Vehicle Antenna Mounting Basics

Some modern vehicles are equipped with collision-avoidance sensors and/or cameras. If your vehicle includes such systems, please note that an antenna positioned within the sensors’ or cameras’ field of view, one that moves while the vehicle is in motion, or one that is a color other than black may cause interference or reduce system performance. It is strongly recommended that you consult your vehicle dealer or manufacturer prior to installing any antennas or accessories to ensure compatibility with the vehicle’s safety systems.

How To Install An Antenna On A Vehicle

1. Choose the Right Antenna Type

Common mobile antenna mounting types:

Magnet mount – easiest; great for temporary or non-invasive installation.
Trunk-lip, Boot-lip, Bonnet-Lip, Gutter mount – stable, semi-permanent or permanent
Bullbar or mirror mount – typically used for trucks, vans, RVs.
Tilt mount – typically used out buildings construction sites and Marine.

Choose an Antenna based on:

Desired range (longer antennas = longer range but not as good in hilly country)
Whether you want a permanent or removable setup
Vehicle type (Boat, Bike, Car, Truck, Tractor, SUV, RV, 4WD)
Think of the conditions

2. Select the Antenna Mounting Location

The higher and more centered, typically the better the performance.

Center of the roof give the best ground plane meaning the best overall performance (Not always practical)
Side of the Vehicle, Roof edge, Bonnet, boot-lip
Bumper, Bull Bar (least ideal; poor ground plane)

Important:
The antenna needs a good ground plane, meaning a metal surface under it for the best signal. there is also options for ground independent that will partly compensate for reduced ground planes

Pick the best antenna to suit what you are using it for – The following drawing is more focused on VHF, UHF & Mobile Phone Antennas. The more gain or dB of the antenna typically the more line of sight for the signal to travel if in flat terrain the higher gain is better. In hillier gain less gain can work better

3. Install the Mount or Base

Mag-Mount Antenna

Clean the roof to avoid scratches.
Place the magnet on a flat steel surface.
Make sure the coax exits without being pinched by doors window etc...

Trunk-Lip, Boot-Lip or Roof-Lip Mount

Loosen the clamp screws.
Slide the mount over the lip of the trunk or hatch.
Tighten screws evenly.

Bumper/Mirror/Side Mount

Bolt the bracket securely to a rigid metal part.
Ensure the mount has ground contact.

4. Route the Coax Cable

Good coax routing avoids noise, interference, and damage.

Do:

Run through door seams or weather stripping without crushing the cable.
Keep away from hot engine parts.
Keep away from high-power electrical lines (like alternator wires).
Use existing cable channels when possible.

Don’t:

Coil excess coax tightly.
Instead: loosely loop it (8" loops) or route the full length.

5. Connect the Coax to the CB Radio

Connect the PL-259 connector to the back of the radio.
Do not overtighten.
If your antenna uses a separate grounding wire, attach it to bare metal.

6. Tune the Antenna Using an VSWR Meter

Tuning is essential for:

Better range
Protecting the radio from signal reflection

You need:

An VSWR meter (or a CB with built-in VSWR)
A short jumper coax (if using external meter)

Procedure:

Connect the meter between radio and antenna.
Set CB to Channel 20 (middle of the band).
Key the mic and read VSWR.
Adjust the antenna length:
- High SWR on lower channels: antenna is too short → lengthen it.
- High SWR on higher channels: antenna is too long → shorten it.
Aim for SWR 1.5:1 or lower (ideal is 1.1–1.3).

7. Test Your Setup

Turn on the radio and check reception.
Make a radio check call (“Radio check please” on channel 19 or 14).
Inspect for wind noise, rattling, or loose mounting hardware.

8. Maintenance Tips

Periodically tighten your mount.
Check coax for wear or pinching.
Keep the antenna whip clean and rust-free.
Avoid automatic car washes with tall antennas attached.