Nmo base

[thesavo]

I am ready to have an installer drill the holes and install two NMO mounts of the roof in my new bronco sport.

I'm curious, what prevents the base of the antenna from scratching the paint as it's tighted down? I understand that I have to remove the whip before entering a car wash. So there will be a lot off on and off with that. I plan to have a Laird rain cap for each one.

Do I have anything to worry about?

Thanks

QWRCB - Laird Rain Cap for NMO Mount, Black Metal (Quantity 1) https://smile.amazon.com/dp/B06W9J2...abc_PDZ66XZKD1GQS03JSWR9?_encoding=UTF8&psc=1

 

[w8jfj]

Years ago, when I was installing GE and Motorola antennas the package included an "O" ring that the antenna would tighten on to to keep water/corrosion from getting up and under the antenna. Also protected the paint underneath.. Not sure if various suppliers include them any more. They should.

 

[w8jfj]

Something like this: (need to verify size)

NMO Mount Antenna Gaskets Washers Rubber 5-Pack HEAVY DUTY QUALITY - by W5SWL | eBay

(W5SWL location code 1FC). Neoprene Rubber Gaskets / Washers to fit NMO Antenna Mounts. Fits around the normal NMO body mount and seals out water and protects the car surface. Most antennas will use this style gasket to compress when tightened.

www.ebay.com

 

[merlin]

I put 3 NMO mounts on my Cadillac with no issues at all. There seemed to be no scratching at all removing antennas for car washes. The rubber gaskets provide enough protection.
If the NMOs are ever removed, there are plugs that will seal any holes.

 

[mmckenna]

I've never had an issue with antennas scratching a roof, unless someone went at it with a 18" adjustable wrench to "make sure it was tight". Just remember, it needs to be snug. It's not the one screw that holds the entire vehicle together. I've been doing this for 30 years, and never had an issue. I've had vehicles come to me straight from the dealership for antenna installs, and I have no qualms about doing it.

Some antenna manufacturers are better at this than others. Pick out good name brand antennas, not the cheapest thing that will fit. The gaskets (different than the o-ring) that come with the Larsen antennas will seal everything nicely and won't damage the paint.
EM Wave has a nice sealing design also. If you are doing all this work to put antennas on a nice new vehicle like that, don't skimp and buy the Cheap Chinese Antennas. Stick with the commercial quality stuff. It's worth the extra $1 you'll pay for them.

As for the antennas and gaskets, it's wise to remove them periodically and clean underneath them. Make sure the gaskets are good and there isn't any moisture accumulating under the antenna. It's a good idea to use some Armor-All on the gaskets periodically.

 

[thesavo]

Awesome. Thanks for the good advice. I was thinking about putting in a quad band radio. Does Larsen or anyone good make a fair antenna that will work on the lower ham bands?
10, 27 mhz in addition to 144,440 mhz?

 

[mmckenna]

Awesome. Thanks for the good advice. I was thinking about putting in a quad band radio. Does Larsen or anyone good make a fair antenna that will work on the lower ham bands?
10, 27 mhz in addition to 144,440 mhz?

The quad band radios are specific to the ham market, so I'm not aware of any reputable quality quad band antennas. I know there are some on the ham/hobby side, but never used them. The quad band radios aren't type accepted for CB, so you won't find anything for that market.

The good news is that you can get antennas like the Larsen NMO-27 or the Laird C27 will work well for CB. I believe the C27 can sort of "split the difference" between CB and 10 meters, with associated higher than ideal SWR on both bands.

On the 144MHz and 440MHz side, Larsen makes a couple of different dual band antennas designed for ham radio use that are good performers:
Larsen NMO-2/70 - longer antenna, more gain, will find low tree branches and parking garages. Known to whistle you a tune at highway speeds due to the open center coil. Spring can be purchased separately and the whip shortened to keep it tuned.
Larsen NMO-2/70SH - Shorter 1/4 wave VHF antenna with a close loading coil in the center. About 20" long, spring at the base so if you get in some low clearance areas you're probably safe. In mountainous locations, the 1/4 wave VHF designs can work better.

 

[thesavo]

OK. So limiting to the commercial and public service antennas, it would be best to split the setup. That's fine, I can work with that. I would rather focus on a good antenna and get a radio that will work with it.
There are only two quad band radios I can find. A discontinued yeasu and tyt 9800. I plan on two nmo holes so I CAn probably make two radios with remote heads work.

 

[mmckenna]

OK. So limiting to the commercial and public service antennas, it would be best to split the setup. That's fine, I can work with that. I would rather focus on a good antenna and get a radio that will work with it.

Yeah, good plan.

The antenna is the most important part of your radio setup. Far too many people will buy a $500 dual band amateur radio and then hook it up to the cheapest magnetic mount antenna they can get their hands on, and wonder why it works like crap. You are off to a good start with permanently installed NMO mounts. That puts you ahead of probably 95% of the amateur radio operators out there. Add a good antenna, and you'll be out in front.

Please post photos when it's done. I'd like to see a good install on one of those new Broncos.

 

[thesavo]

Photos. Definitely.

As for the antennas and gaskets, it's wise to remove them periodically and clean underneath them. Make sure the gaskets are good and there isn't any moisture accumulating under the antenna. It's a good idea to use some Armor-All on the gaskets periodically.

Also, since I have an unlimited carwash plan, I won't have that to worry about that. it will get removed quite often.

 

[thesavo]

So I am starting to have trepidations about the holes getting drilled. How much antenna performance would I really gain over a glass mount antenna.

 

[cwhill]

Honestly, as it’s been said if you want the best performance do it right. Have a radio shop drill the hole. I’ve taken every brand new ram truck I’ve owned and had a hole drilled. I also have unlimited car wash tag. I use a Larsen with the rubber gasket also pointed out here and never ever, ever had a single issue. When I trade in I put an NMO rain cap on and move on.

 

[mmckenna]

So I am starting to have trepidations about the holes getting drilled. How much antenna performance would I really gain over a glass mount antenna.

Comparisons between a center of the roof permanent install and glass mount antennas show 0.5 to 3dB of loss depending on location. 3dB is half the signal.
Depending on what frequencies you plan on using, glass mount antennas can be pretty tall since they need to be half wave. That may be a problem off road. It's also going to severely limit your antenna/band choices.

If you are not expecting much from your radios, then the glass mount will work well enough. If you want the radio to work well, then you know the answer.
As I said above, never had an issue with a permanent mount antenna, and never once regretted it.

 

[R8000]

If you are doing all this work to put antennas on a nice new vehicle like that, don't skimp and buy the Cheap Chinese Antennas. Stick with the commercial quality stuff. It's worth the extra $1 you'll pay for them.

Yup, 100% agree.
I used to cringe when a brand new public safety vehicle would roll in for a install and they handed me a box with a 10 year old light bar with faded lenses, and a 1/4 wave VHF antenna with a dry rotted base. When asked about new lenses and a new antenna, I was always told there was no budget for it and that I had to re-use "everything". *sigh*.
I love Larsen's base and seal design. I have used them for my own antennas for25 years with very little problems.