I have a friend that is a plumber . I ask him the other day about some used copper pipe . My thoughts where YAGI turned at 146 . He called me and told me he had me 4 12' pieces of 1/2 " used copper nice and straight . I have already made the tape measure yagi so I kinda got the thery down . I need some ideals . 3 element only . What can I use for a base structure to put these elements on . Any ideals would be a great help
Since weight is no object how about a cast iron girder? A 1"x 2" furring strip would be suitable. Widely used for V/U antennas.
Plumber's delight Yagis have been around for ages. Don't suppose you have an older ARRL Antenna Book handy, do you? Probably would have some designs (or search QST archives if you are a member). Seem to recall plans for a 6 meter one years ago...
Use copper tubing to make the boom as well. You can use copper TEE fittings to attach the reflector and the director. As for the driven element.....see if you can get hold of part of a wooden shipping pallet. They use oak. Cut some oak to use as an insulator for the driven element. Use a saber saw to cut it to size. You can also make your mast to boom clamp out of oak. Sand the oak down to a fairly smooth finish and give it a few coat of oil based paint. Rust-oleum paint is oil base paint. Use brush on paint, not spray paint. Go to the hardware aisle of a big box store and you can get rubber cap that go of furniture legs. Use those to cap the ends of the elements Because of the element length to element diameter ratio, depending on the formula you use, you may find it resonant very low in frequency. No big deal. Just use a copper tubing cutting and trim the elements just like you would a simple dipole. Better too long than too short. Super easy to cut copper rather than add copper. Good luck with your project, Barry
I built an FM broadcast band plumber's delight Yagi-Uda with quad driven element using 1/2" copper tubing. I can post dimensions for 146MHz if anyone wants them.
K7MEM's very useful Yagi Calculator: http://www.k7mem.com/Ant_Yagi_VHF.html (If I put that much expen$ive copper in my garden I'd wanna fit a burglar alarm to it ! )
Here is a 3 element 146 MHz plumber's delight copper tubing Yagi. It is dimensioned for forward gain and impedance without regard to front-to-back ratio. Tubing is 1/2 inch copper which has an outside diameter of 0.625 inches. 145MHz gain, 9.1 dBi 146 MHz gain, 9.0 dBi 147 MHz gain, 8.8 dBi 146 MHz F/B, 7.6 dB 146 MHz SWR, 1.1:1 2:1 SWR bandwidth, 2.8 MHz The driven element is a folded dipole split at the top for connection to the coax and balun (if used). The top and bottom folded dipole tubes are spaced 2.5 inches center-to-center. The driven element length is approximate and should be adjusted using an SWR meter before soldering it together. The driven element connects to the boom with two tees, one tee to the boom halves and another tee above the first tee connects to the two element halves. The driven element dimensions are tubing center-to-center. The director and reflector are measured to the ends. The reflector and director are spaced 15" = 28cm from the driven element. Dimensions Reflector, 41.0" = 104.1cm Driven element, 34.0" = 86.4cm Director, 36.0" = 91.4cm
Nah, just do what Mick Jagger did with all of his copper Yagis a long time ago---it's so very simple and still works today! He even wrote a song about the process; "Paint It Black" if I remember correctly...
