Introduction: Homemade TV Antenna
This TV antenna is not only omnidirectional, but also compatible with the new digital television. I actually get more stations with the new digital television signals than the old system. I get 35 channels and I an a long way from any large city. Some of the stations are over 60 miles away.
Construction is simple using copper tubing, PVC pipe and minimal tools. Tools include a hack saw, drill (hand or electric) screw driver and tape measure.
Step 1: Making the Antenna Step 1
Start with some 3/8 or 1/2 inch copper tubing. Bend a half circle in a 26 inch diameter with an additional 1 inch extra on each end. Flatten the inch on the ends and bend them OUT. Now make another half circle and bend the ends IN.
Step 2: Step 2
Take a 1/2 or 3/4 inch PVC cross (depending if you used 3/8 or 1/2 inch copper tubing). add a piece of PVC to each connection so you can bolt the flattened edges to two of the PVC ends and the middle will fit into a notch to support it. Notice the two pieces of copper tubing do NOT come into electrical contact with each other except for the 300 ohm matching transformer.
Bolt the cross to a 2" PVBC end cap. Use a lock washer or double nuts so it doesn't loosen up. Glue the cap to a 20 foot piece of 2" PVC pipe.
Connect a 300 ohm matching transformer to the two pieced of copper tubing as in the picture. Connect cable to transformer, tape and run down the 2" PVC pole.
Drive a piece of pipe in t ground with about a foot above the ground and set the antenna mast over it and firmly mount the mast at roof level. As long as you mount it at the edge of the roof and don't go over 20 feet you don't need guy wires. if you go higher I would suggest adding some guy wires.
Trees between you and the station could reduce the signal so you may have to go above trees for log distance stations.
If you use a metal pole, it should be grounded to the ground rod by your electric meter.
8 days ago
what do you call this type of antenna??
3 months ago
I made my first in 2014 and I've made about 8 of these things, since. Every time I show someone this thing, they want one.. so I just keep cranking them out and giving them away. In the center of Tucson, no commercial omni antenna I've tried works better. Doing a scan with my most recent one gives me 82 channels in the center of Tucson, AZ.. completely unamplified. There are a pile of duplicate channels so I got about 65 channels after I edited the list.
I build them with just a single piece of PVC, instead of a cross... they've held up to monsoon winds with no issues. I found good quality outdoor sealed transformers on amazon.. that makes a noticeable difference.. I was originally using transformers I found at garage sales and thrift stores but after cutting a few open I noticed that some of them don't actually have a transformer in them... they just connect the f connector to the twinlead, directly. The ones with transformers do make a difference. I noticed in an older installation that getting a minimum of 6' over the top of the roof makes an enormous difference. I was not able to do that in my most recent location... but its still performing better than any commercially built antenna I've tried.
I have not tried a distribution amplifier on this antenna, yet. I only have one TV in this house that I use, so there's no point. I've put one on commercial antennas at other peoples homes and they seem to really work, so presumably with this antenna and a distribution amp you could get tv all over the house. I have not tried an LTE filter, either.
Ive noticed that this antenna does have a reception pattern. The ends of the copper are dead spots. the broad sides have reception... so, with my construction, you wind up having these fairly narrow dead notches 180 degrees out from eachother at each end of the PVC.. I aim those notches in the direction where there are no towers. At my house I have towers at 15, 180, and 270 degrees... so I aim the notches at 320 and 140 degrees.
1 year ago
Several posts say you can use 26" bike rim.
But in the origanal post says not to let the ends of the tubing electraly touch.
I have a bent aluminum rim would this work and would i need to clear the coating off of them?
Answer 11 months ago
I think he means that you can use it to bend the copper.
Best Answer 1 year ago
You would need to cut the rim in half. It is two half circles not electrically connected to each other except through the balun. The clear coat will not be a problem
9 years ago on Introduction
Check out my variation on the present design. They both work well from inside the house. Outside function should be great.
Reply 5 years ago
So what did the second loop do if anything? Do you find this to be omnidirectional? What spacing did you use between the two ? Did you try one circle first then add a second to se if it made a difference?
Reply 12 months ago
Sorry for being soooooo late on this reply. I did it both ways just to see if there was more gain on the double loop. I did get better reception. But I didn't have the proper gear to take measurements of signa strength. So, I can't give any gain numbers. Sadly, I have a wife that abhorred the idea of that being outside of our house. So, I never put it to real use.
Reply 9 years ago on Introduction
Great, thanks. If it works out do an instructible and put a link to it here. You might experiment with the spacing between the two rings. That could affect the operation some.
Question 1 year ago
Is there a gain pattern to this antenna? Is one direction more sensitive than another. Would rotating it slightly help to get weak signal better
Question 2 years ago on Step 2
So the circumference of 26 inches will pick up uhf and vhf? Would it make a difference if I made a ridiculously large version of this? For instance 10ft circumference. If it was going to be larger what would a circumference larger than 26 inches that would still pick up uhf and vhf signals? I don't know the math to this. Thanks!
Answer 1 year ago
The diameter is 26” which makes the circumference around 82”
Answer 2 years ago
it wouldn't help because , making the element too long would throw it's frequency off, you'd make the antenna resonate at a lower bandwidth. so to improve the signal, height would be what you want to do to make your antenna work better VHF and UHF are ' line of sight ' signals. so the higher up away from obstructions would make the antenna 'hear' better. just think of being able to see the transmission tower. the better the antenna can "see" the areas where the transmitters on the horizon are the better it will work.- good luck.
2 years ago
I think a lot of people are getting too technical. This is made from junk. Since tv band is so wide, an inch is not going to matter. I have made these without a tape measure. I have made them out of wire taped to the ceiling, I have made them out of aluminum foil. Instead of going to the hardware store, look in your neighbors junk pile.
2 years ago on Step 2
I made this omni, Thank you for the instructions!, from Indonesia
Question 2 years ago on Introduction
1) Could this be used for FM radio reception at 98MHz?
2) How to calculate length of tube? i.e formula to calculate.
Answer 2 years ago
hope this helps, my math is 6th grade from 60 years ago LOL, add subtract multiply and divide. I asked a ham operator how big a circle I needed and he said 26" so I made my first out of an aluminum rim so whatever you come up with for length just bend each one in a half circle and make sure they don't electrically connect. They don't have to be mounted this way, I have nailed them to my attic floor but the higher the better. If anybody is a boater, when you swing on the anchor and the picture fades in and out, Mine didn't.. That was the reason I built my firstone. Then I found I was getting more stations that the people onland were.
Reply 2 years ago
Thank you for your reply. Let me try out something similar at my home. Thanks again.
Question 2 years ago on Step 2
Instead of copper tubing can one use solid core copper wire??
I guess I’ll find out, lol.. I’m about to give it a go!!
3 years ago on Step 2
I built one of these in 2014 and it worked absolutely amazing... far better than the amplified metrostar I previously owned. I just moved to another home and built another.... In the center of Tucson I get 50 stations... this includes channels from towers in mountains to the north, west, and south. Very omni directional.
I am trying to figure out HOW this works, though. Normally you narrow your band as much as possible and choose a frequency in the center of that band... in this case the uhf tv band is 470-810 so center would be 640mhz... 300M/640M=.69m=18.5in.... At 26", this antenna sits around 450mhz. Thats outside of the UHF tv range all together... It took me a lil while to realize that this was designed to be the center of the entire TV range... 54-806, including all bands. The problem here is that the signal gets exponentially weaker as you move away from the resonant frequency... so much so that the thing should be totally dead in the higher end of UHF, and VHF low. Its exactly resonant on the HAM 70cm band(almost like it was designed tobe there), so any hams in the area should be interfering with it. THis thing should probably perform horribly, yet it works really well.... how? am I missing something?