VE3KL Selecting a Portable HF Antenna Basic Issues Ease of operation: Mechanical Design(weight .. Efficiency…minimum gain around – 3dBi a goal. Antenna patterns.. Some are quite directive Ease of matching…. Very important Transmission Line Losses A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4nec2 Simulator Sotabeams Trap David Conn VE3KL 12/1/2018

Presentation Outline Problem Definition Typical Portable Antennas Transmission Line Types…How to select Case Studies Conclusion A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits James Clerk Maxwell Georg Simon Ohm

Types of Portable Operation Summits On The Air (SOTA). Extreme Pedestrian Portable. Very specialized Casual outings in a park Weekend camping…….. Dual band plus VHF Field Day… More serious…need performance Portable Operation from a vehicle.. ….. A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Antenna Classification (for spotting good DX designs, not NVIS) Big antennas that are mounted well off the ground: ≥ λ/4 High Gain at 30 Deg Elevation Small and/or near ground antennas Low Gain at 30 Deg Elevation A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 12/1/2018

Antenna Classification (Base Numbers… Antenna Classification (Base Numbers….No Losses, Perfect Ground) 30 Degree Elevation Angle Halfwave Dipole, 14 MHz, 30 deg.elev. 7m High, Horizontal 5.5 dBi Max Gain Vertical Antennas, Length ≤ λ/4 3.5 dBi Max Gain A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 12/1/2018

Typical Antenna 30, 17 Metres Trapped Inverted V Performance? Mini Toroid Trap VE3KL Design A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Antenna Photo Collage Source SOTA/Hfpack Diamond A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits http://www.bing.com/images/search?q=sota+antennas&qpvt=sota+antennas&qpvt=sota+antennas&FORM=IGRE http://hfpack.com/moderators/#n0vz 12/1/2018

Some Antenna Candidates Inverted V…. Monoband Trapped Inverted V…. Multi band Inverted L … Monoband with One Radial (SOTA) Quarter Wave Ground Plane… four radials above ground Rotating monoband dipole Pedestrian Vertical…one insulated radial Random Wire, End Fed, Small/Big Loops, Diamond A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Some Antenna Candidates Diamond Shape Apex Angle Trap or Loading Coil A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Base near ground David Conn VE3KL 12/1/2018

System Simulation Includes Cable Skin Effect Cable Dielectric Loss Cable Internal and External Inductance Cable DC Resistance Cable Velocity Factor Antenna Wire Loss (Copper or Al) Antenna Wire Insulation ( Dielectric, not losses) Antenna Ground Type (Average) Trap and Loading Coil Loss..Q = 100 for all cases A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Transmission Line Selection Loss not too important (Short Lines Used) Light weight Easy to use Coax preferred…. Open wire hard to use A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Transmission Line Selection RG-8X 10 m long 0.36 dB Loss 14 MHz (Belden 9258) Recommended RG-58U 10m long 0.5 dB Loss 14 MHz (Belden 8219) Recommended Transmission Line Selection Approx Skin Effect Limited 0.1 MHz and above Skin Effect Limited 1 MHz and above A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Transmission Line Selection RG174 U 10 m long 0.84 dB Loss 14 MHz (Belden 7805) OK ??? RG174 U 10m long 1.1 dB Loss 14 MHz (Belden 8216) Poor Transmission Line Selection Skin Effect Limited 1 MHz and above Skin Effect Limited 1 MHz and above A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Approx Skin Depth Limited Above 20 MHz Very High Loss at 100 MHz

Case Studies Full Size Dipole..20 Metres Trapped Inverted V...30 and 17 Metres Sota Inverted L...20 Metres Hamstick/Buddipole Type Dipole...20 Metres Vertical Diamond...20 Metres Pedestrian Vertical...20 Metres Short Vertical_Four Low Radials...20 Metres 12/1/2018 David Conn VE3KL

Case Study #1 Full Size Dipole 14 MHz Just Manageable in Moderate Wind Al Tubing Height = 7 metres AL Telescoping Tubing Light Balun 1:1 at top Light mast: guy ropes RG8X 0.4 dB loss A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Radio Average Ground

Full Size Dipole H = 7 metres Gain = 5 Full Size Dipole H = 7 metres Gain = 5.1 dBi @30 deg BW = 1 MHz Very Good Not an SOTA Antenna.....Great for Field Day A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Case Study #2 30,17 Metre Trapped Inverted V 18 MHz Trap Ferrite Choke 6 Sections A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits T 50-6 Powdered Iron Toroid 22 Turns 30 pF 12/1/2018

Polar Pattern. Elevation Gain @ 10 MHz= 1 Polar Pattern..Elevation Gain @ 10 MHz= 1.8 dBi 17 and 30 metres, Height = 7 metres Broadside 90deg A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Gain @ 18 MHz = 4.3 dBi 17 and 30 metres, Height = 7 metres Broadside 90deg A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Trapped Inverted V 4nec2 Simulation Frequency Response A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Measured Frequency Response AIM 4170 Vector Meter Tuned Slightly Low (Both Bands) A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits David Conn VE3KL 12/1/2018

Case Study #3 SOTA Antenna: Inverted L with one Insulated Radial 20 and 40 metres with tuner Top Light weight Height = 10 metres Top = 8.6 metres Lradial = 3.0 metres Radial Height = 0.5 metres Wire gage #16 Copper 4:1 Balun Light mast: guy ropes Height A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Radial 4:1 Balun Radio Feed Point

Inverted L One Short Radial Optimized for 20 and 40 metres Gain (14 MHz) at 30 deg = 4.0 dBi….Good Broadside Radiation A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Inverted L One Short Radial Optimized for 20 and 40 metres Gain (7 MHz) at 30 deg = -1.0 dBi….OK End Fire Radiation A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Inverted L One Short Radial Frequency Response Good SWR Z0 = 200 Ω A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Broadside Radiation

Case #4 Buddipole/Hamstick Like Antenna Small Dipole with Loading Coil Good Field Day Back Up on 20 metres Poor Choice for 40 or 80 metres Length = 4.9 m Height = 3.5 m Lcoil = 10 uH Q = 100 Average ground A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits http://www.bing.com/images/search?q=sota+antenna+pictures&qpvt=sota+antenna+pictures&qpvt=sota+antenna+pictures&FORM=IQFRML

14 MHz Buddipole/Hamstick Type Dipole on a Tripod Two Loading Coils Bandwidth = 0.2 MHz Gain = -1.0 dBi @ 30 Deg A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Broad Side Radiation Azimuth = 0 deg

Buddipole Type Dipole on a Tripod Two Loading Coils Bandwidth = 0 Buddipole Type Dipole on a Tripod Two Loading Coils Bandwidth = 0.2 MHz Might Need A Tuner 14 MHz A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Case Study #5 Vertical Diamond Optimized for 50 Ω Input Impedance Apex Angle 14 MHz L = 4.6 m Lcoil = 3 uH Base Height = 1.0 m Apex Angle = 56 deg Total Height = 8.1 m (Use a slightly bigger coil) Loading Coil Or Trap A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Increasing Lcoil Reduces L and Lowers Gain :Still Matched

Vertical Diamond Four Loading Coils Gain = 3.4 dBi A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Case Study #6 Pedestrian Vertical with Loading Coil One Trailing Radial (long or short) Height = 2.0 Metres Radial Height = 0.05 Metres Coil Q = 100 Copper Wires East A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Walking or Cycling West Radiating East

Pedestrian Vertical Long Radial BW = 0 Pedestrian Vertical Long Radial BW = 0.4 MHz Lcoil = 14 uH Lradial = 4 metres Gain = -6.6 dBi A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits High Directivity but low gain Long Radial

Pedestrian Vertical with Loading Coil One Trailing Radial: Length = 1 Metre Gain = -11 dBi BW = 0.2 MHz Lcoil = 20 uH A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Short or no Radial Bicycle frame acts as a counterpoise

Case Study #7 Short Vertical, Loading Coil, Four Radials Close to Ground Height = 3.0 Metres Radial Length = 1.05 Metres Radial Height = 0.05 Metres Lcoil = 10 uH, Q = 100 A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Gain = -7.8 dBi @ 30 deg Elevation Zin close to 50 Ohms due to losses Does not meet minimum Gain of -3dBi {best to use PSK31} A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Case Study #8 End Fed One Wavelength 14 MHz 7 Metres High Length = 18.7 Metres Height 7 Metres at Far End Feed Point 1 Metre High Feed Point Impedance 1900 Ω Counter Poise 1.5 Metres Long Far End Feed Point Max Current High Off Gnd A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Transformer 1900:50 Ω Radio Counter Poise Average Ground

End Fed One Wavelength Transformer Matched 14 MHz Gain = 2 End Fed One Wavelength Transformer Matched 14 MHz Gain = 2.6 dBi @ 38 deg Azimuth A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits

Recommended Antennas Full Sized Dipole, Inverted V, Diamond End Fed, Trapped Inverted V Low, small Dipole with loading coils Pedestrian (walking or bicycle)…very low gain Small Vertical with four radials…use a small dipole A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 73 Dave VE3KL

Summary See my 4nec2 files on ve3kl.com for all details Maxwell & Ohm give insight Simulators crunch numbers Only eight case studies given….many more Really short antennas are inefficient All reasonable portable antennas are fun to use A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 73 Dave VE3KL