NMO34 with the W640 (64" whip) vs NMO-27 vs CWB-27

[slowmover]

LARSON NMO34b (base coil)

Springb (6” spring option)

W640b (64” whip)


b = black

 

[jcrmadden]

It’ll look great on that Yukon.

I'm leaning in that direction...

I had ordered the NMO27 with 49" whip, but now I'm thinking that should go on our '02 Superduty.

The truck only makes two or three trips a year (roughly 100 miles round trip each time).

In terms of bang-for-the-buck I think the Yukon deserves the better install with better components (her daily driver).

Breedlove #505 in the cart, but I've never had any dealing with ring terminal or with swapping coax ends (time to figure it out I guess).

How hard is it to pull the antenna on these NMO mounts? Say she wants to slide through the car wash?

 

[slowmover]

#505 kinda big.

#503 more suited, IMO.

Ring terminal was new to me with doing the #601. Took me three (3) tries before I was satisfied. (Quality of connector; ANCOR or similar).

Getting an FT240-61 Feedpoint Choke for 11M closest means I need to do it again. I’ll need a length of (142?, something that’ll wrap tight; see @Varmonter thread on same).

There’s those that say these’ll go thru a wash, but it’s a long whip even with spring.

I’d dedicate a plasti-dipped tool.
And get the cap.



Low Perf on a Ford = Yeah, that’s a match.

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[mmckenna]

Breedlove #505 in the cart, but I've never had any dealing with ring terminal or with swapping coax ends (time to figure it out I guess).

The challenge with these Breedlove mounts is that you need full access to both sides of the mount. You want the mount in the center of the ground plane. That's going to mean you'll have to drop the headliner in the Yukon. That's going to be a time consuming process.

Standard NMO mounts will work just fine with this antenna, and they can be mounted without removing or dropping the headliner.

Unless you really want the challenge of removing the headliner, you'll find that the regular mounts are more than capable of handling this antenna.

 

[slowmover]

The challenge with these Breedlove mounts is that you need full access to both sides of the mount. You want the mount in the center of the ground plane. That's going to mean you'll have to drop the headliner in the Yukon. That's going to be a time consuming process.

Standard NMO mounts will work just fine with this antenna, and they can be mounted without removing or dropping the headliner.

Unless you really want the challenge of removing the headliner, you'll find that the regular mounts are more than capable of handling this antenna.

As it’s wifeys I’d concur. She ain’t gonna pull over in the rain like you or me to git that irritant gone.

If it weren’t for the way I’m mounting the radio I wouldn’t recommend dropping the headliner.

X-nay the feedpoint choke and get a better one at transceiver end? If ya gotta have it, access it thru dome light.

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[jcrmadden]

Is the whip adapter screwed onto a regular 3/8" stud?

Low Perf on a Ford = Yeah, that’s a match.

Ha! Shots fired!

She ain't much to look at, but the ol' 7.3 is still getting the job done (hauling cattle) with almost 400k on the clock...

 

[jcrmadden]

Unless you really want the challenge of removing the headliner, you'll find that the regular mounts are more than capable of handling this antenna.

I was hoping to avoid the headliner drop altogether. I was thinking I could pop the dome light out and have enough working space to get it done.

 

[slowmover]

Similar to this.

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[slowmover]

I was hoping to avoid the headliner drop altogether. I was thinking I could pop the dome light out and have enough working space to get it done.

You can. I had to because of 6” X 6” backing plate



All Larsen would be easiest.

According to the guru @mmckenna they don’t sacrifice durability for price.

I’d want the #503 only if use with an adapter to run a light top load. Even taller if stationary.

.

 

[mmckenna]

Is the whip adapter screwed onto a regular 3/8" stud?

No, those coils screw onto an NMO mount, which is 1 1/8" diameter.

The stud on top of the coil is 5/16", if I recall correctly. It's specific to those types of antennas, and they don't match up with 3/8 x 24 CB antennas.

 

[mmckenna]

I was hoping to avoid the headliner drop altogether. I was thinking I could pop the dome light out and have enough working space to get it done.

On an antenna like this, there's zero benefit to dropping the headliner and going with a mount that large. California Highway Patrol has been running low band antennas this size on standard NMO mounts for decades, and they've put way more mileage and abuse on them than you ever will.

I've run trucks with NMO mount antennas up overgrown site access roads with zero damage. I've had NMO antennas get physically damaged by low parking garages, again, with zero damage to the mount.

There's no benefit to going through all the hassle to drop the headliner and install an overbuilt mount like that, other than bragging rights.

This is all you need:

Larsen NMOK - NMO 3/4" Hole Mounts PL-259

Larsen NMOK NMO 3/4" Hole Mounts PL-259 - Manufacturer: Radiall Larsen; Description: The Larsen NMOK vehicle roof mount antenna installation hardware kit is a

theantennafarm.com

 

[slowmover]

Well, custom coax length ain’t quite “bragging rights”, but I agree with the premise.

— Depends on how far away is the radio plus any associated gear and wanting a feedpoint choke.

I don’t know what is total roof length, or location of dome light, but “it looks like” (generic 2013 M-Y pic) that exterior roof center is ahead of C-pillar.

If this interior pic is correct . . . ?



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[slowmover]

Low Perf on a Ford = Yeah, that’s a match.

Ha! Shots fired!

She ain't much to look at, but the ol' 7.3 is still getting the job done (hauling cattle) with almost 400k on the clock...


Then that 27 + 510 oughta be: right match.

That’s the combined rig needs a PA so somebody can sing them cattle onto the trailer.

Trad Wife

Let them other girls win the county fair baking contests, right?

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[mmckenna]

Well, custom coax length ain’t quite “bragging rights”, but I agree with the premise.

The NMO mounts come with the connection loose, so cutting cable to length before installing the connector is SOP. One of the reasons I did not recommend one of the Chinese mounts with 'preinstalled' connectors.

 

[slowmover]

The NMO mounts come with the connection loose, so cutting cable to length before installing the connector is SOP. One of the reasons I did not recommend one of the Chinese mounts with 'preinstalled' connectors.

THANKS! News to my ignorance.
Then it looks like the coax that’ll tightly wind a toroid is all that’s left (past connectors).

RG-400 equivalent, IIRC.

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[prcguy]

I was hoping to avoid the headliner drop altogether. I was thinking I could pop the dome light out and have enough working space to get it done.

You never need to completely drop a headliner. Pull the rubber door molding down at one door part way then you can gently pry a small section of headliner down and see between it and the metal roof to make sure there are no obstructions. Then I like to slide a long piece of cardboard or better yet a 1ft wide by several ft long piece of thin hard plastic up between the headliner and roof to catch debris from drilling and to protect the headliner if you shove the drill bit or hole saw in too far. Early in my installer career I used to carefully measure the center of the roof only to find it looks off from the front or rear because the mirror or external trim may not be perfectly centered in relation to my perfectly centered antenna. I learned to place a bolt on top of the roof and eyeball its location from the front and rear using that to find the most pleasing looking "center".

Then drill your hole, insert and install the NMO mount from the top and route the coax to the side pillar and down to the floor inside the plastic side pillar trim. You might need a coat hanger to snag the coax and pull it out the opening or sometimes you can shove the coax in from the top at an angle and it will head towards your opening.

You then pull up the lower plastic door entry thing, forget what its called and route the coax from the side pillar through the channel under the lower plastic door entry thing or under the carpet to the front for a front or dash mount setup or to the rear or to the center console or ?? All of this can be done in about 15min including drilling, routing coax and putting all the parts back together. I've done about a thousand vehicle installs with at least half being roof mounts using the above procedure.

 

[RFI-EMI-GUY]

The NMO mounts come with the connection loose, so cutting cable to length before installing the connector is SOP. One of the reasons I did not recommend one of the Chinese mounts with 'preinstalled' connectors.

I have some of those Motorola OEM mounts for 800 MHz which have a prefitted mini UHF connector that can go easily through the roof hole. They are nice teflon coax. The only thing I have wondered about is they have a very small button (low capacitance) while the OEM VHF have a large button on the NMO. Have you tried those 800 mounts?

 

[mmckenna]

I have some of those Motorola OEM mounts for 800 MHz which have a prefitted mini UHF connector that can go easily through the roof hole. They are nice teflon coax. The only thing I have wondered about is they have a very small button (low capacitance) while the OEM VHF have a large button on the NMO. Have you tried those 800 mounts?

The mini-UHF connectors are, of course, easier to route. Also, Larsen has their "FME" connector that is even smaller and allows easy installation of their adapter. I think I've used exactly one of those in my lifetime. Worked fine, but for obvious reasons, prefer to just install the correct connector.

I think I've had those 800MHz mounts. Never an issue with them, but maybe I wasn't pushing the envelope on them.

 

[KX4KDH]

Does anybody have any current supplier links to the CW27 model family mentioned? I'm only finding things for the C27 model family. As noted above a key difference seems to be a 49" whip vs the 67" whip on the CW line.

Given the radio choices available these days, as well as the good band conditions, a mobile antenna capable of 11M and 10M is pretty attractive.

The data sheet for that antenna shows it being a 64” whip. I’m betting the Larsen NMO34 with the 64” whip will accomplish the same thing.

 

[RFI-EMI-GUY]

The data sheet for that antenna shows it being a 64” whip. I’m betting the Larsen NMO34 with the 64” whip will accomplish the same thing.

The "W" in CW27 is for wideband, the coils are very much different.