Topband: Re:Topband: shunt fed short tower

[i4jmy@iol.it]

First of all I suggest You to forget about strange things like a 3 wire 
unipole.
What you need is an omega match, that's all.
The shunt feeding of a short monopole it's not the best way to feed 
because the current will be almost constant along the structure and the 
BW quite narrow, if losses are limited.
If there is no other alternative it can be done, and the feed 
attachment should be as high as it is possible. 
The antenna will be a sort of folded unipole and the feed wire need to 
be large.
An important advice is to install the hat (the beam) at the very top of 
the structure and not below.
The second advice is to use all the precautions (components and joints)
to minimize ohmic losses.
Just to give you an idea, a 36 ft tower with a KLM KT34A on the top 
(elements grounded to the boom) was resonant around 3.5MHz.
It was good on 80m and reasonable performant on 160m with a 1:3 -+15KHz 
BW.

73,
Mauri I4JMY  

> Is this a 
> possible candidate for a 'short' shunt fed 160 mtr ant? Will the 24 fo
ot 3 
> inch boom offer much capacitive loading? I understand that there are s
everal 
> ways to get this to play. 
> 
> Lane
> Ku7i
>