Page 1
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Antenna Modeling “101” Based on ARRL Antenna Book SW
Much cheaper (and faster) than (re)building them!
Larry Banks, W1DYJ
First licensed: 1962 (KN1VFX)
W1DYJ since 1966 – Amateur Extra
10 Matthews Way Harpswell ME
33 Blueberry Hill Road Woburn MA
Page 2
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Agenda
• Some W1DYJ background
• A brief view of ARRL Software
• ARRL Handbook
• ON4UN’s Low Band DXing
• The Antenna Book
• TLW
• YW
• HFTA
• EZNEC
Page 2
And hopefully you will learn
some theory and gain some
understanding about
antennas in general…
Page 3
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
An antenna story ~ the Gotham V80 (1962)
Page 3
• New novice KN1VFX
• My first antenna for 80M
• $16.95 was “big bucks” for a
sophomore in HS in 1962
A 1962 QST
Advertisement
Page 4
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
An antenna story ~ the Gotham V80 (1962)
Page 4
• New novice KN1VFX
• My first antenna for 80M
• 16.95 was “big bucks” for a sophomore in HS
in 1962
• I knew nothing about antennas
• Never worked – Best DX was a 40M OO
report: “Out of Band”
• Have not believed advertisements since!
• I also now believe you need to understand
the physics of antennas
modeling
Page 5
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
33 Blueberry Hill Rd -- Woburn
Page 5
Page 6
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
33 Blueberry Hill Rd -- Woburn
Page 6
Page 7
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
33 Blueberry Hill Rd -- Woburn
Page 7
Page 8
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Agenda
• Some W1DYJ background
• A brief view of ARRL Software
• ARRL Handbook
• ON4UN’s Low Band DXing
• The Antenna Book
• TLW
• YW
• HFTA
• EZNEC
Page 8
Page 9
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
SW: ARRL Handbook (89th Edition ~ 2012)
• TubeCalculator Design tube-type High Power linears
• ClassE Designs single-ended Class E RF amplifier
• Diplexer Designs both high-pass/low-pass and
band-pass/band-stop types of diplexers
• Helical Designs and analyzes helical-resonator bandpass filters
usually used in VHF and UHF
• Elsie A lumped-element filter design and analysis program (the student edition)
• MeterBasic Designs and prints professional-quality analog meter scales
• OptLowpass Designs and analyzes transmitter output low-pass filters
• PIEL Designs and analyzes pi-L networks for transmitter output
• QuadNet Designs and analyzes active quadrature networks
• SVCFilter Standard-value component routine to design low-pass and high-pass
filters
• Supplemental Files Additional discussion, additional projects, full-size PC board etching patterns, program examples and other useful information
Page 9
Page 10
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
SW: ARRL OH4UN’s Low Band Dxing (4th Edition ~ 2005-2007)
• Conversion_calculator Excel spreadsheet that converts signal levels
typically encountered at receiver inputs between μV, mV, dBμV, μW, etc
• Receiver_Levels Excel spreadsheet tool shows you levels
involved with radio signals from transmit power to received signal
• RX_noise_figure_and_MDS_calculation Excel spreadsheet tool shows you the
relation between receiver bandwidth, temperature and receiver MDS
• ON4UN Low-Band DXing Software (DOS) Propagation Software; Mutual Impedance and
Driving Impedance; Coax Transformer/Smith Chart; Impedance, Current and Voltage Along Feed Lines;
Two- and Four-Element Vertical Arrays; The L Network; Series/Shunt Input L-Network Iteration;
Shunt/Series Impedance Network; Line Stretcher (Pi and T) Stub Matching; Parallel Impedances
(T Junction); SWR Value and SWR Iteration; Radiation Angle for Horizontal Antennas; Coil Calculation;
Gamma-Omega and Hairpin Matching; Element Taper
• ON4UN-Yagi-Design (DOS) The Analyze Module; Generic Dimensions;
Element Strength; Element Taper; Mechanical Yagi Balance; Yagi Wind Area; Matching;
Optimize Gamma/Omega; Feed-Line Analysis; Rotating Mast Calculation
Page 10
Page 11
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
SW: ARRL Antenna Book (23rd Edition ~ 2015)
• TLW Computes parameters for transmission lines and antenna-tuner
• YW Computes parameters for Yagi-Uda antennas
• HFTA Evaluates the effect of local terrain on the launch of HF signals
• Plus Supplemental Files on the CD
• EZNEC 6 General Antenna Modeling SW (on Web)
• Many of the apps from previous editions are available at: www.arrl.org/antenna-book
• AAT Automatically evaluates antenna tuner networks
• Arrayfeed1 Computes parameters necessary for feeding 2-element and 4-element phased-arrays.
• GAMMA Computes the parameters for a gamma match
• LPCAD30 For computing LPDA designs
• MOBILE Evaluating and designing mobile whip antennas and coils
• Range-Bearing Computes the range/bearing from one lat/lon point to another
• SCALE Scales Yagi designs to other frequencies
Page 11
Page 12
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Agenda
• Some W1DYJ background
• A brief view of ARRL Software
• ARRL Handbook
• ON4UN’s Low Band DXing
• The Antenna Book
• TLW
• YW
• HFTA
• EZNEC
Page 12
Page 13
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
TLW – Transmission Line
Program for Windows R. Dean Straw ~ N6BV ©ARRL
Page 13
Basic Purpose: • Input = cable type, frequency, and dimensions,
and load impedance
• Output = SWR at input, load, and feedline loss
Page 14
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
SWR = 1.09:1
TLW – Transmission Line Program for Windows
Page 14
Question: Which is the better situation?
440 Dipole @ 100’
Coax Feed
System
SWR = 1.38:1
50W FM
440 Dipole @ 100’
Coax Feed
System
SWR = 1.02:1
440 Dipole @ 100’
Coax Feed
System
Page 15
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
TLW – Transmission Line Program for Windows
Page 15
Answer: Beware the Myth of low SWR!
440 Dipole @ 100’
100’ Andrew LDF6-50A
1 ¼” Heliax
Total Loss = 0.734 dB
(SWR loss = 0.044 dB)
SWR = 1.38:1
Ndb = 10Log10 (P2/P1)
P A = PT (10N/10)
100’ RG-58A
(Beldon 8259)
Total Loss = 13.885 dB
(SWR loss = 0.154 dB)
440 Dipole @ 100’
42 W 2 W
And it affects
the received
S/N too!
50W FM
440 Dipole @ 100’
0 W
100’ RG-58A
(Beldon 8259)
Total Loss = 80.714 dB
(SWR loss = 66.983 dB)
SWR = 1.09:1 SWR = 1.02:1
SHORTED!
Page 16
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
TLW – Transmission Line Program for Windows
Page 16
(1) Choose
cable type
(2) Choose
cable length
(3) Specify
frequency
(4) Enter load (antenna)
impedance
(5) The Results
Page 17
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
TLW – Transmission Line Program for Windows
Page 17
Coax SWR
@70cm
Loss
@70cm
Delivered Power
70cm
1 ¼” Heliax 1.38:1 0.734 dB 42 W
½ ” Heliax 1.31:1 1.544 dB 35 W
LMR 400 “RG8” 1.22:1 2.843 dB 26 W
8267 RG213 1.12:1 5.283 dB 15 W
LMR 240”RG8X” 1.12:1 5.377 dB 14 W
LMR 200 “RG58” 1.08:1 7.142 dB 10 W
9258 “RG8X” 1.05:1 9.081 dB 6 W
8259 “RG58A” 1.02:1 13.885 dB 2 W
50 W @ Transmitter / 100’ Coax
Page 18
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
TLW – Transmission Line Program for Windows
Page 18
Coax SWR
@70cm
Loss
@70cm
Delivered Power
70cm 2M 10M 80M
1 ¼” Heliax 1.38:1 0.734 dB 42 W 46 48 49
½ ” Heliax 1.31:1 1.544 dB 35 W 41 45 49
LMR 400 “RG8” 1.22:1 2.843 dB 26 W 34 40 47
8267 RG213 1.12:1 5.283 dB 15 W 25 34 46
LMR 240”RG8X” 1.12:1 5.377 dB 14 W 25 33 45
LMR 200 “RG58” 1.08:1 7.142 dB 10 W 19 28 43
9258 “RG8X” 1.05:1 9.081 dB 6 W 16 27 43
8259 “RG58A” 1.02:1 13.885 dB 2 W 2 19 41
50 W @ Transmitter / 100’ Coax
Page 19
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
TLW – Transmission Line Program for Windows
Page 19
Left to you for Homework…
If you know the impedance in
your shack, you can estimate the load impedance
You can use TLW to help you design
a TransMatch.
NOTE: Antenna Tuners
DO NOT tune anything!
You can look at the Voltage,
Current, Resistance, and
Reactance on the transmission line
Page 20
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
TLW – Transmission Line Program
for Windows
Page 20
Helps you understand and design your
Antenna System
Page 21
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Agenda
• Some W1DYJ background
• A brief view of ARRL Software
• ARRL Handbook
• ON4UN’s Low Band DXing
• The Antenna Book
• TLW
• YW
• HFTA
• EZNEC
Page 21
Page 22
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW – Yagi for Windows R. Dean Straw ~ N6BV ©ARRL
Page 22
Purpose: • Input = dimensions of traditional monoband Yagis
• Output = graphs/patterns of Gain, F/R, SWR
Page 23
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW – Yagi for Windows
Page 23
Description • Similar to earlier DOS based program: YO from Brian Beezley, K6STI
• Computes Gain, worse-case F/R, SWR, E- & H-plane patterns
• Generates on-screen graphs
• Results compare closely with YO, EZNEC, NEC-Win Plus, NEC-4
• Runs much faster
• Includes design files for 80+ Yagi designs included in ARRL Antenna Book
Limitations • Works only for “traditional” monoband Yagis
• Evaluations done over flat “perfect” ground
• Not accurate below height of λ/8
• Not accurate in stacks, near other antennas, etc.
• Does not generate output data files
• No optimization routine – like YO
Page 24
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi on 24’ boom
Page 24
5 El ~ 10M 24' boom YagiBased on ARRL Antenna Book,
17th edition, 1994, p11-10
lwb:\ham\ant\10M_5EL.vsd
14 April 2000
p.1
10' 5' 0
7'
1'
0
1.5"od Al Boom
24' long
(4 pieces 6' long)
3/4"od x 4'
Al tubing, typ.
5/8"od x 21"
Al tubing, typ.
Rivited,
4 places,
3" overlap, typ.
1/2"od
Al tubing
Slotted, w/stainless
steel clamp
4"-6" overlap, typ.
Parts List:
(5) 4" x 4" x 0.190" AL plates
(10) 3/4" U-bolts
(10) 1.5" U-bolts
(10) #8 SS self-tapping screws
(5) 6'" x 3/4" od AL tubing (cut into 5x48" lengths)
(40) pop rivits
(4) 6' x 5/8" od Al tubing (cut into 10x21" lengths)
(10) SS hose clamps
(10) 6' x 1/2" od AL tubing (cut into 10 specific
lengths)
(4) 6' x 1 1/2" od Al boom
(1) 6' x 1 3/8" od Al Boom (cut into 2x9", 3x18")
(6) SS 1/4" x 2 1/2" bolts
1'2'15'20'25' 24'
2'
3'
4'
5'
6'
8'
9'
1'
2'
3'
4'
5'
6'
7'
8'
9'
3"
Element to Boom Plate
4' x4"
5 Pieces
24"
18"
36"72"171"
50.75"
(57" overall)
55"
(61" overall)
57.125"
(62" overall)
58"
(63" overall)
65.625"
(72" overall)
282"
D3
15' 5 1/2"
D2
16' 2"
D1
16' 6 1/4"
DE
16' 8"
REF
17' 11 1/4"
Splice Detail, typ.
18" 1 3/8" AL
2 1/2" x 1/4"
SS bolts @ 7"
from splice
9" 1 3/8" AL
End Detail, typ.
#8 x 1" SS
self-tapping
screws
Boom to
Mast Plate
This is my
10M Yagi,
based on
the ARRL
example.
Page 25
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 25
Initial Screen
Page 26
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 26
Start with one of the
included files
This is my 10M Yagi K1FO 40el / 432MHz
K1FO 22el / 432MHz
8el / 6M / 36’ boom
Page 27
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 27
Free Space Results
Gain (dBi)
F/R (dB)
SWR
Free Space, unmatched
Page 28
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 28
Free Space Results
Enter Yagi height
Page 29
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 29
Free Space
Note that Gain has increased,
@ 16°elevation angle.
SWR unchanged - Now we need to match it
30’ High, unmatched
Page 30
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 30
Match it (Gamma Match)
Z=0 Z= Z=50
Page 31
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 31
SWR is “tamed”.
30’ high, matched
Page 32
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 32
1
2
3
4
5
6
7
27.5
0
27.6
0
27.7
0
27.8
0
27.9
0
28.0
0
28.1
0
28.2
0
28.3
0
28.4
0
28.5
0
28.6
0
28.7
0
28.8
0
28.9
0
29.0
0
29.1
0
29.2
0
29.3
0
29.4
0
29.5
0
29.6
0
29.7
0
29.8
0
29.9
0
30.0
0 CW TECH FM
W1DYJ 10M Yagi SWR
Autek 5/2000
Autek 11/2010
Autek 12/2014
Autek Smoothed
MFJ949E @ 10W
FoxDelta AAZ914
Band
Compare to Actuals
27.5 MHz. 30MHz.
Page 33
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 33
Plot the patterns
SWR is NOT
the only
criteria!
Page 34
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 34
30’ high, matched
Antennas are PASSIVE – they generate
“gain” by redirecting the RF.
Page 35
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 35
30’ high, matched
POLAR Plot Same Data CARTESIAN (Azim/Elev Plot)
Elevation
Azimuth
Page 36
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 36
30’ high 15’ high
45’ high 11°peak
16°peak
26°peak
60’ high
8°
peak
Idealized pattern at different heights
Page 37
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example:
What’s really going on with different heights?
Page 37
© ARRL
Antenna Book
Page 38
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example:
What’s really going on with different heights?
Page 38
C
Page 39
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW Example: 5el 10M yagi
Page 39
Change Elements
YW does not have the “automatic” optimization routine that YO had.
Element <> Boom Plate
Position on Boom
Element
Diameter
Element
Length
Elements
Page 40
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
YW – Yagi for Windows
Page 40
Helps you understand/design your
monoband Yagis,
but – assumes flat, perfect ground
Page 41
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Agenda
• Some W1DYJ background
• A brief view of ARRL Software
• ARRL Handbook
• ON4UN’s Low Band DXing
• The Antenna Book
• TLW
• YW
• HFTA
• EZNEC
Page 41
Page 42
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain
Assessment R. Dean Straw ~ N6BV ©ARRL
Page 42
Purpose:
Assesses the effect of uneven local terrain on the
transmission and reception of HF signals.
Page 43
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain Assessment
Page 43
Agenda
• Problem / Description / Limitations
• What are Elevation Statistics?
• What are Terrain Files?
• Using HFTA
• Example — My 10M yagi in MA
• DX Azimuths
• My Local Terrain
• 10M Yagi Results
Page 44
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain Assessment
Page 44
What problem does HFTA attempt to solve?
Fig 14.30 ©ARRL Antenna Book
Fig 14.29 ©ARRL Antenna Book
Page 45
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain Assessment
Page 45
Description • HFTA is a ray-tracing program designed to evaluate the effect of foreground terrain
on the elevation pattern of up to four multi-element HF monoband Yagis in a stack.
• Models horizontally polarized Yagis, “works” with simple horizontal dipoles
• Takes into account the effects of Fresnel horizontal ground-reflection
• Takes into account diffraction
• Includes Elevation Statistics Files ~ at what angle the RF comes from
• Latest version of earlier “YT” program
Limitations
• Does not work with vertical polarization
• Free-space gain assumed for the default four-element Yagi model is 8.5 dBi
• Does not take into account mutual impedance ground effects
Additional Requirement • Requires a Terrain Data File ~ used to be a pain, now it’s easy!
Page 46
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain Assessment
Page 46
Agenda
• Problem / Description / Limitations
• What are Elevation Statistics?
• What are Terrain Files?
• Using HFTA
• Example -- My 10M yagi in MA
• DX Azimuths
• My Local Terrain
• 10M Yagi Results
Page 47
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Elevation Statistics
Page 47
Fundamentally Where is the DX? At what angle (from the horizon) does the RF arrive?
We must always remember this simple truth:
The ionosphere controls the elevation angles of the
RF we receive at our location, not our antenna!
Page 48
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA ~ Elevation Statistics Example: 80M: EU MA
Page 48
The angle the RF arrives from.
Frequency
Elevation File:
W1-MA <-> Europe
(There are MANY files
included with the SW.)
The
percentage
of time the
RF is at
this arrival
angle.
Example:
About 8.5% of the time,
80M RF from Europe arrives
at an angle of 13°
Note:
The statistical
data is an
overall average
of all time; i.e.
for any time,
any day, any
season, any
part of the 11-
year sunspot
cycle.
Specific
propagation
“today” will be
very limited in
angle.
Conclusion, from this one graph:
About 80% of the time, European 80M RF arrives at arrival angles between 5 22°
Page 49
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA ~ Elevation Statistics Example: 20M in MA
Page 49
4-18°
2-15°
3-10°
3-15°
Europe
Africa
S. America
Japan
Page 50
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain Assessment
Page 50
Agenda
• Problem / Description / Limitations
• What are Elevation Statistics?
• What are Terrain Files?
• Using HFTA
• Example -- My 10M yagi in MA
• DX Azimuths
• My Local Terrain
• 10M Yagi Results
Page 51
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Terrain File Unique to your location
Page 51
360 ASCII files that describe
the terrain in all directions
from your antenna site.
It used to be difficult to obtain:
• Measure from a topo map
• Pull from xxx.gov web site
• Use MicoDEM to generate
Now it’s easy:
• http://k6tu.net/
• Create a free account
• >> HF Terrain Analysis • At bottom under “Documentation”
• Read directions & request a Profile
• Download
Page 52
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain Assessment
Page 52
Agenda
• Problem / Description / Limitations
• What are Elevation Statistics?
• What are Terrain Files?
• Using HFTA
• Example -- My 10M yagi in MA
• DX Azimuths
• My Local Terrain
• 10M Yagi Results
Page 53
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Using HFTA
Page 53
Initial Screen
Enter the frequency of interest
Select your terrain,
antennas, & heights
Choose one of HFTA’s elevation
files
Page 54
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Using HFTA
Page 54
Select Antenna Types & Heights
Clicking here opens up the folder with your terrain files Then select the
antenna type… …and enter the
height
Page 55
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Using HFTA
Page 55
Enter Freq. / Select Elevation File
&
Plot Terrain
Elevation File:
W1-MA <=> Europe
Page 56
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Using HFTA
Page 56
Enter Freq. / Select Elevation File
&
Plot Terrain
Elevation File:
W1-MA <=> Europe
Finally: Compute
Page 57
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Using HFTA
Page 57
Finally: Compute
Figure of Merit (dBi):
Weighted statistical average
of gain times % open.
Page 58
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain Assessment
Page 58
Agenda
• Problem / Description / Limitations
• What are Elevation Statistics?
• What are Terrain Files?
• Using HFTA
• Example -- My 10M yagi in MA
• DX Azimuths
• My Local Terrain
• 10M Yagi Results
Page 59
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
DX Azimuths @ 33 BBHR
Page 59
10,000 ft
5,000 ft
Delorme Topo USA
Page 60
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
33 BBHR 3D Maps
Page 60
Note: Vertical dimensions are enhanced by a factor of 8 Delorme Topo USA
Looking North Looking South
Looking West Looking East
Page 61
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – Local Terrain @ 33 BBHR
Page 61
31° India 53° England 70° Spain
110° South Africa 154° French Guiana 177° Argentina 181° Chile
249° New Zealand 270° California 337° Japan 300° Australia
35° Iceland / EurRussia
Page 62
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA– HB 5 el 10M Yagi @ 33 BBHR
Page 62
53° England Note: Antennas are IN FRONT of Hill
177° Argentina Note: Antennas are BEHIND Hill
337° Japan Note: Antennas are IN FRONT of Hill
Page 63
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
HFTA – High Frequency Terrain
Assessment
Page 63
Lots of steps. Uses standard Yagis. Helps
you understand your local terrain’s effects
to plan/assess your antenna system.
Page 64
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Agenda
• Some W1DYJ background
• A brief view of ARRL Software
• ARRL Handbook
• ON4UN’s Low Band DXing
• The Antenna Book
• TLW
• YW
• HFTA
• EZNEC
Page 64
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Agenda
• Some W1DYJ background
• A brief view of ARRL Software
• ARRL Handbook
• ON4UN’s Low Band DXing
• The Antenna Book
• TLW
• YW
• HFTA
• EZNEC
Page 65
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC
Page 66
Basic Purpose: from an X-Y-Z “wires”
description of an antenna, generate tabular and
graphical outputs of SWR, far field response,
RF antenna currents, etc.
Page 67
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Agenda
• NEC Numerical Electromagnetics Code and NEC Software
• EZNEC Inputs & Outputs (Simple 40M dipole)
• Ground Characteristics
• EZNEC Example (40M Vertical)
Page 67
Page 68
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
NEC Software NEC: Numerical Electromagnetics Code
• Uses a Method of Moments algorithm (fields from many mutually-coupled straight-line
segments are evaluated and vector-summed)
• NEC-2 (1980) – available to the public and free
• NEC-4 (1992) v4.2 (2011) (requires license: $300+ from Lawrence Livermore Labs)
• fixes stepped wires; wire junction; ground issues, etc.
EZNEC 6 W7EL’s (ROY LEWALLEN) website: http://eznec.com
• EZNEC v.6.0 Demo Version (20 segments) (free) NEC-2
• EZNEC v.6.0 (500 segments) $99 NEC-2
• EZNEC+ v. 6.0 (2000 segments + more features) $149 NEC-2
• EZNEC Pro/2 v.6.0 (45,000 segments + more features) $525 NEC-2
• EZNEC Pro/4 v.6.0 (+ requires NEC-4 license) $625 NEC-4
Other NEC Shells or Wrappers
• NEC-Win Plus/Pro, MultiNec, MMANA, 4nec2 (free), MiniNEC
Page 68
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Agenda
• NEC Numerical Electromagnetics Code and NEC Software
• EZNEC Inputs & Output (Simple 40M dipole)
• Ground Characteristics
• EZNEC Example (40M Vertical)
Page 69
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Inputs ~ 40M dipole @ 18 feet
Page 70
Start by entering the antenna dimensions in Cartesian coordinates
Add a source
Best to start in Free Space
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Inputs ~ 40M dipole
Page 71
The “usual” equation
L = 468 / F
468 / 7.05
~66.38 ft 67 ft
Z
X
Y +18’ +33.5’
-33.5’
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Output ~ 40M dipole
Page 72
Free Space
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Output ~ 40M dipole
Page 73
F = 7.13 MHz
SWR = 1.44:1
Z = 71.79 – j 3.12 Ω
Tweak Length:
FOLD = 7.13 MHz FNEW = 7.05 MHz FDELTA = 0.08 MHz
LNEW = LOLD * (1 + 0.08/7.13) = 33’ 11” [33.9”]
F = 7.05 MHz SWR = 1.44:1
Z = 71.91 –j 1.673
Free Space
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Output ~ 40M dipole 7.05 MHz
Page 74
Free Space
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Output ~ 40M dipole
Page 75
Free Space
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Output ~ 40M dipole @ 15M?
Page 76
7.05 MHz 1.44:1
21.5 MHz 2.11:1
7 MHz = 1.5:1 7.3 MHz = 2.6:1
21 MHz = 4.62:1 21.45 MHz = 2.13:1
Free Space
Page 77
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Output ~ 40M dipole 21.1 MHz
Page 77
Free Space
Page 78
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Output ~ 40M dipole 21.1 MHz
Page 78
Free Space
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Agenda
• NEC Numerical Electromagnetics Code Software
• EZNEC Inputs & Output (Simple 40M dipole)
• Ground Characteristics
• EZNEC Example (40M Vertical)
Page 79
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – EZNEC inputs
Page 80
So far, this has been in “Free Space” – which doesn’t exist here on earth.
Click on Ground Type
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – EZNEC inputs
Page 81
Choices change…
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – EZNEC inputs
Page 82
Choices change… Click on Options Default Ground Construction
Page 83
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – EZNEC inputs
Page 83
What you see in most QST articles
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – EZNEC inputs
Page 84
What you see in most QST articles
What we on the New England coast are
!!!
Page 85
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – Change Ground
Page 85
21.5 MHz
Free
Space
7.05 MHz
90°2.12 dBi 40°3.0 dBi
A dipole (0 dBd) = 2.12 dBi
Page 86
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – Change Ground
Page 86
21.5 MHz
Free
Space
7.05 MHz
6.95 MHz 21.5 MHz
18’
.005 S/m
DC=13 30°6.64 dBi 90°5.47 dBi
90°2.12 dBi 40°3.0 dBi
Page 87
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – Change Ground
Page 87
21.5 MHz
Free
Space
7.05 MHz
6.95 MHz 21.5 MHz
18’
.005 S/m
DC=13
18’
.002 S/m
DC=10
7.00 MHz 21.5 MHz
30°6.64 dBi 90°5.47 dBi
30°6.43 dBi
90°2.12 dBi 40°3.0 dBi
90°4.76 dBi
Page 88
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – Change Height
Page 88
18’
.002 S/m
DC=10
7.00 MHz 21.5 MHz
~3/20 λ ~2/5 λ
30°6.43 dBi 90°4.76 dBi
Page 89
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – Change Height
Page 89
18’
.002 S/m
DC=10
7.00 MHz 21.5 MHz
7.00 MHz 21.5 MHz
40’
.002 S/m
DC=10
50°5.64 dBi 15°8.35 dBi
~3/10 λ
~3/20 λ ~2/5 λ
~7/8 λ
30°6.43 dBi 90°4.76 dBi
Page 90
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Ground Characteristics – Change Height
Page 90
18’
.002 S/m
DC=10
7.00 MHz 21.5 MHz
7.00 MHz 21.5 MHz
40’
.002 S/m
DC=10
50°5.64 dBi 15°8.35 dBi
66’
.002 S/m
DC=10
7.10 MHz 21.5 MHz
30°7.02 dBi 10°8.8 dBi
~1/2 λ
~3/10 λ
~3/20 λ ~2/5 λ
~7/8 λ
~1½ λ
30°6.43 dBi 90°4.76 dBi
Page 91
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Agenda
• NEC Numerical Electromagnetics Code Software
• EZNEC Inputs & Output (Simple 40M dipole)
• Ground Characteristics
• EZNEC Example (40M Vertical)
A Practical Example in Harpswell, Maine
Page 91
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DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 92
My 2nd QTH in Harpswell, Maine
Situation:
• I had DXCC on 10 / 15 / 20 and was working on 40M
• No tall trees 40M dipole @ 18’ high off my house
• What antenna would work better?
Page 93
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 93
Original 40M dipole: 18’ high: assumes ground = 0.002 S/m; Diel Const = 13
Azimuth @ 45°Elevation
Elevation @ 0°Azimuth Elevation @ 90°Azimuth
4.96 dBi 4.96 dBi
Page 94
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 94
Azimuth @ 30°Elev
Elevation @ 90°Azimuth
8.06 dBi
Elevation @ 0°Azimuth
5.14 dBi
“Perfect” Dipole 1/2 λ high Perfect GND “Perfect” Vertical 120 radials(0.2’)
Page 95
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 95
Azimuth @ 30°Elev
Elevation @ 90°Azimuth
8.06 dBi
Elevation @ 0°Azimuth
5.14 dBi
Vertical w/120 radials vs. dipole @ ½ λ
Perfect Ground
15°
38°
“Perfect” Dipole 1/2 λ high Perfect GND “Perfect” Vertical 120 radials(0.2’)
Page 96
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 96
Azimuth @ 30°Elev Elevation @ 90°Azimuth
7.09 dBi
Elevation @ 0°Azimuth
-0.27 dBi @ 25°
Was 8.06 dBi
Was 5.14 dBi
Ground Characteristics affect
verticals more than horizontals
“Perfect” Dipole 1/2 λ high New England GND “Perfect” Vertical 120 radials(0.2’)
Page 97
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 97
Azimuth @ 30°Elev
Elevation @ 90°Azimuth
7.09 dBi
Elevation @ 0°Azimuth
-0.27 dBi @ 25°
Vertical w/120 radials vs. dipole @ ½ λ
Ground = 0.002/13
“Perfect” Dipole 1/2 λ high New England GND “Perfect” Vertical 120 radials(0.2’)
Page 98
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 98
Elevation @ 0°Azimuth
Elevation @ 90°Azimuth
4.96 dBi -0.27 dBi @ 25°
Vertical w/120 radials
vs. dipole @ 18’
Ground = 0.002/13
25°
18’ Dipole New England GND “Perfect” Vertical 120 radials(0.2’)
Page 99
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
40m Vertical – Radial Choice
Page 99
From the ARRL Antenna Book: Practical Suggestions For Vertical Ground Systems
At least 16 radials should be used if at all possible. Experimental measurements and calculations show that with this number, the loss resistance decreases the antenna efficiency by 30% to 50% for a 0.25 wavelength vertical, depending on soil characteristics. In general, a large number of radials (even though some or all of them must be short) is preferable to a few long radials for a vertical antenna mounted on the ground. a. If you install only 16 radials they need not be very long - 0.1 lambda is sufficient. b. If you have the wire, the space and the patience to lay down 120 radials (optimal configuration), they should be 0.4 lambda long. This radial system will gain about 3 dB over the 16-radial case. c. If you install 36 radials that are 0.15 lambda long, you will lose 1.5 dB compared to optimal configuration.
From QST, March 2010, pp 30-33: An Experimental Look at Ground Systems
for HF Verticals (and references)
Rudy Severns, N6LF
…four elevated radials at a height of 48 inches are within 0.2 dB of 64 radials lying on the ground.
Assume four elevated
radials high enough to
be safe: 10 ft
Page 100
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 100
“Perfect” Vertical New England GND Vertical w/4 raised radials -0.27 dBi @ 25°
Vertical w/4 elevated radials
vs. “Perfect Vertical
Ground = 0.002/13
+0.25 dBi @ 25°
Page 101
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC Example – 40M Vertical [Harpswell, Maine]
Page 101
4.96 dBi
Vertical w/4 elevated radials
vs. dipole @ 18’
Ground = 0.002/13
25°
40°
18’ Dipole New England GND Vertical w/4 raised radials +0.25 dBi @ 25°
Page 102
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
The Actual Antenna
Page 102
1 1/4” 5’6”
7/8” 2’8”
3/4” 2’8”
1/2” 4’9”
1” 5’6”
1 1/8” 5’6”
1 3/8” 6’
5/8” 2’9”
11’6”
22’6”
30’7”
35’4”
17’
25’2”
6’
27’10”
Page 103
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
COMPARE ~ 40M Reality
Page 103
Noise:
Worse on Vertical by ~1-1.5 S-units
Coax feed: Δ = – 0.25 dB @ 7.1 MHz.
Dipole 35’ of RG8x = 0.25 dB @ swr 1.5:1 = .29 dB
Vertical 15’ of RG8x + 105’ of Bury-Flex = 0.5 dB. @ swr 1.5:1 = .55 dB
(12.50)
(7.50)
(2.50)
2.50
7.50
12.50
17.50
22.50
27.50
0 1000 2000 3000 4000 5000 6000 7000
dB
Dif
fere
nce
Distance
Compare: Vertical vs. Dipole
40M Log. (40M)
Page 104
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC:
Lots of functionality left for your homework
Page 104
Page 105
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
EZNEC
Page 105
Complicated, but allows you to model and
discover antennas and compare them to
reality, AND LEARN.
Page 106
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Conclusions
• You Can’t Beat Physics
• Understanding antennas understanding ANTENNA SYSTEMS
• HOW YOU WANT TO USE YOUR ANTENNA
• EFFECTS OF TRANSMISSION LINES
• LOCAL TERRAIN
• GROUND CHARACTERISTICS
• All antennas are COMPROMISES
• All models are SIMPLE EXAMPLES of reality
• Your real antenna WILL NOT MATCH your model
Page 106
Page 107
DXCC WAS VUCC WAC WPX W1DYJ ~ Larry Banks
Antenna Modeling MMRA ~ March 2016
Summary
We’ve looked at:
TLW – Transmission Lines
YW – Simple Yagis
HFTA – Effects of Terrain
EZNEC – Antenna models over “real” ground
We’ve seen how the SW can be used to plan your antenna
systems
Questions???
• Presentation at Bottom of: http://www.qsl.net/w1dyj/
Page 107