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K9AY Loop Arrays for Low Band Contesting

K9AY Loop Arrays for Low Band Contesting. Richard C. Jaeger, K4IQJ May 16, 2013. INTRODUCTION. K4IQJ Interests /Background Introduction RDF Definition Basic K9AY Loop Pair K9AY Array Comparisons 2-3-4 Element Arrays 4 Element Array Design & Simulation Array Implementation

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K9AY Loop Arrays for Low Band Contesting

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  1. K9AY Loop Arrays for Low Band Contesting Richard C. Jaeger, K4IQJ May 16, 2013

  2. INTRODUCTION • K4IQJ Interests /Background • Introduction • RDF Definition • Basic K9AY Loop Pair • K9AY Array Comparisons • 2-3-4 Element Arrays • 4 Element Array Design & Simulation • Array Implementation • Discussion / Observations Dayton 2013 Dayton 2013

  3. 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

  4. 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

  5. BACKGROUNDRDF: 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

  6. BACKGROUNDReference Antenna - Short Vertical (20’) RDFdB = Gfor(dB) - Gavg(dB) RDFdB = 1.0 – (-3.9) = 4.9 dB • RDFdB = Gfor(dB) - Gavg(dB) Dayton 2013 Dayton 2013

  7. BACKGROUNDBasic K9AY Loop • 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 Signal Arrival RDFdB = Gfor(dB) - Gavg(dB) RDF = (-24.7) - (-32.1) = 7.4 dB Gary Breed, “The K9AY terminated loop – A compact, directional receiving antenna,” QST, vol. 81, no. 9, pp. 43-46, September 1997. Dayton 2013 Dayton 2013

  8. LOOP ARRAYSMulti-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” Dayton 2013

  9. TWO-ELEMENT END-FIRE ARRAY80’ Spacing – 200o phasing • Two-Element Array • Equal amplitudes • Single phasing line • Rear element lags front element by > 180o • Gain: -25.6 dBi • RDF: 10.5 dB (+3 dB) • Beam Width: 96o • W/C F/B: 16.6 dB • Take Off Angle: 25o Element 2 Phasing (-200o) Dayton 2013 Dayton 2013

  10. TWO-ELEMENT END-FIRE ARRAYSimulation Results - 160 M RDF 10.7 dB Gain -26.4 dBi F/B 15.2 dB Note: RDF Falls as Gain Drops RDF = 7.5 dB at 45o points Dayton 2013 Dayton 2013

  11. LOOP ARRAYS3 & 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

  12. LOOP ARRAYS3 & 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 Dayton 2013

  13. K9AY ARRAYSRDF Comparisons (1-2.4-2.4-1)  (0.42-1-1-0.42) Dayton 2013

  14. ARRAY IMPLEMENTATIONCross-Fire Feed (W8JI) From Low Band DXing [3] Dayton 2013 Dayton 2013

  15. ARRAY IMPLEMENTATION0o Hybrid Combiners Z Z From Low Band DXing [3] Dayton 2013

  16. 4 EL ARRAY IMPLEMENTATIONAmplifiergs & Coax Phasing Lines • Desired Gains (Hi-Z Plus-6 Amplifiers) • Elements 1 and 4: 0.42 or -7.5 dB • Adjust Output Resistance • Elements 2 and 3: 1.00 or 0 dB • 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

  17. 4 EL ARRAY IMPLEMENTATIONAmplifier & 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 Dayton 2013 Dayton 2013

  18. ARRAY IMPLEMENTATIONCoax Phasing Lines • Network or Antenna Analyzer • Measure The Resonant Frequency Or Fault Of Open-circuited Line • Calculate Phase By Frequency Scaling Dayton 2013 Dayton 2013

  19. FOUR-ELEMENT ARRAY Simulation Results – 160 M Spacing: 100 Ft Amplitudes: 0.42-1-1-0.42 Crossfire Phasing: 0, -190o, -380o, -570o Dayton 2013

  20. FOUR-ELEMENT ARRAY Simulation Results (Cont.) Dayton 2013

  21. 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 Dayton 2013

  22. FOUR-ELEMENT ARRAY Simulation Results - 80 M Dayton 2013

  23. ARRAY IMPLEMENTATIONLoop Termination and Switching 560 W Termination DPDT Relay Dayton 2013 Dayton 2013

  24. ARRAY IMPLEMENTATIONLoop Design and Array Control • Loops as Identical as Possible • High Impedance Amplifiers • (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 Loop Support, Direction Control Box, Hi-Z Amplifier Hi-Z Amplifier Direction Control Dayton 2013

  25. 4 EL ARRAY IMPLEMENTATIONLoop & Controller Individual Loop Controller During Installation Dayton 2013

  26. 4 EL ARRAY IMPLEMENTATIONLoop Alignment! N/S Array E/W Array Fiberglass Support Poles (Max-Gain Systems) Control Cables and Coax in PVC on Ground Array Looking NE Array Looking SW Dayton 2013 Dayton 2013

  27. ARRAY IMPLEMENTATIONSystem Design • Combiner – Spare DXE 4 Square Controller • Hi-Z Plus 6 Amplifiers • 500  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) Dayton 2013 Dayton 2013

  28. ARRAY IMPLEMENTATIONSystem Design Delay 1 Delay 3 Delay 2 Dayton 2013

  29. MULTIELEMENT ARRAY COMPARISONS • Verticals are Easier to Install • No Direction switching • Vertical Footprint Somewhat Smaller • 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

  30. K9AY LOOPS & SHORT VERTICALSComparison of Simulation Results Dayton 2013

  31. K9AY LOOPS & SHORT VERTICALSExperiment 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

  32. K9AY LOOPS & SHORT VERTICALSQualitative 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

  33. SUMMARY • I Hear Well on the Low Bands • Big Advantage in NAQP and DX Contests • The Arrays Act Similar to Yagis • 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) Dayton 2013 Dayton 2013

  34. REFERENCES • 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

  35. THANK YOU FOR YOUR ATTENTION • QUESTIONS? k4iqj@mindspring.com www.k4iqj.com Dayton 2013 Dayton 2013

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