3 Simple Ways to
Share What You Make

With Instructables you can share what you make with the world — and tap into an ever-growing community of creative experts.

PhotosPhotos

Share one or more photos of a project, recipe, or whatever you've made, quickly and easily.

Step by StepStep-By-Step

Share your step-by-step photos with text instructions of what you made so others can do it too!

VideoVideo

Share your how-to video. You'll need your embed code from a video site such as YouTube.

Build a Large DB8 HDTV Antenna: Big Bertha

Step 2Building the reflector

Building the reflector
«
  • 01edge fold over.jpg
  • 02pounding edging.jpg
  • 03back-pounding edging.jpg
  • 04bending angle bar.jpg
  • 05bending wing.jpg
  • 07Angle bend check.jpg
The reflector can be made of any metal. You could use a solid sheet but in a big wind it would be a problem. And all that is really needed is horizontal bars or wire that are separated by no more than 2 inches vertically. Anything larger than that and it would exceed the wavelength and would not reflect the signal to the wiskers. I found some 36" wide rolls of something called galvenized wire netting at Home Depot. It's got 1/2 inch squares of stiff galvenized wire that is welded at each crosslink. The 36" is perfect for the width of the array. Wider could be used but it would go wasted as the reflected signal wouldn't hit anything useful.

Unroll 40 inches (for the hight) and cut it with snips. To reinforce the sides (40" side) I used thin 1/4" wide angled aluminum trim. I placed one side of it under the mesh and pounded it over with a hammer.

Picture 2 shows this more clearly. I then turned it over and pounded the other side to flatten the mesh as the aluminum tended to curl in the direction of pounding. Do the same thing to the other side.

4th picture
Next, use two, thick, 1inch wide X 36 inches long aluminum bar to reinforce the top and bottom. As the measurements show the two sides of the array are wings that will be slightly folded in. Place the bar in a vise and bend 10 inches of the bar 2 1/2 inches forward. Do the same to the other end. To assist, make a wedge 10 inches long and 2 1/2 inches wide out of hardboard to act as a guide. Or just measure it. Make another angled brace for the bottom of the array.

5th picture
To prepare to install the two bent top and bottom braces, measure 10 inches of the side of the mesh and bend it slightly on the edge of the workbench. Do the same to the other side.

6th picture
The bar is on the bench with a final angle check. Drill small holes. 2 on each end of the angled bend and one in the center of entire bar. I used 3/4" size 8 machine screws and nuts with washers on each side to bolt the bar to the FRONT of the mesh. Bolt one to the top and one to the bottom.
« Previous StepDownload PDFView All StepsNext Step »

Pro

Get More Out of Instructables

Already have an Account?

close

All Steps Viewing
View all steps of an Instructable on the same page when you're a Pro Member.

Upgrade to Pro today!
35
Followers
2
Author:deceiver(deceiver)
Retired Jr. High teacher of 30 years. Always into lots of things. Now I seem to be into them more. Love woodworking, guitar, portrait painting, building things. Married to Joyce (totally wonderful exp...
more »