Build a Large DB8 HDTV Antenna: Big Bertha

We've had Cable TV and Cable Internet. It seems that there is less and less on cable than there ever was. Cable in my area is $49. I eventually cut down to basic for $20 and supplemented with Netflix. Netflix is excellent by the way but that's another story. We also have my macintosh connected to the TV so we can Hulu any program that played recently.

I'm finding that even basic cable has little 'value'. By value I mean I get the basic local channels and a bunch of junk otherwise. The channels I look at I could get for free if I used an antenna. Hence, I've decided to minimize.

Here in Southern Maine the TV stations are mostly in Portland about 30 miles away. Some are further, about 50-60 miles away. Most HDTV antennas work for 30 miles and a few claim to get up to 60 miles. I decided that I need more antenna than that. Something where 60 miles might be the limit but a doable and good limit. I've decided to produce a DB8. A DB8 antenna has 8 receiving elements, or 4 pairs of elements. It's basically two DB4 antenna's combined. The last picture in the segment is a commercial one.

What follows is my foray into the world of HDTV antenna construction and trying to squeak the most out of it for a moderately fringe TV area I live in.

BTW, the last segment contains all kinds of HDTV signal information and links to places to assist you in learning more. I was a teacher for 30 years (no I don't want any help with my grammar, I said I used to be a teacher) My job was simplification and clarity. I hope this instrucatble is up to that.

Step 1 Plans and measurements

I want to give credit to this website for the dimensions for the antenna. And the diagrams uploaded as part of this instructable. At the site you can find a bit more information.

http://www.frontiernet.net/%7Emclapp/Antennas/diagrams.html

The measurements should be exact or as exactly as you can get them. I will describe the materials as the steps to building this occur. Most of the actual antenna construction part can be purchased at Home Depot which is where I got the raw construction materials.

The first diagram gives the overall dimensions of one array.
The second diagram shows the wiring and dimensions of the wiskers
The third diagram shows the measurements of the wiring

I suggest you print these three pages.

Comments

[Hamosia215]

Anyone ever try to make 3 or 4 of these and combine the signal? Any thoughts or advice with this idea? Also stacking them vertically doesn't have any negative effect on the signal? Thanks for your reply!

[deceiver]

You lose a little with the splitters but combining more should make the array signal stronger just as putting these two together does.

Ghosting used to occur if you put two antennas close together when we did VHF but the digital nature of the UHF signal isn't affected by this. So, stacking antennas used to be a no-no with VHF. With UHF digital you can stack all you want. The added benefit of stacking is that you have less effect of side to side movement by the wind so for fringe stations your signal is better aligned in windy situations.

[lynbrookinc]

I forgot to tell you in my first post that we made the antenna out of materials we already had except for the 2 baluns and signal combiner, we alsio bought a cheap amplifer that actually does increase the signal on some channels for us to view them.

[deceiver]

I still have my amp that I haven't installed yet. Things seem to work well without it. I may put it on sometime though just to see.

[lynbrookinc]

I have just made an antennae according to your post and I will admit I was skeptical about it actually working but times are tough and we couldnt afford satelite service anymore so we looked for options we were going to buy an antennae but by the time we would have been done it would have cost us close to 200.00 dollars because we are also 50 - 70 miles from any transmitter in the past about 20 years ago we had a regular tv antenna and could only get 3-5 channels and depending on the time of day very snowy reception, so when we told our kids we were going to do this and explained that the picture wasnt going to be what they were used to , We were all amazed at the clarity of the picture and reception we had been in the dark about free OTR television because we had been so used to thinking we had to have satilte for reception in our area, now we are mad at the amount of money we have wasted paying satilite companies, and want other people to know if they are having it rough , they can have free tv,
Thanks for the info.

[deceiver]

So glad it worked out! It felt good to cut the cable for us.

[niko75]

at what distance captures this antenna signal that I'm 70 miles away and did not know I will make this antenna work or not?

[deceiver]

Odd wording of your sentence. I'll attempt to answer it. 70 miles is a far distance but it's also determined by line of site. If you've got hills or mountains or lots of trees between you and the tower then it might not reach. Look down in the instructions I give and there are links that will let you type in your zip code and help you determine the signal strength of a station from it to your house. It will also show you the terrain between it.

[halstead]

I constructed test configurations of the "Gray-Hoverman", "Coat-Hanger (or db4) with 7" whiskers" and your configuration of the "Big Bertha" with 9.5" whiskers and oversized reflector using 1/2 inch hardware cloth. The test configurations were all made of wood. After testing each, the "Big Bertha" exceded both the "Gray-Hoverman" and "Coat-Hanger" designs. I am located 30 miles from a cluster of TV antennas that serve the Sacramento, California region but my precise location is behind a rather large ridge with no direct access to line of sight transmission signals. The other antennas had signal strengths that varied from 72 to 100 percent. However, I now have nearly all channels registering between 92 and 100 percent signal strength. Thanks for the design. By the way, I am replacing a rather large Channel Master VHF antenna that had a range of 70 miles but only produced signals in the 60 to 80 percent range.

[deceiver]

That is very interesting. I always wondered how it would stand up to other designs. The commercial ones try to use numbers to outdo each other. In a perfect world about 70 miles is possible I'd guess but only line of site and I'd think a high antenna mast at that. I'd guess that at 60-70 miles with the commercial one they 60-80 percent would drop and if something were in the way it would be sporadic reception at best. Even bertha has trouble sometimes with my 62 mile station when the air is filled with heavy rain or snow.

Thanks for taking the time to share this.

[resago]

when you connected to a combiner, make sure to use exact same length coax jumpers.

[deceiver]

Resago is right. Attenuation is important in antenna's. If your signals are strong you might not notice any issues with it but if not it could make a difference. Some types of antennas particularly in radio communication have attenuators that can tune out differences. Some are even manual. Ham radio operators certainly know about this.
thanks Resago.

[resago]

to further optimize your antenna, you could make a half wave balun instead of an off the shelf model, you could pick up as much as 3 db over a radio shack balun.

8" of RG-59 would do the trick.

Google half wave balun for more info.
if you don't want to solder, then just use a quad grounding bar with F-connections, and some extra center conductor pushed into the other end.
this will make sense after you Google the design.

[vincent7520]

I cannot make any comment on your antenna although it seems very well done …
But I would love to have a better look at your workshop : it looks like it is both beautiful and very professional and : congratulations !…

[deceiver]

I've got a few pictures of the shop at Lumberjocks website here.

http://lumberjocks.com/deceiver/workshop

[vincent7520]

browsed through you pictures ; it's definitely beautiful: congratulations ! …

[da winksta]

thanks for posting your project! I too am in southern maine (kennebunk) and trying to do the same thing. in Nashville I got over 40 dtv channels in my RV, we really need to catch up. Most of the towers appear to be above portland to the west. thanks again

[deceiver]

Yes, In cities people hang a couple of wires on a piece of cardboard behind the TV and get 50-60 channels as they are all within a few miles of them. Not here in Maine though. My nephew lives in Southern New Hampshire and most of the stations are in Maine. This puts him out of range of most of the reception. Too bad, before, using analog signals you could get stuff from a long way's off, even Boston.

Being in Kennebunk you do have a bit of an advantage. You are closer to the ocean, Unless you are nearer the Arundel boarder you should get a flatter line of site to Portland and even the Fox station upstate a bit. It is even possible that you might get some Boston area stations as Boston is almost at sea level. You would be at a limit or over though considering the curvature of the earth. In your case, the higher the better.
Thanks for commenting.

[da winksta]

I actually am in Arundel but east of Route 1, so almost kport. Right now we're getting 6, 8, 13, and 26, although sometimes 6 and 13 break up. This is using the coat hanger antenna with 7"X3" whiskers and no reflector. I would like to pick up at least 51, 21, and 11 to cancel my cable subscription.
Will using larger whiskers like yours give better reception? How about even bigger? I assume at some point the signal wavelength will be small enough that bigger isnt better? thanks!

[deceiver]

I get 6, 8, 13, 10 +26 which are PBS (maine/NH and 23 which is Fox channel (american idol for the wife). But that's it. channel's 6,8,13 are the strongest, so much so that I can move the rotor to tune in 23 which is the hardest to get and the others are strong enough to come in without adjusting. 6 and 13 are in Portland which is close and 8 is further away but the antenna is on Mt. Washington so it's signal carries far.

I'm not sure what 51and 21 is.. is that the cable number or the actual station number? Maybe it's my pbs26 and Fox?

My design has whiskers that are one size and optimized for a range of channels that are common to hdtv signals. By having 4 of them with a reflector it multiplies and concentrates that signal. Then by doubling the antenna as a dual array it doesn't double that signal but adds significantly to it. Add to that the antenna is upsized for more reflectivity to the whiskers. I live on a lake so I'm in a vallley. I feel fortunate to have managed to tune in the channels that are available here.

[da winksta]

With a reflector I was able to pick up 11 when I point it shouthward.

So the 9.5inch X 5.5 inch whiskers is optimal? I have four sets as well, but I just used a different design that listed 7inchX3inch instead. I will try the bigger whiskers for my next version.

hmmm 21 and 51 are listed as WPXT and WPXG, CW and ION

Where I am, the dtv.gov map says that the Fox out of sabbatus area should be stronger than the one out of boston.

[deceiver]

I don't get 21 or 51 either. Both have a fairly low transmitting strength. It could be the terrain from there to my place too.

[COMMODORE64]

Will it makes any difference if I uses the satellite splitter rated as of 2000MHZ/3000MHZ with 300/75 OHM transformer instead of those 900MHZ one for UHF/VHF splitters?

Any difference on using RG59 and RG6U cables?

[deceiver]

The splitter with the high rating shouldn't be a problem as they are designed to work up to 3000 mhz. They are expensive though and a lower frequency one is good enough.

You do need RG6 cable though the RG59 is generally supplied with DVD players and VHS players because it works fine in short lengths. If you're going to run a longer length from the antenna say from a roof then you should use the RG59

[Weegee097]

Awesome job!!!!! The best phased array DIY guide I have ever seen. 5/5! The end result looks VERY professional and so is the performance.

[deceiver]

Well thanks. It's been awhile now and it still works. Had a big thunderstorm move through the other day. When there is a lot of moisture in the air we lose the fringe station. But other than that it works all the other times.

[maury_997]

Great job, thanks much. I am in zip code 12789 with a height above sea level of about 1100 feet. Do you think I can get the NYC channels from the Empire State Building? Also, how do you think your antenna compares to the HD Stacker http://estore.websitepros.com/1129733/-strse-177/HD-Stacker-Antenna-/Detail.bok? Finally, I will likely add a preamp like the WInegard 8700.
BTW- I am guessing you are getting closer to 20db of gain. Thanks again.

[deceiver]

 Type in your zip code into the field at the address below then zoom out a bit till you see new york city. You'll see dots showing the channels you'll get and  since it's a ways off and you have a mountain range there I doubt you'll get it even though it is transmitting on top of the empire state.
www.tvfool.com/

[maury_997]

I am afraid you may be right about that mountain range being in the way unless the signal can either bounce off clouds or get around it somewhat diffracted. Thoughts on the Stacker?

[deceiver]

 The digital signals bounce of metal but nothing else. They're line of site only. As far as the stacker antenna. I don't know. You'd have to look at it at some site that has user reviews like amazon to see what they have to say about it. It's not easy to go by some reviews though as everyone has a different scenario. Some guy might get great reception from far away but live in an area that's flat with no trees. another guy might have a tv station very near but a high mountain in between and thus complain about the antenna. Hard to judge.

[dZed]

Hello, deceiver! This a question for you because you seem knowledgeable, more than a direct question about your project.

So my father recently built your antenna -- he commented somewhere on here, I think -- and loves it, though our rural WV home still presents some reception problems. He had previously built Make magazine's coat hanger hoverman antenna which didn't do much for him (hence the upgrade to Big Bertha). He gave me that antenna, and it's been doing great for me here in rural PA. It's attached to a little amplifier on the pole, which has a plug in component next to the TV.

The thing is, while making room for the antenna in the attic, I found, under a pile of junk, another hoverman antenna! It's slightly larger, has a grill on the back, and has different dimensions than the one my Dad built. It too had an amplifier attached the the pole, but I couldn't find the plug in part for it. I detached my antenna and tried this found one out (using the same plug in component of the amplifier), and it seems to work slightly better. Here's the question (at last!), is there a way to gang these together for super reception? I was thinking of trying a splitter/combiner right there in the attic and mounting them both, facing away from each other. But what about this amplifier thing? Should I instead take the two wires from one antenna and connect them to where the two wires from the first are connected on the amplifier (parallel) or run one to the other than back to the amplifier (series)? Does it matter that they're different sizes (I'm sure it does, but what exactly is the effect)? Would combining them post box-on-antenna amplifiers reduce my plugged-in-amplifier-component to a smoldering box?

Thanks a million, and a great instructable!

[deceiver]

 Use a combiner and put the amplifier on the coax coming out of the combiner going to the house. Keep in mind that a combiner will give you a little signal loss but using two antennas would give you more gain so it's sort of like one step backwards but two steps forwards.
The only thing is that if you put these antennas back to back you aren't taking two steps forward as one will get signals from one direction and the other from the other direction so the loss from the splitter will give you a weaker signal but the north facing antenna doesn't get a boost from the other one as it's looking for a different signal. The only way you'd get a boost is to put them together side by side or atop each other facing in the same direction.

[Senseless]

Galvenized wire netting is also called construction cloth in some parts of the country,

Excellent Instructable!  I might make one of these to store under the house for use after a hurricane.

[zwheel]

But what will you do for internet? Dialup?

[deceiver]

Internet providers will, by law I think,  let you have internet without cable tv. If they didn't then many people wouldn't have any option for internet. Here in my area of Maine I'm too far from an extchange to have DSL and dialup is unacceptable. Some people also like dish televesion too. So, I keep my cable internet, I have my  phone service via the internet through Vonage which works exceptionally well. We have the 15.99 plan for 500 minutes each month. I never go over. We're not big phone talkers and you only get charged minutes for calls you make.

[zwheel]

I used to work for a cable company which charged more for internet without TV than they did for internet w/ TV.  They didn't tell the customers this but their excuse to the employees at the time was that they didn't have a reliable way to filter out the basic TV channels w/out making the cable modem buggy. 

The customers actually had limited basic TV service if they added a splitter to the line that fed the cable modem.  Thus, the price difference was the same as the price of limited basic TV. The customer was buying TV but didn't know it. 

I believe they have since gained the ability to filter out all TV w/o filtering out the internet.  I'm pretty sure they still charge the same though. If I were a customer still however, I wouldn't trust the new filter to not harm the internet service at least a little.  I no longer work there plus live in a different state with a different provider so my information is kind of old.

That's a nice antenna you built btw.  I don' t mean to discourage you.  I'm tempted to try it myself just for fun even though we have a roomate who pays for our cable.

[shortw]

Basic cable and cable internet together is more expensive than cable internet alone.
If you look at your itemised bill for cable internet, if you drop your basic cable, then only your internet will go up by 5 dollars at least around here, but your total bill will be lower.
I had extended basic cable and  cable internet and I dropped cable tv altogether, but I keept the internet.

Yes there is a filter on the cable internet, but around here you still can get 13 channels. You would need a digital Tv and a analog tv will not work , a converter will not work.
You will need a high quality 2-way splitter 5-1000 mhz 7.5 db( mine was $12.00 ).Internet cable to "in" on splitter, one "output" from splitter to cable modem, one "output" from splitter to tv. Set tv to cable and scan tv  for digital chanels.

   For those who are not able to get cable tv or OTA (over the air ) antenna signals because of location you may consider true FTA (free to air) satellite, this would be free and legal satellite reseption. Just google "true fta".
I have antenna and internet cable Tv for locals, and satellite.

I agree That is a realy nice antenna and exellent documentation.Good job, well done.

[deceiver]

 Here our cable internet is about 40% of the bill for standard cable TV. for 23 channels it's another $25 beyond cable internet. I don't have any other high speed internet options. I had standard cable TV. about 75 channels. I cut my bill by $60/month and still get most cable stuff either on the antenna, or with my Mac connected to the TV.

[deceiver]

 They said they put a trap on the line outside the house. I have data from internet speed websites so I'll check after it gets disconnected.

[makedoinwv]

I too liked  your design and built two units. We lost TV when it went digital. My old antenna didn't seem up to the task.  We have transmitters from 24-31 miles away but our terrain is very challenging.

I used wiring I had on hand, building the whiskers with 10 guage copper and connecting with 12 guage.   I'm glad to read the 10 guage is sufficient, the issue being holding the form.

I had concerns about the splitter so I just took it out and connected the two units with 12 guage wire.  I used the same white-black configuration connecting the whiskers on each unit, so I connected white-to-white and black-to-black between units.  I have the units mounted vertically on a pole, so I then connected the balun to the lower unit and the coaxial cable to it.  Is this an acceptable way to connect the units together?

My previous attempts at bringing in stations were null, but this AM was successful bringing in the three versions of the local PBS channel 30.8 miles away.

At the moment, the antenna is only 13-20 feet off tyhe ground.  This PM it is going up on the house to be about 32-39 feet up.  Hopefully that will bring in the other stations.  I'm thinking about a preamp as well.