Mobile Radio Antennas on Aluminum Body Vehicles (F-150, etc.)

David_Webb · December 30, 2025, 2:14am

Does anyone have experience with putting mobile radio antennas on aluminum body vehicles? I have an F-150 pickup, and the magnetic mount antennas don’t work. I put a bracket, grounded to the body, where the windshield A Pillar meets the engine hood and the side panel. This works fine for the 2 meter band. It is terrible for the 70 CM band (SWR readings between 4:1 - 5:1), and is even worse for the 10 meter CB radio frequencies (SWR readings over 10:1). I’m guessing the A Pillar is reflecting the radio signal back to the antenna for the 70cm and 10m frequencies. I’ve never seen anything like this, even though I’ve put antennas on vehicles in several different places over the past 40 years.

Does anyone have any educated guesses, knowledge from experience, or insight into what is really happening, and what, if anything, can improve the situation?

Thanks for your thoughts and help.

73,

-Dave

Harry_Mamaux · December 30, 2025, 3:53am

@David_Webb

Dave,

Take a look at the Comet FO3ANTNCG. 2015 to 2020 Ford F-150 mount

https://www.gigaparts.com/fo3antncg-ford-specific-fender-mounting-bracket.html

You could use lip mounts like the Diamond K400CNMO or others, but would need to use grounding braid from the hood latch to the body. Additionally, you could use ground braid from metal to the back of your FT150 to provide additional grounding.

https://www.gigaparts.com/diamond-antenna-k400cnmo.html

or the Diamond K412CNMO

https://www.gigaparts.com/diamond-k412-2.html

or the Comet HD-5NMO

https://www.gigaparts.com/comet-antennas-hd-5nmo-heavy-duty-lip-mount.html

Each of these will mount to frame or hood, and use NMO base for mount to metal on your F-150.

David_Webb · December 30, 2025, 4:17am

Harry: I’ve looked at these type of brackets. The Comet FO3ANTNCG is not very solid. So I went with the bracket used for off-road lights. See the photo below. I confirmed the bracket is grounded to the truck with a continuity tester. It is solid and secure in high wind situations. Antennas on this bracket were fine for the 2 meter band but terrible for the 70 cm band and worse than terrible for the 10 meter band. Mystifying…