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.
I built this one a couple months ago for my grandparents. Closest station is 65 miles, farthest close station 90 miles. This thing is picking up both sets of dtv stations. Now im going to duplicate and add on another antenna to this one to pick up a single set of vhf stations and combine them hopefully
<p>i have 3/4 inch pipe for pole bought a threaded cap for the pipe drilled through it and the center of the 4 way fitting bolted the cap to it let my pole down and screwed the antenna right to the pole </p>
<p>made one works really great better then the antenna i had thanks for the plans </p>
<p>Made this antenna today and it performs a lot better than the amplified indoor antenna I was using. Mounted on the roof of the boat on a 4&quot; tall pipe (total about 7' off the ground). Receives channels up to 60 miles away. Purchased all parts at Lowes for about $30.00. I used a 3/4&quot; cross for a stronger center hub then reducer bushings to mount 1/2&quot; pvc radials. The loop is 1/4&quot; copper tubing fastened as per instructions with brass bolts. Rather than slot the ends of the 2 support radials, I drilled a hole and slipped the tubing through the pipe. The cross is bolted to a 1-1/4&quot; PVC threaded cap (this cap is flat on top instead of rounded like the slip cap) it's screwed to a slip to thread coupler, this will allow me to rotate the antenna some on the threads if needed or remove it for trailering the boat. Once I'm anchored I'll be able to add a 6' to 8' section of mast (1-1/4PVC) if needed.</p>
Thanks for the update. Glad it worked out for you. Enjoy
<p>Going to make this antenna soon as I can find some 4 way plastic tee,s seem hard to find here .thanks for the help and setting me straight on the measurements and size.Ross</p>
<p>Mine came from a hardware store but you might have to go to a plumbing supply store to find them. If you have trouble finding them you could terminate the mast with a floor flange. Bolt a piece of plywood to it and bolt the braces to that. </p>
<p>Very good design: nice, easy, cheap and efficient. This week I will make one of these. </p>
<p>Great, let us know how it comes out.</p>
<p>Well, after a few days doing other things, today I finished and installed it. It works perfect for UHF, but for VHF is poor. I wonder if the adapter 300 to 75 Ohms is really necessary.<br><br>The hardest part of all was placing it on the ridge of the house, because put in place the reins to stand it upright was not easy, I broke four colonial tiles, which are not cheap nor easy to get.<br><br>At end, I am very satisfied with the result, thanks for the idea. I regret not having taken any photo, is that I worked hurry because here is winter and the afternoon is short.</p>
<p>For best operation, the match is important. It also covers any mistakes in length of the antenna halves.</p>
<p>When you say &quot;match&quot; &iquest;do you refer to the 300 to 75 Ohms adapter? Please consider I don't speak English. Neither I understand when you say &quot;antenna halves&quot;, pardon.</p>
<p>YES.</p><p>The better matched the antenna is to the receiver, the better they both work.</p>
I made this antenna after a snow storm destroyed the new antenna I had bought a week ago. It works great and much better than the one I had bought. It was made with scraps I had around the house. Thanks so much David V. I am out in the country( Missouri Ozarks) 90 miles from any station. I get nine chanels clear
<p>The best thing is that you will NEVER have to buy another one.</p>
<p>I try to recycle as much junk as possible. Some of the junk projects were an arc welder from microwave oven transformers, battery chargers from microwave oven transformers, a wast oil processor to make fuel for a diesel generator from waste motor oil made from my junk pile, a tow behind the boat electrical generator for my engine-less sailboat and a hydrogen generator to improve gas mileage in my truck etc etc. The less trips to the hardware store the more of a success I consider the build.</p>
<p>Folks in DVBT countries (as opposed to the lower frequency ATSC) may have more luck making their loop with a 16-18in. (41-46cm.) loop since these systems generally use 650-800MHz for the bulk of multiplexes.</p><p>75 ohm twin feeder or coax is optional but you will lose some signal in the impedance mismatch. Your TV or STB will usually (but not always) have the impedance in ohms in the manual or on a label.</p>
<p>I have never heard the term DVBT. What is it? </p><p>I am in the usa. This is for the old style antenna channels. Yes the frequency has changed from what the antenna was designed for HOWEVER, the converter box takes care of any frequency mismatch. The reception is much better than the old style TV, BUT IT STILL NEEDS THE CONVERTER BOX. Like I said, it has lots of room for errors.</p>
&quot;Digital Video Broadcasting / Terrestrial&quot; -i.e. the European standard for digital TV via roof antenna. It broadcasts on the same frequencies as the old analog channels.<br><br>The converter box is called a &quot;balun&quot; (http://en.wikipedia.org/wiki/Balun) and yes, often handles impedance mismatches by way of transformer action (the balun itself provides the impedance load). It helps that receiving loops are quite forgiving of mismeasurement and fairly wideband to boot.
<p>I recognize the term Balun from when I first got into radio through cb and marine band radios. I figured that I should at least understand how they work. I know just exactly enough to myself in trouble. When I was a kid, me and a friend learned code and built a spark gap transmitters. My friend noticed a van with a lot of antennas and we thought they looked like the law so we quit using them. It turned out we were messing up every bodies TV and radio every evening for about 10 miles. Then later there was CB radio. That was not going anyplace good either, so now I just mess with receivers LOL.</p>
OK thanks for explaining that. Yes with that big of a frequency difference, a smaller antenna would definitely be in line. I never even thought that TV would be in any other frequencies. Silly me. why would the rest of the world agree with us LOL.
<p>I have had great success with your design. I have stations in about 4 different directions so this is perfect. I get all the stations TVfool says I should. Thanks so much! Someone was talking about keeping the birds off so I went a bit crazy with the Ty-raps and have had no <br>perching issues. See the photo. I found that if turned it just an inch or so I was able to tune in the stations I was missing. One problem I do have since I live right next to a shipping channel here in Richmond BC I get signal loss when the larger boats go by. There's nothing I can<br> do but wait for them to pass but it's amazing how often it's right when something dramatic or exiting is happening on the screen. I can certainly live with that for free TV.</p>
Thank you for the comment and the photo. The wire ties are a great Idea. In fact that would be a good idea for any tv antenna.
Okay, I'm about to give this a try. Although, the one variation I'm dealing with us the copper tubing I have is one inch. I'm hoping this doesn't have a negative effect on it. I'll keep y'all posted with progress. Also, shouldn't just be able to cut the connector off of some rg-6 and split the line. Using the braided outer layer as one and the copper inner &quot;stinger&quot; as the other connector?
There is not much that won't work. Over the years have made many of these for myself and others. There really isn't much that affects the reception including guessing at measurements.<br><br>As for the braided ground covering, as long as it will hold shape it should be OK.
<p>Hi All,</p><p>First of all let me say thank you to rbodell for making this instructable. I made this antenna and so far its not working for me. I am probably 60 to 70 miles from the nearest towers. I have the antenna on my roof so it is probably 35 ft or so up in the air. How close to 26&quot; in diameter should it be? Does it need to be really close to round? Mine is much closer to an oval. I have tried amplifying it but still when I make my tv search for channels nothing happens. I would appreciate and advice any of you guys can give me. </p><p>Thanks,</p><p>Arlen</p>
This antenna is very forgiving. I have had people build it without a tape measure and just guess at the measurements and they worked good.<br><br>My guess is that there is an electrical connection between the two halves of the antenna. There should be no connection between the two contacts of them
<p>Thank you for getting back to me. I will double check that the two sides are electrically separate but I am pretty sure nothing connects them but the transformer. Is there a minimum distance the bolts should be apart between sides? Also I know my bolts are a little on the long side as compared to the ones in the pictures of your antenna. My bolts are just standard bolts from the hardware store, did you use special bolts? Thanks again for all your help.</p>
<p>Considering the distance between the wires in a piece of coax, anything you can comfortably work with should not be a problem. I just used off the shelf bolts it they are a little long it is not a problem.</p>
You might also check for continuity between the two wires of the lead in cable. The only other thing is that some people forget the antenna matching transformer. If those all check out look for things like trees pr mountains that might interrupt the signal. There isn't really much that will keep it from working.
<p>I am experimenting with this design with materials I have on hand and getting good results. I'm about 40 miles from Atlanta stations, I have only one semi-circle of bare steel fencing wire (#9 gauge) without a transformer, it's up about 12 feet, signals are blocked by large oak trees and still I get great reception of 58 stations. One station that I really want is GPB channel 30, but can't get it yet. Any ideas why? I plan to add a second loop and the transformer to see what happens. Does the transformer just combine the two opposing currents from the antenna halves with some magic to produce a single signal? Anyone know?</p>
at 40 to 50 miles they should blast in there unless there is a mountain between you. I once put one of these up to replace a brand new Radio shack 150 mile antenna on a 40 foot tower and it got twice as many stations. <br><br>Since everything else seems in order that older coax is probably the next thing.
<p>I am now getting 4 channels from greenbay which confuses me because for a brief period of time yesterday I had 6 channels from wausa which is sort of the other direction. I went higher when the antenna and lost the 6 wausa channels but now I get the four greenbay channels which I was't getting before. I don't understand why I would lose channels going higher. Could turning the antenna have any effect as I took it down when I made the mast longer and it may therefore not be facing the same way it was before. Thanks again for all your help ad advice.</p>
There could be a slight directional capability in a borderline situation if the two splits in the two halves of the antenna are lined up with a station, but it is small and generally non-directional.Try turning it 90 degrees and see what happens. If the two halves are lined up with a station, a 90 degree turn would make the weaker station better.
<p>Update I checked my connections and one of connectors from the transformer was very close to the copper tubing on the other side so I loosen the bolt and turned the connector away. Now I am getting some stations but just barely if I hook up a little tv directly to the coax that comes down from the antenna. The longer runs of coax to my tvs in the house are weakening the signal too much to get anything at all. I tried to use an amplifier that plugs into the outlet and has a coax connection for in and out but I get no signal at all with it. Any ideas besides prehaps going higher yet with the antenna?</p>
I guess the size of the cable could have something to do with it. I don't know how long of a run you can make with smaller cable bit I can't imagine what the max distance is. I have run it 150 feet without any noticeable loss. that doesn't mean anything because I am no expert here.<br><br>Are you sure about the distance to the transmitter? I have gotten stations way over 100 miles with it on flat ground and the antenna above the trees.<br><br>Pardon me if this sounds silly, but do you have a converter box if you are using an older television? <br><br>On longer distances higher antennas work better. Preferably above surrounding trees in the direction of the station.<br><br>.
<p>Thanks again for your help. I went higher with the antenna but I think the coax cable I used to make sure I would have enough to get down to the ground is bad and/or the female to female coax adapter so I,m going to go back to using just the coax I started with as it is brand new. The transformer which is a outdoor matching transformer is also brand new. Here is a link to the report for my area on tvfool.com http://www.tvfool.com/?option=com_wrapper&amp;Itemid=29&amp;q=id%3dec2f31a9f0a7fe I guess I misspoke in my earlier post it looks like a number of the towers are 40 to 50 miles away. I do not have a converter box but I am using newer tvs bought in the last 5 years or so, so I do not need one. I am sure there are people out there who might forget about needing one though with an older tv. Thanks again so much for all your help.</p>
<p>Check out my variation on the present design. They both work well from inside the house. Outside function should be great.</p>
<p>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.</p>
<p>Hi there,</p><p>I recently came across your homemade omni directional VHF antenna and I decided to make one. I live in Guyana and approximately 30-40 miles from the source of transmission. The antenna is picking up the signals at a guesstimate of 75 % of full clarity. <br>I tried adding a amplifier/ booster but somehow it just made the signal strength weaker and had to take it off. what addition/ or adjustment can I make to get a stronger signal? The current diameter of the copper circle is 28''. Does the diameter size pose a problem?</p><p>Awaiting your response. Thank you. I appreciate all the information that I have gathered from the website.</p>
<p>Try to get the diameter to 26 inches.</p><p>get it as high as possible. Trees and hills in the line of sight will weaken the signal.</p><p>Also make sure the two halves of the copper are electrically disconnected. You don't want them to tough.</p>
<p>Thank you rbodell for providing the instruction to build this great omnidirectional TV antenna. I also built it with excellent result, see picture below. Please take a look at my patent pending Circular Folded Crossed Dipole (CFCD) omni directional TV antenna &quot;Omni UVOX&quot; at http://www.omnitenna.com</p>
<p>Glad it worked out for you. I like the one you also built. Very nice design.</p>
<p>Thanks, this commercial omni antenna design shown on the above image is the epitome of 2 prototypes I also built for testing, I'm very proud of it.</p>
<p>This looks amazing; I appreciate the pics and instructions. However, I'm not wanting an antenna outside. Has anyone tried this model in an attic? Would any adjustments need to me made (besides omitting the 20' pole, of course)?</p><p>All my nearby HD broadcasters are within 11 miles (most are within 5), but I need an omni-directional antenna since ONE of them is nearly 110 degrees away from the cluster where all the other ones are.</p>
<p>Being that close you could probably put it anywhere. In the attic would be out of the way. You shouldn't have to make any adjustments. Metal objects close by might affect it.</p>
I noticed you used a 75ohm coaxial cable to connect to the matching transformer. Is this part of the design or would a 300 ohm ribbon work better instead?
Interesting question, thanks for asking. I see no reason it shouldn't work as long as you have an older television where the antenna connection has screws you can put the other end under. If not you will need the matching transformer on the television end of the 300 ohm cable to connect to the more modern coax connection.<br><br>As for it working better, I Don't THINK so.<br>The ground around the outside of the 75 ohm cable shields it from other signals where the 300 ohm wire won't be protected from spurious signals of different frequencies such as engine spark plugs florescent lights and transformers.<br><br>With the ribbon wire you mentioned, the spacing is determined by the frequency. I don't even know if the ribbon wire does reject any outside signals from other tv frequencies. AS FAR AS I KNOW the spacing only keeps the signal from interacting between television frequencies and coax protects it from all frequencies. Would somebody correct me if I am wrong.<br><br>In the end it will probably be harder to find the 300 ohm wire and I seriously doubt the price will be worth the hassle.<br><br>If you do give it a try, please comment back and let me know the results of your experiment.
It's a perfect tv antenna. Its omnidirectional design is just right where we live considering the source of the signals from different tv stations at different strengths. Now, I can pick em all up like they come from just one direction only. But my only problem was that the loop offers a strong invitation to birds to alight on the tubes. One medium sized bird did alight one day and broke my PVC ... I redesigned the loop to face the wind instead ... the signal is still the same. . . but the birds are gone. Thanks a load.
Actually, coax and twinlead prettymuch equally reject noise. The reason twinlead rejects it is because it's a balanced pair - and the noise is equal on both leads - it gets canceled out in the input transformer, as long as the noise signal is equal on both leads. <br>The disadvantage with twinlead is that it shouldn't touch metal, which can change the impedance on the cable. That's why the standoff insulators are important when using twinlead.

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Bio: I am a retired old geezer with way too much time on my hands for my own good.
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