GMC Sierra 2500 HD AT4 (2024) - Antenna Placement Options

[htdnet]

So I have a Uniden BearTracker 885 Hybrid and a Uniden SDS200 that I've settled on mounting them inside the center console. Bonus it will hide the electronics out of view, con it will obscure my view of the displays unless I flip open the center console. Too bad neither have a removable head like hams or I would just put them under the vehicle control buttons in front of the cup holders, not that I really need access to the CB but viewing the scanner information can be somewhat important.

My problem is finding antenna mounting positions or options that don't look dumb. The rear I'll probably put the CB Antenna with some kind of tailgate mount with a fiberglass whip but I need either a left and right mount for the two scanner antennas or a dual mount, and I have no idea where I should mount them. I've seen some hood mounts but that might look dumb to have two additional antennas plus the AM/FM stock one. I don't think a third break light mount is a good idea but... that is mounted to a piece on the roof which is separate from the cab roof that I could possibly access for mounting points, I just don't know what that would look like without pulling the headliner down and removing that piece.

I will be installing a powered cover for the bed which may prevent mounting spots on the rails but may also produce additional points to mount depending on its construction.

Has anyone had an success finding other ways to mount to this vehicle?

 

[mmckenna]

Has anyone had an success finding other ways to mount to this vehicle?

Probably not what you are looking for.

Anything short of center of the roof is going to have some amount of compromise. Antennas want a ground plane under them, and ideally that ground plane needs to be 1/4 wave length at the lowest frequency in all directions under the antenna. Getting a 1/4 wavelength on CB on a road legal vehicle is impossible, but the more you can get the better.

Same with the scanner, but due to higher frequencies (compared to CB), the ground plane can be smaller.

Ideal setup is the CB antenna mounted dead center on the cab roof. Scanner antenna at least 18" in from any roof edge.

Gets to be a challenge if you have a sun roof. Even more of a challenge if you are reluctant to drill a hole. But it really is worth it if you want your radios to perform to their full potential.

If you are dead set against that, then you have to deal with the reduced performance. Decisions to make will be on what you are willing to put up with.

A CB antenna can work fine behind the cab on a bed rail. No, not ideal, but it'll work. You can mount off the fender also.

Scanner antenna with the higher frequencies will easily get shadowed by the cab, so you don't want that directly behind the cab, and front fender mounts are less than ideal.

There are mounts that will go in between the cab roof and the third brake light. Some issues though:
The mounts are expensive.
They are difficult to get them to seal correctly, and many users report leaking water into the cab.
They put the antenna at the edge of the ground plane, which results in a directional pattern.

And remember, you want separation between the antennas. Too close and you can get enough RF into the scanner front end to damage it. Also, if the antennas are not spaced apart, it can make them directional, also.

So, decision making time….

 

[htdnet]

Thanks mmckenna great information! I was able to find a mounting point on the third break light mounting bar which extends the width of the cab but is not technically "part" of the cab itself, it is a separate piece. I would have to remove the headliner to access some bolts to remove it and then I can dill into it for the mounts. However it only has about a 6" x 6" area I could mount it to on either side and I think it is made of plastic so I may need to get creative to ground the antenna mount out to the frame somehow, like you said not ideal probably could do better with the larger surface area for the scanner antennas but most of what I listen to is 800mhz digital from the county and generally I could receive that out here with an antenna inside the cab on a cookie sheet lol. Although trying to listen for other frequencies or distant ones might make that less than ideal.

 

[mikewazowski]

I ended up with one antenna on the roof for my main VHF/UHF/800 radio and two front fender mounts. One for a scanner and the other for less important radios.

 

[NYAirOne]

htdnet

I had a 2021 GMC Sierra double cab that i used one of those NMO fender mount brackets on. Its very easy to mount the bracket and i had good results with everything that i listened to on my scanner. If you look on the Antenna Farm website you can see the brackets for each vehicle. If you open your drivers door look about half way down the door pillar and you will see a rubber body plug. You can run your coax through that and it will come out under the dash. I had the bucket seats with the full floor console. I brought it around the front of the console under the dash and between the console/dash. i was using a handheld in my cupholder. With the bracket mounted to the fender, you can sneak the coax between the rear of the fender and the firewall down to that rubber plug. I made a slice in the plug and fed my coax through it and then used some rtv sealer just to make sure no water got in it. I have a Larsen 150/450/800 scanner antenna. If you are going to take that roof spoiler off be careful because there are special sealing washers that seal the holes to the roof. I work at a GM dealer and we have had issues with some water leaks in trucks. I just got a 2024 Chevy Silverado and will be doing the same thing to it as i had on the GMC. I also had a 2018 Silverado and a 2014 Sierra that i have used those fender mounting brackets on in the past with no problems.