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It would most likely be better to build one of the GH or M4 antennas discussed in the other threads here. I've built both from #14 or #10 house wire. The M4 I built from #10 wire has been in service outdoors for over 2 years.
 

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DavUng welcome here but could you tell us what your goals have been with those designs in the photos? :) Have you looked through our site's existing designs before starting your projects?

If you can post detailed measurements of those designs we can subject them to 4nec2 testing in order to evaluate their performance capabilities.
 

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When using solid copper wire, it's always best to 'straighten' the wire prior to cutting/bending in to elements.

Just tie off one end of a long length of stripped wire to a vice, an eyebolt, or whatever else is handy to use as a third hand. Place the other end in the chuck of a drill and run the drill until it twists taut and straightens itself out.
Now you are ready to do whatever it was ya were gonna do with it.
 

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Discussion Starter · #8 ·
Thanks, Stampeder. No goals in mind. Just puttering around and giving them away to friends and saving them from wasting money on rubbish antennas being peddled around TO. The only item that need to be bought are the matching transformers/baluns (~$2 each). So far, these DIY antennas perform better than those being sold.

I failed to mention, in my initial post, that there are plenty of details in the caption of each photo, including the dimensions of the wires. Anyone interested may click on the Info icon of Google Photos to display the captions.

I'd just started learning to use xnec2c (a Linux version of NEC2). I will post the GW statements soon, after I'm satisfied that I won't be posting something riddled with rookie mistakes.
 

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Discussion Starter · #9 ·
I was trying to address the needs of friends who live in apartment/condo buildings. So these are for indoor use only. Also, the baluns I bought (in TO, from Sayal and Princess Auto) are indoor quality only. You're probably right about their performance compared to the outdoor ones discussed in this forum. But, these copper wire antennas are easy to build and so flexible that I can twist and turn them into many shapes and see if they perform better. I don't have any measuring equipment; I rely on what the TV set tells me, e.g., whether it receives the channel or not, and, if the TV set is smart enough, what signal strength/quality it detects.

I glanced through many of the designs posted in this forum and elsewhere. The closest in design is the "fractal HDTV" of WilliamRuckman How to make a fractal antenna for HDTV / DTV plus more on the cheap.
 

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DavUng: Could you do a test for me. Make a square loop 170mm per side. Put the balun in the middle of one of the sides and test this design. From balun connection to the left 80mm then up 170mm then right 170mm then down 170mm then left 80mm to other balun connection.
 

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DavUng, we are big believers in not re-inventing the wheel. My advice is to go through the Area 51 thread to see what we've been up to over the past 10 years because you will be able to identify successes and dead ends for your future tinkering: Area 51 for Antenna Modelers & Builders (See Post #1)

As for fractal antennas, we've had a thread here for years that features terrific analysis as well as the "father" of fractal antennas, Prof. Nathan Cohen: Fractal TV Antenna Research & Development

Your use of xnec2c is intriguing. The common tool here has been 4nec2 on Windows and we have a member who has been working on the OS X version called CocoaNEC. Always nice to know about Linux/Unix options! :)

So, please immerse yourself in our OTA Forum (a level above this Antenna Research & Development subforum) and you'll get up to speed quite well with a minimum of dead ends and wasted iterations.
 

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My "hands down" favourite for performance coupled with ease of construction is the Stealth Hawk. A hunk of wire, a few bends, attach a balun and you've got a good performing antenna. Tape it to the inside of a window and it's almost invisible. I like it because of it's hi-vhf performance. Here in Hamilton ch 9 from the CN tower can be a challenge for a UHF only antenna. The stealth gives that little bit of gain needed at vhf frequencies.
 

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Discussion Starter · #13 ·
Hi Xauto...I happen to have a length of scrap copper wire and I formed a square loop and attached it to a spare push-in matching transformer. Then, I connected that antenna to a TV set and compared it against the DIY copper wire antenna I suggested. the Square-loop antenna was not as effective - the TV set failed to receive 2 of the stations that it previously received with the DIY-copper antenna. Sorry, can't be more precise - I don't have any electronics measurement equipment.

What did you have in mind with this Square-loop antenna? How did you arrive at the 170mm length for each side?
 

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Thank you for testing the square loop. The 170mm length should get you an antenna for ch. 14 to 51 with a gain of about 3. The antenna that you made has maybe a gain of 1.3 to 1.0 for ch. 14 to 51. Your signal are every strong at your site. The better the gain of the antenna the more you overload the TV, thus failing to receive some stations. Bigger is not always better. Your antenna would be a good design for 900 MHz phone (gain of about 5). To get the design to work well for ch.14 to 51 it would have to be about 1.5 time bigger in size, but then you would have a gain of about 5 and overload the TV.
 

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Discussion Starter · #15 ·
Hi Stampeder...I puttered around with 4nec2 over the past week. The 4nec2 model I ended up can be downloaded at https://drive.google.com/folderview?id=0B8Zy0q48dfhja2NkUHJRT1pDLVk&usp=sharing. Also, I uploaded a few screenshots of some of the plots from 4nec2 and xnec2c into the album mentioned in Post #1 of this thread. I apologize in advance for any mistakes - I'm a rookie at nec2 modelling/analysis; would appreciate any advice/instruction from anyone more experience.
 

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MINOR correction: In "EX" Statement, the SOURCE needs to be in the MIDDLE Segment of the 15 segment long wire, which would be "8" vice "7".

Terrible Gain & SWR....not sure what you are TRYING to do....also note that the bottom half is NOT connected to the top half.
Perhaps it would perform better if the bottom part is slid upwards and uses a COMMON SOURCE wire (vice separate Horizontal wires)????

Also bear in mind that VERTICAL Wires generate VERTICALLY Polarized signals (and vice versa)....so if you are trying to create a Horizontally Polarized Antenna for TV Bands, the Vertical Wires won't contribute very much to Horizontal Gain.....unless they are simply interconnections to Horizontal wires....
 

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Overload ? I don't think that is what is happening.
Not trying to be disagreeable but I live very close < 1 mile from several high power stations and I had to put up a 40 ' tower and resort to a high gain antenna to keep the multi-path from destroying my reception.
I now have no problems with my signal with an ~12 dBi yagi.
Actually the problem went away at ~25 feet above ground but I could get by with 40' so I went as high as I could.
IDK maybe the tuners I use are tolerant to overload.

DavUng I posted an improved Coch star (ruckman ) fractal in the fractal thread.
the original is to small.
 

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holl_ands said:
MINOR correction: In "EX" Statement, the SOURCE needs to be in the MIDDLE Segment of the 15 segment long wire, which would be "8" vice "7".

Terrible Gain & SWR....not sure what you are TRYING to do....also note that the bottom half is NOT connected to the top half.
Perhaps it would perform better if the bottom part is slid upwards and uses a COMMON SOURCE wire (vice separate Horizontal wires)????
Thanks for the feedback. I'm a novice, learning a lot and am climbing a steep learning curve. In addition to the "getting started tutorials" for NEC2 and 4NEC2, I'd gone back to the 2008 posts between DTV Student and 300ohms, Autofils & others in the "4nec2 & Other Antenna Design Modelling Software" forum. Yes, that's a rookie mistake; the feed-point should be at segment 8 of either element #1 or 2 - modelling where the balun wires are attached in the real antenna. What I still have to figure out is how to model the balun which effectively connects the bottom and top halves together - maybe add a short GW element connecting elements #1 & 2 or a TL element? This will off-topic in this forum; so, I'll move the discussion to the "4nec2 & Other Antenna Design Modelling Software" forum.
holl_ands said:
Also bear in mind that VERTICAL Wires generate VERTICALLY Polarized signals (and vice versa)....so if you are trying to create a Horizontally Polarized Antenna for TV Bands, the Vertical Wires won't contribute very much to Horizontal Gain.....unless they are simply interconnections to Horizontal wires....
Good point. The model I posted is a 'first cut'; a stylized version of what I had built. In fact, the real antenna that was pictured and works best has the V-shaped 'petals' oriented more diagonally. I am still fumbling with the 4NEC2 graphical editor and will adjust the model to match the real antenna, as close as possible. The concepts of SWR, raw gain and net gain are still new to me. The calculated SWR and raw/net gain figures suggest that this antenna design sucks; yet, the antenna works in real life! I still wish to reconcile reality with the model. I'll continue discussion in the other forum. I'd learned so much in the past weeks that I have a greater appreciation of what it takes to come up with a great antenna - it takes a lot of science and engineering, plus a dash of arts & craft sometimes. I salute the moderators and contributors to this forum/website for furthering the arts, craft and science of antenna design, building and improvement.
 

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Discussion Starter · #20 ·
Moving the discussion to "4nec2 & Other Antenna Design Modelling Software"

I improved on the 4nec2 model previously mentioned in post #18 - corrected a few rookie mistakes. The updated 4nec2 code may be viewed in the file DIYcu-VS-DP-FW2.nec. The 4nec2 results seem more consistent with how the real antenna performs.

The charts & plots from 4nec2 for this model were also uploaded to Google Photos album "DIY Indoor antenna made with copper wires...". Like the other photos in the album, the charts & plots are annotated/captioned. Please click on the Google Photo Info icon to display the captions/annotations.

Since the discussions will be mostly about modelling, I'll be posting them in the "4nec2 & Other Antenna Design Modelling Software" thread.
 
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