Antennas

 
80m
 
NVIS Delta Loop
 
 

2020

Preparations

The BICC top section features the same 18-in face and 7/16-in solid serpentine Zig-Zag bracing as the standard BICC tower sections and it also comes with a tapered top and integrated support. First these sections needs cleaning and painting.

     
 


     
 

Measure

The intermediate space between the support towers is 33m

Using old rolling scaffold aluminium tubes that are cut on 1.5m each.

     
       
  Pulleys

Bought some ball bearing pulleys with extended swivels to support the Dacron ropes.
     
 

NVIS Delta Loop

Big Full Wave Loops provide good NVIS at their native full wave frequency. Using a 1/4 inverted V @110ft (33m) for EU and some DX, this horizontal monoband delta-loop is a experimental setup for NVIS communications within PA.

 

The feedpoint of a full wave length (1 × λ ) loop has an characteristic impedance of approximately 100Ω. A horizontal loop with a circumference of approximately 83 m is a good NVIS antenna.

PA1A is using a 1/4 λ stub matching the antenna to 50Ω

   
  Hardware

Ceramic insulators from a former commercial broadcast station.
     
       
  Center

Composing the center suspension point from the junk bin.
     
       
 

Suspension point

Details of the feedpoint.

Cutting 20, pieces DACRON wires for the pulleys

     
       
 

Wires

83m and 8mm copper bronze antenna wire is fairly heavy, therefore using also 8mm DACRON

Measure 3x28m for the corners of the triangle.

     
       
  Connect

Using stainless steel wire clamps
     
       
 

Installation

Calculated teroretically, excat turns out to be correct in practice.

     
       
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Connector

Using 7/16" male-male and sealing with Scotchfill anf finishing with Scotch tape with sufficient force.

Finish: Burying the coaxial cable in the lawn

     
       
       
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