2.125" x 6ft with splits at top and bottom
2" x 6ft with splits at top
1.875" x 6ft
2" x 3ft with splits at the bottom.
By splits is meant that the tubing has small slots cut along its long dimension about 1/2 in in length every 90 deg around the perimeter of the tubing. This allows a hose clamp to compress the outer tubing onto the inner tube which is telescoped into it, forming a clamp The 2.125" clamps onto the fiberglass pole coming up from the base, and sits on the PVC spacer. This keeps the vertical from twisting. The upper end of the 2.125 clamps around the 2" which telescopes about 9" into it. The top of the 2" piece clamps to the 1.875" tube which telescopes 9" into it. over the 1.875 piece is placed a 3 ft section of 2" which acts as a spacer onto which the fibergalss mast is placed. The full 3ft of this 2" piece is placed inside the fibergalss to act as a support.
The fibergalss mast is a 40ft spider pole used in Spider beams. It is very light at 7 lbs. It ranges from 2.16" in dia. at its base to about 1/3" at its tip. There are 12 sections each about 40" long that telescope into each other. The sections are held together by friction. This was not satisfactory for a more permanent installation so a method was devised to make the joint more secure.
Around the upper and lower part of the joint was sound some vinyl tape. This gave a compressible surface for hose clamps to clamp to. Around the upper and lower part of the joint was then placed a stainless hose clamp. The lower clamp was to ensure the fiberglass tube at this point would not split, and the upper clamp was to ensure the upper tubing did not telescope into the lower tube once the antenna had been raised vertical.
The mast had a very good fit onto the 2" aluminum tube, but not a tight fit, so I placed around the aluminum some aluminum tape, just enough to give a snug fit. This allowed me to use a hose clamp to tighten the fiberglass by compressing it to the 2 " tube. The fiber glass was NOT split for this, but merely deformed slightly. The hose clamp has the advantage of both keeping the fiberglass from splitting and it keeps the mast from rotating.
Pentrox is used liberally on the insertions of the aluminum tubing.
This mast was designed with no holes. Since it will be experiences lateral stretch in the wind, I have found hole in aluminum become elongated and cause a point fatigue.
