From the top of the stack, a stressed Moxon for 50 Mhz, and two Arrow style yagis for 144 Mhz (4 elements), and 432 Mhz (8 elements).
The mast is a Kelty extendable tarp pole, which extends to 99" (8'3"). It is 1" (25mm) diameter, except for the lower section, which is slightly larger to telescope over the 1" section. I use it upside down, with an additional two 24" sections of 1" tubing above the guy ring to mount the antennas. The top of the mast is at ~12'.
Except for the Kelty mast, all of the components in this stack are homebrew.
This Moxon is made from 24awg (19x36) pvc hookup wire.
The insulators between the legs are made from pieces of a large nylon ty-wrap.
The center insulator is a small piece of 1/8" plexiglass.
The feedline is rg-58, with a nylon "snail" ty-wrapped to it, which is attached to the top of the plywood plate with a machine screw.
The center support is a piece of 1/2" birch plywood, with brass screw inserts to mount the mounting bracket, and the feedline strain relief.
The rods are 3/16" fiberglass rods from Tap Plastics, cut into 24" segments, and coupled with #10 nylon standoffs drilled out to 3/16", and epoxied to one segment.
The wire loop is attached to the rods using #10 standoffs, drilled halfway to 3/16", and drilled cross-ways for the wire, with a #10 nylon screw trimmed to length to hold the wire in place.
The rods tend to flop around, so some braided nylon "mason twine" is used to provide some diagonal tension to keep the loop square.
The mounting bracket is a piece of 3/4"x3/4" aluminum angle, with a piece of 1/2" aluminum channel, notched out to fit the mast contour, with a pair of #8 stainless machine screws and wing nuts.
The yagi's are custom Arrow type designs, using aluminum arrow shafts as the elements, with 8-32 threaded inserts and 8-32 threaded rod to attach them through the boom.
The designs were done in NEC4, for target frequencies of 144.250, and 432.150.
The boom is 1/2" square aluminum tubing left over from some wall mounted wire shelving. The boom length is 42", and once I cut them, and add the splices (3/8" aluminum rod inside the tubing), will break down to less than 24" per segment. The mounts are similar to the Moxon, with a strip of aluminum, and a pair of screws to hold the boom to the aluminum angle.
The gamma matches are made from 1/2" square bar stock, drilled to accept a chassis mount BNC at one end, using some teflon RG-6 with the shield removed as the internal element. The internal element passes through the block, and out the side into the stub, which forms the capacitor. The shorting bar is a sandwich of two pieces of 1/2"x1/4" aluminum bar stock. The design was a WAG (Wild A** Guess), but after some fiddling, tuned up nicely with the aid of a HP network analyser.
They guy ring is a piece of 1/16" aluminum plate, punched with a 1" chassis punch, trimmed into a octogon with tin snips, drilled with holes every 3/8", and the edges sanded. It fits over the 1" mast extension, at the top of the Kelty pole (which is really the extendable bottom section, with is larger than rest of the mast, which is 1"). The guy lines are braided mason twine.
The mast extension segments are 1" aluminum tubing, with a coupler made from a 3" piece of a scrap aluminum handlebar (which happens to fit perfectly inside the 1" tubing), drilled and tapped for 4-40 machine screws to hold the pieces in alignment. Eventually I will drill and tap the rest of the mast to allow the whole mast to lock together in alignment over the entire length.
A 1" internally threaded PVC plumbing fitting with threads filed down to form a friction fit keeps the mast extension from slipping down, but will be removed when I get around to drilling and tapping the mast to lock it together all the way up, to allow it to be rotated from the bottom.
The top of a plastic food container is drilled to accept the spike at the bottom (top) of the Kelty pole, and is marked with compass headings in 15 degree increments. (not visible in these photos). This allows the mast to be turned from ground level, from under a tarp, or inside a tent .
The Kelty pole I use is this one: http://www.kelty.com/p-134-adjustable-pole.aspx
