CORNER FED L

[flintstone mop]

I do not want to confuse or hi-jack the Inverted L thread so I am starting this one.

There was mention from Darrell KF4DX about a Corner Fed Inverted L. And
I find it quite interesting. Googling a Corner Fed L brings me back to amfone
http://amfone.net/Amforum/index.php?topic=12573.0

But the info and the thread about this antenna are like a mystery magic antenna.
Frank WA1GFZ gave me a little more info about an LB Cebik and that connected to his website, which is like trying to get into Fort Knox.
http://www.antennex.com/guests.html
If you want to register it gets a little complicated.
Apparently Mr Cebik (SK???) has a lot of research on antennas and did some experiments on this "Corner Fed L"
Anyone here using one, besides Darrell??
I'd like to get better info on this antenna and specifically how the vertical element is built.
I would like to expand on the construction and use my existing dipole as the top part of the "L" and create the vertical element with whatever was originally designed. I don't want to confuse anyone and go down the road of a "T" type of antenna. Because the way this "L" is FED is at the corner......................
The icing on the possible cake is a better aerial for 160M and no radials.
Darrell used an existing ladderline as his vertical element.
Ques. here would be spacing of the wires.......I know it would be creating a cage type of element for bandwidth. Anything critical here??

Thanks
Fred

[W4AMV]

Hi Fred. After I read this thread I also looked a little closer into the inverted L on EZNEC DEMO. It is easy to enter the wire segments, there are only 2 as I corner FED the antenna. As opposed to the bottom or end FED where radials are required, the corner FED is easy to feed with 50 ohm line. Looking at 40 meters with the corner point at 45 feet height, the vertical segment dropping down to  33 or so feet and the horizontal at the same length. The elevation take off angle is ~ 40 degrees, not a cloud burner, and the gain is about 3 dBi. The main advantage I see is the support for the corner point of the antenna, as this shares support for the feed line, as opposed to having no support in a CF V or dipole.

Alan

[Steve - K4HX]

It's always good to compare the antenna you are modeling to a dipole at a similar height or a vertical with a particular number of radials. Otherwise, 3 dBi doesn't mean much. Model a dipole over average ground and at a height of 50-60 feet or more and you will see a "gain" of 7-8 dBi.

[W4AMV]

Hi Steve. I agree, and while that effort is worthwhile, I just wanted to provide a point of reference for the particular case studied. In this case, the corner feed point at 45 foot height and the wire above "so-called" poor ground, i.e. pastorial clay. Bottom line, for such a simple antenna topology, you could do much worse.

[KW4DE]

I used the info from the Cebik corner fed L when trying this antenna.  I feed with ladder line. I have quite a few trees to experiment with .  It helps to have a tree or two at 60+ feet for the horizontal portion (let the vertical hang). You could let the horizontal slope down but this would likely affect the pattern more toward an inverted V pattern.  I especially noticed signals from the west coast last winter to be stronger than a flat dipole, no doubt due to the vertical leg.  The orientation of the horizontal quarter wave  seems  to benefit the higher angle daytime signals but at a slight signal loss over a flat dipole orientated the same direction.  I use nylon twine pulled over the highest suitable limbs (with the aid of my spinnning rod/reel)for support.  I posted a couple of years ago a version of the same antenna I used for 160 that used a folded back vertical 1/4 wave portion and a full 1/4 wave horizontal portion....works FB if space/height are limiting factors.

[flintstone mop]

I'd like to get better info on this antenna and specifically how the vertical element is built.
I would like to expand on the construction and use my existing dipole as the top part of the "L" and create the vertical element with whatever was originally designed.

The icing on the possible cake is a better aerial for 160M and no radials.
Darrell used a ladderline as his vertical element.

Ques. here would be spacing of the wires.......I know it would be creating a cage type of element for bandwidth. Anything critical here??
I would like to drill down to the info on the vertical part of the antenna and the spacing of the wires.
I would like something more specific that Cebig used.
Thanks
Fred

[flintstone mop]

OK all,
A better way to de-mystify the "corner FED L" is to call it a center fed L.
Easier to find more info..............Mr Cebik is good stuff.