NMO antenna mount rain cap question…

Hello all,

I’ll be installing a GMRS radio soon. I won’t be leaving the antenna mounted all the time and am considering a cap for the NMO mount. They are available in plastic or metal versions. The common gripe with the plastic versions is that the threads are easy to strip. My thought is that I’d rather have the plastic threads on the $7.00 cap be stripped than the threads on the NMO base be stripped by a metal cap.

So — plastic or metal?

If there’s another place I should have posted this, I apologize.

Thanks in advance for your reply.

 

Either should be fine. True that either could be stripped or cross threaded but provided the cap is installed and removed with care, I don't see how either should be a problem.

 

Plastic. Avoid a poorly finished metal cap from oxidizing itself permanently onto the antenna. I just spent 20 minutes removing, with a pipe wrench, a fancy pants flexzilla garden hose from the hose bib. Almost tore the plumbing out from my house. Somebody thought it would be clever to use “aircraft grade” anodized aluminum for the hose end. I guess they thought they needed to make a 100 foot hose lighter? Anyway, aluminum goes great with brass after 5 months or so….not!

Stripping a thread shouldnt be an issue with plastic unless the threads are incorrect or poorly made. Mind sharing a link? I think I want one too.

 

I’m looking at this one. Unlike some others it has a hexagonal portion so I can take an adjustable wrench to it if need be.

Thanks for the advice, guys! More opinions are welcome.

 

I got the plastic. I've never had an issue with it for YEARS. They have a hex / 6 sided flange on them and I bet these knuckleheads who strip them are putting a tool on that flange. Just tighten it by hand to snug and then like a hair beyond snug. There's an o-ring in the base that seals up and compresses so it doesn't need to be super tight.
EDIT I replied to the first post, didn't see the last post. As I noted DO NOT take a tool to that flange.

 

I never had issues with a plastic cap.

 

This will work fine. I have one by Tram that looks just like it.

 

Thanks everyone for the replies.

@MeefZah: I would only take a wrench to the cap to remove it if it were being stubborn. I think I’ve seen in another thread that you keep a radio under the seat. Does it get hot? Has it melted or otherwise affected the carpet? I’ll be putting a Midland MXT575 under there. It’s 50 watts and has rather large cooling fins that suggest it gets hot.

 

I understand about the hex to remove it. That makes sense as I guess weather cycles and differing materials (plastic and metal) could potentially cause the cap to stick on there harder than you might like it to.

Yes, I have a IC 2730A under the passenger seat and have for years on several different trucks. It's got 'hook' velcro on the bottom and just sticks to the carpet. I have never had an issue with the radio overheating, or the carpet melting. There's plenty of airflow under there plus the cooling fins on radios generally are on the back of the unit, not the bottom, so as long as those remain mostly unobstructed you should be good. I'd have no converns about tossing any remote head unit under a seat.

 

Nice looking setup. Thanks for your reply. Have you had any issues with rear seat passengers kicking the head unit? Also, I notice you chose to mount the antenna on the passenger side. I was planning to mount mine on the driver’s side, mainly to discourage tampering by passersby when parallel parked at the curb. Can you imagine any issues mounting the antenna on the driver’s side and routing the cable through the firewall, behind the kick panel, under the driver’s door scuff plate, and then under the seat? I plan to get power by tapping into the wires that feed the 12v outlet in the center cubby. That should be sufficient unless I decide to run a fridge.

 

No issues with passengers though I rarely have them. It's not really realistic for passengers to shove their big ol' clodstompers up under the seat.

I actually have my current antenna (that was an older pic from when I had an antenna on each side, one for CB and one for 2m) on the driver's side and routed close to how you describe; though the coax goes through the firewall at the main harness, then under the dash to the center console, then under the console to the area adjacent to the passenger seat, and then out from under the console and under the seat to the head. I see no issues with your setup idea.

 

You're saying you plan on powering the radio off the 12v on the console? I don't know that it can reliably supply a 50w radio. You should really go to battery for that.

 

According to the Toyota owners manual the three outlets can handle 120 watts. I’ll give it a try.

Many thanks for your replies.

 

I have two way radios "under the seat" in both my 4Runners. I like to mount my radios on 3/8" plywood which also gives me room to mount a power distribution block near the radio. No problems with airflow or overheating, but I make sure nothing obstructs the fan on each radio.

I prefer to power my radios directly from the battery (using a relay, fuses and switch for control) rather than using in-cabin power. Powering directly from the battery (I use #10 or #8 wire) gives cleaner power. I can also power a scanner, cell charger and other low current accessories from the power block by the radio. I favor Anderson Powerpole connectors for convenience.

 

Thanks for that advice Photo8. I sent off an email to Midland about the cooling issue. They said that the head unit could be mounted as close to other objects as I want, without actually touching. The MXT575 comes with a mounting bracket. I have a nice piece of ½” Delrin that I’ll cut to size to use as a stand-off by mounting it between the carpet and the bracket. I’ll attach to the carpet using some barrel nuts and fender washers. (Velcro tape won’t stick to the Delrin.)

Cheers.