NMO Cb antenna

[4x4mike]

I know I've posted about this before but I decided to start a new thread because it's a bit different than the others. I've got an NMO with coax attached sitting on the work bench ready to go on the 4Runner for CB duty (2m NMO is already installed). I'm going to drill a hole, no mount, and had a question before I do the deed.

Question is if I'm on the right track. I plan on getting a 27mhz Larson with NMO base. One issue I have with this antenna is that it's close to 4 feet long. It isn't a huge problem but here and there it will be an issue. I have no problem with unscrewing it for parking garages, trees, brush etc. I want the NMO because I can install it clean and when I'm not using the CB I can cover the threads and go about my business. Another reason for the NMO is flexibility, just like with my 2m setup.

I found this adapter:
http://www.walcottcb.com/opek-nmo6-nmo-to-38-24-thread-adapter-p-1231.html

Before I drill a hole I want to make sure I have usable flexibility. Like I said the Larsen will be on duty when I use it but something smaller will be nice. I was thinking this adapter and then a flexible (not fiberglass and NO spring) whip will be nice. Something like this (just a quick google search):
http://www.solidsignal.com/pview.as...nable-Stainless-Steel-CB-Antenna-Whip-(A-110)

So again with the question. Is this a solid route to take? It's the 3/4" hole in the roof that is causing the doubt and question. I know a short antenna will have decreased range and other down sides but just wanted to bounce it off someone and I didn't want to have the 4 footer as the only option.

TIA,
Mike

 

[KI4LTX]

I can fully recomend the Larsen NMO mounts and antennas. I use the mounts for 10m, 6m, 2m, and 70cm on the roof of my 2005 F150. I use the the Larsen NMO27 for 10m, NMO50 for 6m, and NMO2/70 for the 2M and 79cm bands. The 10M antenna has received a lot of use over the past few weeks. The band is wide open!

I have used the Larsen antennas for over 15 years, with no problems. I do add the spring to them, though, and that removes any issues with branches in the back country. I just switch the open coil NMO2/70 to the closed coil for those areas.

John
AA4TX

 

[4x4mike]

Thanks. I have the larsen 2/70, 1/2 wave and a 2m, 1/4 wave that I like a lot. Because they have treated me well I want one for 11m but don't want to deal with the height all the time.

 

[BigJimCruising]

x2 on Larson equipment! Good sturdy strong stuff! But that shorty CB antenna combined with that conversion coupler will just be a bad idea. First off trying to get any useful signal from that short of an antenna on CB is not going to work. Maybe car to car (assuming they're right behind you!) but that's about it. Also as you start building up attachments and tall antenna base's it won't take much of a hit to bend your roof!! And that's where leaks begin. Not to mention you're pretty much defeating the reason for using the NMO in the first place. Overall it might be a good time to take a step back and give some new thought to what kind of CB antenna you should use and how it should be mounted. Best of luck! Jim.

 

[4x4mike]

w

Thanks Jim. Basically the reason for starting the thread was me stepping back and evaluating. I've got a wilson lil wil right now but am tired of the magnet and the coax on the roof. My planned hole for.the cb is right next to a support in the roof so I believe it to be really stiff. I'll look aroumd some more to figure out what exactly I need. Thanks guys.

 

[theksmith]

i have the 4ft version of that antenna you posted, just wanted to let you know that's it's holding up fine even though it's a no-name deal. it's also very flexible, haven't needed a spring (like i did with the Firefly) yet. however, having the 4ft length works to my advantage for flexibility. if you nail a low branch you certainly could rip the 2ft off the roof, if not pull through the mount some and bend your sheet metal.

as far as performance - it works at least as good if not better than the 4ft Firefly that it replaced, and was very quick to tune. i would imagine that a 2ft centered on a roof as the ground plane would work just as good, if not better than a longer antenna mounted lower. all that really matters very much on receive is the portion of the antenna that's actually above the vehicle. and on transmit, being centered on a nice ground plane is going to be a plus.

you might consider the diamond motorized mount for both your antennas if you are determined to keep them on the roof - it has a spring with give to let the antenna fold down when hitting something (scroll down, and towards the bottom are more pics of it in use too): http://www.expeditionexchange.com/diamondantenna/

there's also a manual fold-down type mount on that page that would let you fold over your antenna when not needed instead of removing it. just some options for you