Grounding - how important for mobile scanner use?

[KI4LIV]

I am curious - how important is it to have a good ground for an exterior mounted antenna on your car?

Lets say you have one of those cars that doesn't have a grounded trunk, but youre using a trunk lip mount antenna on the trunk? How much of an improvement would you see by grounding it?

What kind of impact would it have when monitoring... lets say 800mhz trunked systems for the sake of discussion?

 

[rpgbigman]

YOU NEED A GROUND.
I put a ant on a Plastic pcs on my Van and I had a heck of a time hitting Repeaters. I put a Ground on it and took care of the problem!
I also had 2 ants in my back window that I didnt' have Grounded and always had problems picking up local stuff. but after I grouned them I pick up lots of stuff now. so YOU NEED A GROUND. just run a Wire from the Trunk to the bottom of the ant mount.

 

[N_Jay]

YOU NEED A GROUND.
I put a ant on a Plastic pcs on my Van and I had a heck of a time hitting Repeaters. I put a Ground on it and took care of the problem!
I also had 2 ants in my back window that I didnt' have Grounded and always had problems picking up local stuff. but after I grouned them I pick up lots of stuff now. so YOU NEED A GROUND. just run a Wire from the Trunk to the bottom of the ant mount.

At 800 MHz any "piece of wire" over 3 inches is not a "ground", its an extension to the antenna system.

If the antenna mount is bonded to the trunk lid, and the trunk lid is metal, and the coax shield is good, then you are fine.

 

[KI4LIV]

At 800 MHz any "piece of wire" over 3 inches is not a "ground", its an extension to the antenna system.

If the antenna mount is bonded to the trunk lid, and the trunk lid is metal, and the coax shield is good, then you are fine.

Thats what I thought - at least for receive purposes.

 

[N_Jay]

Thats what I thought - at least for receive purposes.

Even for transmit.