GMRS antenna mount inside vehicle

JetMech
May 07, 2022

Rank 0

May 07, 2022

I have purchased a couple of Midland MX275 GMRS radios for mine and my wife's Broncos. Reading on the Midland site it mentions that Jeep owners (yeah I know this is a Bronco forum) can mount the antenna inside the vehicle if it has the hard top as the fiberglass doesn't block the signal. Since we both have a hard top I was thinking of mounting it to the roll bar using the two mount holes (aft side of the bar on 4 door and window side on the two door model. Has anyone tried a similar installation? If so, any recommendations? If that doesn't work out I'm considering using the flag mount on the tailgate since it does have two holes.

Antenna mount.jpg
SlashRacer
Moderator

RedNexican X Apalacian American: Goofyness!

May 08, 2022

#1
Intresting idea. No idea how practical it is as most antennaes need a grounding plane of some kind. Im sure ive misrepresented it in some way. Do some digging on antennae design and application.


L.R.

I like round lights and I cannot lie...

May 09, 2022

#2
Intresting idea. No idea how practical it is as most antennaes need a grounding plane of some kind. Im sure ive misrepresented it in some way. Do some digging on antennae design and application.
Depends on what you are running, but If you are setting it up for trail coms, you dont need much. Loads of Jeep guys run a Ghost antenna inside of both soft and hard tops and it works fine. Midland says their ghost antenna does not need a ground plane, but I would want it over something metal, just to be sure. The sticky metal disc midland ships is probably enough, but depending on how you mount it, you might not even need that (either enough material in the mound itself, or like flush mount against a panel). Again, you are not going for max range here, just reliable trail coms.

https://midlandusa.com/collections/...cts/micromobile-mxta25-3db-gain-ghost-antenna
Perfect is the enemy of the good here. Yeah, there are more optimized set ups, but really good enough is good enough MX275 is 15 watts and that is plenty of power. I will probably end up cowl mounting the antenna on the bronco (whenever it gets here) mainly because of how I want to mount my headset- I run a MX275 in my vehicle, and that will end up remote mounted in the truck and all the firewall grommets are right there and it will make it easier.
LoneRanger, ResidualGenius and 3 others

Rank 0

May 15, 2022

#3
This is how I did the antenna installation for my MXT275

Antenna.jpg
TechnicalDisaster, Mal and 5 others

I like round lights and I cannot lie...

May 16, 2022

#4
This is how I did the antenna installation for my MXT275
Excellent. Where did you end up putting the head unit?

Rank 0

May 20, 2022

#5
Excellent. Where did you end up putting the head unit?
I put the unit under the center console and routed a cable extender up to the console next to the USB port. That's where I plug the microphone in at.
Mal, Hobgoblin

Rank VII

May 20, 2022

#6
I put the unit under the center console and routed a cable extender up to the console next to the USB port. That's where I plug the microphone in at.
Where did you find the extender? Either I'm blind or just stupid LMAO

Rank VI

May 20, 2022

#7
Huh, you've never mentioned being blind before...
ResidualGenius, Deano Bronc and 1 other

Rank VI

May 20, 2022

#8
By the way, I mounted my Midland MXT400 in the cab with an antenna on the tailgate. I think it's the cat's meow.

Rank VII

May 20, 2022

#9
Huh, you've never mentioned being blind before...
Dont tell the DMV, I haven't had to redo the driving test yet LMAO
AcesandEights

Rank VI

May 20, 2022

#10
Slightly off topic. How much better is having a mounted GMRS than a hand-held GMRS?

Rank VI

May 20, 2022

#11
Great question @ChuckO Typically the handhelds are limited in power, maybe 5W and the fixed/portables can be anywhere from 15W to 50W (legal limit). The antennas are much better on the fixed/portable.

That all being said, from vehicle to vehicle (like on a trail run), the handhelds work great and I would suggest those to most people. They are also easy to give to someone walking down the trail to look at an obstacle (a spotter), or to hand one to a friend if they don't have a radio. You can buy a two-pack for about a nickel nowadays, so getting handhelds is a great idea. The problem is when you're in rough terrain without line-of-sight between units, where more power means better range, but they are still limited to line-of-sight, you just get more distance.
ChuckO, ResidualGenius and 3 others

Rank VI

May 21, 2022

#12
So does the inny ant. work as well as an outty ant.?

Rank V

May 21, 2022

#13
Has there been any info on radio waves inside the cabin?

I like round lights and I cannot lie...

May 23, 2022

#14
The big benefit to hard mounting the GMRS radio verses the hand held is you get much better antenna options. Most hand held antennas are pretty dinky. Nothing wrong with them (I use hand helds all the time when driving with people and we can communicate car to car easy, just without as much range as something more powerful), but you get a lot more capability with a better antenna. There isn't much functional difference between some of the higher wattages (a MXT275 at 15 watts is not 66% worse than a 50Watt MXT575) because obstacles in the line of sight will limit you much more than power. Better antennas help, but it doesn't matter how much power you are pushing when you are terrain masked, you are terrain masked.

In a closed metal car, a handheld is at a disadvantage because the car's structure acts like a faraday cage and can mess with the ability of a hand held to receive and transmit. That's much less of a problem in a soft top (or even hard top) Jeep or Bronco just due to the nature of the construction. @AcesandEights is exactly right about hand helds on trails- the line of sight is really the limiting factor, but they are going to be great for spotting and communicating with the group. Always a good move to have a couple hand-helds around to give to your spotters or other people in your group. I always clip one to my elderly father in law's belt whenever he goes somewhere with us just in case he gets lost. Cheap insurance.

The other advantage is that generally speaking, a hard mounted radio will be more likely able to use your local repeater network. There are many different hand-helds that can do this too, but almost all the mobile radios can and that's a benefit where I am. Clearly a nice to have not a have to have so YMMV, but a good repeater helps solve that terrain masking problem. this is probably not an issue on a trail ride- you are probably always going to be within LOS (radio wise anyway) so not something to really worry about. Here in NM, there are lots of places with no cell service, but I can hit the repeater network from my car and could probably call for assistance in a pinch.

Finally, and maybe this is just lazy on my part, but a hard mounted radio is just one less thing for me to loose. That's worth something to me.

@jimFish you asked about radio waves in the cabin- anytime you are irradiating anything that's going to be a concern. That being said, I have no problem using a 5 watt handheld right next to my head and in a closed car. I might not be super calm about say attaching an antenna to a hard hat and running a 50 watt radio through it, but that 15 watt MXT 275 is going to be okay. In a Bronco or Jeep, there is an escape route for the wave so there is not going to be a lot of refraction in the cabin. Also, you are only radiating when you are transmitting so thats a pretty small time window. But again if its a concern, there are all kinds of good mounting options outside of the bronco- Rear mount, lip mount on the hood, cowl, or even on the trail sights.
AcesandEights, ChuckO and 2 others

I like round lights and I cannot lie...

May 23, 2022

#15
By the way, I mounted my Midland MXT400 in the cab with an antenna on the tailgate. I think it's the cat's meow.
Where did you mount the MXT400? Im thinking about replacing my 275 with a 400 or a 500, but haven't seen a mounting location that a really liked 100% yet.

Rank VI

May 23, 2022

#16
I have a Wrangler, not a Bronco, so I don't know if it would mount easily in the same space. In the Wrangler, there is a bolt that is easily accessed. It is for the console, and it is covered by a trim piece. The mounting bracket slides under the console trim and the bolt securely mounts the radio mount. There are hot, ignition and four aux switches wiried in the passenger footwell, as well as a couple of solid grounds. My radio is always hot (battery hot).

Attachments

Mal

I like round lights and I cannot lie...

May 23, 2022

#17
I have a Wrangler, not a Bronco, so I don't know if it would mount easily in the same space. In the Wrangler, there is a bolt that is easily accessed. It is for the console, and it is covered by a trim piece. The mounting bracket slides under the console trim and the bolt securely mounts the radio mount. There are hot, ignition and four aux switches wiried in the passenger footwell, as well as a couple of solid grounds. My radio is always hot (battery hot).
Always hot is the way to go, especially with something that powerful. I will probably run it right off the battery if I decide to upgrade. Mounting seems to come down to side of the console or on the dash. Really don't know which is better.
AcesandEights

Rank 0

May 25, 2022

#18
Where did you find the extender? Either I'm blind or just stupid LMAO
Sorry been busy getting ready for Moab. I bought a cable extender from Amazon. Mounted the head unit inside the console and routed the cable extender up next to the USB port. There I plug my microphone into it and operate it from there.

Attachments

Deano Bronc, ResidualGenius and 1 other

I like round lights and I cannot lie...

May 25, 2022

#19
Sorry been busy getting ready for Moab. I bought a cable extender from Amazon. Mounted the head unit inside the console and routed the cable extender up next to the USB port. There I plug my microphone into it and operate it from there.
Looks like you have a good amount of room. Do you think there is enough room for the MXT 575 to mount Its this much bigger.

275.575.compair.jpg
ResidualGenius, LoneRanger

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