One-Radial Ground Plane vs Dipole

[Riverman]

I am going to make a base station antenna out of two 5' Firestiks. Am trying to decide between a ground plane and a dipole. The GP would have one antenna as the vertical and the other angled beneath it as the radial.

I will be mounting in close proximity (less than a foot) from horizontal aluminum rain gutter along the eave of my house.

Everything else being the same (height, coax length, etc.), which would be the better antenna?

I am new to the site and this is my first post. Hope I posted in the right place.

Thanks!

 

[nosepc]

One antenna as the vertical and the other angled beneath it as the radial; present this directivity to half wavelength high... (18' )

modeling using an real ground plane





at 36'

 

[Riverman]

nosepc,

That pretty much went zipping past this old brain of mine without even slowing down!

I've been out of the radio hobby for some forty years and am just getting back in.

Of the two I mentioned, which antenna would you go with?

Thanks!

 

[Beetle]

There's no real way to tell which way would be "better", if at all. Too many variables.

Best thing to do is experiment and SEE what works best. Then make a change - just one change at a time - and see if things improve or go downhill. Take notes and pictures. Learn.

 

[Riverman]

Do you think one would be more affected by the rain gutter than the other?

 

[M0GVZ]

nosepc,

That pretty much went zipping past this old brain of mine without even slowing down!

I've been out of the radio hobby for some forty years and am just getting back in.

Of the two I mentioned, which antenna would you go with?

Thanks!

OK in simple terms:

A normal dipole has more gain than a vertical especially if you can get it a half wavelength or higher so 16ft or more for 11m band...

The vertical with one ground plane at an angle. Imagine the ground plane looking from above as a circle. Imagine that circle cut into quarters. Every quarter where there is not a radial it will be 3-6dB down from the one where there is. So if you have only one radial and its pointing north, the antenna will have more gain to the north than the other four directions.

An alternative is to create a vertical dipole which overcomes this but you need to bring the coax out horizontally for several feet.

 

[Riverman]

Thanks, MOGVZ!

That's the kind of info I was hoping for.

 

[nosepc]

if you install the v-shaped dipole at 36'

 

[Robb]

if you install the v-shaped dipole at 36'

If you install the v-shaped dipole at 36', then it would have an omni-directional pattern, some of the RF energy would go skyward, the ends would need to be slightly shorter to tune on a given freq, little ground loss, and the impedance would approach 60 ohms.

The question was: He wanted to know how to install what he had.
As a rule, I would keep any antenna away from a metal rain gutter, or anything else that is metal. As this will detune the antenna and it will have tuning problems.

Beetle's answer was the best and most informative.
Experiment, take notes, and learn.

 

[Lil'Yeshua]

Balcony antenna?
Sirio Balcony 27 W 10m & CB Base Antenna [balcony27] - $38.95 : Sirio Antenna, High Performance Antenna Made in Italy

 

[hotrod]

Balcony antenna?
Sirio Balcony 27 W 10m & CB Base Antenna [balcony27] - $38.95 : Sirio Antenna, High Performance Antenna Made in Italy

good choice. imho id think a TRUE halwave dipole base antenna would be better than
trying to use a mobile antenna especially one shorter than a 1/4 wave long.
now as far as interacting with rain gutter im not sure you,d have to try it
and see really.dnjradio also sells this dipole antenna also

 

[Lil'Yeshua]

It reminded me of Sirio's Bakcony antenna. I haven't read this thread yet. I thought that there maybe some simularites.

 

[hotrod]

i dont know if any similiarities. but he was asking about a dipole . so i was
referring to sirios dipole.thought they also called it a balcony antenna ,guess not.
opps my mistake. i still stay with my recommendation wirh the dipole over a shotened
mobile antenna

 

[Riverman]

nosepc,

I have a dumb question. Are those transmission reflection patterns, or reception?

 

[Riverman]

Funny y'all should mention the Sirio Balcony 27. I have been looking at that one but can't find hardly any reviews. Apparently these are really popular in Europe.

Am a little confused. I thought it was a ground plane with 1 radial, not a dipole, since it can be mounted to metal. Can someone clear this up for me?

Thanks!