After reading an article by N2UHC on a 10M vertical dipole, I decided to build my own. The antenna in the article was made from electrical conduit. I had some problems with the electrical conduit as I was very hard to tune. I have built several of the Copper Cactus 2M antennas and have also been building EH antennas, so I decided to use similar building methods and materials for my 10M vertical dipole (copper pipe and PVC pipe). I used 3/4” copper pipe for it’s rigidity and the 1/2” copper pipe allows for adjustment. I began by modeling the antenna using EZNEC. I decided to mount the antenna close to the ground. This gives the antenna a low angle of radiation. You can notice that you have a decrease in the gain but I think the low angle of radiation will make up for the loss in gain.
Materials 3/4” X 10’Copper PipeLowe’s - Home Depot1/2” X 10’Copper PipeLowe’s - Home Depot1 1/2” X 10’PVC Sch. 40 pipeLowe’s - Home Depot3/4” X 1/2”Copper Pipe ReducerLowe’s - Home Depot#8 or #10X 1/2”Sheet Metal ScrewsLowe’s - Home DepotSS Hose ClampLowe’s - Home DepotWith the price of copper you might want to use aluminum tubing.
Start by cutting the 3/4” copper pipe into two 5’ pieces. On one of the sections mark 1’, 2’, and 3’. At the marks drill a 3/8” hole through the tubing on one side (not all the through). On the other section mark at 6” and 1’ and drill a 3/8” holes through the tubing on one side. These holes will be used for mounting the copper pipe to the PVC pipe. The 2 reducers have to be modified. Using a hack saw cut a groove in the 1/2” end down to the 3/4” section. This will give the hose clamp room to compress the reducer and hold th 1/2” pipe. Now on the inside of each reducer you will find a little tit. This is used to stop the pipe at the correct position when soldering. You will need to file the tit down smooth so the 1/2” pipe can slide down into the larger pipe. Solder the reducers onto each of the two sections.
Cut two - 3’ sections of the 1/2” pipe. This will be used for the ends of the antenna. Lay the PVC pipe and the two sections of the antenna. The spacing between the two sections should be about 1”. Drill a hole through the other side of the tubing (opposite the 3/8” holes). The hole should be sized so the sheet metal screw rotates freely. Now place the copper pipe and PVC according to the drawing. The PVC should extend approximately 14” above the center of the dipole. Using a 1/8” drill bit drill through the holes in the PVC. Fasten the copper pipe to the PVC using the sheet metal screws. Now mount the coax to the antenna. The braid of the coax should be on the section closes to the ground. There are many ways to connect the coax do the antenna (using screws, hose clamps, soldering, etc.). Slide the 1/2” copper pipe into the antenna and adjust to 2’. Mount the antenna - mounting solutions is up to you. The antenna may be guyed using non-conducting rope. After antenna is mounted check the SWR and adjust if needed.
This antenna was published in 10-10 magazine - July 2013 issue.
I have a friend that turned the antenna horizontally and mounted it in his attic.
6M Vertical Dipole
You can make a 6M vertical dipole using the same construction technique. The 6M vertical will require the 3/4” pipe to be 3’ long and the 1/2” pipe is 3’ long. Antenna should be 2 1/2’ above ground to 11 1/2’. I started with the antenna at 2 feet above ground similar to the 10M but after tuning the 1/2” copper pipe ended up being 1/1/2’ above ground instead of 2’.