aerial ground plane ?

hi guys, im looking at a desktop aerial for use at home but somebody somewhere said it wouldnt work unless i had a ground plane, this is a mag mount aerial: https://www.ebay.co.uk/itm/Skyscan-...canner-aerial-antenna-25-1300MHz/201857673615
so my question is, what size ground plane can i use, somebody suggested a biscuit tin ??

Looks like a bunch of misstuned j-poles and you pick out the signal at the cold end.
If a groundplane makes a different its size will depend of the frequency. It should be something like a 1/2 wavelenght in diameter. I believe the longest element are for 120Mhz which is a 250 centimeter wavelenght.

450Mhz have a 65 centimeter wavelenght.

/Ubbe

One of these with a larsen tri band will suit you fine. https://www.theantennafarm.com/catalog/pctel-maxrad-mbsuhf-1651

vampyre32 said:

hi guys, im looking at a desktop aerial for use at home but somebody somewhere said it wouldnt work unless i had a ground plane, this is a mag mount aerial: https://www.ebay.co.uk/itm/Skyscan-...canner-aerial-antenna-25-1300MHz/201857673615
so my question is, what size ground plane can i use, somebody suggested a biscuit tin ??

Click to expand...

That's a lot of money for that antenna, but it's up to you.

The antenna will work without a ground plane, but it'll work better with one. The biscuit tin under it will work. Ideally you want a 1/4 wavelength in all directions under the antenna for optimum performance. Try the tin lid first and see if it works. Don't expect wonders. An indoor antenna is going to be limited in what it can do.

Theoreticly each individual element are tuned to 120-250-340-850Mhz but are unpredictable as they interact with each other, so it depends of if that are the frequencies you are interested in. Remove that colliniar element with the coil and you have a civ-mil air antenna. But as mentioned if you have it inside a room it will be exposed to all kind of interferencies from electronic devices and some window glass reflects RF signals and walls could have metal nets, or if built of concrete could have iron rods for support, that also will inclose the room in a screening shell that will keep interferencies inside the room and block RF signals from coming in. So placement of antenna are of upmost importance.

/Ubbe

That is just a bunch of elements for different frequencies jammed together.
It's a lame way of make a multi-band antenna that looks impressive.
Unless 26.99 pounds translates to $10.00 USD at the most, runaway.
There are plenty of good multi-band antennas available, and they will be a bit expensive.
What frequencies are you trying to receive? (and don't say DC to Light)

And yes, a biscuit tin would be better than nothing.