Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: [1] 2 Next   Go Down
  Print  
Author Topic: NMO or ?  (Read 9265 times)
K6DTF
Member

Posts: 9




Ignore
« on: December 07, 2016, 06:39:54 PM »

Just ordered an antenna mount. Now need to order an antenna for my jeep. But need to know whether to go NMO or ? Thanks in advance.
Logged
K5LXP
Member

Posts: 5293


WWW

Ignore
« Reply #1 on: December 07, 2016, 08:49:28 PM »


NMO is the commercial standard.   You find a better selection of antennas in NMO than any other mount, so there's little reason to pick anything else.

Mark K5LXP
Albuquerque, NM
Logged
W8JX
Member

Posts: 12080




Ignore
« Reply #2 on: December 08, 2016, 01:59:00 AM »


NMO is the commercial standard.   You find a better selection of antennas in NMO than any other mount, so there's little reason to pick anything else.

Mark K5LXP
Albuquerque, NM


Not quite true.  While NMO is a standard, 3/8-24 stud mount is a commercial standard too. The later is a stronger mount allowing it to support heavier antennas and also quick disconnects. If you only plan to use VHF/UHF antennas you can go with NMO but if you may play with HF too you should consider 3/8-24. NMO mount antennas usually cost more too.
Logged

--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
G8YMW
Member

Posts: 656




Ignore
« Reply #3 on: December 08, 2016, 05:31:00 AM »

Over here in the amateur radio market, the NMO mount is about as rare as rocking horse manure.
Not sure about the PMR market
Logged

73 de Tony
Windows 10:  Making me profane since March 2017
W8JX
Member

Posts: 12080




Ignore
« Reply #4 on: December 08, 2016, 08:08:46 AM »

Over here in the amateur radio market, the NMO mount is about as rare as rocking horse manure.
Not sure about the PMR market

The 3/8 x 24 is a lot older standard than NMO. Is it popular there?
Logged

--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
G8YMW
Member

Posts: 656




Ignore
« Reply #5 on: December 08, 2016, 06:23:04 PM »

Yes it is John, most HF and CB whips are 3/8. VHF/UHF are SO239
Logged

73 de Tony
Windows 10:  Making me profane since March 2017
K7RBW
Member

Posts: 481




Ignore
« Reply #6 on: December 08, 2016, 07:36:04 PM »

The 3/8 mount is pretty solid, but is suitable for 1/4 or colinear type of antennas because it has only the center conductor. The NMO connector supports 1/4-wave antennas as well as base-loaded coils because it provides both conductors: center and ground. I like the NMO mount for the variety of antennas it supports, but they are mostly 30 MHz and above. For HF and lower bands where the car body is 1/2 of the antenna, the 3/8 mount makes sense and supports some pretty solid antennas.

For a Jeep, I'd stick with an NMO mounted on a fender (front or rear). Keep the antenna short and out of the way. You give up some range and gain some longevity; however, on VHF freqs, the terrain is usually the limiting factor more often than the antenna.
Logged
KK4YDR
Member

Posts: 673




Ignore
« Reply #7 on: December 09, 2016, 01:14:17 AM »

Like W8JX said ... NMO is great for a lightweight antenna and they are water tight and they work wonderful but ....big long HF whips require the strength of 3/8-24 mount.

I have an NMO to 3/8-24 adaptor and I have never used it out of fear of bending or damaging the sheet metal on the roof of my truck.
Logged
KT4NR
Member

Posts: 548




Ignore
« Reply #8 on: December 12, 2016, 09:55:25 AM »

Just ordered an antenna mount. Now need to order an antenna for my jeep. But need to know whether to go NMO or ? Thanks in advance.

Since you already ordered the antenna mount, that kinda drives the antenna to get. Thus making this whole conversation moot. It seems that the tastes great, less filling crowd skipped that. Adapters from one to another add loss and mechanical weakness that is really not desired. So what mount did you buy?

Also, what bands are you looking for an antenna for?

FWIW, however, as an academic exercise....

If you are in the market for 10m or HF then yes, 3/8x24 will work. While you can get antennas that have other connectors, 3/8x24 is the most plentiful on HF.

If you are in the market for VHF and above, NMO is superior and will take a beating on the trail better. Not to mention it is waterproof and nearly indestructible if you buy a good one. The Larsen NMO270 is about the best you will get for 2/70cm antenna.

I have had both Diamond and Comet NMO antennas in the past. They fall apart pretty easily so buy Larson. (I run an NMO270 on my 4Runner which does see both on road and off road use.)Remember, skip the gain game and look at pattern. You do not want lobes in weird places giving you dead spots.

Enjoy!
Logged
W8JX
Member

Posts: 12080




Ignore
« Reply #9 on: December 12, 2016, 01:18:07 PM »

If you are in the market for VHF and above, NMO is superior and will take a beating on the trail better. Not to mention it is waterproof and nearly indestructible if you buy a good one. The Larsen NMO270 is about the best you will get for 2/70cm antenna.

You are being way too generous. NMO is a relative new comer to market compared to 3/8 x 24 and no where near as rugged. (if it was it would easily hold HF antennas but it cannot) And NMO taking a beating better on trail is BS too. You are more likely to damage or break a NMO antenna at or near mount with a impact with a limb off road than a 3/8 x 24. On waterproof part, so are 3/8 x 24 mounts or there would be ten of thousands of dead ones out there. If you want rugged you get 3/8 x 24, if you want a lighter duty mount that while it looks impressive but lacks strength to hold large antennas and will fail long before a 3/8 x 24 then get a NMO. I use twist off quick disconnects on my 3/8 x 24 bumper mount and I can change/swap or remove antenna in near blink of a eye and replace it blindfolded.
Logged

--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
W6EM
Member

Posts: 1642




Ignore
« Reply #10 on: December 12, 2016, 05:55:17 PM »

If you are in the market for VHF and above, NMO is superior and will take a beating on the trail better. Not to mention it is waterproof and nearly indestructible if you buy a good one. The Larsen NMO270 is about the best you will get for 2/70cm antenna.

You are being way too generous. NMO is a relative new comer to market compared to 3/8 x 24 and no where near as rugged. (if it was it would easily hold HF antennas but it cannot) And NMO taking a beating better on trail is BS too. You are more likely to damage or break a NMO antenna at or near mount with a impact with a limb off road than a 3/8 x 24. On waterproof part, so are 3/8 x 24 mounts or there would be ten of thousands of dead ones out there. If you want rugged you get 3/8 x 24, if you want a lighter duty mount that while it looks impressive but lacks strength to hold large antennas and will fail long before a 3/8 x 24 then get a NMO. I use twist off quick disconnects on my 3/8 x 24 bumper mount and I can change/swap or remove antenna in near blink of a eye and replace it blindfolded.
Most of the 3/8-24 bumper mounts I've owned used a small washer as the insulator between the socket and the metal part anchored to the bumper.  Ball-based body mounts are a little better, as the fiber base is a couple of inches in diameter and the distance from ball to body bolts is about an inch or so.  Rainwater would not likely short out a ball mount, but may a bumper mount when it gets wet and exposed to road dirt, salt, etc.

The beauty of the NMO is that it has heavy threads on the perimeter and antennas have O-ring seals to keep moisture out of the mount.  The only issue I recall was a difference in center spring contact position between manufacturers.  Palomar was not the same as Motorola or Larson.  I might have that wrong, but that at one time was an alleged issue.  It could have been the height of the center contact on the NMO mount.  I forget which it was.

In any case, though, the NMO wasn't ever meant to hold anything more than a high band VHF or UHF 5/8 wave.  Trying to use that mount for anything heavier would be risking auto body damage, IMO.
Logged
K6JH
Member

Posts: 402




Ignore
« Reply #11 on: December 12, 2016, 06:21:56 PM »

How many VHF/UHF antennas are there with 3/8-24? The Hustler CG-144 is the only one I can think of, and I wouldn't want it whacking into trees off-road. I have recollections from my youth of their trunk lip mount bending sheet metal!

Seems to me the choice for VHF/UHF is between NMO, UHF, and perhaps the Larsen LM 5/16-24 stud mount.

HF is another story.

- Jim
Logged

73
Jim K6JH
W8JX
Member

Posts: 12080




Ignore
« Reply #12 on: December 13, 2016, 02:53:03 AM »

How many VHF/UHF antennas are there with 3/8-24? The Hustler CG-144 is the only one I can think of, and I wouldn't want it whacking into trees off-road. I have recollections from my youth of their trunk lip mount bending sheet metal!

Seems to me the choice for VHF/UHF is between NMO, UHF, and perhaps the Larsen LM 5/16-24 stud mount.

HF is another story.

- Jim

I have used a near bullet proof 5/8 wave 2m for many years on a 3/8 x 24. I agree there is a better selection of VHF/UHF antennas but I like a mount that supports HF antennas too.
Logged

--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
W8JX
Member

Posts: 12080




Ignore
« Reply #13 on: December 13, 2016, 02:56:23 AM »

Most of the 3/8-24 bumper mounts I've owned used a small washer as the insulator between the socket and the metal part anchored to the bumper.  Ball-based body mounts are a little better, as the fiber base is a couple of inches in diameter and the distance from ball to body bolts is about an inch or so.  Rainwater would not likely short out a ball mount, but may a bumper mount when it gets wet and exposed to road dirt, salt, etc.

In over 25 years of using bumper mounts on metal bumpers I have never had a issue with water or road grit shorting it out. (BTW I always use a little silicone RTV to seal mount when I install it) Never used one on a plastic bumper.
Logged

--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
N3QE
Member

Posts: 4880




Ignore
« Reply #14 on: December 13, 2016, 10:06:01 AM »

If you are in the market for VHF and above, NMO is superior and will take a beating on the trail better. Not to mention it is waterproof and nearly indestructible if you buy a good one. The Larsen NMO270 is about the best you will get for 2/70cm antenna.

You are being way too generous. NMO is a relative new comer to market compared to 3/8 x 24 and no where near as rugged. (if it was it would easily hold HF antennas but it cannot)

Well, they are both newcomers and wimps compared to the 1in x 14TPI Marine Mount :-) !
Logged
Pages: [1] 2 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!