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Re: Topband: beverage lobes

To: "Larry Molitor" <w7iuv@yahoo.com>, <topband@contesting.com>
Subject: Re: Topband: beverage lobes
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Tue, 9 Jan 2007 05:29:48 -0500
List-post: <mailto:topband@contesting.com>
Larry wrote:
> In an ideal perfect-phase lossless world ........I'm not 
> going to argue theory. I happen to agree with the 
> theoretical case as you presented it. However that does 
> not account for the fact that I can really see a dramatic 
> difference in performance with the longer Beverages 
> installed here. Since I make the observations on real 
> topband signals and A/B switch around the various wires I 
> can only assume that there is a difference between the 
> theoretical case and my practical installation that has 
> not yet been accounted for. When the model does not agree 
> with the measured results, either the model is wrong or 
> the measurement is wrong. Since the measurement is copy/no 
> copy and is repeatable, there must be an inconsistency in 
> the model.

It certainly sounds like you did your homework. We have to 
be very careful to not base opinions on "bumps in the night" 
where we operate a day or two between long periods of rest 
and conclude the entire world works the way it does in those 
two days. Any of us experienced on 160 know at any given 
moment the world can turn upside down an a lousy 40 meter 
dipole can suddenly seem like the best receiving antenna in 
the world.

Since I haven't been in Washington and operated weeks and 
weeks watching antennas, I can't say things there are the 
same as they are in Ohio (where I had 30mS/m wet black loam) 
or Georgia (where I have a mixture of swampy black dirt, red 
clay, and rock that is supposed to average a few mS/m).

On the other hand I do know in extended periods of listening 
I wind up using 700-800 foot long Beverages in broadside 
pairs as the best overall antenna, while my longer antennas 
aren't useful much of the time. When I use an antenna 
thousands of times and it is better only one or two times, I 
don't feel comfortable recommending it as a general 
cure-all.

I just get a little distrustful in methods or conclusions 
when I read exaggerated claims like 10dB gain when length is 
quadrupled when we all know (or should know) the ceiling is 
3dB per double length. I'm even trying to overcome my 
problem with MFJ antenna ads, but that will take a lot of 
visits with Dr. Phil. :-)

73 Tom 


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