Topband: Capacity Hat Wire Size

[VK3HJ]

In my station for the past several years I have run a top loaded vertical of 
similar dimension to what you propose.

A Spider pole is something I would only use in a portable application, not a 
permanent home station antenna.

My antenna uses telescopic aluminium tubing tapering from about 65 mm to 25 
mm and is around 19 m in length. I originally used six top loading wires of 
around 6 m each of Flexweave wire. This turned out to be too heavy and 
unwieldy and made the antenna unstable, especially when erecting it. I 
changed the top hat to three wires of about 9 m each using medium duty 
hookup wire (14x0.32, 1.13 sq mm). Now what I did, I think is rather 
ingenious if I may say so, in that I used 4 mm poly rope to guy the top (and 
three levels below) and wove the top loading wire into the top guy rope, so 
that the rope did the supporting as a guy, and also carried the top loading 
wire. This has the advantage of holding up the top loading wires, which are 
terminated in a lug onto a small stainless bolt at the top of the aluminium, 
and also does not seem to attract the cockies with their bolt-cutter beaks. 
The wire is light, and does not cause excessive sag. I secure the top guys 
out about 20 m from the centre.

This has survived some decent storms, and bird attack.

Current at the top of the antenna should not be an issue. The main concerns 
would be mechanical.

When I have used a Spider pole on DXpedition, medium duty hookup wire as 
described above seems ok, even to the feed point, but I've only used a low 
duty cycle mode like CW.

73,

Luke VK3HJ