[lenl]

I mean no disrespect but:

At some point it seems to me that you modeling experts will have run out of ideas or the software will pretty much have been exhausted as far as the umpteen great models it can produce.

I can understand the rapture you guys get from the modeling. But I am truly amazed that there are zero actual builds shown on this forum except by guys who look at what you have done and build. For all your work you seem to have only models to show for it. Are any of you hands on builders? I would think the big thrill would come not from modeling but from taking the model and then building!

Let me say that you folks do provide a tremendous service. I have the bug and want to build and experiment. I have even downloaded the 2nec4 software. I have to learn how to use it. However for me the satisfaction is to build and results of a real antenna.

I would love to see the actual builds by 300OHM, Nikiml etc. down the road.

 

[stampeder]

lenl, this is the Antenna Research & Development forum, after all.

Modeling is done on a regular basis to hash out ideas, and frankly a lot of those designs are already known by the modeler and others to not merit a physical build. The reason such models are created is to expand knowledge by challenging assumptions and testing theories, not to necessarily be built. We used to put all such "not ready for prime time" work into a thread called Area 51 in order to keep everyone clear on how experimental (and often not useful) some of the designs had become, but lately with the maturation of some of the newer designs I've been letting a few of those have their own threads, such as the Stealth Hawk. Those threads might contain models that are not build-worthy.

As for members here who actually "hang metal" out there time after time to test physical changes to designs, most of us think of mclapp's lengthy and carefully logged work on his many M4 versions, but even with all his great build work he still uses computer models.

So, if you're not sure which of the many design modifications or versions will suit your situation best, just ask and we'll give the best advice possible.

 

[300ohm]

For all your work you seem to have only models to show for it. Are any of you hands on builders?

Heh, are you kidding me ? Ive got lots of builds. With my builds and my collection of commercial antennas, I just run out of room to where to put them anymore.
My 2 DBGHs were overkill for me in the first place, so building another with say, another tweaked db or two of gain, wouldnt do much for me in practice.

 

[ota_canuck]

I have many antenna skeltons [100s] in my shop and they all work, but they all work differently, to serve the needs of different reception situations. I should take a picture of the back wall of my shop and post it here. Stampeder,... How much bandwidth am I allowed to use for this picture?

 

[ota_canuck]

My Antenna Doghouse

This is the back wall of my shop where all of the tested trials go to rest. And a quick shot of what's currently floating around on the shop roof.

Note: all of these antennas shown in these pics work fine.

 

[300ohm]

The SHs can stack up nicely on a hook, heh.

 

[nikiml]

What can I say...
1. posting a model is so much simpler than posting a picture.
2. modeling on the computer brings so much less questions than hammering in the basement ( i am a programmer after all )

but you put my handle in a list with 300ohm's therefore I'll go the extra step...

But I have only built two.

 

[Xauto]

I have made 14 different types of antennas and modelled many more that I have not built. Not all have been pictured here. I am now using 3 different antennas on 3 different TV's. Still looking for the magic bullet.

 

[ota_canuck]

The SHs can stack up nicely on a hook, heh.

But, that would totally botch up my whole 'liquid-filing-system' and I wouldn't be able to keep track of which antenna is which antenna. The only antennas that go into one common place are those who end up in file#13

 

[majortom]

10,000 years from now, imagine the facial expressions of the folks
doing an archeological dig near ota_canuck's house...
Like huh, what do we have here??

 

[300ohm]

Evidence of alien abduction ????

 

[ota_canuck]

It's funny to hear the comments and reaction of all the local Dutchmen passing by my shop, because you never know what your going to see sticking up over the roof. Over the past couple years I'd thought I learned a cool new German word from many passing by looking skyward in awe saying: "wothahellizat'

I had considered naming the SH antenna a 'Wothahellizat', but then it turns out that it wasn't a German word afterall. As a matter of fact it's the name of an Australian survival vehicle, so I had to settle with calling the little antenna the Stealth Hawk instead.

To this day I'm not sure if they were looking at the antenna or a survival vehicle flying overhead. So bullyboxer,.. if your reading this... were you flying around Dunnville in your wothahellizat?

So recently I heard some saying 'stealth hawk' as they looked overhead and I now wonder if they're looking at the antenna or are there fighter jets circling my shop.

http://www.autoblog.com/2006/07/23/the-wothahellizat-winnegabos-weep-in-its-presence/

http://img265.imageshack.us/img265/1961/wathahellizat.jpg

 

[lenl]

NIKIML,

Wow! Only thing is they don't look like they are being used! Free standing?

Anyway I hope you folks took no offense to my comments and I mean't only to see what you guys may have built with all these great models you provide us. After the gold model and super gold model and platinum model I think you will get to the point where you have tweaked the GH variations to death and the only thing left is to build them based on the best models developed.


I am working on my 3rd GH now. The first was a trial quick and dirty trial. The second went up and works almost as well as my store bought CM4228 which is higher up on the chimney. (300OHM has seen my pictures and offerred more ideas). I am really happy with the GH and can thank you modelers for the info that was the basis for my build.

Now I am working on an even better build (double GH) to add into the mix. All thanks to you guys who do the modeling!

 

[nikiml]

I am using the GH, the SH is there only for the picture.

 

[Dalek Prime]

I do a fair bit of digital design. The ease of creating and testing in a simulator (Digital Works) without having to waste time and materials is an absolute godsend. As well, I can share my designs with ease. If it wasn't for the ability to model and test digital circuitry in a sim, I wouldn't do it at all, so I totally "get" why antenna builders do the same.

Whether you're an architect, an engineer, or a hobbyist, it just makes sense to plan a project first, before any actual build. And for some, the intellectual challenge is a rewarding goal unto itself. eg. Look how many people do Sodoku and crossword puzzles. They don't do it to accomplish anything. They do it to challenge themselves.

PS. Thanks for the pics of your "Doghouse" and roof, ota_canuck. Enjoyable.

 

[stampeder]

± and error margin prediction = Modeling win

Could a smidgen of measurement error here, a teensy-weensy bit there, make a difference? In the RF world the answer is yes.

If two builders are attempting to create the exact same antenna but in different conditions, with different resources and materials, the results will be different. In the modeling world created by computer, the results are uniform due to the ease of sharing data in absolute dimensions, angles, sizes, tolerances, and error margins.

As an example, if I lay out a large antenna on my driveway and get out my calipers, protractor, and measuring tape, I can thoroughly document the dimensions and angles in a spreadsheet, but I am going to have to try to guess at the ± factors in my materials, instruments, and my own methodology. What if 2 builders use slightly different nuts and bolts, or one of them cuts from the outside of a marking line and the other from the inside, or the pipe manufacturer's tolerances are greater than those from the other place? Add up enough of these and a difference in the ultimate product will result in different performance results. Will the difference be much? Maybe not, maybe so, but in R&D it is important to nail such things down.

So, the computer model can set a ± tolerance and error margin baseline while the builder can only guess at ± values for that particular location and not for others.