NMO antenna on aluminum L-bracket?

[jhal94]

So here I have purchased two antennas and an NMO 3/4'' BNC mount. I am wondering if this will work correctly
with an aluminum L-bracket that I have fabricated. The L-bracket has to be re-bored as the antenna doesn't have good contact because it's too thick as of now but i'd like to know if this will work at all before I pay someone for milling, however I am curious as to weather the bracket could pose reception problems. Here are a few pictures of my setup so far.

 

[LtDoc]

I figure it should work.
- 'Doc

 

[n9mxq]

Since there are so many aftermarket brackets that do the same thing. I'd say it'd work just dandy.


No bits were harmed in the posting of this message.

 

[N5TWB]

They make NMO mounts for that situation with a thick metal bracket.

 

[Rt169Radio]

Have you tried testing signal reception? Sometimes if my NMO antennas don't make good contact with the NMO mount, the signal is not too good.

 

[jhal94]

Have you tried testing signal reception? Sometimes if my NMO antennas don't make good contact with the NMO mount, the signal is not too good.

Signal is bad when on the mount because its too thick and doesn't contact. Without the mount it's great. I think i'm just going to have to mill it out deeper again, thanks everyone.

 

[KZ9G]

Round those corners off if you can. Bend over to pick something up and stand up and whack a nice cut.

 

[n5ims]

Couple of comments.

First off, with a bracket that thick a normal NMO mount won't do the job, you'll need one of the thick mounts (Thick Surface NMO Mount Hardware : The Antenna Farm, Your two way radio source) or the center connection won't make contact.

Second, I'd route the coax so it's much better protected. Perhaps inside the bed and into the cab through a well sealed hole where some existing wires feed through the chassis.

Third, I totally agree that the sharp corners need to be rounded off and ground smooth so they don't provide a guaranteed serious injury if someone simply walks by your truck a bit too closely. While this won't help if there's much of an impact, it will help for those slow pass by incidents. It should also help out with preventing a gas pump hose from being cut open by the sharp corners.

 

[Rt169Radio]

Yup, what n5ims said. ^

 

[mmckenna]

I've done that on a few installations with thinner aluminum and mounts designed for thicker surfaces. It'll work fine, but if you plan on transmitting, your SWR can get wonky due to the offset ground plane. Not an issue so much for receiving only.

You can get the NMO mount designed for the thicker surface, or you could mill out the underside a bit to allow it to fit properly.

Seal up the underside really well when you are done. Since the solder joint under the NMO will be exposed, and a bit of copper, you can have corrosion issues when it's exposed like that. Some RTV sealant will work fine. Visually inspect it often for signs of corrosion and deal with it before it gets too bad. Also, with any antenna, remove it often and inspect the mating surfaces for corrosion or water ingress. make a point of doing this whenever you wash your truck, etc. Putting a bit of Armor-All on the gaskets helps them last longer.

And yes, for Pete's sake, round off those corners! I had a friend that mounted a CB antenna like that many many years ago and was always gashing himself and tearing his shirt. Makes me hurt to look at it!