A bit help please (ground Plane)

[leon]

Hi Guys, I have purchased a new antenna for our rig so that we may get a bit better reception when traveling, i have researched a bit and found the one we have purchased is quite suitable for our means.

It has a magnetic base, and that is all good, however it says that it needs to be stuck to some sort of ferrous metal to work to its highest potential.

Our rig dose no have a metal roof, so how would i go about this, and how beneficial would it be anyway.

It suggests a metal surface no smaller than 25 cm square and the larger the better, it has to do about Ground Plane :shrug:

Many Thanks.

Leon:thumbsup:

[DavidU]

Tape down a square piece of foil to the roof and place the antenna on to it.

[taminga16]

Hi Leon,
Place it onto the roof of your tow vehicle.
Cheers.
Greg.

[leon]

Thanks guys i did expect that that was the answer, just needed to be sure, many thanks.

Leon

[ballaratdragons]

Leon, they don't mean the Antenna gets better reception from the Ferrous metal.

It means the Magnet will stick better to Ferrous metal. :thumbsup:
Magnets do not stick to most Non-Ferrous metals.

"to work to its highest potential" = The magnet,
and see Barry's post below about how the metal base helps with signal increase through reflection :P

[Barrykgerdes]

The magnetic base is to make the aerial sit nicely on the roof of a car. A dipole or extended dipole like you have can be thought of as half of the aerial the other half is the "reflection" from the ground plane.

The theory of radiation from that aerial is a bit too complex for a simple reply but essentially it will behave like 3 half waves in phase and give a theoretical gain over a basic isotropic aerial of about 8db. Or about 5db over a dipole.

If you don't have a metal roof on the van the side of an old computer case will make quite a reasonable ground plane. That's what I use and it gives a good match to the cable.

Barry

[leon]

Much appreciated, i will find something suitable today and get to work, thank you.

Leon