Batboard

Hello, there!

I've got an NMO mount and was wondering if there were any NMO GPS antennas that you'd all recommend? I've always been favoring of whip antennas over the pucks, but not sure if that's possible in this case.

If you couldn't tell, I have pretty much no clue in this area, but if anyone could provide me with some information on the antenna type I've listed above or maybe a good noob writeup on GPS antennas, I'd greatly appreciate it!



Thanks for your help.

I don't think there are any gps antennas for NMO mount.

Sure there are.

http://www.tessco.com/products/displayP ... upId=91289

I highly recommend the Larsen option. I've run the Antenex/Laird pucks previously... on a black roof in the Texas heat, they would shut down frequently. Once I got up to speed and cooled them off, no problem. Larsen never failed me.

There are also a number of options out there that aren't NMO, but do use a 3/4" hole. They may even have multiple elements inside - I'm about to install a 5-coax puck that has 2 MIMO LTE antennas, 2 MIMO 802.11 2.4/5GHz antennas, and GPS, all built together.

One word of warning: GPS antennas are almost always active - they have a ~26dB amplifier in the antenna itself, powered by DC bias on the coax from whatever receiver you're using. Be careful with this around test equipment, etc. It's not usually an issue, but you don't want to tempt fate and risk letting smoke out.

Learn something new everyday. Thanks.

I've only ever worked with pucks with integrated cables. Sometimes they have a short stinger with a SMA, BNC, or OSX connector. Sometimes it's 12ft of RG174. Sometimes it's RG58. With or without connector. Depends on what gets ordered for that project spec'd by some engineer. NMO mount would simplify things somewhat, though it could get confusing on the roof if there is more than one NMO up there, and no clear visible difference between them.

The one thing I have learned about mobile active GPS antennas is cable loss doesn't matter. You want all you can get. You want that 26db gain to be gobbled up before it gets to the rcvr, or you may overdrive it and experience nav errors.

tvsjr wrote:I highly recommend the Larsen option.

+1

We have installed hundreds of the Larsen GPSNMO02 and I can't remember a failure.

When you get that Larsen installed.... i'd like to see how it came out.. I thought ALL mobile antennas required a ground plane on a vehicle. I see on the tessco site they have some that dont and soeme that do
Gig

I can vouch for the Larson ones as well. However the white ones will tend to turn yellow over time. But they do work reliably. After they turn yellow and unsightly on company vehicles, I tend to use them on higher profile rigs where they are not seen as much, and also on small vessels in the fleet.

Black is better for UV resistance, but sometimes they get too hot and start to act up. The white Larson antennas work well, but turn yellow after a few years in the weather.

Hey there,
Thanks for the reply.... I had no idea that the white would fade. that's something to think about. Black would be the natural choice anyhow. hopefully the black WONT act up as you said... I guess I can see that happening- specially on a black roof in the summer.

giguchan wrote:Hey there,
Thanks for the reply.... I had no idea that the white would fade. that's something to think about. Black would be the natural choice anyhow. hopefully the black WONT act up as you said... I guess I can see that happening- specially on a black roof in the summer.

The black Antenex did for me (basically the amp would shut down... GPS would unlock). The black Larsen never did. That's on the roof of a black Knapheide steel topper and later a black ARE aluminum topper, parked outside, in August, in Texas. Unless you're heading to Australia or the equator, you won't get much hotter!

thanks for that!!
Yeah I heered it gets powerful hot in Texas.. I'm in NY.... we don't get that kind heat here. Larsen for me then- when the time comes.

There's someone else who makes a grey colored one; I've seen it...I want to say it was Motorola for some reason...

thanks for the reply...
I think that black would look the best. I mean a high quality black antenna should do the job... I have never seen a Grey antenna though!