Ham antenna mount location questions (1 Viewer)

Mr Cimarron

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Finally joining the ham crowd. Been wanting to take the exam for months but been out of town on the weekends they are giving the test. Next weekend looks like it will finally happen. Now for the questions.

Already have my CB antenna mounted on the Slee tire carrier. I could use this location for the ham antenna but would rather still keep my CB for now. Roof isn't an option due to Inti-rack up top. I suppose I could use the rack but don't know what effect it would have being aluminum. Seen a few mounts for the rear gate but wondering how they mount to the body.
 

sheepdawg

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I mounted my 2m antenna to my roof rack and it works great. It is up high and provides good reception. My CB antenna is a mag mount, since not too many people I wheel with use CB anymore. The higher up it is mounted the better it is an nothing beats the roof. I have an ARB roof rack and a large portion of it is a wire grid. I just mounted a flat piece of metal to the grid and put my 2m antenna to the metal piece and works great. The same could be used for the aluminum rack. I don't think that will be an issue.
 

Mr Cimarron

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I mounted my 2m antenna to my roof rack and it works great. It is up high and provides good reception. My CB antenna is a mag mount, since not too many people I wheel with use CB anymore. The higher up it is mounted the better it is an nothing beats the roof. I have an ARB roof rack and a large portion of it is a wire grid. I just mounted a flat piece of metal to the grid and put my 2m antenna to the metal piece and works great. The same could be used for the aluminum rack. I don't think that will be an issue.
Yeah I am thinking the rack would be the best place. Do you use a grounding strap on your setup?
 

Mr Cimarron

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Ended up going with a clamp mount for the roof rack. I bought two antennas, Larsen 2/70SH and a Comet SBB1, which should be at my door Monday. Still need to buy my cable and run that. Best thing is I passed the test today so I should be up and running in about a week.
 

LandCruiserPhil

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Ended up going with a clamp mount for the roof rack. I bought two antennas, Larsen 2/70SH and a Comet SBB1, which should be at my door Monday. Still need to buy my cable and run that. Best thing is I passed the test today so I should be up and running in about a week.

Congratulations on passing you will soon wonder why you waited to make the move to HAM.
 

Mr Cimarron

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i didn't take any when I installed it and I am out of town for a few weeks. I'm not happy with the roll bar mount I ordered. It's a bit small and has a lip so the antenna base doesn't fir with my Larsen antenna.
 

Josie'sLandCruiser

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Hi all,

I am using a nice stainless steel antenna bracket on my Tacoma pickup that mounts between the fender and the hood on the driver's side. The antenna is a Larson NMO 5/8ths wave. Getting real good reception with this combo.

On my FJ40, will be switching over from a mag-mount to a hard-mount 5/8ths wave antenna this winter.

Regards,

Alan
 
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For the rear maybe like a Comet-NCG HD-5M or a Diamond K400C, they have a few different versions. They are pretty good for a lip mount.
 
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Congratulations on your exam. You picked a good antenna. I had a Larsen 2/70 but ended up selling it as it was a bit too floppy and tall for my roof top.

Something to consider about HAM antennas is a ground plane. For example, a 2 meter 1/2 wave antenna does not require a ground whereas a 1/4 wave 2 meter antenna does. Will the 1/4 wave still work? Yeah but not as well without the ground. I've seen write ups that say a good ground would be 2-3 square feet of ground.

From what I found online the 2/70SH is a 1/4 wave on 2m and 3/4 wave on 70cm. If this is true you might need more of a ground plane than a carrier offers. I had the 2/70B which was a 1/2 wave antenna and didn't require the ground plane. There is some good information in the first few minutes of this video:
I use NMO mounts in my roof. They required drilling a hole but it's easy and I prefer this mounting method when it can be done. You can also use the NMO mounts in tabs and other mounts. I would suggest using an NMO as you can easily change out antennas. I assume by your antenna choice that you're running a dual band radio. I run a dual band 8800-R but use the 70cm portion very rarely. As such I run around with a $10 1/4 wave 2 meter antenna most of the time. I have a nicer 1/4 2m one, a 5/8 wave one and two dual band antennas. Switching them is cake and I can pick an antenna that fits my needs. If you're going to spend most of your time on 2m, maybe pick a mounting location that will make a 1/2 wave work in regards to amount over the roof line and not so high it gets caught in the trees (the problem I had with my 2/70).
 
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I have a Diamond K400SNMO on both of my 80 Series on the upper left of the hatch. Center of the mount is approx level with the 2nd defroster line on the rear windshield. I have a variety of antennae, but I really like my dual band Comet SBB-1NMO. It doesn't flog around and go off axis on the highway like my Larson 150 whip (2m only), doesn't get bothered by trees when in the woods like my 2 Diamond dual band antennae, and it gets out pretty well IMO.
 

rusty_tlc

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Congratulations on your exam. You picked a good antenna. I had a Larsen 2/70 but ended up selling it as it was a bit too floppy and tall for my roof top.

Something to consider about HAM antennas is a ground plane. For example, a 2 meter 1/2 wave antenna does not require a ground whereas a 1/4 wave 2 meter antenna does. Will the 1/4 wave still work? Yeah but not as well without the ground. I've seen write ups that say a good ground would be 2-3 square feet of ground.

From what I found online the 2/70SH is a 1/4 wave on 2m and 3/4 wave on 70cm. If this is true you might need more of a ground plane than a carrier offers. I had the 2/70B which was a 1/2 wave antenna and didn't require the ground plane. There is some good information in the first few minutes of this video:
I use NMO mounts in my roof. They required drilling a hole but it's easy and I prefer this mounting method when it can be done. You can also use the NMO mounts in tabs and other mounts. I would suggest using an NMO as you can easily change out antennas. I assume by your antenna choice that you're running a dual band radio. I run a dual band 8800-R but use the 70cm portion very rarely. As such I run around with a $10 1/4 wave 2 meter antenna most of the time. I have a nicer 1/4 2m one, a 5/8 wave one and two dual band antennas. Switching them is cake and I can pick an antenna that fits my needs. If you're going to spend most of your time on 2m, maybe pick a mounting location that will make a 1/2 wave work in regards to amount over the roof line and not so high it gets caught in the trees (the problem I had with my 2/70).
The OP got his ham license over a year ago, just a heads up on that. ;)

Rule of thumb for ground planes: the ground plane for a 1/4 wave antenna should be approximately 1/4 wave length radius, for 2M that is about 79 inches/4 or 19.7 inches. 19 inches works fine. This for a 50 Ohm system.
A 1/4 wave antenna with no ground plane has an input impedance of 75 ohms with a ground it has and input impedance of 50 ohms.
 
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Brentbba

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I use the same Diamond K400 hatch mounts as jonheld. One for ham and one for CB (didn't give CB up because of one friend I wheel with is still CB only). SBB7 for on road use and SBB1 for offroad. You'll be happy with the flex and performance of that little SBB1. I've seriously whacked both antennas and the Diamond mounts have held solid. CB antenna is a 4'er with a heavy duty spring and it's taken a pounding on tree branches. SBB1 is much shorter and flexible, so not so much.
 

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