may be copper for the bent elements and aluminum for the straight will give you the best of both.

unclesam, what will you use for reflectors?

Unclesam,
I take it a metal mast is going to go thru those crosses. That will be fine, in case youre wondering. :)
Youre going to want to put a light coat of spray paint on that plastic for use outdoors, for longevity. A neater job can be done before putting on the reflectors. :)

and the washers were found at local TruValue hardware store, sold as "burrs" for use with conventional copper leatherworking rivets.
Ahh, good find. The leatherworking places also have the old fashioned pound together with a hammer copper rivets. Fabric/Button stores may carry them too.

http://www.digitalhome.ca/forum/picture.php?albumid=647&pictureid=3472
nikiml, I will use three-eighths-inch diameter aluminum tubes salvaged from a defunct commercial antenna, because they were handy. I realize this is a departure from your posted GH10n3 model, but I have no way of knowing what might be the effect of the change on performance. I flared the inside ends of the tubes for a sliding fit inside half-inch CPVC plastic pipe. A length of smaller plastic tube slit lengthwise defines each gap between the two pieces of each reflector that requires a gap. An aluminum pop rivet in each tube contacts the inside of its plastic pipe cap, which keeps the rod from pulling out. If image does not appear in this posting, see my photo album GH10n3.

There are two varieties of common quarter-inch diameter copper tubing, I have worked with both, and antenna builders may want to look for the thinwall variety. It is lighter, cheaper and easier to work with, as in rolling short lengths straight and flattening their ends. Home centers in my area sell the tubing two ways in the same store, by the foot and by the pre-boxed coil. By-the-foot tubing has a thicker wall, is heavier and stiffer, tougher to work. In-the-box tubing, which is sold for the same plumbing purposes, can easily be shaped by hand, but care must be taken in handling completed assemblies, lest they be unintentionally bent before applying them to the antenna's framework. A store that sells tubing only by the foot is selling the thickwall variety. You can spot the heavier tubing by its reddish color, and you will not be able to crush the end of the tube using just your fingers. The thinwall tubing will have a more golden-bronze color outside and a very golden color inside, and you can partly close the tubing's end with your fingers. A wheel-type tubing cutter cannot be used with the thinwall variety, it will smash it. The boxed tubing can be checked in the store by rotating the coil within the box to expose one end in the cutout window provided in the cardboard box. Check the inside color and squeeze the exposed end of the tubing. I have described using copper tubing to make active elements and NARODs for GH antennas in a series of three Instructables that have links within this Final Assembly Instructable: http://www.instructables.com/id/Gray-Hoverman-TV-Antenna-Final-Assembly/

The thinwall tubing will have a more golden-bronze color outside and a very golden color inside, and you can partly close the tubing's end with your fingers. A wheel-type tubing cutter cannot be used with the thinwall variety, it will smash it. T
Wow, I dont think Ive seen copper tubing in my area that thin walled yet. :o

I think I would be scared to use it for plumbing purposes.

300ohm, I should supply a more objective description of the thinwall quarter-inch copper tubing. I used a boxed coil of copper tubing for the elements on the GH10n3 I pictured, and it was cheaper and much easier to work than the by-the-foot tubing, even though I cannot squeeze this particular sample closed using my fingers. It can be uncoiled nicely by holding the free end against a tabletop and unrolling the coil along the tabletop. Gross bends can be removed by pressing it against the tabletop with the palm of the hand. Just a few rolls between a board and a benchtop will yield a perfectly straight short length. It's box is marked Steamline, Mueller Industries, Inc., Made in USA, and it has a "Copper Usage Guide" on the box. Indeed, this box is marked "Utility Coil*," on the red sticker on the box's spine, and the Guide's asterisk says to check local codes before using it in plumbing, air conditioning or refrigeration applications. From this I can only presume that it is distributed primarily for building TV antennas.

From this I can only presume that it is distributed primarily for building TV antennas.

Heh, heh yeah. Or for building those lawn ornament type water sprinklers. :p:p

I want to see how you do that. Post some pictures of that step. :)This may not look too elegant but it is rigid and the metal doesn't split. UncleSams method of flattening and riveting corners together would also be easy. The soldering method I haven't had opportunity to try yet.

Regarding a picture, I've apparently reached my limit for now, so I guess a verbal image is all I can give you. I just squashed the corner with a pair of pliers until it was about 1/4" diam. again. This also creates a couple of ridges on the outer part of the corner that act as stiffening ribs. It only takes about 10 seconds. Because the metal is so soft to begin with, all these operations help to 'work-harden' it a bit and this adds to it's stiffness. Straightening would probably crack it.

I previously posted photos of the single spine, a continuous length of one-inch PVC pipe, for a GH10n3 I am building here at Do Little Farm (Motto: "I love the smell of NARODs in the morning"). See my photo albums. I recently attached the bling, active elements and NARODs made from the thinwall version of quarter-inch copper tubing.........

Great photos and documentation unclesam. I admire your craftsmanship. I haven't decided on what type of frame to use yet but when I do I'll post some photos as well.

http://www.digitalhome.ca/forum/picture.php?albumid=647&pictureid=3691
I had rubber tips on hand (Advance Auto Parts, used to cover unused vaccuum inlets on auto engines, many diameters available) to cover the ends of the 3/8" dia aluminum reflector tubes for the GH10n3 I am building. They look nifty, but they will add some weight and wind resistance at the tips of the reflectors, and they are not cheap. I made another try at crimping the ends of sample tubes, and I had good results when I gripped the tube in a flaring tool while flattening just the tip of the tube. It works best to allow about a half inch to protrude from the flaring tool, and the sharp corners can be filed off for safety.http://www.digitalhome.ca/forum/picture.php?albumid=647&pictureid=3692

unclesam,

I like the rounded corners. The flaring tool would work well also.

300ohm, I now recall that the quarter-inch copper tubing that I used to build the active elements of my SBGH6 (my photo albums), a "Utility Coil" that was golden color inside and whose end could be deformed with finger pressure, was marked "heche en Mexico". That just happened to be what I picked up at a home center, probably because it was the lowest price of any of the tubing offered. I did not know to specifically look for that label again when I picked up another "Utility Coil" for building the GH10n3. The new coil did not work as easy the Mexican, but much easier than the higher grades, such as that sold by the foot. I formed and installed the active elements and NARODs for the GH10n3 pictured in post 336 in two afternoons' work.

2Bits, I'm thinking about giving the flashing a try to roll some tubes for my first VHF-Hi Yagi. There's a 10 foot roll of Amerimax flashing at home depot with a thickness of .0092. I have a 1/2" copper pipe on hand (5/8 OD) to use as the basis for the tubes.

I'm just wondering if there's any tendency for the tube to unfurl? Will it make much difference in performance having the overlapping edge on the tube instead of a solid piece?

I'm just wondering if there's any tendency for the tube to unfurl?
Yes, on a larger diameter the bend isnt as tight, so some unfurling may occur. You could overlap and pop rivet the seam on larger diameters.
Will it make much difference in performance having the overlapping edge on the tube instead of a solid piece?
Not if its overlapped tightly and smoothly.

For short uhf elements, cut up beer cans could substitute for flashing. The taller the can the better, heh.

http://www.digitalhome.ca/forum/picture.php?albumid=716&pictureid=3694
I installed the 3/8" diameter aluminum reflector tubes using the method pictured in post #341 above. I crimped closed the ends of all but three of the rods, used rubber tips on those. The fit is pretty snug, but I wanted to be sure the tips would not get blown off, and I did not want to mess with adhesive. I formed tiny barbs that should keep the thick-walled tips from pulling off. Clearly, precision drilling of the antenna's spine is paramount for having the components in their correct spatial relationships. Where mine erred, I used an electric heat gun to warm the offending CPVC pipe near where it exited the spine just until it would yield to pressure. I moved the reflector into proper position, by eye, and held it there while applying a wet cloth to the warm section to fix it in place. I made the footed stand to support an antenna, on top of a 10-foot section of metal mast, on the lawn for reception tests. Used with a short section of pipe, it serves nicely as an assembly stand while the maze of reflectors is added. I will report the antenna's final weight and its performance in the thread "Top Hat" GH with NARODS......., within a few days, as soon as the snow is off the cherry blossoms.

2Bits, I'm thinking about giving the flashing a try to roll some tubes for my first VHF-Hi Yagi. There's a 10 foot roll of Amerimax flashing at home depot with a thickness of .0092. I have a 1/2" copper pipe on hand (5/8 OD) to use as the basis for the tubes.

I'm just wondering if there's any tendency for the tube to unfurl? Will it make much difference in performance having the overlapping edge on the tube instead of a solid piece?

No, the tube shouldn't unfurl mostly because it's being formed, not rolled. It's soft and easy to work with but as I mentioned in another post, forming it work hardens it to some extent and it becomes pretty rigid because of that and of course the fact that it's now circular. The overlapping edge is just for strength. Conductivity wouldn't really be affected if the seam was open or overlapped. For your tubes, being of a greater diameter, they should be even easier to form but it also might be possible to roll something that diameter. I've never tried that.

Nice looking antenna unclesam. :p


formed tiny barbs that should keep the thick-walled tips from pulling off. Clearly, precision drilling of the antenna's spine is paramount for having the components in their correct spatial relationships. Where mine erred, I used an electric heat gun to warm the offending CPVC pipe near where it exited the spine just until it would yield to pressure. I moved the reflector into proper position, by eye, and held it there while applying a wet cloth to the warm section to fix it in place.

Good tips.

Jeez I'm having a tough time bending this flashing into shape. The 10' x 10" roll I bought says .0092 on the page specs but I'm thinking this must be a lot thicker than what 2Bits used. It feels like coffee can thickness. I got it into the channel but as soon as I remove it the thing pops open a bit and its real tough to fold with my fingers. Very springy. Getting the edges closed is gonna be a chore.

2Bits do you have a link to the type of flashing you used? I see in one of the pictures its rolled out. Mine just recoils on itself.

Is that definitely the aluminum stuff, Javaman, and not the galvanized steel flashing? I was in an HD store a couple of days ago and they were side-by-side on the rack.

The label says aluminum flashing and it matches the model number. One side has a gold color to it. I tried a blowtorch and it was a bit easier to bend but the edges were still difficult. The result was not a pretty sight. Well at least I've got my copper folded dipole done.