NMO ground plane on a car?

[IronArcher]

So I picked up an antenna mount with the intention of mounting it on the crossbar of my luggage rack.

Looking at it now, it seems as though it is at best metal covered in a plastic sheath.

[SUPERG900]

There's no such thing as a free lunch concerning antenna mounts.

The car's roof is a sufficient ground plane - it's actually the optimum place to put an antenna. You don't need some sort of an add-on ground plane. There's really nothing wrong with a well-built mag-mount antenna. You might be making more work for yourself than necessary.

[IronArcher]

I have a habit of doing that.

I’ve just seen paint issues (maybe from dirt, some say from the rf, I don’t know.)

Also, I have a slight concern with a mag mount as that would put part of my antenna below the rails and cross beams on my luggage rack.

And of course, part of me is interested if “tuned” ground plane has any benefit over just using a whole car.

I’m leaning towards drilling/tapping for a few ground plane radials, or just getting the 1/2 wave antenna.

[gman1971]

Another option I've found to be a good compromise is to remove the sharkfin/oem antenna on the roof and install the NMO mount there. I've relocated the sharkfin internal components to the spoiler or to the third tail light on my cars. Saves the hole drilling dilemma, its easily reversible and no more scratching paint magmount shenanigans, or any other magmount issues. Works sufficiently well, although its a little less optimal than drilling the hole in the dead center of the roof... but my cars/vans have large panoramic sunroofs so makes it quite impossible to drill holes on a glass roof... so, the only place left is the OEM sharkfin location. UHF is not as bad as VHF, a 6 inch antenna is not even noticeable on a minivan.

 

G.

[IronArcher]

Slick idea.

Unfortunately, I have no shark fins

[gman1971]

Well, it doesn't need to be a sharkfin, any regular antenna that is mounted in the roof would work, you just replace the entire base,  put the NMO and relocate the GPS/XM/AM/FM circuitry on the tail light.

 

G.

 

 

Slick idea.
Unfortunately, I have no shark fins

[1URFE57]

I have a habit of doing that.

I’ve just seen paint issues (maybe from dirt, some say from the rf, I don’t know.)

Also, I have a slight concern with a mag mount as that would put part of my antenna below the rails and cross beams on my luggage rack.

And of course, part of me is interested if “tuned” ground plane has any benefit over just using a whole car.

I’m leaning towards drilling/tapping for a few ground plane radials, or just getting the 1/2 wave antenna.

Been using mag mounts with my mobile setups and no issue with it I clean the base from time to time because it will accumulate moist, dirt and salt (winter, salt on the road/air). Last time I saw a ground plane on a mobile setup is from a friend using CB but you can try it, radio communication is a science you keep experimenting good luck!