After examination of several NMO Mobile Mount Options in a previous post, I shrunk the field to two choices: a 3/8″ and a 3/4″ inch both from Laird.
I definitely notice a strong bias toward the use of the 3/4 inch hole mount over the 3/8 inch. Reasons vary from “It’s Stronger” to “You can install entirely from the outside” to “The whole mount plus its cable can be removed and re-installed into another vehicle.”
The last two points seem perfectly valid and are very good reasons to go with the 3/4 inch mount. The first seems like wishful thinking.
To get a better idea of how these mounts mount, I took a scrap piece of metal and punched four holes in it: two 3/8 and two 3/4 inch holes. I mounted the two Laird contenders into two of the holes. The remaining two holes are simply there for reference.
I am not entirely sure why I did this, but the test plate provided me a way to see how these mounts function up close and personal. I also handed the test jig to several mechanical engineers, a few machinists and others who have nothing to do with mobile mounts. I wanted their honest unbiased assessment of which style mount is stronger. They all took a good hard look at each mount both from above and below. Here is what they saw…
Their thoughts summarize to:
- The 3/4 inch mount with its much larger thread area between the top antenna piece and the bottom foot should be stronger than the far more narrow thread coupling of the 3/8 inch. That said the universal feeling is other parts of the mount and/or the mounting surface will fail before either threaded coupling.
- The foot of the 3/4 mount grabs at the tips of the flange while the 3/8 mount engages far more area of the mounting surface.
- Most folks appreciate the unique ability of the 3/4 mount to install completely from one side. One was heard to say… “Nice.”
- All mentioned if push came to shove, the 3/8 inch would win the “Let’s rip the antenna off the vehicle” test since two little flange tips are a lot less “grabbing” area than the entire flange.
- Most said, however, both designs would probably damage the vehicle long before they failed. They were quite impressed by the whole NMO mount approach.
I installed the 3/8″ mount on my Taurus along with a 19 inch whip. It works just fine and looks trim and neat. Does it work better than my mag mount? Well, maybe just a little, but testing awaits.
I know I wish I had these pictures before I bought “one of everything” to examine. I hope the pictures above allow readers of Ham Help Desk to make a better informed choice for their next through-hole antenna installation.