Ground planes for antenna

[Excalibur]

On pmr446 how big and how many would one make the ground planes/radials for a 16cm vertical antenna? Also would a large biscuit tin make a good temporary "ground" for it?

Excalibur

[ChelseaCat]

I would say make a dipole even lengths either side

[g7kxm]

Assuming 16cm is a 1/4 wave (had a drink and can't be bothered to check maths) then the radials should also be 16cm each. If the biscuit tin is at least 32cm diameter then yes it would be fine, but as ChelseaCat suggests why not try a dipole first, very simple.

[Excalibur]

thanks for the advice guys. The antenna is this type magmount http://www.ebay.co.uk/itm/ICOM-UHF-PMR4 ... 4178f3917c so it needs a ground plane in order for it to work correctly which is why I'm using a biscuit tin for indoor use.

How would one make a dipole for this type of antenna? Is it possible?

Many thanks.

[Bigdave]

Like this works well.............

[Dragonfly]

Not shure if a dipole that small would give a 50ohm load ,
I made a 4 x 16cm ground plane angled at 45 degree out of new brake pipe and stuck the mag straight on it , works a treat .

[RadioPixie]

A dipole could easily between 50 and 80 ohms. Say 75 ohms, that would be a SWR of 1.5:1. I wouldn't bother wasting my time trying to get it lower as the performance difference is bugger all.

[ChelseaCat]

Here is a one I made dead cheap for2 metres it will be the same for your antenna but at different lengths, this cracks out on 2 metres.

http://www.transmission1.co.uk/viewtopi ... 2&p=355638