Offroad Antenna Suggestions

[tricon]

Hey all, got a question on an Antenna for my car to car radio setup. I have a side by side with a VGC-NR7500 UHF/VHF radio hooked up to a Rugged Radio intercom system. This allows me to speak with all my passengers in the car through our helmets and when I hit my PTT button I can transmit to the other cars in our group. My issue is that I seem to lose reception of the other cars rather quickly and they say its very hard to hear me.

I'm pretty sure I have a sub optimal antenna setup, but I'm not exactly sure which way I should go.

I currently have a wide band UHF/VHF antenna, I have tried one of those stealth mount stubbys as well. This is what I'm currently running. I don't believe it requires a ground plane, which is why I have it mounted where I do (picture below):

https://www.amazon.com/gp/product/B08H24P613/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

To throw a wrench in the mix, one of my riding buddies Kenwood radio is stuck on 151.025 MHz, so we typically just stay on that channel.

So my questions:

1. Do I need to move my antenna to the roof for better reception?
2. Would a Larson NMO150C or Tram 1121b tuned to around 151 MHz give me much better performance? I don't mind swapping antennas if I need to use UHF.
3. Is there a different setup I should be looking at? I do not care about length as I take the antenna off to transport the car. I would prefer not needing a ground plane, but I prioritize performance over this preference.
Any help would be greatly appreciated.

 

[tricon]

Not sure why the picture went to base64, but here it is.

 

[mmckenna]

Antennas on a UTV will be a challenge.

I'm running a VHF radio in a Polaris Ranger with an antenna mounted on the top of the roll cage behind the passenger.

It works well, but I'm using high end commercial stuff, Motorola mobile radio, Laird antenna, Larsen NMO mount, etc. I've had this setup since I bought it new in 2010, and the Ranger has about 6,000 miles on it, a lot of that rough trails and low tree branches.

Looking at your system, I would not immediately jump to the antenna as the issue, although it could be.

There's a couple of things you need to look carefully at if you want any sort of decent performance out of a radio like this:

1. Is your radio working correctly? Do you have the tools to test it? Is it programmed correctly? There is more involved than just typing in a frequency.
2. Are you pulling power for the radio DIRECTLY off the battery? Never tap into existing circuits or cigarette lighter plugs.
3. Is your antenna cable/mount in good shape? You need to suspect the connector, cable, mount, and everything in between. It's really easy for the coaxial cable to get damaged on a vehicle like this. Visually inspect every inch of it. Make sure there is zero corrosion on the connector, antenna mount, or anywhere along the cable.
4. Remove the antenna from the mount, and disconnect the plug from the radio. Use an ohm meter to test the cable:
-Test for continuity from the center pin on the UHF connector (the one that plugs into the radio), to the center pin of the antenna mount. There should be continuity. If there isn't, there's a break somewhere and you need to fix/replace that.
-Test for continuity from the outer shield of the UHF connector to the outer ring of the antenna mount. There should be continuity. If there isn't, there's a break and it needs to be fixed/replaced.
-Test for continuity between the center pin of the UHF connector and the outer shield of the UHF connector. Make sure the antenna is REMOVED. There should NOT be continuity between those two. If there is, there's a short in the connector, mount, or somewhere the cable has been damaged. Remove it all, toss it and replace with new.
5. If you've checked all that and it's testing good, you should suspect your antenna. No offense, but that is not a high quality antenna, and I would suspect damage if it's been on the buggy for a while, been down rough trails, or hit any tree branches.


That antenna you linked to is not a high quality antenna. It is not a ground plane independent antenna, either.
For the mounting location, it looks like you may have some amount of ground plane under the antenna, but it's going to be lopsided and less than ideal. In a perfect install, you want the antenna in the middle of a metal ground plane at least 18" in all directions under the antenna. A half wave antenna may work slightly better in that sort of install, but I don't think the antenna type itself is the issue (other than it being low quality and probably not very durable). Either way, switching to a half wave antenna isn't going to make a huge difference in performance if everything is working correctly.
I'd really lean towards the antenna being damaged.

Make sure the metal bracket attaching the antenna to the roll cage is actually showing an electrical connection between the mount and the cage. That'll give you a bit of help.

I'd replace that antenna with something more suitable/higher quality.
The Larsen NMOQ would be a good start. It's a 1/4 wave antenna and will be much more durable. It's broad banded and will work on VHF well without a lot of fuss. Larsen NMOQC 136-512 MHz Field Tunable Two Way Radio Antenna NMO Mount
The antenna does require cutting to the correct length, but it comes with a chart that will show you what length it needs to be.

Or.

You could do this half wave antenna, which -might- work slightly better in your application:

EM Wave EM-M10014-GPI - VHF No Ground Plane Antennas

VHF 2dB gain roof mount antenna w/ spring 144-174 MHz (tunable range) No Ground Plane Required. Warranty 2 Years

theantennafarm.com

But, before you start spending money on this, remember that radios work in both directions. You not being able to hear other riders may mean that there radios/antennas are not working properly also. You need to look at the entire system, including the other radios.. There is much more to installing a two way radio than buying parts of Amazon. I see a lot of UTV's running around with really crappy radios and even worse antenna installs. It's not surprising that many have issues with them.

You wouldn't buy a Harbor Freight single cylinder gas engine to replace the motor in your buggy, so why buy cheap Chinese radios and antennas and expect high performance? You gotta look at the entire system.

 

[mmckenna]

Noticed something else in your photo...

Some of those LED light bars are noisy and will cause problems with your radio. Try the radio with all the LED's and as many accessories as possible turned -all-the-way-off-. Some will generate enough noise to wipe out your radio receiver.

 

[jeepsandradios]

According to the antenna link thats a ham radio antenna on 144mhz. Unless you were able to retune it to 151 your most likely way off. As @mmckenna said you need tools to test it. I'd swap out to a VHF quaterwave myself to start

 

[GlobalNorth]

Junk that stubby 'stealth' antenna. They are virtually unusable in the VHF band and not much better at 450-470 MHz.

 

[steeevo85]

I see this thread has aged a little but thought I would chime in for future readers.
The absolute best way to set up a VHF antenna on a UTV is to run a 5/8-wave antenna like the larsen NMO150B right in the middle of the roof with an NMO mount. make sure the nmo mount is grounded to the roof on the bottom side (strip away paint for direct metal contact around the hole)
Tune the antenna and use quality coax.
Check out this video which dives into losses due to improper tuning and coaxial losses.