4NEC2 antenna simulations

Part #7 of the "Roger Writes" series - October 2023

Background

Recently, I've been researching antennas, especially the less traditional (non dipole, Yagi, EFHW, longwire, etc.) options, and there is a lot of mis-information around (J-pole gain, radiations angles, 5/8th whip effeciency, etc.). During this research, I came across 4nec2 and EZNEC. I've modelled quite a few antennas, and built a few of them, here are the models that I have so far!

These use the advanced features of 4NEC2, if you try to import into EZNEC watch out:

EZNEC doesn't have variables (the SY command), or expressions
- Run them through 4NEC2 to evaluate the variables
- Use the ASCII import feature of EZNEC to import the .inp file (from the 4nec2\out folder)
EZNEC doesn't understand the GM (move/copy) command
- You will need to manually move/copy the segments (in the .inp before importing)
EZNEC doesn't understand GA/GH (arc/helix) commands
- You will need to manually calulate the arcs/helix path and create GW segments (in the .inp before importing)
EZNEC ignores the EX line, and assumes the input is in the middle of segment 1
- Make sure to edit the .inp file to move the driven segment to be the first
- If the driven segment isn't the middle one, after importing, edit the segment number to the correct one

These are mainly untested, and for theoretical experimentation only
I'm not asserting copyright on any of these, they are either based on public examples, or my random experiments, the world is welcome to use these as a starting point!
All of these 4nec2 files in one tgz file.

biconical-2m Horizontal 6 wire biconical, based on the diagram on https://en.wikipedia.org/wiki/Biconical_antenna
biconical-wb Vertical 4 wire stepped biconical, based on the diagram on the "Making Antennas for Amateur Radio" facebook group
bowtie-horiz-80 A horizontal Bow tie for 80m, a pair of equilateral triangles, with a taller centre pole and 4x shorter outer poles, 4:1 balun
cobra Centre Fed Linear Loaded Dipole (Cobra Junior) based on design from https://owenduffy.net/antenna/cobra/index.htm
cobweb-10-12-15-17-20 5 band Cobweb (single wire) for 10m/12m/15m/17m/20m needs 4:1 balun
cobweb-20-30-40 Triband Cobweb (single wire) for 20m/30m/40m - need 4:1 balun
cobwebb-10-12-15-17-20-halo-40 Mixed 5-band 10m/12m/15m/17m/20m Cobwebb (speaker cable) + 40m quad halo loop
cobwebb-10-12-15-17-20-v-40-80 5 band Cobwebb (speaker cable) for 10m/12m/15m/17m/20m with dual inverted V for 40m and 80m
cobwebb-10-12-15-17-20 5 band Cobwebb (speaker cable) for 10m/12m/15m/17m/20m
cobwebb-10-20 Dual band Cobwebb (speaker cable) for 10m/28.85MHz and 20m/14.1MHz
cobwebb-20-40 Dual band Cobwebb (speaker cable) for 20m/14.1MHz and 40m/7.1MHz
cu-quad-2el-2m 2-element Cubical Quad for 2m, based on https://www.qsl.net/n6bg/thunt/quad.html, gives 7.8dBi forward gain
cu-quad-2el-4m 2-element Cubical Quad for 4m, based on https://www.qsl.net/n6bg/thunt/quad.html, gives 7.91 dBi forward gain (2.9dB back)
cu-quad-3el-2m-1.17 3-element Cubical Quad for 2m, gives 9.81 dBi forward gain (with 2.68 dBi rear)
cu-quad-3el-2m-fb 3-element Cubical Quad for 2m, optimised for FB gain, gives 9.78 dBi forward gain (with 0dBi rear)
cu-quad-3el-2m Shortened (1.03m) 3-element Cubical Quad for 2m, gives 9.78 dBi forward gain (with 2.86 dBi rear)
cu-quad-3el-4m 3-element Cubical Quad for 4m, based on https://www.qsl.net/n6bg/thunt/quad.html, gives 9.23 dBi forward gain
cu-quad-4el-220MHz 4-element Cubical Quad for 220MHz/1.25m, gives 15.73dBi forward gain (5m high)
cu-quad-4el-2m-short Short 4-element cubical Quad for 2m, based on https://www.qsl.net/n6bg/thunt/quad.html, gives 10.91dBi forward gain
cu-quad-4el-2m 4-element Cubical Quad for 2m, based on https://www.qsl.net/n6bg/thunt/quad.html, gives 11.2dBi/15.7dBi forward gain (freespace/2.5m high)
cu-quad-4el-4m-short Shortened 4-element Cubical Quad for 4m, gives 10.8 dBi forward gain (with -1 dBi rear)
cu-quad-4el-4m 4-element Cubical Quad for 4m, gives 11.3 dBi forward gain
cu-quad-5el-4m 5-element Cubical Quad for 4m, based on https://www.qsl.net/n6bg/thunt/quad.html, gives 12.6dBi forward gain
d-8w4b-cross-10-20-40-80 Quad band dipole/inverted-V (80/40/20/10m) with tall centre pole and lower outer legs, two wires per leg, in a cross configuration
d-8w4b-star-10-20-40-80 Quad band dipole/inverted-V (10/20/40/80m) with tall centre pole, one wire per leg, in a star configuration
delta-40m-loop Simple 40m delta loop - Based on a question by Brent Carroll in the "Making Antennas for Amateur Radio" FaceBook group
dipole-2200m 2200m/136kHz dipole, based on https://wd7ale.wordpress.com/g5rv-and-end-fed-diople/
dipole-6x-radials-2m Simple quarter wave with six dogleg radials for 2m
dipole-end-cross-10-20 Dipole with + shaped ends, based on https://www.pa9x.com/how-to-build-10-and-20-meter-band-square-halo-antenna/
dipole-horiz-80 Horizonal(ish) dipole for 80m, with taller centre pole, and lower ends
dipole-n-radials-2m Simple quarter wave with multiple radials for 2m
dipole-radials-2m Simple quarter wave with 3 radials for 2m, based on the one built by MW7EYC
dipole-radials-40m Simple quarter wave with 3 radials for 40m
dipole-vert-40m Simple quarter wave for 40m, needs 3:1 balun (150 ohm)
dual-2m-70cm-ru4sj 2m loop with resonators for 70cm, by Vladimir Semenov RU4SJ (iron stubs?)
dual-sloop-80-40-20-15-10 A dual version of the "One Masted Sloop" by KI8GX, based on https://f5nhj.fr/pdf/onemastedloop.pdf
dual-tee-40m Rectangular bottom fed 40 meter quad, based on the design by L. B. Cebik, W4RNL
efdqw-40 An end fed dual quarter-wave, with a quarter-wave phasing droop in the middle
efhw-40-zigzag End fed halfwave for 40m, zig zagged over a roof apex, tuned for 50 ohms (1:1.59 at 7.1MHz)
efhw-80 End fed halfwave for 80m + harminics, expects to be fed from a 1:49 balun
eflw Simple End fed long wire with counterpoise, expects a 9:1 balun, so 450ohms
fan-dipole-80m Simple fan dipole for 80m
folded-10-11-15-17-20-40 Folded multiband dipole, for 10/11/15/17/20/40 meters, based on http://sm0vpo.altervista.org/antennas/small-hf-ant.htm
folded-40-80 Folded linear dipole for 40 and 80m, based on http://sm0vpo.altervista.org/antennas/small-hf-ant.htm - Note: Doesn't tune very well!
folded-80m Folded linear dipole for 80m, based on http://sm0vpo.altervista.org/antennas/small-hf-ant.htm
folded-dipole Folded dipole for 20m, based on https://www.pa9x.com/how-to-build-10-and-20-meter-band-square-halo-antenna/
folded-skeleton-sleeve-40m-10m A Folded Skeleton Sleeve dual band 40/10 M antenna from the May 2011 QST article by Joel Hallas
g5rv-d G5RV based on dimension from https://drive.google.com/file/d/12BMDf95UBbT8-ZrKCv1pEAWUiVei_B6G/preview - 2x102ft top wire + 34ft feeder
g5rv-g7wek 80m Antenna for small gardens, based on https://wd7ale.wordpress.com/g5rv-and-end-fed-diople/
g5rv-zs6bkw Retuned G5RV, by ZS6BKW and W0BTU based on https://wd7ale.wordpress.com/g5rv-and-end-fed-diople/ - 93ft top wire + 39.8ft feeder
g5rv G5RV based on dimension from https://www.hamuniverse.com/g5rv.html - 102ft top wire + 34ft feeder
hb9hby-hb9as 2-element stepped beam for 21MHz, based on diagram in "Making Antennas for Amateur Radio" Facebook group, by HB9HBY
hen-delta-2m Hen-delta hybrid for 2m, based on https://w6nbc.com/articles/Hen-delta%206m.pdf
hentenna-2m Hentenna for 2m, by JE1DEU/JH1FCZ/JH1YST, based on https://hamuniverse.com/hentenna.html
hentenna-dir-2m Hentenna for 2m, with directors, based on https://www.qsl.net/dk7zb/Quadlong/Hentenna.htm
hexa-20m 20m hexabeam with straight reflector (So W feeder, and U reflector)
hexa-40m 40m hexabeam with straight reflector (So W feeder, and U reflector)
hexaw-20-40 Classic Hexabeam with W reflector for 20 & 40m (So W feeder, and W reflector)
hexaw-20m Classic dual-W 20m hexabeam, based on dimensions from http://karinya.net/g3txq/hexbeam/classic/ (So W feeder, and W reflector)
hexaw-40m Classic 40m hexabeam, based on dimensions from http://karinya.net/g3txq/hexbeam/classic/ (So W feeder, and W reflector)
horiz-m-dl Horizontal folded dipole/halo for 160m, in an M-shape - Back garden experiment
horiz-m Horizontal folded dipole/halo for 160m, in an M-shape - Back garden experiment
j-pole-2m Copper pipe J-Pole, based on https://qsl.net/w/wa3mej/Articles/Antennas/JPOLE/copperjpole.pdf, gain is 2.92 dBi
j-pole-80m A horizonal J-Pole for 80m!
j-pole-top-fed Copper pipe J-Pole, based on W4ULD design from https://ia800208.us.archive.org/32/items/fea_A_146_and_445_MHz_J-Pole_Antenna/A%20146%20and%20445%20MHz%20J-Pole%20Antenna.pdf
jl-pole-2m-thin Copper pipe stacked J-Pole + L-pole from brake pipe, gain of 4.23 dBi
jl-pole-2m Copper pipe stacked J-Pole + L-pole, gain of 4.6 dBi
linear-folded Folded linear dipole for 80m, based on http://sm0vpo.altervista.org/antennas/small-hf-ant.htm
m0ukd-j-pole J-pole starting from https://m0ukd.com/calculators/slim-jim-and-j-pole-calculator/
m0ukd-slim-jim Slim Jim starting from https://m0ukd.com/calculators/slim-jim-and-j-pole-calculator/
mag-loop-40m Simple mag-loop for 40m using aluminium foil over plastic pipe.
mj-pole-2m Dual stacked copper pipe J-Pole for 2m, based on https://qsl.net/w/wa3mej/Articles/Antennas/JPOLE/copperjpole.pdf, gain is 2.92 dBi
morgain-20-40-v2 Morgain 40/20m, based on http://f6kht.free.fr/document/multi.dipoles.filaire.pdf
morgain-40-80-v2 Morgain 40/80m, based on http://f6kht.free.fr/document/multi.dipoles.filaire.pdf
morgain-40-80 Morgain 40/80m, based on https://www.iw5edi.com/technical-articles/morgain-antenna-4080
morgain-80-160-v2 Morgain 80/160m based on http://f6kht.free.fr/document/multi.dipoles.filaire.pdf
moxon-hb9dsp-10-15-20 Moxon tri-band beam, based on a diagram by HB9DSP on the "Making Antennas for Amateur Radio" facebook group
moxon-tri-10-15-20 Moxon tri-band beam, based on a diagram by HB9DSP on the "Making Antennas for Amateur Radio" facebook group
moxon-tri-vo-10-15-20 Moxon tri-band beam, with vertical offset, based on a diagram by HB9DSP on the "Making Antennas for Amateur Radio" facebook group
multi-loop-doublet-radcom-aug-2019 Broadband multi-loop dipole for 14-30MHz, based on the Radcom August 2019 design
ocfd-10-12-17-20-40-80 Off centre fed multiband antenna, based a diagram in "Making Antennas for Amateur Radio" Facebook group by Chuck McAllen
ocfd-10-20-40-windom Off centre fed multiband antenna, based on discussion about the Windom antenna - Needs a 5:1 balun
ocfd-17 Open loop off centre for 17m, based on https://rsars.files.wordpress.com/2013/01/4-band-20-17-15-10m-cola-g8ode-iss-1-0.pdf
ocfd-20m Open loop off centre for 20m, based on https://rsars.files.wordpress.com/2013/01/4-band-20-17-15-10m-cola-g8ode-iss-1-0.pdf
orig-folded-multi Folded multiband dipole (40/20/17/15/11/10m), based on http://sm0vpo.altervista.org/antennas/small-hf-ant.htm
qha-noaa Quadrifilar helicoidal antenna for the NOAA satellites, an nec2 helix and arc example with comments
quad-vert-40m Vertical folded halo for 40m, scaled from the Cobwebb 20m loop
round-halo-2m Circular halo for 2m, based on construction in http://fedler.com/radio/2m_loop.htm
s-open-loop-20m Bruce array S for 20m, a pair of 3/4 wave open boxes, needs 4:1 balun
skeleton-slot-2m Circular skeleton Slot Antenna for 2m. at 145MHz, SWR 1:1.48, Peak gain 6.57dBi
skyhopper-3el-40m 3-element skyhopper for 40m, based on calulations from the program on http://www.ve3sqb.com/ gives 5.46dBi forward gain
skywire-40m Horizontal full length loop for 40m, based on dimensions from http://www.n1su.com/loop.html, needs 4:1 balun
skywire-80m Horizontal full length loop for 80m, based on dimensions from http://www.n1su.com/loop.html, needs 2:3 balun
sloop-10-15-20-40 "One Masted Sloop" by KI8GX, based on https://f5nhj.fr/pdf/onemastedloop.pdf
slot-cube-2m Slot cube antenna from http://www.w6nbc.com/articles/2019-01QSTcubeslot.pdf, reasonably omni-directional, with 5.46dBi gain
slot-cube-stacked-2m Dual stacked Slot cube antenna based on http://www.w6nbc.com/articles/2019-01QSTcubeslot.pdf
sq-halo-10-12-15-17-20 Square halo from speaker cable for 10m/12m/15m/17m/20m
sq-halo-10-20 Dual band square halo for 10m and 20m, based on https://www.pa9x.com/how-to-build-10-and-20-meter-band-square-halo-antenna/
sq-halo-20-40 Square halo from speaker cable for 20m/14.1MHz and 40m/7.1MHz
sq-halo-20 Square halo for 20m, based on https://www.pa9x.com/how-to-build-10-and-20-meter-band-square-halo-antenna/
sq-halo-40-rect-offset Horizontal folded dipole/halo for 40m with offset feedpoint, scaled from the cobwebb 20m loop
sq-halo-40-rect Horizontal folded dipole/halo for 40m, scaled from the cobwebb 20m loop
sq-halo-40 Quad halo for 40m, based on dimensions from spreadsheet
sq-halo-4m-dual-diagonal Square halo for 4m, based on https://www.g0ksc.co.uk/2013-yagis/all-quads/sc0404q.html
sq-halo-4m-dual-stack Dual square halo, for 2m and 4m, based on https://www.pa9x.com/how-to-build-10-and-20-meter-band-square-halo-antenna/
sq-halo-4m-quad-stack Quad-stacked square halo for 4m (10cm between loops), based on https://www.g0ksc.co.uk/2013-yagis/all-quads/sc0404q.html
tefv-mb End fed inverted V with 9:1 balun and matching resistor - Really inefficient!
tri-2m-wimo Tri WIMO for 2m based on a sketch on a Facebook group
tri-70cm-wimo Tri WIMO for 70cm based on a sketch on a Facebook group
tri-dipole-2m Tri dipole for 2m based on a sketch on http://on5au.be/content/amod/amod145.html, for series (150ohm) tri-dipole
v-10w5b-star-10-15-20-40-80 5 band Horizontal/Inverted-V for 15/20/30/40/80, with tall centre pole, 10-wire 4-pole star arrangement
v-10w6b-cross-10-15-20-40-80-160 Hex-band Horizontal/Inverted-V for 10/15/20/40/80/160m, with tall centre pole, two wires on 2 legs, 3 wires on 2 legs, in a 10 wire, 4-pole X arrangement
v-12w6b-cross-10-15-20-40-80-160 Hex-band Horizontal/Inverted-V for 15/20/30/40/80/160m, with tall centre pole, three wires per leg 12-wire 4-pole X arrangement
v-12w6b-cross-10-20-30-40-80-160 Hex-band Horizontal/Inverted-V for 15/20/30/40/80/160m, with tall centre pole, three wires per leg 12-wire 4-pole X arrangement
v-2w1b-classic-160m Classic Inverted V for 160m, taller centre pole shorter outer poles, with mid-span supports
v-2w1b-classic-20m Classic Inverted V for 20m, taller centre pole shorter outer poles
v-2w1b-classic-2m Classic top fed Inverted V for 2m
v-2w1b-classic-40m Classic Inverted V for 40m, taller centre pole shorter outer poles
v-2w1b-horiz-160m L shaped Inverted V for 160m, taller centre pole shorter outer poles, with mid-span supports
v-2w1b-horiz-2200m Horizontal V, for 2200m
v-2w1b-horiz-40m Horizontal/Inverted V for 40m, with taller centre pole
v-2w1b-tri-40m Horizontal/Inverted V for 40m, with taller centre pole and triple 1/2 wave per leg
v-3w2b-tee-80-160 Dual inverted V as T with shared leg
v-4w2b-cross-20-40 Dual Horizontal/Inverted V for 80/40m, with taller centre pole, in X arrangement
v-4w2b-cross-40-80 Dual-band Horizontal/Inverted-V for 80/40m, with tall centre pole in a 4-pole X arrangement
v-4w2b-cross-80-160 Dual-band horizontal/Inverted V for 160/80m, with taller centre pole, and 4-pole X arrangement
v-4w2b-cross-halo-15-20-40-80 Quad-band Horizontal/Inverted-V for 80/40m, with dual band halo underneath, tall centre pole in a 4-pole X arrangement
v-4w3b-cross-20-40-80 Horizontal/Inverted V for 80/40/20m, with tall centre pole, shared 4-wire/4-pole cross arrangement
v-4w3b-dual-20-40-80 Tri-band horizontal V for 80/40/20m, with tall centre pole, uses 4 wires / 2 legs
v-4w3b-dual-40-80-160 Tri-band horizontal V for 80/40/20m, with tall centre pole, Uses 4 wires / 2 legs
v-4wmb-cross-246-281 Horizontal/Inverted V using overly long wires 3rd harminic multiband coverage, tall centre pole with 4-wires to 4-poles in a cross arrangement
v-4wmb-cross-266-295 Horizontal/Inverted V using overly long wires 3rd harminic multiband coverage, tall centre pole with 4-wires to 4-poles in a cross arrangement
v-6w3b-cross-20-40-80 Tri-band Horizontal V for 80/40/20m, with tall centre pole, two wires on the long legs in a 4-pole X arrangement
v-6w3b-star-20-40-80 Tri-Band Horizontal V for 80/40/20m, tall centre pole, and 6 pole star arrangement at 60 degree intervals
v-6w3b-star-40-80-160 Tri-Band Horizontal/Inverted V for 160/80/40m, tall centre pole, and 6 pole star arrangement at 60 degree intervals
v-6w4b-cross-15-20-40-80 Quad-Band Horizontal/Inverted V for 80/40/20/15m, tall centre pole, and cross arrangement, with sparse 6 wires
v-8w4b-cross-10-20-40-80 Quad-band Horizontal/Inverted-V for 80/40/20/10m, with tall centre pole, two wires per leg 8-wire 4-pole X arrangement
v-8w4b-cross-15-20-40-80 Quad-band Horizontal/Inverted-V for 80/40/20/15m, with tall centre pole, two wires per leg in a 4-pole X arrangement
v-8w4b-star-15-20-40-80 Quad-band Horizontal/Inverted-V for 80/40/20/15m, with tall centre pole, 4 long legs in a 4-pole X arrangement, with 4 extra wires at 45 degrees (near centre pole)
v-8w6b-cross-10-15-20-40-80-160 Hex-band Horizontal/Inverted-V for 160/80/40/20/15/10m, with tall centre pole, only two wires per leg 8-wire 4-pole X arrangement
v-8w6b-cross-10-20-30-40-80-160 Hex-band Horizontal/Inverted-V for 160/80/40/30/20/15m, with tall centre pole, only two wires per leg 8-wire 4-pole X arrangement
v-double-quarter-40 A horizonal V, each leg has a pair of quarter-wave, with a quarter-wave phasing droop in the middle
v-trap-40-20 Simple 20m / 40m inverted V with traps for 40m
vert-dipole-2m Simple vertical Dipole for 2m, needs matching to 600 ohms
vert-quad-4m Vertical 15mm water pipe quad for 4m, using the dimensions from https://www.g0ksc.co.uk/2013-yagis/all-quads/sc0404q.html
vp2e-20m Vertically Polarized 2 Element antenna for 20m
w8jk Folded dipole for 80m, based on http://www.hard-core-dx.com/nordicdx/antenna/wire/w8jk.html, expects 9:1 balun, so 5.5555 ohms
wd330 HF Folded dipole, based on WD330 - https://www.diamond-ant.co.jp/english/commercial/com_6dipole.html
wire-2el-40m-20m twin wire Inverted V 40m and 20m
wire-yagi-2el-40m Inverted V wire yagi - 2 element 40m - Based on dimensions from https://practicalantennas.com/designs/parasitic/wireyagi/
wire-yagi-4el-40m Inverted V wire yagi - 4 element 40m - Based on dimensions from https://practicalantennas.com/designs/parasitic/wireyagi/
zl-mini-quad-20m ZL Mini quad for 20m, based on based on discussion by G3PHO/ZL2BDA of his 1968 design

The Roger Writes series

I research / dabble with lots of things, and figured that if I write my notes here, I can quickly reference them, also, sometimes, they are useful to others!
Here is what I have so far:

Cosplay Arduino programming (RW#13 - June 2024)
ATU-100 modifications (RW#12 - February 2024)
Garage door open warning (RW#11 - January 2024)
Horizontal Halos and Vs (RW#10 - December 2023)
Faking Dell PSUs (RW#9 - December 2023)
Designing NEC2 antennas (RW#8 - November 2023)
4NEC2 antenna models (RW#7 - October 2023)
3-element cubical quad for 2m (RW#6 - September 2023)
Cobwebb Antenna dimensions (RW#5 - August 2023)
WS2812 and similar 'Smart' LEDs (RW#4 - January 2023)
Investigation and details of the AFHDS-2A protocol (RW#3 - June 2022)
Changes we've made to our caravan (RW#2 - January 2022)
Basic solar/battery/off-grid calculations (RW#1 - January 2022)
Credit card size walking robot aka Monster-Chan (RW#0 - Originally 2016 - Moved here 2022)
Why you should avoid certain number of drives with ZFS (aka why isn't my ZFS/raidz array the size I expected)
Simple way to connect a Servo to a PC (RS232 port)
Using ZFS with FreeBSD

Homepage.
This page was lasted updated on Saturday, 20-Apr-2024 11:56:47 BST