma Mount Bracket
Now you will need to get some more sheet metal to build the SHORTENING strap of the gamma this may vary in size depending on the tubing size and the space from driven to the gamma match.
The gamma match is mounted along the side of the driven after you have soldered the innner conductor of the gamma to the center od the SO-239.
The spacing is usally about 1.5 to 2 inches from the driven element (Dosen’t make much difference).
To make the SHORTENING strap make a 1 inch strip about 6 inches long. Take this strip and bend it around the driven and over to the gamma.
Make sure it folds back over so that you can drill 1 hole at each.