Transcript Document

K9AY Loop Arrays for
Low Band Contesting
Richard C. Jaeger, K4IQJ
May 16, 2013
INTRODUCTION
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K4IQJ Interests /Background
Introduction
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K9AY Array Comparisons
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2-3-4 Element Arrays
4 Element Array Design & Simulation
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RDF Definition
Basic K9AY Loop Pair
Array Implementation
Discussion / Observations
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Dayton 2013
INTRODUCTION
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Interests
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Low Band Contesting
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NAQP CW
ARRL & CQWW 160 Contests
Stew Perry
CW Sprints (Alabama Low Power Record)
DXing
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Top of the Honor Roll, Need P5 on CW, CQ WAZ
300+ Countries Worked on 80 – 10
255 Countries Worked on 160M
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Dayton 2013
INTRODUCTION
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Need to Hear Well on 160/80 M
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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)
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100 foot spacing (330’ total length)
RDF greater than individual beverages
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Dayton 2013
BACKGROUND
RDF: Receiving Directivity Factor
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Design Goal Here: Maximize RDF
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RDFdB = Gfor(dB) - Gavg(dB)
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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
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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
•
•
•
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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
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“Lossy” Antennas
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Resistive termination
Little or no mutual coupling
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Loops are Broadband –
Usable over a Wide
Frequency Range
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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
Dayton
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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
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Binomial Endfire Array
Nominal Amplitudes
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3 EL (1-2-1)
4 EL (1-3-3-1)
RDF Optimization
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(1-2-1)  (1-1.84-1)
(1-3-3-1)  (1-2.4-2.4-1)
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LOOP ARRAYS
3 & 4 Element Endfire Arrays
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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
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Desired Gains (Hi-Z Plus-6 Amplifiers)
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Elements 1 and 4: 0.42 or -7.5 dB
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Elements 2 and 3: 1.00 or 0 dB
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Adjust Output Resistance
Output Resistance at 75 W
Desired Phase Delays on 160 M
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Element 1: 0o
Element 2: 190o = 180o + 10o
Element 3: 380o = 360o + 20o  20o
Element 4: 570o = 540o + 30o  180o + 30o
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Dayton 2013
4 EL ARRAY IMPLEMENTATION
Amplifier & Coax Phasing Lines
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Desired Phase Delays on 160 M
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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
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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
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Network or Antenna Analyzer
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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
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Loop Support, Direction
Hi-Z Amplifier Direction Control
Control Box, Hi-Z Amplifier
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(Hi-Z Plus 6)
•
ac Coupled (loop dc short)
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Single 510-W Termination
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Flooded RG-6 Coax
•
DPDT Relay Switching
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A 3’ Ground Stake at Loop
Center
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Four 20’ Radials Under Each
Loop (45o relative to loop)
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Fiberglass Poles (MaxGain
Systems)
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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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ARRAY IMPLEMENTATION
System Design
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Combiner – Spare DXE 4 Square Controller
Hi-Z Plus 6 Amplifiers
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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
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Verticals are Easier to Install
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Vertical Footprint Somewhat Smaller
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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
Dayton 2013
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
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Simulation
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Aluminum Supports Do Not Disturb K9AY Loops
Loops Must be Floated to Avoid Vertical Array Pattern
Distortion
Hearing of Both Arrays is Similar
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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
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SUMMARY
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I Hear Well on the Low Bands
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The Arrays Act Similar to Yagis
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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
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(Although with Unknown Patterns)
Dayton 2013
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.
Dayton 2013
Dayton 2013
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THANK YOU FOR YOUR ATTENTION
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QUESTIONS?
[email protected]
www.k4iqj.com
Dayton 2013
Dayton 2013