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HDTV Antenna not a "wood" working project.....

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Project by Hooligan__j posted 01-03-2010 07:04 PM 7615 views 12 times favorited 15 comments Add to Favorites Watch
HDTV Antenna not a "wood" working project.....
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Thought that I would share this. I know it is not a wood working project, but figured maybe someone else out there might want to build an antenna that actually gets better signal than a store bought antenna. And, there is a scrap 2×4 involved….so…..
Parts list:
1. Find some metal laying around the house. I used welded wire mesh fencing material I had left over from a gardening project, and some 9 guage wire I bought to hold up a new grape plant we just threw in the ground. (You could use 6 or seven appropriately cut and sized metal hangers)
2. Locate a piece of wood to screw it onto.
3. Find (or go to radio shack for) one of those old school y to coax connectors (the kind you used to have to screw on the back of a TV to get cable).
4. Four wood screws, eight washers (whatever sie you have, but the loops on nine guage wire will be large, so make sure that you can cover those loops) and….something else….um….some wire pliers…..oh yeah, and a drill.
throw it all together: Bend whatever type of wire you are using so that you can secure it to the wood. I cut one of the middle sections of the fencing, giving me four total “ends” and bent each end into a small loop. I used some needle nose pliers for the fencing, and some linemen’s pliers for the 9 guage wire. It was a pain to try bending the 9 g. into a loop to go so if you have a vise, that might make it easier. I mounted the fencing first, then the 9 g loops, covering the loops with a washer. Then I put the Y connector, followed by another washer. I plugged in the coax to the antenna, and then to the TV, then my wife said my project looked hillbilly, and was interfering with her decor, so once I tested it, I mounted it to the side of my house, and am now getting signal not only from the bigger city about 40 miles from here, but a couple of HD stations from one about 80 miles from here, with the signal being as clear as I have seen, and no signal loss that I have seen. I am thinking about plugging in an inline amplifier, and seeing if I can get signal from the city 200 miles from here…..





15 comments so far

View Mean_Dean's profile

Mean_Dean

1787 posts in 1895 days


#1 posted 01-03-2010 09:40 PM

Hooligan,

Great application of a great idea!

A couple of questions: How did you determine the curvature of the “mesh” part of the antenna? Is it a parabolic curve?

Also, how did you determine the size and shape of the “hoops”? And how do they relate function-wise to the operation of the antenna?

Thanks in advance!

-- Dean

View Hooligan__j's profile

Hooligan__j

18 posts in 1815 days


#2 posted 01-03-2010 10:53 PM

Thanks for the comments.
To determine the bend of the mesh, I used trial and error. I am not really sure that a bend was necessary but it seemed to help when I was testing this indoors, now that it is on my outside wall, I could probably flatten it out. I work on electronics for a living, and a wire mesh like this would probably work well without any bend, depending on where you mount the antenna.
Before I added the loops, the signal for lower on air channels (10 and below) were being recieved, but with a good deal of stop and start signal drop off. I tried the loops because I remembered that my old antennae (: had a loop, and thought that might help.
Hope this helps!

View Eric in central Florida's profile

Eric in central Florida

3672 posts in 2324 days


#3 posted 01-04-2010 12:11 AM

Really smart idea.
Thanks for sharing it.

-- All glory comes from daring to begin.

View Jim Jakosh's profile

Jim Jakosh

12352 posts in 1853 days


#4 posted 01-04-2010 12:13 AM

Hey Hooligan, You’re a man after my own heart. I love making stuff like that and I have been looking for way to build a simple antenna to hook to my digital TV we also use for a monitor but I need to get the local NBC and ABC stations. I brought home two antennas and bought one off E bay. All they got was 1 channel- channel 17. So I found some old rabbit ears tha have the two extendable rods and that get 6 stations, but not the two local ones. I’m going to borrow your idea and make me an antenna just like yours!!

Also, I have been looking for someone who works on electronics. I found a circuit diagram and plans to make a metal detector on the internet from a guy in the UK. I built a cool dectetor body and wired the circuit but can’t get it to work. I used a stirng of resistors to get the values and thought that migh be a problem. so I went to our old time radio shack( not the chain store) and bought all new components and it still does not work. It sould cost me about $90 to ship it to England for him to trouble shoot it. Would you want to look it over and see wher I screwed up?

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

View Jimthecarver's profile

Jimthecarver

1123 posts in 2533 days


#5 posted 01-04-2010 12:21 AM

I also was wondering what determines the length for the wire hoops to receive that wave of transmission. I have one of the very old cat whisker type UHF antenna’s and the length is a set lenght for that wave of transmission.
I find it performs well but if your antenna will do a better job I am all for it.
Thanks for the post….it gets me to thinking.

-- Can't never could do anything, to try is to advance.

View Dan Hux's profile

Dan Hux

576 posts in 2122 days


#6 posted 01-04-2010 12:57 AM

very cool,,I made my own,,it’s great,, the HD is great,, I made this one
http://uhfhdtvantenna.blogspot.com/ I got 15 channels with mine around Raleigh, NC
worked like a champ, I don’t miss paid subscriptions at all.

-- Dan Hux,,,,Raleigh, NC http://whitdaniel.com

View Jeison's profile

Jeison

947 posts in 1856 days


#7 posted 01-04-2010 02:06 AM

haha awesome!

-- - Jei, Rockford IL - When in doubt, spray it with WD-40 and wrap it with duct tape. The details will attend to themselves.

View RZH's profile

RZH

73 posts in 1857 days


#8 posted 01-04-2010 02:46 AM

My next project! Thanks for the post. BTW did you put a ground on it?
Ron

-- Ron

View BTKS's profile

BTKS

1971 posts in 2212 days


#9 posted 01-04-2010 03:37 AM

cool, going straight to favorites. if it will pick up the childrens channels i might get by with dropping the dish.
thanks for the post, BTKS

-- "Man's ingenuity has outrun his intelligence" (Joseph Wood Krutch)

View Hooligan__j's profile

Hooligan__j

18 posts in 1815 days


#10 posted 01-04-2010 03:48 AM

Jim Jakosh : I wouldn’t mind looking at your detector, to figure it out, but please keep in mind I am on sea duty in the Navy right now, and my deployment cycle (what we call the preparation and deployment) has already started.
I will be in and out a lot, but if I can help, I will. When you say strung together, does that mean end to end, or is it in parallel?

Jimthecarver: I don’t know how to determine the length… I know how do do the math, (Navy taught me) but it has been so long since I have done it….. but I guess I got lucky…..I made them a length to contact the mesh, and also use the same holes as the one securing the mesh. (only had eight things I could use as washers and didn’t want to go to the store)

RZH: I was going to ground it, but then thought….what the hey, I don’t remember the last time we had a lightning storm around here…..

And for better directions, on how to build your own, watch this video:
http://www.youtube.com/watch?v=EWQhlmJTMzw

I would have done it that way, but didn’t have enough coat hangers…..or the time to prepare them to be mounted. So hence the wire fence.

View OutPutter's profile

OutPutter

1198 posts in 2738 days


#11 posted 01-04-2010 05:42 AM

Man, you guys need to move in out of the sticks. How can you get internet without cable? DSL or something? Whew! What a pain that must be. And, how can there be 15 channels in the vicinity of Raleigh? Are they 5 ABCs, 5 NBCs, and 5 CBSs? Weird. My wife is from a small town too but they have Dishes there at least. Where are you guys from anyway?

Best of luck,

-- Jim

View versa's profile

versa

29 posts in 1881 days


#12 posted 01-07-2010 08:11 AM

I am surprised you receive any signal with that thing. That is essentially an omnidirectional UHF antenna with a back splash that blocks any signal from the rear (which your house already does a pretty good job of). And there is no way you could get a UHF signal from 200 miles away, UHF is line of sight only, and the curvature of the earth prevents it from being received more then about 65 miles away. VHF can bounce off the ionosphere thus making it theoretically possible to receive 200 miles away, but your antenna is not a VHF antenna and would not pick it up unless it was very close and very strong. If you want to build your own antenna I would suggest picking up a book and making either a yagi or 8 bay bowtie. With digital TV if you receive a signal at all the picture would look great no matter if you have a good signal or a poor signal, the only difference is how often the picture drops, usually due to high wind moving trees that change the multipath reception or passing plane/helicopter/car/truck. You will also usually get much better signal the higher you mount the antenna (less ground clutter to create multipath). Multipath is what we used to call ‘ghosting’ in the old analog days, it is caused by the signal bouncing off of another object before it gets to you, causing you to receive the original signal and the bounced signal a moment later.

Amplfication is also a bad idea. Amplifiers are not receivers, they don’t know what is signal and what is background noise so they amplify everything, in addition to adding their own noise (nothing is perfect). Amplifiers are only useful as preamplifiers, aka if you have a distance of 100 feet or more between your antenna and your receiver you will have significant line loss or resistance and to overcome that loss a preamplifier might be necessary.

If you would like more information about what is available in your area, check outhttp://www.antennaweb.org/aw/Address.aspx

View Hooligan__j's profile

Hooligan__j

18 posts in 1815 days


#13 posted 01-07-2010 09:39 PM

Versa, Thanks for the tip(s), the drive by add placement, lesson in UHF/VHF signal, and taking the time out of your day to try to make me sound like a nincompoop.
You can say what you want, and go spend your money on buying one, but this works. No signal loss, no “ghosting” or drop in picture/sound. Of course weather does affect this antenna, just as it would any antenna that is mounted outside. But as of right now, I have not had the television lose any picture while I was watching it…..who knows? Maybe just so we can both be right, it loses all kinds of signal when I am not watching it…...
Pull up yonder google maps, and check the distance from Lemoore, Ca. to Bakersfield Ca. as the crow flies, it is more than 80 Miles, and I get two stations (including when the antenna was mounted inside the house for testing I might add). This next part might be beneath you: let me get my pocket calculator, and you get yours; do the math with me if you want. (more than 80 miles – your 65 mile limit for UHF)
I can see how the appearance of my homemade antenna may cause you to doubt whether or not I am getting any channels. I understand the line of sight thing (I do work with Commmunications equipment in the Navy) But bottom line, I am getting signal, and I didn’t have to buy anything to do it.
And, you are right, amplification is most likely a bad idea. But since you are suprised that my antenna gets any signal at all, I think I might try it anyway.
Thanks again.

View versa's profile

versa

29 posts in 1881 days


#14 posted 01-08-2010 09:14 AM

I have no affiliation with that website, it is simply the best resource for anyone using tv antennas, it will give the exact location for any station you are trying to receive, and tell you which stations you can receive. Letting you know exactly how far your location is from the transmitter as the crow flies.

FYI, in the digital age, you won’t see ghosting anymore, you either get the picture or you don’t, however your receiver still gets ghosting, and if it can’t sort out the ghosting problem you don’t get a picture, or get an intermittent picture. If you lose the signal in high winds, you need a better antenna.

View Jim Jakosh's profile

Jim Jakosh

12352 posts in 1853 days


#15 posted 04-10-2010 04:26 AM

Hi Hooligan, Your antenna works good for me. I get 2 analog stations and 16 digital stations all the time with the antenna sitting inside the window of my computer room. I have yet to try it outside.
The only problem I have with it or any other antennas I tried is that I cannot get channels 2-11 with an indoor antenna. The $50 boughten antennas are the worst.
From an antenna designer website I wrote down the following formulas for the length of the antenna needed to get the any channels. Here it is. Do you think that if I used a 98 1/2” rod with your antenna, I could at least get channel 2?
For Example. The frequency (f) for channels 2-4 = 6 X channel number +45… so channel 2 frequency =(12 +45) 57Hz
The wavelength = the velocity factor (.95) x resistance of twin lead (300ohm) /all over frequency (f) which would equal 5 Meters.
The antenna beam length = wavelength / 2 =5M/2= 2.5 M= 98.42 inches

By these formulas, the antenna length for channel 17 would be 11.4” and it comes in good on this wire fence antenna which is about 18” long . For channel 8 it needs to be 30.6” and it is short of that and I cannot get channel 8.So it figures.

Do you get the lower channels with your antenna?

The rest of the formulas
Channels 5&6 (f) =6x channel+49
Channel 7-13 (f) = 6x channel+ 135
Channel 14& above (f) = 6x channel + 389

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

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