Fender location of GMRS Antenna - best worst case

[DrBombay]

I've done some searching but not a bunch of info out there, mostly "just put it on the roof".  I know fender mount is far from ideal, and realize that I'm trying get best results from worst option, but with all the gear I'm planning for the roof on my Land Cruiser its not practical to roof mount antenna.  

What have people done with success for fender placed GMRS antennas on SUV?  Going to be running the new KG XS20G.

Advise, warnings, opinions, tips, rumors all welcome!  TIA

[OffRoaderX]

I have a tailgate mount at fender level (about 3 inches from the fender) on my Jeep using a MXTA26 antenna- the tip reaches about 1 inch above the roof line.

Using this setup with both my KG-1000G and Motorola XTL5000 has worked great - hitting repeaters 30, 50, 70 miles away and talking with other vehicles up to 20 miles away.

Be wary of "some people" that will try to grossly overcomplicate it:  Yes, it would work better on the roof, but with my fender/tailgate mount I am able to have many fars.

[kidphc]

No matter what antenna you choose a gmrs antenna is going to be too short to clear the roof line. What that means is skewed radiaton pattern and loss of range. As well as irradiating you and your passengers a bit at high power.

On my landcruiser I mounted the 2/70 ham antenna to the hood mount on the driverside. On my suburban it was mount smack in the middle of the roof. It had much better reception and less picket fencing.

I plan on adding another 2m/70cm antenna to the roof.

Pics welp going to have to wait.



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[wayoverthere]

Is mounting to the roof rack an option? That would at least get you above the issue of the 'greenhouse' shading the signal, and the RF over you instead of through.

That said, off the top of my head the closest compatible stuff with enough length to maybe clear the roofline (while also being compatible with gmrs) that I can speak from experience on are the comet ca2x4sr (dual band) and the browning br-1713-b-s (UHF only). The comet is ~36", and the browning is ~32", both not including a mount.

The browning had been on both vehicles,l for both games and 70cm, and only recently came off the car in favor of a shorter dual bander. The comet was on the truck, but got swapped for a shorter comet for garage height reasons now that I have to be in the office again some days.

[BoxCar]

6 hours ago, DrBombay said:

I've done some searching but not a bunch of info out there, mostly "just put it on the roof".  I know fender mount is far from ideal, and realize that I'm trying get best results from worst option, but with all the gear I'm planning for the roof on my Land Cruiser its not practical to roof mount antenna.  

What have people done with success for fender placed GMRS antennas on SUV?  Going to be running the new KG XS20G.

Advise, warnings, opinions, tips, rumors all welcome!  TIA

I'm going to use a Tram 1191 on the left rear window of my Discovery to work both VHF and UHF frequencies.

[PACNWComms]

I have run fender and trunk mounted antennas on several cars, with good results. While not the best position as the ground plane is not equal, use the shortest cable run necessary, do not kink or bend the cable beyond bend radius, use the correct connectors and fewest adapters (if any), and give the antenna mount a good ground to bare metal. These methods will still get you great range for UHF and other bands.

I manage 12-16 miles with a twenty watt DB20-G mobile and a Tram antenna on my rear fender. The antenna does not extend above the roof-line. Picture in my gallery page, as well as VHF and UHF antennas on previous car running a 45 watt Vertex VX-3200. Fender mounts will work, with just a little impact from its position. 

Mount your antenna to the fender and then report the results here, so others can learn from your install. Each vehicle and hardware install is different, but can provide insight to others. 

[SargeRN]

Take a look at some of these and see if any of them fit your needs:

 

amateur radio antenna mounts for toyota land cruisers - Bing images

 

Sarge

[kidphc]

Have had the chance to upload the photos.

Here is a link too my lc100 thread on ih8mud.

Using a massive metal hood ditch mount (photo was before I mounted the ditch lights) for the 2/70 and a trailer tailor hatch mount for my 10m/11m antenna.

Both are on the driverside, both are worth the money imo. May swap the 10/11m antenna for a little tarheel.

Post in thread 'Kidphc's 2000 LC100 attempt to rebuild, maintenance and rebuild/build up.' https://forum.ih8mud.com/threads/kidphcs-2000-lc100-attempt-to-rebuild-maintenance-and-rebuild-build-up.1263236/post-14088632

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[WROZ250]

I was sort of forced to into using a glass mount due to the design of my Ford Edge (with panoramic sunroof) which has almost no usable metal on it (where using a through hole or magnetic mount is concerned). 

Since I don't need a dual band antenna, I went with the Tram 1187 (450-470) mounted on a rear quarter window.  So far it is working as well as any antenna I've used mounted to a vehicle body.  However, due to it's non-center location on the vehicle, it is slightly directional, noticeable when operating in fringe coverage.

 

[WRPG745]

watching this thread... Dr Bombay, what did you do or plan to do?

 

[DrBombay]

10 hours ago, WRPG745 said:

watching this thread... Dr Bombay, what did you do or plan to do?

 

Still researching.....  Many thanks to all who have chimed in.   Initially  I'm considering a Comet 2x4SR NMO on a Gamiviti fender mount and see how it meets my needs/expectations.  Also considering mounting the RTT slightly different so that I can get some roof space.   When I finally commit to some configuration I'll post up.   

KidPHC: thanks for the link, I'm on 'Mud all the time, too much actually.... (REDrum) You have all kinds of antenna goodness on your UZJ100!   Cheers!

[kidphc]

Still researching.....  Many thanks to all who have chimed in.   Initially  I'm considering a Comet 2x4SR NMO on a Gamiviti fender mount and see how it meets my needs/expectations.  Also considering mounting the RTT slightly different so that I can get some roof space.   When I finally commit to some configuration I'll post up.   
KidPHC: thanks for the link, I'm on 'Mud all the time, too much actually.... (REDrum) You have all kinds of antenna goodness on your UZJ100!   Cheers!

Fabulous site. Hoped it helped.

I did see a long time ago on expedition portal that one guy on his 80 had prinsu (actually think it is what started prinsu) build a rack that had ears on the back of the rack. Specifically, for his 2m and aprs antenna. He had the same problem with his rtt.

You could accomplish something similar depending on the rack you are using. At least on the 100 the roof rack screws go though the entire roof.

Should note i changed the configuration of the massive metal hood mount. I brought the antenna inboard and flipped the mounting ear and moved the pod light outside towards the fender, as well as dropped the pod mount lower.

I wanted to get the nmo coil to be a little less obstructed by the pod light. It seams by the seat of the pants to have helped. Might be pseduo pill effect. If it did help I wonder if it because more horizontal groundplane (hood) underneath and not next to it (fender) or was a bit of height.
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[DrBombay]

Ok, so. Here is where I went with it all:

- KG XS20G

- Comet 2x4SR antenna

- Gamiviti fender mount antenna (could not make center of roof work for my use)

Over the weekend I got it all hooked up and running on my Land Cruiser 100.  Metered it last night and got 1.80 SWR at 24.43 watts.  I'm pretty happy with that!   

IMG_2162.HEIC

[kidphc]

Ok, so. Here is where I went with it all:
- KG XS20G
- Comet 2x4SR antenna
- Gamiviti fender mount antenna (could not make center of roof work for my use)
Over the weekend I got it all hooked up and running on my Land Cruiser 100.  Metered it last night and got 1.80 SWR at 24.43 watts.  I'm pretty happy with that!   

IMG_2162.HEIC

Same location, same mount, same antenna, and same car.

Moved from a massive metal ditch bracket/antenna mount. There was way too much rocking of the mount with the Comet, combination wind load, stiffness and weight. Wasn't a problem with the 2/70b.

Only thing I noticed is a hair more deafness , and a bit more picket fencing at some locations recieve/transmit at gmrs frequencies.

Great antenna if you need combo 2/70/gmrs. Location of antenna usual so so so performance.

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[marcspaz]

 

 

My primary GMRS antenna is a Tram 1126B mounted with a Comet mount on the side of the hood.  Works fantastic.  In hilly/mountain terrain, I get between 2.5 to 8 miles (VA) mobile to mobile and in flatter, more open areas I can talk 25-30 miles radio to radio.  I have no trouble reaching well built, well placed repeaters 35-40 miles away with 5 watts.

 

I also have the Comet 2x4SR antenna.  I am not impressed with the SWR on the 467 MHz frequencies.  It's acceptable (note great) on the 462 MHz frequencies and all of the covered amateur bands, but he antenna was designed for a cross platform user with FRS/GMRS channels 01 through 7 and 15 through 22.  The antenna isn't meant/designed for good SWR on channels 8 through 14 or the repeater inputs.

 

I have always had Jeeps with either plastic or fabric roofs, so mounting it high has never been an option for me.