Topband: Vertical dipoles in the real world

[Mike Armstrong]

Well Tom, all I can say is that it works...... Here is more data.... The mast was a wood pole about 12 feet long and the feedline was buried, so there wouldn't be much radiation from them.  There could be some from the base of the vertical to the dirt via the feedline, but that would be all that was possible.  Well, there could be some while it is buried in the dirt, too, of course..... Not sure how much since I had a current balun close to the feedpoint. 

I do try to think of things like incidental radiation in my setup.  Can't always do much about it, but I try.  The point here was not modeling, it was experience..... Of which I have considerable.  I have used these antennas alot (half wave verticals) during my 52 years.  They have never disappointed from an actual performance point of view.  I will say, however, that they seemed to work better from Hawaii and my house was VERY close to the sea there almost 360 degrees.  But ANY antenna seems to work better when surrounded by sea water, so that is kind of a given.

If we are talking a modelling contest, then I haven't got a clue with all the variables.  I can just answer someone who asks if I used one..... The answer is no.... I have used many of them and they ALL worked well enough to make me want to keep them.  That is about a good as I can say for any antenna :) :)  BUT I do hear you, which is why I said what I did about the installation..... All of it may well apply to my success with the antenna.  

Mike AB7ZU
Kuhi no ka lima, hele no ka maka

On Sep 22, 2012, at 5:54, "Tom W8JI" <w8ji at w8ji.com> wrote:

>> A ringo ranger is a vertical half wave using "end feed" and they work
>> great.  I prefer end feeding, using hte method of the ringo (which is
>> easy to scale to other bands).  I purchased the 10 meter version some
>> years back and built ones for all bands to 20 meters by scaling the
>> end-feed arrangement.
> 
> When we end-feed a vertical like that, without radials, the system can have as much radiating current on the mast and feedline as the vertical itself has. This can do all sorts of things to the pattern and gain, because the feedline and mast become a major part of the actual antenna.
> 
> There is a basic electrical rule that cannot be broken. In order to force current up into the vertical at the feedpoint, an EQUAL current has to flow back down into the coax shield, the mast, radials, or something else.
> 
> We are kidding ourselves if we look at an end-fed antenna without a ground system and proper feed isolation and assume only the vertical is the radiator.
> 
> This is why, later in the Ringo's life, Cushcraft added a kit that added radials to the Ringo.
> 
> 73 Tom