Looking to replace a mag mount 2m/70cm antenna with an NMO setup

[GREGWTH7MMMAG]

Right now I am running a Diamond mr77 antenna on a 2m mobile in my Jeep Liberty.  I am planning to migrate to a permanent setup, in the roof, and am seeking guidence.  My plans are to install an NMO mount thru the roof, with a dualband antenna for hitting repeaters in the Colorado area.  Is there a preferred brand or type of mount to use, from Larsen, Diamond, Comet, etc?  Wanting to keep the antenna under 20" for normal use, as I park in a carport.  Any tips or suggestions would be great!
73s
KD0PWN

[M6GOM]

Larsen or Motorola in the USA. They seem to be as rare as hens teeth over here in Blighty.

[N6AJR]

I have 4 mounts , all Larsen in the roof of my pickup.  get a NMO mount with a gasket to seal to the roof.  I reccommend using a greenlee punch to make the 3/4 inch hole . I used a  diamond NR72BNMO antenna  for my 2m/440 antenna on the roof, Its under $50 and is only 12 or 14 inches tall   with about 2,15 dbi gain which it about normal for a 1/4  dual band vert.  I like Larsen mounts for nmo, and never had a problem with them ( knock wood) . you will notice better performance with a roof mount. mag mounts leave a bit of gain  due to lack of solid ground plane.

[K3GM]

I also recommend the use of a .750" Greenlee CHASSIS punch. I'd use only genuine Larsen NMO mounts.  They can purchased thru the big retailers online.  For the antenna, I again believe there is only one brand, Larsen. Their NMO-2/70 will last you just about a lifetime.

[GREGWTH7MMMAG]

I was on hamcity, and they have a Larsen NMO-K mount, thats what I'm looking for I think.  I dont see anything about a gasket though.

[KJ4OBR]

The gasket is a rubber O-ring that lives in a groove under the outer threaded collar. Just be sure that the gasket is in place as you tighten the mount and you'll be fine.

+1 on the Greenlee punch for the hole.. those things are amazing. I used one to punch a hole into 16g stainless stock for a custom hood mount. it required one of my bigger wrenches, but the hole was clean. I do recommend a bit of 3 in 1 oil to help with the cutting.

73
Dave

I was on hamcity, and they have a Larsen NMO-K mount, thats what I'm looking for I think.  I dont see anything about a gasket though.

[KD8RFT]

Another vote for the larsen 270 nmo. Love mine.

[GREGWTH7MMMAG]

Looks like the Larsen NMO 2/70SH is the only one in their dual band line thats short enough.  Any of you guys run it with good results?

[K3GM]

I run 10m, 6m, 2m/70cm in the roof of my Tahoe; all Larsen.  The 2/70 is 25 years old. It's been installed on 5 different vehicles. Never a leak, never a problem.

[VA3WXM]

Looks like the Larsen NMO 2/70SH is the only one in their dual band line thats short enough.  Any of you guys run it with good results?

I have one but am not impressed.  From what I can gather, electrically it's 1/4 wave on 2m and 3/4 wave on 70cm.  It's not too bad on VHF but worse than a plain 1/4 wave on UHF.