Transcript Document
K9AY Loop Arrays for
Low Band Contesting
Richard C. Jaeger, K4IQJ
May 16, 2013
INTRODUCTION
K4IQJ Interests /Background
Introduction
K9AY Array Comparisons
2-3-4 Element Arrays
4 Element Array Design & Simulation
RDF Definition
Basic K9AY Loop Pair
Array Implementation
Discussion / Observations
Dayton 2013
Dayton 2013
INTRODUCTION
Interests
Low Band Contesting
NAQP CW
ARRL & CQWW 160 Contests
Stew Perry
CW Sprints (Alabama Low Power Record)
DXing
Top of the Honor Roll, Need P5 on CW, CQ WAZ
300+ Countries Worked on 80 – 10
255 Countries Worked on 160M
Dayton 2013
Dayton 2013
INTRODUCTION
Need to Hear Well on 160/80 M
Big Advantage in NAQP and DX Contests
Loops Seem Most Effective Receiving Antennas
in My Locations (Poor Ground Conditions)
Discussed 2-Element Arrays - 2012
Presented 3-Element End-fire Array – 2011
Latest Effort - 4-Element Array (15.1dB RDF)
100 foot spacing (330’ total length)
RDF greater than individual beverages
Dayton 2013
Dayton 2013
BACKGROUND
RDF: Receiving Directivity Factor
Design Goal Here: Maximize RDF
RDFdB = Gfor(dB) - Gavg(dB)
Noise generally comes from all directions
RDF compares the main antenna lobe gain to
the average gain over the whole hemisphere
of the antenna
Attributed to W8JI
Dayton 2013
Dayton 2013
BACKGROUND
Reference Antenna - Short Vertical (20’)
RDFdB = Gfor(dB) - Gavg(dB)
RDF-dBG= 1.0
– (-3.9) = 4.9 dB
RDFdB = Gfor(dB)
(dB)
avg
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Dayton 2013
BACKGROUND
Basic K9AY Loop
•
•
•
•
Signal Arrival
85’ Triangular Loop
25’ High, 30’ Wide
Resistive Termination
Directional Antenna
-
Easily switched in 2
directions
- 4 directions with an
orthogonal pair of loops
• 9:1 Matching Transformer to
Coax
RDFdB = Gfor(dB) - Gavg(dB)
Gary Breed, “The K9AY terminated loop – A compact, directional
receiving
antenna,”
QST, vol.
RDF
= (-24.7)
- (-32.1)
= 81,
7.4no.
dB9, pp. 43-46, September 1997.
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Dayton 2013
LOOP ARRAYS
Multi-Element Endfire Arrays
“Lossy” Antennas
Resistive termination
Little or no mutual coupling
Loops are Broadband –
Usable over a Wide
Frequency Range
Array Output Decreases as
Number of Elements Increases
(-24 dBi) (-40 dBi)
Luis, IV3PRK: “K9AY Loops Always Seem to Work”
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TWO-ELEMENT END-FIRE ARRAY
80’ Spacing – 200o phasing
• Two-Element Array
-
Equal amplitudes
Single phasing line
Rear element lags front
element by > 180o
• Gain: -25.6 dBi
Element 2 Phasing (-200o)
• RDF: 10.5 dB (+3 dB)
• Beam Width: 96o
• W/C F/B: 16.6 dB
• Take Off Angle: 25o
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Dayton
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TWO-ELEMENT END-FIRE
ARRAY
Simulation Results - 160 M
RDF 10.7 dB
Gain
-26.4
dBiDrops
Note: RDF
Falls
as Gain
RDF
dB atdB
45o points
F/B= 7.5
15.2
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Dayton
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LOOP ARRAYS
3 & 4 Element Endfire Arrays
Binomial Endfire Array
Nominal Amplitudes
3 EL (1-2-1)
4 EL (1-3-3-1)
RDF Optimization
(1-2-1) (1-1.84-1)
(1-3-3-1) (1-2.4-2.4-1)
Dayton 2013
LOOP ARRAYS
3 & 4 Element Endfire Arrays
3 Element Array
80’ Spacing
Gain: -29.5 dBi (20o)
Beamwidth: 66o
RDF: 12.5 dB
4 Element Array
100’ Spacing (Sensitivity)
Gain: -35.6 dBi (16o)
Beamwidth: 49o
RDF: 15.1 dB
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K9AY ARRAYS
RDF Comparisons
(1-2.4-2.4-1) (0.42-1-1-0.42)
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ARRAY IMPLEMENTATION
Cross-Fire Feed (W8JI)
From Low Band DXing [3]
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Dayton 2013
ARRAY IMPLEMENTATION
0o Hybrid Combiners
Z
Z
From Low Band DXing [3]
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4 EL ARRAY IMPLEMENTATION
Amplifiergs & Coax Phasing Lines
Desired Gains (Hi-Z Plus-6 Amplifiers)
Elements 1 and 4: 0.42 or -7.5 dB
Elements 2 and 3: 1.00 or 0 dB
Adjust Output Resistance
Output Resistance at 75 W
Desired Phase Delays on 160 M
Element 1: 0o
Element 2: 190o = 180o + 10o
Element 3: 380o = 360o + 20o 20o
Element 4: 570o = 540o + 30o 180o + 30o
Dayton 2013
Dayton 2013
4 EL ARRAY IMPLEMENTATION
Amplifier & Coax Phasing Lines
Desired Phase Delays on 160 M
Element 1: 0o
Element 2: 190o = 180o + 10o
Element 3: 380o = 360o + 20o 20o
Element 4: 570o = 540o + 30o 360o + 180o + 30o
Combiner: DX Engineering 4 Square Controller
Uses Three Separate Delay Lines
Two Inputs Go Through 180o Phase Inversion Transformer
Two Inputs Have 0o Shift Within the Controller
Antennas Reversed With External Switching
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Dayton 2013
ARRAY IMPLEMENTATION
Coax Phasing Lines
Network or Antenna Analyzer
Measure The Resonant Frequency Or Fault Of Open-circuited Line
Calculate Phase By Frequency Scaling
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Dayton 2013
FOUR-ELEMENT ARRAY
Simulation Results – 160 M
Spacing: 100 Ft
Amplitudes: 0.42-1-1-0.42
Crossfire Phasing: 0, -190o, -380o, -570o
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FOUR-ELEMENT ARRAY
Simulation Results (Cont.)
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FOUR-ELEMENT ARRAY
Simulation Results - 80 M
Spacing: 100 Feet Between Loops
Amplitudes: 0.42-1-1-0.42
Crossfire Phasing: 0, -200o, -400o, -600o
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FOUR-ELEMENT ARRAY
Simulation Results - 80 M
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ARRAY IMPLEMENTATION
Loop Termination and Switching
560 W Termination
DPDT Relay
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Dayton
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ARRAY IMPLEMENTATION
Loop Design and Array Control
•
Loops as Identical as Possible
•
High Impedance Amplifiers
-
Loop Support, Direction
Hi-Z Amplifier Direction Control
Control Box, Hi-Z Amplifier
Dayton 2013
(Hi-Z Plus 6)
•
ac Coupled (loop dc short)
•
Single 510-W Termination
•
Flooded RG-6 Coax
•
DPDT Relay Switching
•
A 3’ Ground Stake at Loop
Center
•
Four 20’ Radials Under Each
Loop (45o relative to loop)
•
Fiberglass Poles (MaxGain
Systems)
•
Aluminum Can Also be Used
4 EL ARRAY IMPLEMENTATION
Loop & Controller
Individual Loop
Controller During Installation
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4 EL ARRAY IMPLEMENTATION
Loop Alignment!
N/S Array
E/W Array
Fiberglass Support Poles (Max-Gain Systems)
Control
Cables NE
and CoaxArray
in PVC
on Ground
Array Looking
Looking
SW
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Dayton2013
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ARRAY IMPLEMENTATION
System Design
Combiner – Spare DXE 4 Square Controller
Hi-Z Plus 6 Amplifiers
500 W antennas connected directly to amplifier inputs
Must Switch Loop Terminations with Controller
Direction
Simple Switching of Inputs to Controller to
Reverse Array
“Common-mode” Chokes (The Wireman)
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Dayton 2013
ARRAY IMPLEMENTATION
System Design
Delay 1
Delay 3
Delay 2
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MULTIELEMENT ARRAY
COMPARISONS
Verticals are Easier to Install
Vertical Footprint Somewhat Smaller
No Direction switching
Extra 30-40 ft Needed for Loops
Loops Appear More Independent of Ground
Conditions
Simulation Gives Loops a Slight Advantage
in RDF (0.5-0.6 dB)
Simulation Gives Verticals a Large Output
Advantage (Not realized!)
Dayton 2013
K9AY LOOPS & SHORT VERTICALS
Comparison of Simulation Results
Comparison - K9AY Loops (85’) and Verticals (26.5’)
# of
Elements
RDF (dB)
Output (dBi)
Loops
Verticals
Loops
Verticals
1
7.4
4.9
-23.6
5.8
2
10.5
9.8
-25.6
5.8
3
13.1
12.4
-29.2
7.9
4
15.1
14.7
-35.6
9.6
*Note: The actual output of the verticals is much lower
when connected to high impedance amplifiers
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K9AY LOOPS & SHORT VERTICALS
Experiment Underway
• Interlaced 3- Element Arrays
NE/SW Array
• K9AY Loops and 26.5’ Verticals
• Aluminum Loop Supports form
• Vertical Array
• Single Switch between Arrays
• In Operation for 6 Months
Through this Year’s 160 M
Season
Dayton 2013
K9AY LOOPS & SHORT VERTICALS
Qualitative Results Thus Far
Simulation
Aluminum Supports Do Not Disturb K9AY Loops
Loops Must be Floated to Avoid Vertical Array Pattern
Distortion
Hearing of Both Arrays is Similar
Loop Array Almost Always has a Small but Perceptibly
Better SNR (Ears can hear the 0.5 dB difference).
F/B of Loop Array is Better
Output of Loop Array is Actually Higher than that of
Vertical Array
Dayton 2013
SUMMARY
I Hear Well on the Low Bands
The Arrays Act Similar to Yagis
Big Advantage in NAQP and DX Contests
Often Hear Signals Well that are Unreadable on
My Transmit Verticals
Signals Pop Out of the Noise
Gain and F/B are Apparent
Unfortunately Not Rotatable
Frequently Usable on All Bands
(Although with Unknown Patterns)
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Dayton 2013
REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Gary Breed, “The K9AY terminated loop – A compact, directional receiving antenna,”
QST, vol. 81, no. 9, pp. 43-46, September 1997.
Gary Breed, K9AY, "Arrays of K9AY Loops: "Medium-sized" low band RX antenna
solutions," Sept. 15, 2007. http://www.aytechnologies.com
John Devoldere, ON4UN's Low-Band DXing, Fourth & Fifth Editions, ARRL,
Newington, CT: 2005 & 2011.
Dallas Lankford, http://groups.yahoo.com/group/thedallasfiles
http://www.fcc.gov/mb/audio/m3/index.html
Hi-Z Antennas 4-Square, http://www.hizantennas.com
DX Engineering 4-Square, http://www.dxengineering.com
Max-Gain Systems, http://www.mgs4u.com
The Wireman, http://www.thewireman.com
Richard C. Jaeger, K4IQJ “Multi-Element End-fire Arrays of K9AY Loops,”
expanded version of 2011 Dayton presentation, May 15, 2011, available at
http://www.k4iqj.com_. Also 2012 Presentation on 2 Element Arrays.
Richard C. Jaeger, “Multi-Element End-fire Arrays of K9AY Loops,” QEX, pp. 22-31,
Jan./Feb. 2013.
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Dayton 2013
THANK YOU FOR YOUR ATTENTION
QUESTIONS?
[email protected]
www.k4iqj.com
Dayton 2013
Dayton 2013