Hex A Beam Spreader Plate
Well I finally got back to work on the antenna! A spring of house fix up and the hot summer stopped the project until the weather cooled off this fall. I made up the spreader cords and then put it all together.
I decided that some protection and reinforcement of the fiberglass tubes was in order, so I added metal to the mix. I slit 4" pieces of 1" hard copper tubing lengthwise and used them to protect the fiberglass from the u-bolts. Before assembly I added the aluminum tubes inside the fiberglass securing them with some Gorilla glue. You can now wrench down the u-bolts pretty tight and no damage will occur. I plan to pin the spreader tubes with 10-32 bolts.
Here's another closeup shot of the spreader to hub connection. Also a shot of the whole center hub assembly.
Here's where I am now, the framework is set up. Now to add the wires!
Progress so far, parts are all in (except the tube flanges) and I have made the center plate. Once the flanges arrive I will finish drilling the center plate and start assembling the antenna. While I had about 30 sqft of 1/4" aluminum I had virtually nothing in 3/16, so I went to the local Metal Supermarket branch where Doug cut two pieces to shape for $23 and the drops are in my scrap box for other projects.
Spreaders have been measured and prepped. I deviated a little from the instructions a little by drilling a hole at the end of the slot where the securing clamp is located to prevent running splits.
I also cut some 0.500 OD aluminum tubing 4" long to use inside the fiberglass to prevent crushing from the U-bolts. These will be glued in with Gorilla Glue. I am also going to split some 6" pieces of 1" copper tubing to place above the fiberglass to prevent the U Bolts from crushing the spreader tubes.
I plan to use the 1.250" fiberglass mast as the conduit for the cabling. I have practiced on a piece of scrap and think I can thread the assembly without cutting holes in the back side to work through. We will see...
Center post construction has commenced...
I elected to make a split bushing from brass stock to make up the difference in the flange and the fiberglass tube. If I had known the play was as much as it was, I would have elected to cast my own flanges. I am going to turn an aluminum center piece to fit up into the fiberglass tube and project from the bottom to attach to the mast on the tower.