Antennas · F1SYH

V-Beam antenna

A V-Beam consists of two long wires forming an open V toward the desired radiation direction.

HF Directive Longs fils

Operating principle

The lobes of both long wires combine along the V bisector. Directivity depends on electrical length and included angle.

Main characteristics

G

Typical gain

Variable selon longueur et angle
Ω

Impedance

Élevée

Polarization

Mixte à horizontale

Difficulty

Avancée

Dimensions and design

Each leg is generally one or more wavelengths long. V angle is optimized for frequency and wire length.

Construction and tuning

Step 1

Choose the main direction.

Step 2

Calculate both leg lengths.

Step 3

Determine the included angle.

Step 4

Install three supports.

Step 5

Feed with balanced line.

Step 6

Add termination for a travelling-wave version.

Advantages

  • Directional gain.
  • Only three supports.
  • All-wire construction.
  • Broadband operation possible with termination.

Limitations

  • Large area required.
  • Frequency-dependent pattern.
  • High impedance.
  • Fixed direction.

History and origin

V-Beam antennas were used as simpler directional alternatives to large Rhombic arrays.

Safety

Long wires must be high enough and securely supported.

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