2016 Chevy Express Antenna Install

[n4fo]

Hi all:

I just acquired a 2016 Chevy Express full size van and I was looking to install my Larsen NMO-270 antenna. I had it installed previously on a Honda Odyssey with a CP-5NMO mount on the back hatch. I have not had a chance yet to check and see if the CP-5NMO mount will fit and have the proper clearance on one of the back doors; if not then I am looking to do something else.

Wondered if anyone else has had any experience in mounting an antenna other than drilling holes.......

Thanks!
Steve H.

 

[mmckenna]

There are a number of clamp on/bracket/mag mount compromise mounts that will get your antenna on the van quickly.

But if you want things to work well, make use of that big expanse of ground plane, and either put the mag mount in the center of the roof, or skip the gimmicks and drill a hole.

I know, I know, you don't want to drill holes….. But there's a really good reason professional installations will have a permanently installed NMO mount in the center of the ground plane. Anything else is some level of compromise.

 

[KevinC]

But if you want things to work well, make use of that big expanse of ground plane, and either put the mag mount in the center of the roof, or skip the gimmicks and drill a hole.

And get rid of that lopsided radiation pattern.

 

[n4fo]

There are a number of clamp on/bracket/mag mount compromise mounts that will get your antenna on the van quickly.

But if you want things to work well, make use of that big expanse of ground plane, and either put the mag mount in the center of the roof, or skip the gimmicks and drill a hole.

I know, I know, you don't want to drill holes….. But there's a really good reason professional installations will have a permanently installed NMO mount in the center of the ground plane. Anything else is some level of compromise.

Mmckenna:

Thanks for the advice; I really appreciate it very much. I pretty much knew that you would recommend "drilling the hole"! I agree with you that would be the best overall solution. I am aware that anything else is a compromise, but I appreciate you pointing that out. I love my Larsen antenna and I know that you are a proponent of them also.

Anyway, I keep my van under the carport so if I do go with something in the middle of the large ground plane I would have to remove it to park it under the carport. Not a big deal to me, just need to remember that. If I decided to go with a mag mount, are there any I should avoid? I think Larsen makes one, so I would probably go with it as I have had such good experiences with their products.

One other question for you. Where would be the best place to get power for the radio? It is a Yaesu FT-7100M dual band mobile. I had previously run some number 12 red/black wire from the battery to the radio, but wasn't sure if that was the best and I am pretty sure you have lots of mobile install experience from what I can recall.

I am looking to get it done before I go on a road trip to Ohio in September so I do have some time to get things together.

Thanks for responding and look forward to your reply.

Steve H.
N4FO

 

[n4fo]

And get rid of that lopsided radiation pattern.

Agreed!

When I had it mounted on the CP-5NMO mount on the back hatch of my Odyssey definitely made it a lopsided radiation pattern.

SH

 

[mmckenna]

Anyway, I keep my van under the carport so if I do go with something in the middle of the large ground plane I would have to remove it to park it under the carport. Not a big deal to me, just need to remember that.

How much clearance do you have between the roof of the van and the underside of the carport? A 1/4 wave VHF whip will work as 3/4 wave on UHF. Most thin 1/4 wave whips won't have an issue flexing.

If I decided to go with a mag mount, are there any I should avoid? I think Larsen makes one, so I would probably go with it as I have had such good experiences with their products.

Larsen makes nice mag mounts. I've had one for about 30 years that I use for testing.

On the 'avoid' list should be any of the Cheap Chinese Brands. Steer clear of the hammy/hobby grade stuff. Avoid Tram, Browning, etc. While the NMO mounts can be OK, they usually use really cheap coax or poorly installed/cheap connectors.

One other question for you. Where would be the best place to get power for the radio? It is a Yaesu FT-7100M dual band mobile. I had previously run some number 12 red/black wire from the battery to the radio, but wasn't sure if that was the best and I am pretty sure you have lots of mobile install experience from what I can recall.

It's almost always best to pull your positive lead directly from the battery. Using existing wiring can result in overloading circuits, or picking up unwanted RFI from other vehicle electronics.
Ground the negative power lead for the radio to the vehicle body as close as you reasonably can to the radio chassis. No need to run a single radio negative all the way back to the battery. Use the body steel for that. It also can help with noise. Grounding radio chassis with a short lead is good practice.

 

[n4fo]

How much clearance do you have between the roof of the van and the underside of the carport? A 1/4 wave VHF whip will work as 3/4 wave on UHF. Most thin 1/4 wave whips won't have an issue flexing.

I went and measured and there is 24 inches clearance between the roof of my van and the bottom of the carport roof; the Larsen NMO270SH is 19 inches tall and I haven't checked the height of the mag mount but that may work. As far as a 1/4 whip, I am thinking the tunable Larsen one would probably work fine it looks like.

Larsen makes nice mag mounts. I've had one for about 30 years that I use for testing.

Any preference of square over round? The square has less pull strength and is 3 inches tall. Round is shorter and about $15 cheaper and does not look as good as quality as the square one.

On the 'avoid' list should be any of the Cheap Chinese Brands. Steer clear of the hammy/hobby grade stuff. Avoid Tram, Browning, etc. While the NMO mounts can be OK, they usually use really cheap coax or poorly installed/cheap connectors.

No worries there. I have been using Larsen antennas and products for over 30 years and I love 'em! Always have given me good service.

It's almost always best to pull your positive lead directly from the battery. Using existing wiring can result in overloading circuits, or picking up unwanted RFI from other vehicle electronics.

Ground the negative power lead for the radio to the vehicle body as close as you reasonably can to the radio chassis. No need to run a single radio negative all the way back to the battery. Use the body steel for that. It also can help with noise. Grounding radio chassis with a short lead is good practice.

Thanks for the tip, much appreciated as well as the antenna/mount advice!

 

[n4fo]

The reply above didn't quite work like I thought, but my replies are there. Thanks again for all of the advice, very much appreciated!

 

[mmckenna]

Shape of the mag mount isn't going to make a difference. If you can save
$15, then go with that.

If you are not going to do a permanent mount, just be cautious about how you get the coax inside the vehicle. Pinching the coax can result in damage to the jacket and allow water to enter and corrode things pretty quickly.

 

[n4fo]

Shape of the mag mount isn't going to make a difference. If you can save
$15, then go with that.

If you are not going to do a permanent mount, just be cautious about how you get the coax inside the vehicle. Pinching the coax can result in damage to the jacket and allow water to enter and corrode things pretty quickly.

I will keep that in mind and again thanks for all of the advice, very much appreciated!
Steve