How to Ground Your CB Antenna?
A CB antenna transmits/radiates signals downwards, vastly different from traditional antennas that project their signals horizontally or at an angle from vertical. Therefore, a metal surface below this CB antenna is required to reflect the transmission into the atmosphere.
The larger and flatter the surface, the better. Now, in this article, we’ll show you how to ground your CB antenna properly. If you are interested, read on.
Table of Contents
Importance of Having a Proper Grounding Plane for Your Antenna
Without a proper grounding plane, the signal will not make it all the way to the atmosphere, resulting in a rather unsatisfactory transmission range. There will also be high levels of Standing Wave Ratio or SWR, that is, the signal generated by the unit being fed back into the transceiver, causing internal damage to your radio unit.
A poor grounding plane will not affect your radio reception. You will still end up receiving a radio transmission from radios elsewhere, with varying degrees of success. However, you will have difficulties in sending out transmissions.
Of course, there are different systems that do not make use of a grounding plane. They use a shield in the coaxial cable instead. Take note that the hardware for a ground plane and a non-ground plane system cannot be substituted for one another, as they are incompatible.
Things to Take a Note of Before We Begin
There are a small number of things to take note of before warping into the installation process. Firstly, check if your antenna can be used with a coaxial plug. If so, it is a simple process of just attaching the mount to the frame of your truck or car, and you should be ready to go. If not, you will need to provide a ground some other way.
Many people prefer using 10-gauge wire. We recommend using braided ground straps for convenience.
Secondly, we determine the best place to ground the antenna system. A good thing for us is to note down. A good idea is to bond several of the metal parts (for example, the trunk lid to the side panel) using ground straps.
This provides two benefits. One, this negates the effect of floating off the negative power lead from the battery. Two, you do not need to place and trace a strap from the battery within your body panels all the way to the antenna mount.
The Best Place to Mount the CB Antenna
Here are some of the best places to mount the low-profile CB antenna.
The best place to mount an antenna would be a car’s trunk lid. A screw right beneath the lip is ideal. The hinges pose a problem, not being a proper ground, which can be easily solved by attaching ground straps, one on the lid and the other on the frame.
Take care to cut out just enough strap to allow the boot to open, and on the flip end, not so much that the strap becomes too baggy.
Similarly, the antenna can be mounted on the front side panels or on the front bumpers (as on the trucks the United Nations deploy).
Again, the most rudimentary step of a good ground is to mount the mount of the coaxial cable to a metal surface. Do not place the mount on any other materials, such as plastic. Attaching additional grounding straps to the mount will also help improve the ground performance.
Tools and Materials We Will Need for Grounding
- A multi-meter (analog/digital, any will suffice)
- Grounding straps (at least 20)
- A screwdriver set
- A paint scraper
- A wrench
General Steps for Grounding and Installation of the Mount
Here’s the step-by-step guide for you:
Step 1: Marking
With a marker, mark the point in the trunk lip/panel where you want to install the set screw for the mount. The underside of the trunk/panel is often painted. Gently scrape away some of the paint on the mark with a paint scraper to reveal the metal below.
Step 2: Bond
Bond all the separate panels and trunk with a grounding strap. This step could be foregone if the manufacturer went out of their way to provide a grounding spot for the car, where the mount for your antenna would be installed.
This step is also not necessary for unibody vehicles as everything is welded together into place.
Step 3: The Multi-Meter
Test if your multi-meter is working properly. To do so, simply touch the two probes together. If the needle turns on its axis to the right. This indicates a good working device. In the case of digital multi-meters, a reading should pop up on the screen.
Step 4: Probe
Lay the first probe where you would want to install your set screws/mounting bracket. Touch the probe to the bare metal we scraped earlier and not anywhere else on the vehicle.
The next probe involves the vehicle’s battery. Exercise caution in this step. The second probe should touch the battery’s negative terminal (very conveniently marked with a negative sign). Do not, under any circumstances, touch the positive terminal (also conveniently marked with a plus sign).
Step 5: Interpretation
The needle of the multi-meter moves all the way to the right as the probe touches the two different points. This is representative of a fine grounding. If there is negligible or no movement at all by the needle, we need to improve our grounding or reconsider the position of the mount. Redo the previous steps in this case.
A fine grounding means we have established a solid grounding plane for our antenna.
Step 6: Installation
Now that we have a good grounding plane, we can move forward and install the mounting hardware for the antenna and the antenna itself from there onwards.
Always keep in mind that the key to creating a good ground is attaching the ground to metal parts instead of plastic, wood, or other materials. Remember to place the coaxial cable’s hot side to the antenna.
Use the multi-meter to discover better grounding points, move the antenna, and mount there to establish a finer ground.
Metal-to-metal contact is highly effective for grounding. So scraping away at the paint at the mounting point is ideal but not recommended for aesthetic purposes. You should have no problems with the reception after establishing a proper ground.
So, there you have it! Be it an original installation, or finding a less than ideal SWR, or not getting the CB radio performance you should, follow the steps above, and you will have a stellar radio reception easily and efficiently!