Building Antennas from Everyday Materials

1
Building Antennas from Everyday Materials

• by Marc C. Tarplee Ph.D., NCE
• N4UFP

2
The Problem

• Weve all seen commercially built antennas or
  construction plans for antennas in magazines
  like QST or CQ
• Weve also seen wire models of antennas that are
  used by simulation software.
• In every case we usually ask ourselves the
  following question
• How to I build the _at_ thing??
• Many projects call for aluminum tubing, stainless
  steel hardware, fiberglass insulators, gamma
  matches, etc. and require the use of tools such
  as a drill press or lathe for construction.

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The Solution

• See what materials are available locally.
• Home improvement stores
• The local hardware store
• Auto parts stores
• Use designs that can be constructed from those
  materials.
• Loops with wire elements
• Wire yagi designs (Moxon, Hex-Beam, etc.)

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Conductors/Radiators

• 14 or 12 THHN stranded copper wire
• Inexpensive ( 7 12 cents/ft)
• Insulation adds strength and protection from the
  elements
• Aluminum welding rods
• Available in various lengths and diameters.
• Easily fabricated
• 10 bare solid copper wire
• Stiff enough to be used for self supporting
  elements
• Flexible and can be soldered/brazed.
• Aluminum angle/channel
• Can be bolted together to make longer elements
• Radiators do not have to have a circular cross
  section!!
• Type L copper water tubing
• Can be bent and soldered
• Relatively heavy may not suitable for large
  radiators.

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Insulators

• Acrylic sheet
• Can be cut by scoring and drilled
• Good dielectric strength
• PET (polyethylene terephthalate).
• Used to make soda bottles
• Good dielectric strength
• Can be cut with scissors
• Non-biodegradeable
• Wood
• Available in many sizes and shapes
• Easily drilled and cut
• Should be painted to prevent water absorption
• PVC pipe
• Easily worked with hand tools
• Good dielectric strength
• Non-biodegradeable

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Booms and Spreaders

• Screen Molding (0.375x0.75 inch)
• Can be used for lengths up to 8 feet
• Should be painted
• Bamboo fishing poles
• Can be used for lengths up to 15 feet
• Should be varnished to prevent deterioration
• Fiberglass fishing pole blanks
• Lighter and stiffer than bamboo
• Non biodegradeable
• PVC pipe
• Many varieties of pipe and fittings available
• Combination of high density and flexibility make
  it unsuitable for long booms/spreaders.

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Example 6m Moxon Rectangle

• Wire used for elements
• Screen molding used for spreaders
• Insulators were made from a 2 liter Coke bottle.
• Everything fastened with standard 6-32 hardware
• Weight lt 5 lbs

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Example 8 element 222 MHz Yagi

• Boom screen molding
• Parasitic elements 1/8 inch diameter aluminum
  welding rod
• Driven element - 10 bare solid copper wire.