Stick-on steel disk for mag-mount antennas on aluminum or fiberglass

[AK9R]

I did not know that this product existed, but I'm not surprised that it does:

UNI-MAG Mounting Plate for Aluma Duty Trucks and RV's

The UNI-MAG mounting plate provides a magnetic surface for vehicles with alloy, plastic, or fiberglass roofs. It's a perfect companion for the UNI-MAG antenna mount. The strong 3M adhesive affixes the plate to virtually any surface allowing you to easily mount your UNI-MAG antenna mount.Measures...

www.ruggedradios.com

Someone asked about this in a Ford Expedition forum (Expeditions since 2018 model year have aluminum bodies). The poster noticed this disk stuck to the roof of his Expedition and didn't know what it was.

 

[bharvey2]

My family and I went on a driving trip a few years ago and rather than caravan we decided we were going to rent a large SUV. The possible candidates were a suburban (steel body) or an Expedition (aluminum body) As such I bought a couple of the disks you mentioned. I did a few tests in preparation. The disk seemed like it might be able to handle a small 2M/70cm mag mount antenna But it didn't seem to have enough ferrous mass to confidently hold a larger CB mag mount antenna. Mind you, I was concentrating on the magnetic capabilities of the disk and hadn't even made it to the adhesive strength. Perhaps there are different sizes of these adhesive steel disks but I wasn't comfortable enough with them to put them in action. Fortunately, we rented a Suburban and I never needed to use them.

 

[slowmover]

NMO34 + W640 the HF whip candidate.
Even if it took a triangle of three.
(DIY the better approach).

Best to make the cut.

.

 

[AK9R]

This is a photo of one of these disks stuck to the roof of a 2020 Ford Expedition with unknown miles:

 

[mmckenna]

If that's the 3M VHB stuff, and the surface is well prepped, it's probably fine for a small mag mount antenna.

As for mounting on a fiberglass roof, 5.5" isn't much of a ground plane, barely enough for 800MHz. No where suitable for UHF, VHF or CB on a non-metallic roof.

I get that some don't want to drill holes, but I'm always surprised at the lengths people will go to. This still has the drawbacks of a mag mount with the added complication of that VHB probably being very difficult to remove from the vehicle if needed.

 

[bharvey2]

If that's the 3M VHB stuff, and the surface is well prepped, it's probably fine for a small mag mount antenna.

As for mounting on a fiberglass roof, 5.5" isn't much of a ground plane, barely enough for 800MHz. No where suitable for UHF, VHF or CB on a non-metallic roof.

I get that some don't want to drill holes, but I'm always surprised at the lengths people will go to. This still has the drawbacks of a mag mount with the added complication of that VHB probably being very difficult to remove from the vehicle if needed.

It seemed a bit "hokey" to me. I only bothered to entertain the idea because it was for a rental. I "REALLY" don't like antenna cables flopping around when I'm driving so if a permanent installation is in the cards, I'd rather go that route. (buttocks)x0.5 installations just cause too many problems to deal with. Might as well just have an HT in the car.

 

[nokones]

My family and I went on a driving trip a few years ago and rather than caravan we decided we were going to rent a large SUV. The possible candidates were a suburban (steel body) or an Expedition (aluminum body) As such I bought a couple of the disks you mentioned. I did a few tests in preparation. The disk seemed like it might be able to handle a small 2M/70cm mag mount antenna But it didn't seem to have enough ferrous mass to confidently hold a larger CB mag mount antenna. Mind you, I was concentrating on the magnetic capabilities of the disk and hadn't even made it to the adhesive strength. Perhaps there are different sizes of these adhesive steel disks but I wasn't comfortable enough with them to put them in action. Fortunately, we rented a Suburban and I never needed to use them.

The Firestik mag mounts do not stay in place on the later model Truck bodies. However, the K40 mag mount bases do well probably because the antenna whip has less wind drag than the Firestik and will bend in the wind easier. The Firestik antennae have more wind drag and will are not as wind forgiving.

Any speed above 40 MPH will blow off the Firestiks.

 

[nokones]

If you intend to do one of those sticky discs, clean the surface with a wax/cleaner before you stick the disc on the body panel and use a quality non-ground plane antenna such as a Laird/ T E Connectivity antenna.