For all you guys who used the spare tire carrier for your CB Antenna, did you use run a ground cord from your mount to a good ground, or just call it good?

I have not ohm'd mine out to ground yet, but just wanting suggestions. I put my CB in today along with the antenna mount. Going to run the cable tomorrow or Saturday and if I run a ground cable (which I probably will anyway just to be sure) would like to do so at the same time.

Just wanting to know if there is an overwhelmingly large group of people who haven't ran a ground and don't have problems so I could save myself the minor inconvenience.

 

The "ground" in the coax for the antenna is a shield to limit noise in the line from other sources. It is grounded only to make the shield be effective, not to transmit anything. If it is grounded on one end, it is fine. The fitting at the radio end will accomplish this. That's why magnetic mounts with rubber bases work. Just mount it and don't worry about it.

 

I ran a grounding strap just inside the rest door. Go thru the grommet and there is a ground right inside the little compartment.

 

Exactly what I needed to know. Thanks!

 

Are you looking to electrically ground the antenna for some reason, or provide a ground plane for the antenna? If looking for a plane, the rear tire mount is less then ideal unless you use a "no ground plane" antenna, which will be less effective but all you can hope for short of sticking a metal disc on your roof under a centrally mounted antenna. i used the adjustable tip firestick no plane kit and get decent swrs from the tire mount. its fine for trail use but i doubt it radiates well enough for any other short term use. you'd be better off grabbing a pair of frs/gmrs handhelds and just pass em off to your trail buddies... or get a ham lisence and get into a local repeater and never worry about range again!

 

Some just skip the repeater.....

 

I was just putting it there for trail use. We were using some cheap smaller cobra handheld walky talky deals, but inside the vehicle they had no range. My buddy had a CB already so I decided I'd just stick one on the Rover; plus it's a requirement for most offroad clubs.

The groundplane is what I was looking for. I'll have to read up on that. I was thinking the ground strap to the mount was going to create one.

EDIT: Looks like a groundplane for a CB would need to be at least 2-3 meters in size (quarter the size of wavelength of 11 meters). I doubt I'll put a peice of metal that big anywhere on my car. so I'll not worry about it I guess.

 

Yea CB's tough to get right on these cars, alot of plasic and fiberglass. Also, on the tire rack, you have obstructions on one side, and no conductor at all on the other. They still work fine for short range trail work, and they will still recieve fine for the most part. What the transmitt pattern actually looks like in real space would be awesome to see in 3d diagram. vhf/uhf are far more suited since thier wavelength is much shorter, thus antenna and groundplane lengths are far smaller, and can even be just simple short radials/counterpoise wires hangin to the side or out. a 4 foot antenna anywhere on the car is still probably going to be as good as or better then a handheld battery cb from inside the car with a lil rubber ducky antenna. if you havent already purchased the coax and antennas, grab a no ground plane kit, they are not as effective as a standard antenna, but since there is little to offer on the tire rack anyway on that terms, its probably much more effective on the tire rack position. I hardly use mine other then to listen in, so i dont really have a good basis on to see what kind of transmitting power/radiation pattern im actually getting. i was toying with the idea of getting a cb field strength meter but ive just never gotten around to buying one since i dont use it much to begin with. plus other then on trails, the modern cb world is horrible... its the wild west of radio, people broadcast for hours at massive wattage levels all over clogging up channels with nonsense... and there is zero fcc enforcement anymore unless you happen to be be disrupting something vital and they not only find the source and file a complaint! you could run 2 cb antennas in cophase but that requires a minimal distance between the antennas to be over 5 feet, with 9 feet being optimal, no worries about ground plane in that setup, but its also highly directional front and back, with short range side to side. looks pretty badass, but thats on big rigs, might be goofy on a lil ol disco haha

 

You guys are definitely taking this to another level. Another option if you have an aftermarket bumper is to locate it up front. That will remove some of the obstruction issues. I know ARB's come with tabs mounted for that purpose.

Here's a link with some info regarding NGP antennas: No-Ground Plane CB Antennas | Right Channel Radios