Inverted V antenna

[KA3PMW]

I am trying to calculate the lengths of the guy ropes for an inverted V antenna. The apex of the antenna needs to be 125 degrees and the height of the antenna is 49 feet. the legs of the antenna are 61' 7" each. I wish to add a length of rope and have the rope 10' off the ground. I need a formula to calculate how long the rope has to be. I want to be able to put different leg lengths in the formula and, keep the same apex angle and height. The leg lengths that I am interested in are 61'7", 32'5' and 16'5". Can someone please point me in the right direction?

 

[igold]

Have you tried Google. In about 2 seconds I came across this. I am pretty sure with some effort you could probably find a calculator online...

Inverted vee antenna - Amateur radio - BasicTables

The inverted vee antenna looks like an upside down V, often at a 120 or 90 degree angle. The antenna has a rod in the center to support the V shape. The inverted vee antenna takes up less space than a standard dipole antenna operating at the same frequency, so it can be a good alternative when...

www.basictables.com

 

[KA3PMW]

I have spent the past 5 hours searching for a calculator but can't find one. I am an extra class ham and know the inverted V antenna well. It is mt antenna of choice. I wanted to create a spread sheet that would allow me to create setups for the various frequencies without having to place a guy stake on the ground and having to guess the apex angle. The apex should be between 120 and 130 degrees for optimum performance. 125 is right in the middle so I would prefer using that angle and placing the ends on a 10' mast at each end about 4 feet from each leg.

 

[igold]

For one reason or another MrExcel is not happy with your post. I know nothing about this subject matter. If you can't find what you need from a Ham Radio site, I would suggest that you bone up on your geometry skills. It would seem that the two go hand in hand.

 

[Toadstool]

Hi Ka3PMW,

I'm stymied.

We know the leg and height so Pythagoras (although he may have changed in the 50+ years since I studied him) tells use the base is 37" 4' but that means the measure you want at 62.5 degrees (half the apex angle) would actually be 37.28 degrees.

If we want the 62.5 degrees we must make the legs just over 106 ft.

Where have I gone wrong?

 

[Joe4]

For one reason or another MrExcel is not happy with your post.

Why do you say that?

 

[KA3PMW]

The length of the wire is given for a certain band. the problem is that we have to add a rope to the ends that will go to a support that will be 10 feet in the air. For example, an 80 meter antenna will have each leg 61 feet 6 inches. Now we have to add a rope to it to extend it so that we have an apex of 125 degrees that is 49 feet in the air, and each end is 10 feet off the ground. The rope will be 10 feet, the wire will be much higher.

 

[igold]

@Joe4 - Because even with all the current answers the post still appears at the bottom of Page 2 and the number of replies and the other usual attributes of an active post are missing.

 

[Joe4]

@Joe4 - Because even with all the current answers the post still appears at the bottom of Page 2 and the number of replies and the other usual attributes of an active post are missing.

The question was originally posted to the "Excel Questions" forums, but was moved to the "General Discussion & Other Applications" forum.
You are probably looking at the "re-direct" from the original post. It is left there in the original location with a re-direct to the new location.
Note that the square box with the arrow icon indicates a "Redirect" (just hover over that and it will tell you that).

 

[igold]

If the re-direct is the square with a arrow sticking out of the upper right then, it is broken. Nothing happens when I clicked on it. Additionally, even though I don't believe in ghosts, you are correct, that is what I was looking at.

My bad.