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6 votes
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4nec2: What does "#12/in" mean?

Yes, the wire gauges like #12 etc. are just predefined symbols that are the radius of that (AWG) gauge of wire, given in metric. If you're using a GS card to ...
hobbs - KC2G's user avatar
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5 votes
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Modelling a "fan dipole" or "fan inverted vee" using EZNEC - unexpected result

Yes, being limited to 20 total segments for two dipoles is likely to be a problem, especially because of your hope / plan / expectation to have the model accurately predict what is built. I created an ...
Brian K1LI's user avatar
  • 7,878
4 votes

Does mounting a ground plane antenna upside down change the takeoff angle?

To answer this very graphically: Flipping the diagram geometrically can't work: What you've actually build is kind of a waveguide, consisting of two grounded planes below (earth) and above (virtual ...
Marcus Müller's user avatar
4 votes

Does mounting a ground plane antenna upside down change the takeoff angle?

If you were to flip the antenna upside-down, ideally with no part of the antenna touching the ground, then your antenna radiation pattern wouldn't change all that much, as you've discovered on EZNEC. ...
rclocher3's user avatar
  • 9,242
4 votes

How to produce a NEC antenna file (and what software to use it with)?

I recommend the xnec2c antenna simulator for Linux. It has a few features that qantenna and 4nec2 do not: Xnec2c supports parallel execution by forking for fast simulation. It uses accelerated math ...
KJ7LNW's user avatar
  • 755
4 votes

Basic antenna matching theory?

Does this mean this antenna can't be tuned to the 160M band, or does this just mean that the impedance is so different from 300 ohms that the SWR is useless? A little bit of both. If you get an off-...
hobbs - KC2G's user avatar
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3 votes
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Mutual impedance of two parallel dipole

I think if you're worried about the load on the other dipole, you need to go back and look at how Z parameters work. $Z_{21}$ doesn't assume anything about the impedance on the two dipoles. It's just ...
tomnexus's user avatar
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3 votes
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How do I specify that wires are connected in 4NEC2?

Rod, Ends of wires are connected if they are at the same location. Your model is correct in this regard. However, the wires need to be about one-quarter wavelength long rather than the full ...
Dick Reid's user avatar
  • 173
3 votes
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Mathematica notebook for NEC2 (NEC, Numerical Electromagnics Code)

I use Mathematica with NEC4 which would work essentially the same as with NEC2. I find Mathematica to be a great front end to NEC4 for not only graphing results but also preparing functions for ...
K7PEH's user avatar
  • 3,008
3 votes

4NEC2 - Radiat-eff. vs. Radiat-power

I just did a bit of tinkering with 4NEC2 and I've got an answer. The Input power is the power generated by the source, and ignores all losses. It might also be called "Total power". The "Radiat-...
Hamsterdave's user avatar
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3 votes

4NEC2 - Radiat-eff. vs. Radiat-power

I'm a NEC2 user, never used 4NEC2, but I think it's the same engine underneath. The radiated efficiency is low because either: - a lot of power is absorbed by the ground, or - you have a structure ...
tomnexus's user avatar
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3 votes
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Raising height of inverted V by 2 meters

When a dipole is less than a 1/4 wavelength above ground, the image antenna formed by the reflection from the ground creates destructive interference at low angles, making the antenna quite useless ...
Phil Frost - W8II's user avatar
3 votes

How to model passive elements when simulating an antenna?

Without any insight into the design of your program, I can only offer some basic guidance. The parasitic elements in a yagi design are shorted dipoles that can also be modeled as a collection of ...
Glenn W9IQ's user avatar
  • 18.6k
3 votes

Does mounting a ground plane antenna upside down change the takeoff angle?

Please see my graphic below. A λ/2, center-fed dipole has about 0.7 dB more gain than a λ/4 ground plane, but otherwise their v-pol, free-space radiation patterns are very similar. Whether the ...
Richard Fry's user avatar
  • 2,922
3 votes
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Does mounting a ground plane antenna upside down change the takeoff angle?

An elevated "ground-plane" antenna with tuned radials has, by itself, a pattern much like a dipole doughnut shape (freespace is what I'm talking about at the moment). Unfortunately we must mount the ...
JSH's user avatar
  • 590
3 votes
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How to correctly model a small helix antenna

In my experience this can't be modelled in NEC. It doesn't handle tight corners, close segments, short segments like this. Your geometry input file looks technically correct, but you're asking too ...
tomnexus's user avatar
  • 11.4k
3 votes
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Impedance of Yagi boom model in NEC

In a Yagi there shouldn't be any longitudinal current on the boom, if the structure is perfectly symmetrical. But this is not the case in your simulation. If you look carefully at the structure ...
tomnexus's user avatar
  • 11.4k
3 votes

Metal panels in 4nec2

NEC2 can model metal structures, using a grid of wires. There's no card for a metal sheet, you need to construct it out of segments. I've done this many many times to model aircraft, buildings, ...
tomnexus's user avatar
  • 11.4k
2 votes

Antenna gain vs. radiation efficiency in 4nec2

Recall that: Antenna system gain (efficiency) includes system r-f losses. If any exists, then a proportional amount of applied power from the transmitter is dissipated as heat in the lossy elements ...
Richard Fry's user avatar
  • 2,922
2 votes

ADS Simulation: How to model an antenna in a simple rectifier circuit?

In order to properly model an antenna in your example, you need to be very specific as to the type of antenna and its installation details. Once this is specified, the antenna can be modeled as a ...
Glenn W9IQ's user avatar
  • 18.6k
2 votes
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How to consider the influence from the PCB that a small antenna is mounted on?

The small antenna is quite poor as a radiator because there is a dimension restrict for the device. It is important to separate cause and effect when designing antenna systems. Recall that the ...
Glenn W9IQ's user avatar
  • 18.6k
2 votes

Modelling a folded dipole

@pymekrolimus: Below is a clip showing the details of a quick study of a model based on your posts so far. The NEC4.2 engine was used for the calculations. The results look close to what might be ...
Richard Fry's user avatar
  • 2,922
2 votes

Modelling a folded dipole

Good simulation work - your results look pretty realistic. A note about patterns - when you talk about Azimuth and Elevation patterns, with the antenna lying on its side, it's not completely clear ...
tomnexus's user avatar
  • 11.4k
2 votes

Do Far-Field Radiation Patterns/Gains of NEC Software Accurately and Always Show the E-M Fields "Launched" by Vertical Monopoles?

The NEC4.2 analysis below compares the intrinsic fields/gains of the same monopole for the definitions and conditions shown in that graphic. Note that the monopole having a 10 Ω path connecting it to ...
Richard Fry's user avatar
  • 2,922
2 votes
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Convert NEC antenna file to .out-file for Wattwächter

Now I'm using the software 4nec2 (with wine) with the description from DL6GL. With this software you can generate the .out files. I hope to succeed.
Tobias M.'s user avatar
2 votes

Modelling a "fan dipole" or "fan inverted vee" using EZNEC - unexpected result

I doubt that the segment limits of the program is your main problem. You should get accurate enough details in spite of that. Part of the problem is at the feedpoint. You need to build your fan ...
Mike Waters's user avatar
  • 8,071
2 votes

How to simulate two antennas in 4nec2

It is more than 15 years ago, that I've done it. But if I remember correctly, the 3D screenshot you're showing is quite misleading. The pattern is drawn around the 1st antenna / center of coordinate ...
Burn's user avatar
  • 41
2 votes

4NEC2 shortening factor "x"

The answer to your question is on page 6 of Antenna simulations with 4NEC2 including an application example for 2300MHz: A symbol (SY), x, is defined as having the value 0.907. This value is used in ...
Brian K1LI's user avatar
  • 7,878
2 votes

How to make ELF-ULF antenna myself?

If you need calibrated output then you probably won't be able to do it. That's why they are so expensive. It's like a \$20 SDR dongle versus a \$2,000 spectrum analyzer, with the most notable ...
Jack0220's user avatar
  • 371

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