In The Workshop - DIY Telly Antenna

Gents, I wanted to pass along my experience building a 4 bay, bow tie style over the air broadcast antenna for television reception. Before we go further, I realise most threads like this are worthless without photographs. Sadly I haven't any to show you of the build process but can get a shot or two of the finished product. It is 'installed' in my mum's living room at the moment. This is why there are no photos. I was thrashing on this for the last day and a half and just didn't think about recording the process. There is a bonus though. I will be making a more heavily built model for my home since it will be installed on a mast outdoors.

A few specifics and some links. First is an antenna building web site http://m4antenna.eastmasonvilleweather.com/Drawings/PDF Drawings.html I am unsure why it is so but I could not navigate to it today. I was on the site earlier this week a number of times and it worked fine. A VAST amount of information there and some really easy to read PDF files on antenna whisker size and spacing.

The other is a fun to watch YouTube channel by a bloke name Danny Hodges. A southern gent with a great sense of humour. He has a real southern accent as opposed to the manufactured twang you hear on country music stations these days. He has a good grasp of the process and installs these things for a living. Watching his assembly videos is both educational and entertaining. Danny S Hodges

I followed Mr. Hodges assembly procedures for the most part with my own customisation and parts list. I also used one of the three element sizes and spacing specifications at the first site. They have three sets of sizes diagrammed and I used the one for mostly higher band UHF and VHF. 9.5 inch element length with 8.5 inch spacing between attachment points.

I used a piece of aluminium channel material for the main beam. It is manufactured to hold 3/4 inch plywood products. It is about 7/8 inch wide and around 1/2 inch tall. An 8 foot piece was about $15 at the local Westlake Hardware store. I used a piece of plastic trim material made for exterior use around windows or similar openings. It is 1.5 inch wide and 5/8 inch thick. I believe this is some sort of PVC material. Very cheap to buy at 10 per stick. I cut three inch pieces to mount the elements and phase wires to. You need something non-conductive for this since the elements cannot 'ground out' against the beam or the mounting mast.

I used #8 solid copper wire for the elements and phase wires. This is about the easiest and most economical material to make the elements from. I would have liked to use 1/8 aluminium rod or 1/4 inch/6.5mm hollow aluminium tube for this purpose for two reasons. First, the hollow tube weighs almost nothing. It does not need to be straightened to use it and has a certain cool factor that makes the project look more like a manufactured product. Two main issues came up. First, I could only fine the tube or the solid rods in 36 inch length. As you will see later, if you need to bend the elements like with the wire or solid rod, you have to start out with a piece about 22 inches long and then trim to length after you are done. There would be over a foot wasted from each piece of the solid rod. The tube would have fared a bit better but even cutting three ten inch pieces and then trimming them to length, you waste nearly a half foot of each stick. Not a good expenditure since each of these products were just over three dollars a stick at the hardware store. And none of them would have been long enough for the phase wires.

Enter copper grounding and bonding wire. I bought a 25 foot roll of this at Menard's for 10.68 plus tax. So lets call it 11 dollars. This made it around 44c per foot as opposed to one dollar per foot for the aluminium stuff. I used most of the roll so keep that in mind if you make one of these.

Mounting hardware was all stainless steel from Menard's. Menard's make this really easy since they have a big selection of pre-packaged stainless hardware in various sizes. Most will have a small size with 6-18 pieces depending upon size of fastener and a larger package of the same sizes ranging from 50-150 pieces again, depending upon size of fastener. Small packages are $1.59 apiece and the larger sizes are $6.59 apiece. The stainless hardware was my choice for one reason. Durability. I can use it indoors or out and will not have to worry about corroded fasteners falling apart twenty feet in the air.

I will break this up into several posts to make it easier to follow.

Making the beam, insulators, and elements.

I cut a piece of the channel material 32 inches long. It is not mast mounted and I was not worried about having enough beam length to clear the mast head or hold an amplifier. If you add a reflector you will need a bit more length as well. I set one piece of the plastic insulator material flush with the top of the mast and drilled a hole through the mast using the insulator(already drill for mounting) as a guide. I then spaced the rest of insulators 8-1/2 inches on center measured from the middle of the first insulator. It would have been easier to just measure from the bottom of that piece to the bottom of the next piece and go from there. Either way works. Just pay attention to detail. I then attached all five insulators to the mast. Five? I thought this was a four bay antenna? You need one placed in the center of the mast between the two center elements. This was 4-1/4 inches from either element in my case. All insulators were mounted with one 10-24 machine screw 1 inch long. A flat washer was placed under screw head and flat washer and Nylon insert locking nut was used on the back to secure them.

Insulators. As I mentioned some dimensional plastic trim material. Nothing exotic but I think it is stable enough to not warp in the sun. Some builders use PVC pipe flattened on two sides to sit flush and level on the mast. Some use HDPE plastic but this stuff is expensive when you can find it. I made each piece 3 inches long. Drilled in three spots for the mast mounting and the element attachment points. I made the holes just big enough to meet light resistance when you thread the screws through. This helps to hold them when you attach the rest of the hardware. Making these insulators/wire mounts were the hardest part.

I settled upon cutting slots across the narrow side of the insulator just deep enough to hold the phase wires where a tiny bit was exposed above the slot. Then when you mount the elements the bent portion rests upon the phase wire to make the contact. I should have soldered or brazed the elements to the phase wires but was in a hurry and used fastener pressure. Making the slots for the phase wires was a pain. I use a hand saw for each piece and ideally you should just wait til they are mounted on the beam and then use a table saw to cut all the slots on one side in one pass. I do not currently own a table saw so this was not an option. Another option is to use a 1x3 or 1/4 material and cut slots spaced the proper distance apart the full length of the material and then cut the pieces across the width about 1-1/ inches wide. Many ways to skin the cat on this one but I want things to look neat.

Elements and phase wires. As I mentioned, my elements were 9.5 inches in length and I settled upon 4.5 inches in spread at the tips. This dimension can vary but just keep the spread consistent for each element. I cut each piece about 22 inches long and then used and old trick I learned on YouTube to straighten the wire. Use a vice to hold one end and then chuck the other in a drill. Spin it up and the wire will straighten right out. Be aware, you are twisting the wire and over doing it will get it hot and break it. You don't need to do it fast and furious. Just do it. I bent the elements by using pliers at the mid point of each piece and bending each side gently til the proper V shape was attained. I then made the phase wires the same way. I left them long enough to reach the end of the insulators on each end and then trimmed to length with diagonal cutters when finished.

Next up assembly. Right now it's the gym. No time to get lazy at this point. I am forty-two pounds down in weight and don't want to ruin it.

Okay, final assembly and tedting.

No matter how many videos you watch , putting something mechanical together the first time is always a bit daunting. After making the main beam I was unsure of which part to go onto next. Well, you need the insulators mounted before you can attach the elements so I did it and then approached the phase wires.

Installing the phase wires was tedious and felt a bit fussy at first. Then it dawned on me to lay each piece on

Pics?

Alright, sorry for the last post. I accidentally hit the post button and didn't realise I was past the 15 minute limit for editing. Honestly, mods, can we get this extended to 30 minutes? This is a real pain when you try to edit a messed up post.

Okay, back to subject. I was a bit intimidated but started in. The beam was first of course. After laying out the insulators and their spacing I started on the phase wires. Hmm. How to do this without stuff flying all over the place. I finally got the old no name 'Work Mate' bench from the garage and used its split top to hold the beam in place whilst I laid the phase wires in the slots on the insulators. I finally realised to attach one side on the two center mounts, screw them down, and then do the crossover bends on each end. You have to do this to make the antenna work. Don't get too scientific with this. Just keep the bends looking the same end to end and don't let them short against each other or the beam. Fiddly but I managed it. Watch Danny's videos for a good demonstration. I also alternated which wire was on top of the other at each end but I am unsure if it is necessary.

Then came the elements. Now this was a bit fussy as well since you need to loosen the screw and lift the washer at each point and slip the element underneath and tighten it down. I was using nuts and machine screws so it looked a bit funny watching me hold each piece and trying to tighten it all down. Finally I learned to run the Nylock nuts down to get them broke in a bit then back them off and set the element underneath. This made reattachment easier. It is then a matter of slightly loosening each one and measuring and setting them straight across the beam and consistent distances from each element above and below. I trimmed the excess at each end of the phase wires and it was done. Looked pretty good too.

I set it up in the living room with a short cable and was surprised to see it get nearly as many stations as my much larger outdoor mast mounted antenna. I wasn't knocking the lights out but it was better than I thought it would be and proved the thing worked before I hauled down the old one for outdoor testing. I got it up on the mast and was pleasantly surprised again. It was getting everything my old antenna did plus two VHF channels I cannot get reliably unless I rotate the antenna directly toward them. Bonus. And we are speaking of an antenna about 36 inches tall and 20 inches wide. About 1/5 the size of my old directional beam antenna.

That old thing is from the pre-digital age and is tuned for channels 2-83. This much bandwidth does not exist anymore. After 2009 the U.S. band only includes VHF mid and high(7-13), and UHF from 14-51. This antenna is scaled for those bands. As I said earlier, the size and spacing of my elements are geared toward the VHF hi band(11 &13 in my area) the upper end of UHF. Most of my UHF channels broadcast on channel 30 or higher so I weighted it that direction. I have a PBS station that actually broadcasts on channel 21 and it captured that signal with ease. So for around here I am not so sure I would not have used the all round model described at the antenna site I linked to.

Future. I am definitely making one of these for my home. This will have a much less, almost unnoticeable footprint on the skyline around my house and be much more wind resistant. That old one shakes in the wind. The only upgrade will be mast material. I think I will go with 1 inch square aluminium tubing for more durability in the winds we have here. These tubes are available at Menard's in 5-6 foot pieces for twenty dollars. I will cut nothing off the length and see how it looks and whether I will need a booster or not. Then I can see about trimming length.

Hardware. Again, make it easy on yourself and stick with stainless throughout. I will not corrode and I believe it does not react badly with copper or aluminium but I am unsure about it. I used 10-24 machine screws throughout with Nylock nuts rather than futzing around with lock washers. I did use flat washers behind every nut and screw head to help minimise damage to the plastic insulators. One inch length will do almost all of it with the shallow channel material. I used 1-1/4 inch length where the balun attached. This went over the phase wires like the element points but then had two nuts put on the ends so I could slip the fork connectors of the balun between them to make a secure mount. Easily removable too.

Process. I will counter sink all mounting holes in the insulators next time. This is better looking and will work at least for the attachment points to the mast. The elements I am not so sure of. It would take much thicker material since they lay on top of the phase wires. And the pattern to do this would be tedious since you would need a triangle shape to clear teh now flush V elements going out the sides of the insulators. I do think counter sinking the rear of the insulators would be good. The 3/4 inch wide beam barely allowed the two balun screws to clear, they will hit a 1 inch wide beam. Counter sinking them will allow me to use the bigger beam with no fear of shorts. Also, I used fender washer with a 5/32 hole in them on the top of the elements. These had to be drilled a bit to allow the 10-24 to pass through them. I wanted maximum contact and pressure on the elements. Also, consider soldering the elements to the phase wires. You will have to do one side at a time and of course you will need a jig of some sort because soldering at the point of mount on the plastic is not going to work. And keep the elements where you measure for them when mocking up. Mark each one with felt tip marker. I would use black marks for one side and red for the other to keep them straight.

Okay, more than enough words for now. I will take a couple of photos and post up the finished product. This works and you can do it at home for not a huge investment.

BSAGuy said:

Pics?

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Sorry, coming up for the finished product. Will try to keep up with a few during the build of the next one.

Here is an image of how my antenna build looks for the elements. Notice the wiring crossovers.

Haha, I made the same one a few years ago, except it was a scrap of 2x4 and wire coat hangars.

Worked fantastically well, but I had to retire it since it looked like a medieval torture device hanging on our living room wall.

Here are some photos as bad as they are. Cell phone, dim light, etc. Sorry. I will document the new build a lot better.

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So awesome! Does anyone know if copper/aluminum/stainless steel react to each other when exposed to the elements? I don't do cable TV, and wonder if this works for the digital TV network broadcasting? Again, awesome work. Majorly jealous here!

Dave, the antenna itself does not care what type of signal it receives as long as it is in the spectrum it is tuned to. As to the possible reaction between the metals, I am not completely sure. The only two metals that touch each other are the stainless hardware and the copper elements. They are isolated from the aluminium beam by the plastic element mount/insulators. None of the hardware touches the beam on the back sides of the plastic. It is why I will have to counter sink the hardware into the plastic when I make the outdoor version. I am going to use 1 inch/25mm square tubing for rigidity in the winds we get here.

I went over to my ma's house last night to get the photos and it was not picking up one of her favourite channels. I moved it three feet to the right on the same wall and presto, signal was locked. I am more than impressed by the performance of such a small antenna. Just pay attention to assembly detail. Size the elements correctly, isolated them from the beam, straight and consistent measurements, etc.

The main thing to remember is go to a site called www.tvfool.com There you can enter your address and it will give you a graphic of the stations near you. I just entered the street number to keep things a bit more anonymous. It will include their call signs, virtual channel they use for an identifier, and the actual channel they broadcast on. The vast majority of stations have moved to UHF no matter their broadcast identifier. One of the most popular in Kansas City is WDAF channel 4. They have broadcast on channel 34 since the digital conversion in 2009. That was the channel she was having issues with even though it is pretty close to us. All the old VHF low band is gone and it does not have to be figured into antenna design now. Nor do you worry with channels 52-83 since they are long gone too. The antenna brings in VHF high pretty well if you have it outside or are very close. In fact, I was stunned by how well it locked onto the two remaining VHF stations we have.

All in all a worthwhile effort. I suppose if you added up all the money I spent on this it was 60-80 dollars. Mostly on hardware I bought because I was not sure what I needed. I still have enough aluminium and plastic to make at least two more like this one. The only thing I need is the mounting hardware and the wire elements. And I am looking at online metals for 1/8 inch aluminium rod so I don't have to fiddle with straightening the copper though it looks pretty cool in contrast with the beam. Hope all this helps.

Interesting. We're "cable-cutters," haven't paid for TV in years.

Do have a neat "Antennas Direct" job that pulls in many, many channels. Block out the ad and religious channels and you're rockin'.

Fooling with my ham technician exam, so antenna design's interesting.

+1 on tvfool; great site.


AA

Mike, we cut the cable nearly five years ago. In March it will be five years to the month. I couldn't be happier. We had broadband internet already for my wife's online schooling and it seemed a natural to add Netflix which was only $7.99 then. Now about ten dollars per month. Still a great bargain most times. We cut the satellite cable, kept the home phone but ported it into a Tmobile pre-paid account(100 dollars for 1000 minutes with a bonus ten percent and yearly expiration/used for months at a time before needing refilled), eventually subscribed to Amazon Prime and now Hulu+, and the bill is still under 70 dollars a month. Less than the poor value satellite we ditched over four years ago.

The antenna idea came about because of me old mum. She does not really want cable and the antenna situation is tough because her rental does not allow attached masts to the structure. There are sat customers with yard set poles but they are NOT attached to the structure. So we had one of those little powered RCA square antennas on her wall and it was not very good. So I hit the net and found this. Most use an ugly board with no separation between the phase wires where they pass over each other. The aluminium channel was really pretty cheap at around two dollars per foot from the hardware store. So not too much. I am unsure about ham frequency antennas but I know there are a lot of homebrew models out there that seem to work well. I am also considering a home built FM receiving antenna for out of doors. It is kind of surprising how hard it is to find a decent, reasonably priced aluminium outdoor FM antenna. Most have to be ordered and you have no idea what you are getting til it gets there.

I did look for better choices in element materials and onlinemetals.com. They have 1/8 inch aluminium rod for very reasonable prices. Until you put them in the cart and realise there is a 'cut fee' that is much more than the metal itself. Plus shipping so I will have to weigh this very carefully. I expected carriage to be a bit dear for the weight and shape of the material but honestly, cut fees for what is likely stock items waiting to be shipped? Anyroad, more investigation into metal for elements is in order. BTW, I did inquire of them what would be the best alloy for outdoor elements and was told the 6061 material would be best for rigidness, tensile strength, and for welding which would not be a bad idea for solid rods against other solid rods. We'll see.

FarmerTan said:

So awesome! Does anyone know if copper/aluminum/stainless steel react to each other when exposed to the elements? I don't do cable TV, and wonder if this works for the digital TV network broadcasting? Again, awesome work. Majorly jealous here!

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Copper will quickly turn green when exposed to the elements. I can't speak with any authority on metal to metal reaction. Todd's antenna looks like it would work best indoors. An antenna sitting outside takes a real beating.

With all due respect to Todd's work effort, you can buy good antennas today and get all the information you need on OTA television broadcasts from good sites on the internet. Here's my favorite:

http://www.dennysantennaservice.com/

There's a lot of information on this site; you get straight answers and he clears up a lot of myths about OTA television and the "digital" confusion that seems to prevail today. The best place to mount an antenna for TV is outdoors. I re-roofed my house this summer and moved the antenna in the attic. I don't get near the amount of reception I had when the antenna was on the roof. I'm going to redo the whole set-up with an eave mount and put it back outside.

TV Fool is overly optimistic on what you'll get for broadcast signals. I don't know where they come up with their information, but a lot of it is nonsense.

Don

Don, I have seen Denny's site before. Very good stuff there. As for oxidation(the part that turns copper green) the same thing happens to aluminium except it is more of a white powder like look. The antennas you buy are almost certainly coated with something to retard it. In electrical use we coat aluminium wires with NoAlox to help keep it under control. I am not sure how it would work on an antenna element.

I don't know about TvFool's accuracy for most but my locale was spot on as to towers and locations. Reception? Well, I would think they are giving best results with line of sight and zero obstructions. If only reality were so good. I mounted my little bugger on the outside mast and it performed much better than I expected. It even locked in the last VHF channels we have at a high signal throughput. We'll see how the newer model fares.

Phog Allen said:

It even locked in the last VHF channels we have at a high signal throughput. We'll see how the newer model fares.

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Have you tried hooking up a pre-amplifier? This may help you get even better reception.

Don

Don, I have not tried a pre-amp and I am not sure I really need it. We are within 50 miles of the most distant transmitter that serves our market. I will know a bit better how things will work once the new antenna is built. It will have a heavier main beam of 1 inch square aluminium tubing with a slightly longer length to allow more mounting options including room for a pre-amp if needed. A rotor is probably not needed for this antenna since it is bi-deirectional and our stations are almost all due east/west from each market serving our area.

Building these is actually a very good learning experience and could lead to some more tinkering with wi-fi and scanner antennae.

I've enjoyed fooling around with dipole (11-meter) radio antennas. Have pulled in Europe on occasion, northern US and Canada easily.

Yes, 11-meter is a fancy name for CB or single sideband, in this case.

TV-wise, can swear by the ClearStream 2Vs (UHF/VHF). My local/DX antenna farms line up: I aim this antenna like a rifle at bearing 270 and collect medium, local and DX TV signals.

TV reception with an antenna is an interesting problem: each and every person/home may require a different solution; there's no one size fits all. What works for me ... May hit a pine tree for you.


AA

It has been a long, long time since I had the old Cobra 148GTL up and running. It may be an aside to this discussion but for the life of me I cannot understand why the U.S. does not follow Australia's lead on UHF citizens band. Their's is a 477Mhz UHF service with something like 77 channels. Some of which are suitable for repeater use.

Well, the whole idea of a citizens band in the U.S. was short range, point to point communications between individuals and small businesses. The old 11 metre band was about as poor a choice for this as they could have made. It is capable of worldwide skip, uses AM tech which is noisy and interference prone on the typically cheap CB equipment sold anymore, and is really a HF service best left where it was; the amateur radio license spectrum. UHF is clear, capable of fairly limited line of sight operations but also works well in structures. Just keep the repeater situation in hand, allow mobile units with removable antenna, up the power to 15-20 watts for said mobiles, incorporate the FRS channels and a few others on the newer 12.5Khz channel spacing on most FM stuff these days and voila, we bring back cheap, easy to use mobile radio. No licenses, fees, subscriptions. I do think they should allocate about 20-40 channels depending upon spacing. I don't know. It may not work at all but the way people flocked to FRS is amazing. I would very much consider something like this for the vehicles.

FRS/GMRS has strict power and antenna requirements which limit their use to walky-talkys, pretty much.

I enjoy scanning those frequencies on trips; they are widely used (though very short range).

The whole notion 1970s notion of CB WAS very strange, giant antennas etc. But UHF/VHF is pretty much kept to law/government and hams who mean business.

CB is far from dead, but inhabited these days by some very strange people ... some with ridiculous power. Just hammer-signals sometimes come from loonies, loudmouths - and some radio geeks like me.


AA