This is the 4NEC2 antenna bend model for: 2-Droop Dipole
To use this model:
Below. Highlight and copy (Ctrl C) the program control codes (CM,
CE, SY,etc).
Open Windows Wordpad and copy (Ctrl V) the control codes into Wordpad.
Go to "File, Save as..." and name your new antenna model.
In Windows Explorer, right-click on your new model and "Rename" the file to end as ".nec".
Open your new model to optimize the Length (L=) of the dipole
wire at the Sag Ratio )R=) of interest.
4NEC2 is an NEC2, NEC4, Windows based antenna modeler and optimizer by
Arie Voors.
It is available free of charge at: www.qsl.net/4nec2/
CM 2-Droop Catenary dipole
CM Standardized 1-feed model for using #14 AWG
CM before droop, 1/2 wave height over ground at 28.4 mc. with
7.32 dBi gain
CM Set sag ratio (0.1, 0.2, etc) and optimize wire length
CM Calculates droop width and 10 points for plotting
CM Uses point-to-point approximation based on average ratios
CM Dick Reid, KK4OBI, Dick, 2016
CM
CE
SY hgh=5.2817 '150/28.4=5.2817m =1/2 wl
SY Wire=5.4275 'Optimized length of 1/2 wave
wire dipole 5.1485 meters
SY L=Wire/2 'L=
Length of half wire for each droop arm
SY R= 0.31
'R = Ratio of sag based on resonant length L
:: R=0.001 for no droop
SY G=L*R
'G=depth of Sag (droop) at middle of each arm
SY DS=((L^2-4*G^2)/(4*G))*Log((L+2*G)/(L-2*G)) 'Droop
Span calculation from G and L
SY S=DS/10 'Size of
each of 10 Droop Segments
SY D1=hgh
'Top of the droop
SY D2=hgh-0.386*G 'Droop next to top
SY D3=hgh-0.662*G 'Droop at 2/3rds
SY D4=hgh-0.848*G 'Droop 2nd from bottom
SY D5=hgh-0.957*G 'Droop next to bottom
SY D6=hgh-G
'Bottom of droop
GW 1 5
0 0 D1
s*1 0 D2
#14 'Top start
GW 2 5
s*1 0 D2
s*2 0 D3 #14
GW 3 5
s*2 0 D3
s*3 0 D4 #14
GW 4 5
s*3 0 D4
s*4 0 D5 #14
GW 5 5
s*4 0 D5
s*5 0 D6
#14 'Bottom
GW 6 5
s*5 0 D6
s*6 0 D5
#14 'Bottom
GW 7 5
s*6 0 D5
s*7 0 D4 #14
GW 8 5
s*7 0 D4
s*8 0 D3 #14
GW 9 5
s*8 0 D3
s*9 0 D2 #14
GW 10 5
s*9 0 D2
s*10 0 D1
#14 'Top at end
GW 11 5 0
0 D1
-s*1 0 D2
#14 'Top at start
GW 12 5
-s*1 0 D2
-s*2 0 D3 #14
GW 13 5
-s*2 0 D3
-s*3 0 D4 #14
GW 14 5
-s*3 0 D4
-s*4 0 D5 #14
GW 15 5
-s*4 0 D5
-s*5 0 D6
#14 'Bottom
GW 16 5
-s*5 0 D6
-s*6 0 D5
#14 'Bottom
GW 17 5
-s*6 0 D5
-s*7 0 D4 #14
GW 18 5
-s*7 0 D4
-s*8 0 D3 #14
GW 19 5
-s*8 0 D3
-s*9 0 D2 #14
GW 20 5
-s*9 0 D2
-s*10 0 D1
#14 'Top at end
GE -1
GN 2 0
0 0 14 6.e-3
EK
EX 0 1
1 0 1
0 0 'next to center
FR 0 0
0 0 28.4 0
EN Back