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Larsen NMO27 reviews? Pictures?

78k10

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I’m thinking about taking the plunge and drilling my roof for a Larsen NMO 27 for my CB. Can anyone give me some real world feed back about how well this antenna will work with a barefoot radio? I really like the more professional look vs the traditional cb antenna appearance. Also, can anyone provide me with some pictures of one mounted on the roof? I can’t really find anything on line to help me visualize how tall it is. Thanks.
 

prcguy

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The Larsen is very good, especially for its size. However, I really prefer the Laird/Antenex CWB27, which is wide band with no tuning from 26.8 to 29.7MHz, 67 1/2" long and puts out a better signal.

I’m thinking about taking the plunge and drilling my roof for a Larsen NMO 27 for my CB. Can anyone give me some real world feed back about how well this antenna will work with a barefoot radio? I really like the more professional look vs the traditional cb antenna appearance. Also, can anyone provide me with some pictures of one mounted on the roof? I can’t really find anything on line to help me visualize how tall it is. Thanks.
 

mmckenna

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I have one sitting in the garage, I'll try to get some photos later. Not sure if I have a photo of it on my old truck.

I've had the same NMO-27 for probably close to 30 years now. I've used it on multiple trucks. It's been off road, hit low branches, been through parking garages. No issues. The whip is pretty flexible.
Larsen has been making professional antennas for a long time. It's what they do. They are not a hobby/scanner/amateur antenna. They are made by a company that has a reputation of making antennas for public safety use. With a minor amount of maintenance, it'll outlast your truck and probably the 4 or 5 trucks that come after that. If something happens to it, you can buy replacement parts. You can buy replacement whips. If you want, you can install a spring on the base. If the coil has an issue, you just replace the coil.
Nice thing about NMO mounts, is that you can mount dang near any antenna you want from CB band on up into the 5GHz range if you use the right mount. If your needs change down the road, you keep the NMO mount and just buy a new antenna. No swapping out mounts needed. No gimmicks, no Chinese crap antennas, no hobby grade stuff.

I've always used them mounted on the roof of the trucks I've owned. With proper installation and tuning, it'll work. I was never into "talking skip", just used it for local use. It always did fine.

Last time I tested it, I put it on my antenna analyzer from work. Here's the plot:

Channel 1 was 1.31:1 for the SWR.
Channel 19 was 1.07:1
Channel 40 was 1.35:1

As PRC Guy said, the Laird would be a better choice if you planned on using it for 10 meter band. The Larsen isn't going to give you a low SWR across that much spectrum. Here's a wider look at the above plot:


The bandwidth is too narrow for CB and other uses. But for just CB it'll be fine. The longer whip on the Laird might be a benefit, maybe a slightly different radiation pattern giving you slightly more gain, but it adds length. If the longer length isn't an issue, it might be a good choice. I was always happy with the Larsen, so never felt the need to try anything else. After cranking through all the Radio Shack CB antennas and the like, when I got to the Larsen, I was sold.
 
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Here's a NMO27 on a hood channel mount.


It's trimmed about 2" shorter than the cut chart said (so 45" IIRC).

Overall, the performance is better than any other offroader I've encountered. I'm not going to say it's the antenna, but probably a combination of the fact both the antenna and radio are properly tuned.
 

RFI-EMI-GUY

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That Laird Antenex CWB27 or CW27 antenna is not in stock anywhere.

For CB, have had good luck with the NMO27 which comes in black or stainless. tuning as always takes care because you dont want to shorten it too much.
 

prcguy

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Hmm, well at least I have two CW27s sitting in my garage for something, not sure what that is though. When I see them cheap on Ebay I just buy them and any other orphaned antenna with a cute face.

That Laird Antenex CWB27 or CW27 antenna is not in stock anywhere.

For CB, have had good luck with the NMO27 which comes in black or stainless. tuning as always takes care because you dont want to shorten it too much.
 

MisterLongwire

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Here's a NMO27 on a hood channel mount.


It's trimmed about 2" shorter than the cut chart said (so 45" IIRC).

Overall, the performance is better than any other offroader I've encountered. I'm not going to say it's the antenna, but probably a combination of the fact both the antenna and radio are properly tuned.
And why was it not mounted on the roof like everyone would expect you to do? It could be any antenna but the "craze"is mount it on the roof...it has to be mounted on the roof. All i hear is mount it on the roof...mount it on the roof. C'mon guys...if one will not mount it on the roof leave it be. If it isn't a Laird...leave it be. If he/she/it is happy about it...good for him...but LEAVE IT BE
 

RFI-EMI-GUY

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And why was it not mounted on the roof like everyone would expect you to do? It could be any antenna but the "craze"is mount it on the roof...it has to be mounted on the roof. All i hear is mount it on the roof...mount it on the roof. C'mon guys...if one will not mount it on the roof leave it be. If it isn't a Laird...leave it be. If he/she/it is happy about it...good for him...but LEAVE IT BE
At least this isn't another one of those "I mounted a FireStick on my (truck bed, Camper, UTV (pick one)) and I have high VSWR" thread. I am in the midst of replacing my old vehicle and the dilemna is over getting what I want and having any roof ground plane. Love that Jeep Gladiator, oh the roof is plastic.
 

RFI-EMI-GUY

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78K 10

You will not be disappointed with a roof mounted, properly tuned NMO27 antenna. I had one on the roof of a huge E350 van, and though it hit a few obstructions giving the upper 9 inches a bit of a bend, it held up very well. It delivered all the power of my SSB radio, and was excellent for receiving.

You should probably unscrew it to go through car washes. It can get caught in the machinery.
 

mmckenna

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And why was it not mounted on the roof like everyone would expect you to do? It could be any antenna but the "craze"is mount it on the roof...it has to be mounted on the roof. All i hear is mount it on the roof...mount it on the roof. C'mon guys...if one will not mount it on the roof leave it be. If it isn't a Laird...leave it be. If he/she/it is happy about it...good for him...but LEAVE IT BE
I don't really care where someone mounts their antenna. If it works, it works.

But when someone posts with a question, we're going to answer it with the most accurate info we can. Mounting a mobile antenna with a proper ground plane under it _DOES_ make a difference, that's physics. Mounting it off to one side creates a directional pattern that may not work well for everyone. I fully understand the desire to adapt to the given situation, that's part of life. We do the best with what we have. But given a greenfield installation with no silly limitations like:
-I don't want to drill a hole.
-CB antenna needs to be no more than 19" long
-My budget is $3.98.
-Etc….
We're going to tell them how to do it right. If the OP wants to go a different route, that's totally fine with us.
 

mmckenna

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For CB, have had good luck with the NMO27 which comes in black or stainless. tuning as always takes care because you dont want to shorten it too much.
I've been disappointed with the black (NMO27B) whips. I had one of those and after a few thousand miles on the highway, bug strikes, low branches, etc. the black coating starts to come off and show shiny metal underneath. Works just fine, but looks crappy. I've been told that Larsen changed their coating, but I'm not sold.
If looks isn't the #1 concern, go with the chrome (NMO27C) whip.
 

krokus

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And why was it not mounted on the roof like everyone would expect you to do? It could be any antenna but the "craze"is mount it on the roof...it has to be mounted on the roof. All i hear is mount it on the roof...mount it on the roof. C'mon guys...if one will not mount it on the roof leave it be. If it isn't a Laird...leave it be. If he/she/it is happy about it...good for him...but LEAVE IT BE
The rack system on the roof makes things like roof mounted antennas prohibitive, since you cannot use both at once. (In most cases, obviously there are exceptions/variations.)

I had the same body Jeep, with a K40 mounted in about the same location, and it worked rather well. Yes, the radiation pattern was not perfectly concentric, but it was rarely a problem.
 

RFI-EMI-GUY

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There is a guy on Youtube with a VW GTI ham radio install. When he attaches a cargo box to the roof rails, he uses an NMO-SO239 adaptor and remotes the antenna to a bracket on the side rail. Dont know how that affects the tuning,
 
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And why was it not mounted on the roof like everyone would expect you to do? It could be any antenna but the "craze"is mount it on the roof...it has to be mounted on the roof. All i hear is mount it on the roof...mount it on the roof. C'mon guys...if one will not mount it on the roof leave it be. If it isn't a Laird...leave it be. If he/she/it is happy about it...good for him...but LEAVE IT BE
Simple, CB isn't a band I really care about. I needed it simply to interface with some groups I used to hang out with and as it's still somewhat ubiquitous in the off-road culture, I keep it in the vehicle. For personal communications between my family and others...there's a 1/4 wave VHF whip on the roof (the ski rack is only in use 1-3 weeks a year and comes off when not in use) just like there is with my other two vehicles.

Another problem with CB...when you properly align the radio and tune the antenna you will constantly deal with desense issues when sitting within 300 yards of other users. It's really not great for short range communications like that (another reason to attenuate by putting the antenna in a non-ideal location).
 

RFI-EMI-GUY

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Wait 3 months when none of the infrastructure in the country is being maintained because of quarantine quagmire and CB will be a thing again.
 

78k10

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That Laird Antenex CWB27 or CW27 antenna is not in stock anywhere.

For CB, have had good luck with the NMO27 which comes in black or stainless. tuning as always takes care because you dont want to shorten it too much.
So the only new NMO antennas on the market are either from Larsen or Browning, correct?

I probably won’t use the CB very often, but when I do I want it to work as well as it possibly can. Thus the antenna on the roof.
 

k7ng

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I have used the PCTEL/Maxrad MLBDC2700 with spring on front fender mount to good effect. The spring increases VSWR bandwidth for some reason. The DC-continuity model is also slightly more broadband. I get 1.6:1 or better across 26.9 - 27.45 MHz after tuning. I use a 'no-drill' vehicle-specific mounting bracket that fits under a fender bolt, IF I can find one for the vehicle of interest.
I used to buy the Larsen but I continuously ran into issues of the whip (no spring is available, to my knowledge) breaking off right at the cone. You can certainly get a cone and whip to replace, but I prefer not to have to. The 2:1 VSWR bandwidth is only about 2/3 of the band, as well. I have had fewer issues with the Maxrad. YMMV.
 

mmckenna

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So the only new NMO antennas on the market are either from Larsen or Browning, correct?
Don't put us through all these questions about good antennas and then bring "Browning" into the conversation.

Yes, a Browning will work, but they are a Chinese knock off brand. They are not on the same level of the Larsen, Laird, Antenex, etc. You might save a few dollars, but you'll likely not get the longevity out of it.
 

k7ng

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Also: I use an NMO mount that is relatively weatherproof, such as the Larsen NMOKHF and put a piece of adhesive-lined heatshrink at the coax crimp ferrule for best weatherproofing, for fender mounting. The 'regular' NMO mounts usually have a soldered connection to the mount, with a plastic cover which is in no way weather resistant. Especially here on the Oregon coast, with salt air, the regular NMO's go bad in months due to corrosion and moisture intrusion. I have had very little problems with the NMO's as I described above.
 
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