108" fiberglass whip on an NMO

[towerdog]

Will the NMO connector hold up. I have an NMO mount drilled through the roof of my car, and I am looking for a 3/8 to NMO adapter to mount a 108" whip. The wider the adapter, or more surface area it takes up, the better.

 

[Captain Kilowatt]

I would not even consider doing that. If you are lucky the only thing that will rip out is the threads. If not then the entire mount will likely rip out of the roof.

 

[towerdog]

I think the whip itself would be the first thing to go. I will still use my maxrad for general use and keep the whip in the rod holder. I will use it mostly while parked or when I know the trip will not involve woods or drive thru . What I think would rip it out would be the flexing of antenna so I need something 8 to 12 inches around to act as a base that goes between ant and roof

 

[w9cll]

As CK said I would not use an NMO mount to hold that antenna. They were never designed for it.

 

[Captain Kilowatt]

Nothing will happen to the whip. You can take them and whack them against trees all day long and never put a bend in them. The base is what will either break or rip out of the roof. If you can reinforce UNDER the roof under the mount itself then that will eliminate the second problem however the first problem still exists. For parked situations OK but rolling down the road whether there are trees or not it's not a good idea. Wind drag is significant on that size of whip.

 

[Lil'Yeshua]

The roof is very thin on my SUV. Even with a magmount for my Sirio Peformer PL 5000,the roof flexes. So far the only things I've hit bugs,birds and drivethrough metal awnings(snail's pace).

 

[VE6SDG]

Not recommended at all. I've seen roofs torn open from a 34" whip on a roof and they went into an underground parking. It wasn't the coil that hit but the whip itself had enough force on it to rip it open.

 

[towerdog]

I am kinda thinking some sort of marine mount at this point, i have seen marine mounts that were designed to just fall down if too much force impacted the antenna, and they fold down
.or the cheapest nmo=3/8 adapter i can find and use it stationary only.
or......nota, what i have is not bad until i can build yagi to take with me up the mountains.

thanks for saving my roof......although i have seen'em break, once they turn green with mildew, salt, sun and rot

 

[Captain Kilowatt]

Not recommended at all. I've seen roofs torn open from a 34" whip on a roof and they went into an underground parking. It wasn't the coil that hit but the whip itself had enough force on it to rip it open.

Saw that happen one time. The Dodge Ram truck had ham plates on it and what looked like a Larsen 2m 5/8 wave antenna on the roof. A woman was driving it into a low clearance parking garage, probably the wife of the ham as I am sure the ham would have thought about the antenna. Anyway I just cringed and went to blow the horn as she pulled in. The roof had about six inches of clearance but the antenna started to rip out of the roof. She stopped and started to back out which then forced the antenna back down the hole smashing the roof nicely....or badly...you know what I mean.