One of the most commonly asked questions about CB antennas is if they need grounding. Do they? We answer this question in detail within this article.
Must I Ground my CB Antenna?
It depends on what you are using. When using a standard CB antenna – anything apart from a no-ground plane or NGP kit – you must solidly ground your Antenna mount on your vehicle’s chassis. You may achieve good ground by ensuring that your CB antenna mount exhibits a direct metal-on-metal connection to the frame of your car.
We must emphasize the importance of attaching the antenna ground to metal instead of plastic or other available materials. Additionally, the hot side of the coaxial cable goes to the Antenna itself. Note that the ground is the side originating from the shield of your coaxial cable.
The Consequences of Incorrect CB Antenna Grounding
Do not confuse an antenna ground plane with an electrical ground. A standard mobile CB antenna transmits in a downward pattern instead of horizontally. Place a metal surface – the bigger and flatter the better – underneath the CB antenna to facilitate the effective launching of the signal to the atmosphere. Failure to obtain a good ground plane surface prevents the signal from traveling into the atmosphere and, in turn, a limited transmission range.
The absence of a proper ground plane may also damage your CB radio. Why so? An improper ground plane results in a high SWR, causing the signal to back feed into the transceiver and consequently internally damaging your CB radio.
However, it’s worth mentioning that an inadequate ground plane or radiating surface may not interfere with your CB radio reception. It may not prevent you from receiving transmissions from other radios. In any case, even a clothes hanger can help you receive transmissions.
Once you are done working on your antenna ground plane, check and set your CB antenna to confirm its functioning correctly. When operating with a fiberglass boat or vehicle, you’ll require a no-ground plane antenna. In such cases, you’ll need a coax shield for counterpoise – a substitute for ground connection.
Tips for a Successful Ground Plane Installation for a CB Antenna
1. Target Ample Antenna Height
One way to get the best CB antenna performance is to get 2/3 of the Antenna above your vehicle’s roof line. It helps to deliver efficient transmission and reception. At a minimum, make sure that the tip of your Antenna is above the car’s roof line, lest you suffer massive performance issues.
2. Remember to Tune your Antenna
You know that antenna tuning is a must for your CB installation to be successful. Don’t fret if you don’t know how to go about it. Utilize the available video tutorials and written guides. It’s pretty straightforward.
3. Ground your CB Antenna Mount
We mentioned this earlier, and it’s something worth repeating. Solidly ground our antenna mount to the chassis of your vehicle. It’s impossible to work on bad ground. First, you’ll have issues tuning your Antenna (it becomes un-tunable), and secondly, you’ll have to deal with the consequences of sky-high SWR levels.
A proper ground goes beyond ensuring that you’ve achieved a direct metal-on-metal connection of your CB antenna mount to your vehicle’s frame. Check if the mount antenna location has paint or powder coating. If present, you may have to scrape off a bit of the powder or paint coating as it can negatively interfere with the connection. (1, 2)
You may also run a short grounding strap from your mount antenna to the grounded part of your vehicle. Remember to keep the strap as short as possible.
How Do I Know I Have a Good Ground?
Can you tune your Antenna? If yes, you are certainly almost there because you cannot tune a non-grounded antenna. It’s impossible. If your CB Antenna is tunable, congratulations. You are on the right path.
No matter what you do, take care of your coax – it’s the one responsible for carrying the signal from the radio to the Antenna. It shouldn’t be overly crimped or impacted at whatever point. Create extra space or use a plush rubber gasket to cushion the coax from the door if carrying it in the vehicle alongside a door frame. Should you have a lot of extra coax in the end, store it properly. Wrapping it in a long narrow shape with extension cords helps keep it in shape. To keep it in place, use two zip ties on both ends. Avoid a circular coil shape as it tends to cause radio frequency issues that can negatively impact your signal.
Take a look at some of our related articles below.
- How to make a ground plane for CB antenna
- How to tune dual CB antennas
- How to tune a CB antenna without an SWR meter
(1) powder coating – https://www.architecturaldigest.com/story/powder-coating-furniture
(2) paint coating – https://link.springer.com/chapter/10.1007/978-1-4615-0531-0_13