Topband: Cage wire performance

[GEORGE WALLNER]

Kenny,
For the Baker Island KH1/KH7Z DXpedition I developed a 43 foot "T" antenna 
with spreader wires (Fat Vertical) with sloping top loading wires. It 
performed very well. I have been using a 65' version at C6AGU for the past 
two years and it has been performing very well. (There is a picture of it on 
the C6AGU QRZ.com page.) NEC modelling indicates higher gain (6 dBi) and 
wider bandwidth, BUT making the antenna "fat" lowers its radiation 
resistance, which places greater demands on the ground system. (Both on 
Baker and C6AGU the antenna was standing in salt-water.)
The C6AGU antenna feed-point impedance was measured at 9 - 130j Ohms. (I use 
a remote tuner.) If you measure a much higher resistive component, it could 
indicated that you need to improve the GND system.
GL and 73,
George,
AA7JV/C6AGU


On Mon, 4 Jan 2021 10:05:47 -0500
  Kenny Silverman <kenny.k2kw at gmail.com> wrote:
> Hello and HNY!
>
> I will be converting a wire inverted-L to a T top loading on a 75’ tall wire hung from a tree. To improve the bandwidth, I was wondering about going to a 2-wire “cage” for the vertical section. I’m actually modeling a skinny triangle where the wires connect at a point on the top, but with a 4 foot spread of the wires near the ground. This adds about 15-20 kc to the 2:1 bandwidth per the model. 
>
> Will a 2-wire section like this always behave as a wide/fat conductor or do I have to worry about voltage/current in Each wire?
>
> Regards , Kenny K2KW 
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