? 75M Inverted Vee GAIN
 

After Google search no luck on any data on gain for this antenna.
Just installed with apex at 33 feet and has 27 degrees full length is
116.63 feet long and has a reduced length of 2.064%. Is there any
gain over a point incident antenna?

? 75M Inverted Vee GAIN
 

Sonny Hood wrote:
After Google search no luck on any data on gain for this antenna.
Just installed with apex at 33 feet and has 27 degrees full length is
116.63 feet long and has a reduced length of 2.064%. Is there any
gain over a point incident antenna?

You can model that antenna with the free demo version
of EZNEC available from www.eznec.com.

Your configuration is unclear. How far above ground
are the ends of the inverted V?
--
73, Cecil http://www.w5dxp.com

? 75M Inverted Vee GAIN
 

Sonny Hood wrote:
After Google search no luck on any data on gain for this antenna.
Just installed with apex at 33 feet and has 27 degrees full length is
116.63 feet long and has a reduced length of 2.064%. Is there any
gain over a point incident antenna?

What sort of accuracy are you looking for? At what frequency?
length of 116.63 ft implies you're working 75 or 80m? So the feedpoint
is 10m (1/8th wavelength) off the ground?

You'll have some directivity over an isotrope, but not as much as a
dipole. You'll almost certainly have some loss due to the ground.

27 degrees is the droop? Endpoints about 6 feet off the ground?

Assuming "average soil" and copper wire.

-2.5dBi straight up is the peak gain

At 15 degrees above the horizon, about -6dBi off the end, about -7.5dBi
broadside.

? 75M Inverted Vee GAIN
 

The gain and pattern will be very close to that of a dipole at a height
of about 24 feet. Maximum field strength will be straight up, and quite
dependent on the ground characteristics.

What's a point incident antenna?

Roy Lewallen, W7EL

Sonny Hood wrote:
After Google search no luck on any data on gain for this antenna.
Just installed with apex at 33 feet and has 27 degrees full length is
116.63 feet long and has a reduced length of 2.064%. Is there any
gain over a point incident antenna?

? 75M Inverted Vee GAIN
 

Sonny Hood wrote in
:

After Google search no luck on any data on gain for this antenna.
Just installed with apex at 33 feet and has 27 degrees full length is
116.63 feet long and has a reduced length of 2.064%. Is there any
gain over a point incident antenna?

I don't understand some of your terminology or precision.

However, as others have told you, a dipole close to ground has a major
lobe that is upwards, and probably at the zenith.

The maximum gain depends on height and ground chacteristics. The article
at http://www.vk1od.net/buddipole/index.htm shows the modelled pattern of
a 40m inverted V and Buddipole and you will see from Fig 2 and Table 1
that the major lobe may be quite high (zenith), and the max gain may be
quite high in the case of the inverted V (6dBi). The Buddipole maximum
gain is affected to some extent by the antenna's conductor losses, but
greatly by the proximity to ground and losses in heating the soil.

Your antenna looks like it is intended for 80m (you leave us guessing),
so it is at lower relative height than the inverted V in the article.

Owen

? 75M Inverted Vee GAIN
 

Cecil, the antenna ends are 6.3 feet above earth ground which is
approx. 5 feet above the water table. I haven't used the program, yet.

On Wed, 27 Feb 2008 22:47:30 GMT, Cecil Moore
wrote:

Sonny Hood wrote:
After Google search no luck on any data on gain for this antenna.
Just installed with apex at 33 feet and has 27 degrees full length is
116.63 feet long and has a reduced length of 2.064%. Is there any
gain over a point incident antenna?

You can model that antenna with the free demo version
of EZNEC available from www.eznec.com.

Your configuration is unclear. How far above ground
are the ends of the inverted V?

? 75M Inverted Vee GAIN
 

On Wed, 27 Feb 2008 15:05:54 -0800, Roy Lewallen
wrote:

The gain and pattern will be very close to that of a dipole at a height
of about 24 feet. Maximum field strength will be straight up, and quite
dependent on the ground characteristics.

What's a point incident antenna?

Hi Roy, I consider it the radiation point of a "0" length element
which radiates in spherical direction.
Roy Lewallen, W7EL

Sonny Hood wrote:
After Google search no luck on any data on gain for this antenna.
Just installed with apex at 33 feet and has 27 degrees full length is
116.63 feet long and has a reduced length of 2.064%. Is there any
gain over a point incident antenna?

? 75M Inverted Vee GAIN
 

Sonny Hood wrote:
Roy Lewallen wrote:
What's a point incident antenna?

Hi Roy, I consider it the radiation point of a "0" length element
which radiates in spherical direction.

It's called an isotropic antenna and that's where the
'i' in dBi comes from.
--
73, Cecil http://www.w5dxp.com

? 75M Inverted Vee GAIN
 

Sonny Hood wrote:
On Wed, 27 Feb 2008 15:05:54 -0800, Roy Lewallen
wrote:

The gain and pattern will be very close to that of a dipole at a height
of about 24 feet. Maximum field strength will be straight up, and quite
dependent on the ground characteristics.

What's a point incident antenna?

Hi Roy, I consider it the radiation point of a "0" length element
which radiates in spherical direction.

Oh, that would be an isotropic source. Gain relative to an isotropic
source usually assumes that the source is in free space, so you get an
automatic 3 dB of gain when you restrict your antenna to a hemisphere by
adding a ground plane.

There's no single answer to your question, since the gain is strikingly
different in each direction and at each elevation angle. The maximum
gain occurs straight up, and you'd only be interested in that figure if
you're doing NVIS work -- and it would vary quite markedly depending on
ground conditions.

The simplest way to find the gain relative to isotropic (dBi) at any
particular azimuth or elevation angle is by modeling. The free EZNEC
demo program at http://eznec.com is adequate, and the Test Drive
tutorial in the included manual takes you through the building of a
similar antenna. You can easily modify the example to imitate your antenna.

Roy Lewallen, W7EL

? 75M Inverted Vee GAIN
 

Sonny Hood wrote:
On Wed, 27 Feb 2008 15:05:54 -0800, Roy Lewallen
wrote:


The gain and pattern will be very close to that of a dipole at a height
of about 24 feet. Maximum field strength will be straight up, and quite
dependent on the ground characteristics.

What's a point incident antenna?


Hi Roy, I consider it the radiation point of a "0" length element
which radiates in spherical direction.


Careful there. A "zero length" (or infinitesimal) dipole (aka a
Hertzian dipole) does not have an isotropic (spherical) pattern. It has
1.64dBi directivity, as I recall.