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The Sigma 4
The DB, I really liked the mod you applied to the sigma4 ring. The unit value ring was quite elegant.
Scratch built models are often more elegant than those with quickly added functionality.
I was anxious to see the effect of changing the ring and went for the quick and ugly (but...
Super penetrator
This model (with long radials) shows very promising gain. Pretty sure this is the highest gain omni I have seen at 11 meter (that is actually deployable)
3.2 dBi may seem small compared to the outrageous claims that are made about some verticals like A99s,
but in the cruel...
This is a starduster type ground plane with 3 adjustable radials
I think this model is pretty well behaved but interprete results carefully and check AGT.
The AGT test is found after you hit the calculate or (F-7) click off of "expert settings" to reveal the "run AGT test" check box.
Running...
Astroplane
I posted an astroplane model on nseepcs ap thread (as did he).
I think this is the most adjustable model I designed.
I never found anything remarkable about this antenna other than it's not that omni-directional.
maybe someone can correct the dimensions and demonstrate the qualities...
This is a 4 element phase steerable array.
When I became dissapointed with the super scanner I thought maybe, I could combine 2 sets of the phased dipoles togather. I don't know of the history of this antenna.
I doubt it has remained unconcieved until now. However I'm not aware of a commercial...
The super scanner
I originally was mistaken about how this was fed.
I spent a lot of processor cycles looking at phased versions.
This is fed like the original, only one hot element at a time (or all for omni).
This one was named stock and was one of the last ones I made ,so it should be at...
Some phased arrays.
This is twin dipoles fed in phase with variable separation. "Broadside array"
Gain 5.68 dBi bw. 64 deg. f/b 1
SWR 1.33
AGT 0.996 (-0dB)
CM 11 meter cb by ghz24
CM sep is half actual separation of dipoles
CM z is half the dipoles length
CM a is the angle of phase feed...
This is a simple variable slope dipole vertical or horizontal or any angle in between.
AGT 0.996 (-0dB)
CM 11 meter Sloping Dipole, by ghz24
CM z is length of the dipole
CM a is the angle of slope in degrees 90 for vertical 0 for horizontal
CE
SY z=210
SY a=80
SY rad=0.0404
GW 1 9 0 0...
First I'd like to encourage anyone to post models here.
I consider posting a model here virtually equal to placing it in the public domain.
Use any model that I post that you like for what ever purpose you like.
If you want to protect your model from others my advice is don't post it.
If I post...
I originally picked average figuring it was just that, average.
due to my recent comparisons it became obvious that average
is far from average.
"Average" values consistently fall outside the range defined by good and poor
How can average be at one extreme not in the center ?
I think we must...
Freespace is a great equalizer but, at cb frequencies it is virtually impossible to escape the effects of the ground
I'd like to find or reach a consensus on what type kind of environment and ground we should model over so as to adequately demonstrate the properties (in general) for the antenna...
Hi all,
Wow looks like I missed lots of fray.
I don't know which theory is right (if either).
Sorry this post turned out a little long winded despite my attempts to keep it short.
Shockwave :
For repeatedly belittling with such authority 4nec2 and nec engine software in general even though you...
Cross polarization loss
I know I'm a little late to this party but I can't resist.
Hi Shockwave
Your logic seams dead on to me but...
It's actually 3 dB loss. The formula is Cosine theta squared.
So Cos (45)= 0.7071..... , squared= 0.5 as in half the signal or 3 dB.
Using the same...
To avoid the sharp angle problem make a short wire stub horizontal to the mast and attach the angleed radials to the end of the stub. Also be sure toi use an EK (extended kernel) "card"
The AGT should tell you how compromized the model is or isn;t.
Where did the extra gain I see in the model I posted come from?
Why does this show in phase radiation.
nosepc this jpg is "show phase as color." option see how all the radials are the same color. and it is only slightly out of phase with the main radiator.
Same color = same phase.
Gee I...
I see, you manually made the radials and they show in phase, not you manually made the radials show in phase.
CM 11 meter cb by ghz24
CE
SY z=324 'driven element length
SY rh=108 'ring height
SY zp=30 'avoid segment errors durring sweeps
SY rsf=0.5 'changes ring diameter
SY agl=240...
Hope that's cool enough because I'm just getting power on again after tornado.
Originally Posted by The DB
the bottom segments are at a highly acute angle with the main element connection. This causes a quick change in average gain.
I'd bet that the average gain being off is the reason...
OK I have to retract my previous statement I reversed wires on nospec's Inverted Vee model and found no effect at all.
I know I've seen it matter before I just can't remember where.
Must be something else at work. Wish I could remember what model it was so I could pin-point the circumstances. I...
What I meant by compare for yourself was:
"Copy" the text in the highlighted Code box . "paste" the text into a new text file (like notepad) and save as "righttest.nec" (or wrongtest.nec ) save/move them to the "4nec2\models" folder.
Open 4nec2, click on the folder icon near the top left...
wire ends
You don't get an error message and it does matter.
I was trying to recreate someones results with this model but it demonstrates what can happen if you reverse wires.
I think this is the right way.
CM 11 meter endfed halfwave (right ends) by ghz24
CE
GW 1 9 0 0 0 0 0 210...
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