WIRE BEAMS

LIGHTWEIGHT YAGI ANTENNS FOR ALL LOCATIONS

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What is a Wire Beam ?

 

A wire beam is a type of Yagi antenna using 2 or more wire elements.  Bamboo or wood was often used as spreaders in the past, but now days we typically see PVC or even better, fiberglass tubes used as supports (spreaders) for the wires.

 

Most of these beams have just two elements, one driven element and one parasitic reflector.

Some wire beams (i.e., Spiderbeam) also have one or two directors.

 

Most of these beams are multi-band beams, covering up to 6 bands.

 

Rotatable Wire Beams are usually only found on 20m and above.  

We often see "Fixed Wire Beams" being used on the low bands.

 

A 40m wire beam is possible, but it can be a real MONSTER, and should not be thought of as small or light.  It is a handful to handle.  A few clever hams have succefully been able to keep their 40M wire beam in the air, year round, but most of these MONSTERS typically come down in the fist real story.

 

Features of Wire Beams:

Physical Characteristics:

  • Wire beams have full size elements.
  • Some are smaller than an equivalent aluminum beam.
  • Wire beams do not use traps.
  • Wire beams are very light for their size.
  • Adding additional bands to a wire beam adds very little additional weight, wind load, or cost.
  • Wire beams DO NOT REQUIRE AN EXPENSIVE TOWER;.
    • they may be mounted on low-cost push-up aluminum masts 
    • CAUTION:  they cannot be mounted on "just any old aluminum mast."  
      • It must be a mast that is strong enough for this purpus.  
      • If you are unsure, ask the mast manufacturer or supplier.

 

Performance Characteristics:

  • Most wire beams are broad banded (not all of them)*
  • Performance remains high at both ends of the band*
    • *EXCEPT for some of the really compact models

 

Additional "Claimed" Benefit:*

  • Wire beams using insulated wires are quieter in a thunderstorm than aluminum beams. *
    • * Although I have heard many users make this statement, and know that some of them have both types of beams installed at their QTH, I have NEVER seen any confirmed test results of this.  
    • Do your own due dilligence.

 

Wire Beams Vs. Aluminum Beams

Physical Characteristics:

  • Size:
    • Although Wire beams have full size elements, they are usually smaller than an equivalent aluminum beam.
  • Weight:
    • Wire beams are lightweight compared to aluminum beams
    • Wire beams are VERY LIGHTWEIGHT compared to aluminum beams with traps
  • Multiple-bands:
    • Aluminum beams add traps or multiple additional aluminum elements, which adds weight and wind load to the antenna
    • Wire beams simply add wire and insulators, which does not increase the weight or wind load much.
  • Wind Load:
    • Wire beams have significantly less wind load than that of an aluminum beam with similar performance
    • Even when the wind load is the same or similar, most wire beam designs exert less torque on the mast and rotor under high wind conditions.
  • Rotor Requirements
    • Most wire beams may be rotated with a TV antenna rotor or very small hf-class rotor.
    • Aluminum beams require heavier duty and more expensive rotors.
  • Tower Requirements:
    • Wire beams DO NOT REQUIRE AN EXPENSIVE TOWER;  they may be mounted on low-cost push-up aluminum masts (see "CAUTION" above).
    • Aluminum beams usually require heavy, expensive towers as a support

 

Performance Characteristics:

  • Wire beams are broad banded compared to trap beams.
  • When both beams are tuned for maximum performance in the center of a band, the wire beam usually has significantly more performance than a trap beam near both ends of the band.

 

Repair Costs:

  • Sometimes masts and towers fall down.
  • Wire beams are much cheaper to repair than aluminum beams.
    • When a mast falls with a wire beam, it usually only breaks a few fiberglass tube segments
      • These segments are inexpensive to replace
    • When a tower falls with an aluminum beam, it often bends every piece of aluminum on the beam.  
      • Replacement aluminum is very expensive.

 

 

NEXT:  WIRE BEAM TYPES

 

OR:  SPIDERBEAM VS. HEX BEAM