Topband: shunt fed towers

[Tree]

On Mon, Dec 08, 2008 at 07:36:04PM -0500, John wrote:

> would like to pose   a question to the antenna experts...read recently that a tall tower say 1/4 wave with large antennas atop of it really does not work well as a 160m antenna...what do the experts say?i have been using one of those for years and i think they work like gangbusters but i'm not an expert so it may be that for years i've been using the wrong antenna...and should shorten mine to say 70 feet or so i would like to have a serious answer and as i'm willing to improve my system on 160m if i've been doing it wrong for 26 years...John K1GUN

I'll assume this is sarcasm.  Okay - I have now heard of at least two 
cases where tall towers work well on 160 meters.  I "eat my words".

However, there sure isn't anything wrong with a 70-80 foot tower as 
my results speak for themselves.  I do think a taller tower will have
sharper bandwidth according to the printed information - but maybe if
you get them tuned, they work fine.  

If you have something in the order of 200 feet tall - something that 
approaches 1/2 wavelength - I would think using either the reverse
feed method or 1/4 wave slopers down the tower aways (about 1/4 
wavelength from the ground) would be an attractive option.  

I have a 105 foot tower with a full sized 3 element 40 on it.  Perhaps
I should try loading it and see if I can compare the two antennas - but
since they are pretty close to each other, it might be difficult.

73 Tree N6TR
Boring, OR