I installed my CB antenna using a mirror mount on the 3rd brake light holder.



Do I need to ground it? I thought I was fine until I saw some pics on here where people did ground it when using the same mounting spot. I was testing the ground using a volt meter and those 4 screws sticking out were all grounded. When I touched the mounting plate itself, it seems like it was not grounded. That doesn't really make sense since the screws are touching the mounting plate. I didn't really worry about it since my CB seems to be working fine. Whats the best way to test ground. And if I do need to ground what the easiest place back there to run the ground wire to. thanks

 

So long as your SWR is low 1.5:1 or lower and you are not getting any excessive noise or hash in receive mode (from alternator, fuel pump, exhaust, etc.) you are probably okay. Ideally, proper installation usually includes running a braided grounding strap from the mount to the frame (if the antenna mount is not mounted to the frame).

 

X2 The best way to tell if it's grounded is to do an SWR test if the SWR is good then it must be grounded at some point. Low SWR is very inportant, Hi SWR can cause severe damage to your radio.

 

K thanks, Ill have to get my hands on a SWR meter. This was a pre-tuned antenna (ya, I had to go the cheap RS route) so I haven't tested it yet.

 

The antenna installation is the most important part of a radio installation. Cutting your SWR from 2:1 to 1.5:1 doubles the signal getting to the antenna. I have two antennas mounted to the tire carrier. Here is what I found and did, and I am putting full power into the antennas.

The bolts that hold the tire carrier/ 3rd brake light to the rear tail gate have fiber washers and the bolts are painted. This makes it hard to get a good ground.
Replace the washers with metal ones and scrape off the paint and your ground will improve.
I also ran a ground strap from the tail gate to the bolt that holds the subwoofer on.
Good Luck

 

For a scanner - do antenna's need to be grounded to not hurt the radio as well? Or does that only apply to CB's?

 

Scanners will receive on most any antennas one cut to the correct length for the frequency most used will work better, grounding is recommended for all installations, Correct SWR and grounding is needed for any type of radio that transmits IE. CB/HAM Exc.
I guess to answer you question your scanner is safe.

 

Thanks!! I was thinking along those same lines - but wasn't sure if it only was necessary for TX vs. RX. Thanks!

 

I originally mounted my antenna there. when you put the hard top on (if you do), the rear wiper will hit.

mine seams to be working ok. it has the same potential as any other electrical device ground resistance. best to use swr to find ideal length. good luck.