Tin Foil Ground Plane

[LouisvilleScanMan]

I read something on the web a while back about using a sheet of tin foil as a makeshift antenna groundplane for mobile magmount's.I put one together today using a 12"x12" piece of reynolds wrap backed with duct tape to prevent riping and taped it to a cardboard tube so that it can be rolled up.

I tested it by putting a foot and a half long 1/4 wave mag mount 2m antenna on it and connected to my mobile/base and was able to hit a local repeater about 7 miles away from my basement using 25w.I don't have an SWR meter for VHF so I can't tell you what the SWR was but I was told that I had almost a full quieting signal.

Has anyone else tried this and if so what were your results?

 

[kb5udf]

I tried it

I tried the same a few months ago. I put a load of foil under some rugs I had recently been given w/antennas on top. It worked very well until my kitten discovered how much fun it was to attack, chew, and roll the foil into little balls!

Jean

 

[LouisvilleScanMan]

Well no pets here so I don't have to worry about that.

 

[trace1]

Hmm, may have to try that myself, been looking for a cheap way to make something similar.

 

[LouisvilleScanMan]

Today I'm going to make a bigger one.Probably about 24'x24'.

 

[k8mcn]

you can get the same or better results by just sticking your mag-mount to a cookie sheet. pizza pan, or even the top of a metal file cabinet ..........

 

[RESCUE4NFD]

Tin Foil Antenna

I just turned on my scanner while wearing my "Tin Foil Hat" and it seems to receive trunk systems better...

 

[SkipSanders]

Probably the quickest way to make a 'fake roof' to stick a mag-mount on is to get a metal 'drip pan' sheet from an automotive supplier. They're big enough to make a fair ground plane, though perhaps a little less than 'perfect'.

A 'real' ground plane should be 1/4 wave in all directions from the antenna base, or about 19" for 2 meters. (So, a 38"x38" square)

Yes, that means your car roof isn't all that great as a ground plane for CB. But good enough, mostly, so it should be fine on 2 meters, or other scanner ranges.

 

[kb5udf]

Cookie sheet

Actually I was using the top of an old desktop computer case, but from some of my readings, the ground plane it provided was insufficient in area (like a pizza pan is) for the frequencies I was using, e.g. VHF-hi, and VHF-low. So I increased the area beneath with the foil. It markedly improved the vhf-low and vhf-hi.

 

[LouisvilleScanMan]

I wanted to use something flexible so that it could be rolled up and stored somewere until needed.