Offroad Trailblazers and Envoys

Trailblazer tail light guards with integrated CB mount

Any special projects involving a decent amount of fab work (bumpers, sliders, roof racks, etc)

by v7guy » Mon Sep 30, 2013 9:02 pm

HARDTRAILZ wrote:Look cool, but wouldnt they grab shit that is sliding down the side of truck...like branches?

I may be mistaken, but dual antennas don't help much at all for our use offroad. http://cbradiomagazine.com/May%202007/D ... ything.htm


You could do a integrated flag mount on other one for use at offroad parks and such. Saw a nice idea with using quick connect air chucks for flag mount.



Truthfully I was just thinking dual antennas for the looks lol
I've read a bit that it might be helpful on the highway, but I don't know about the accuracy of the info.

I do like the idea of a flag mount, I noticed Badlands was saying it was required out there. It may be something I should consider.

I did briefly consider it might grab more stuff, but the rod loop going up to the claw mount is on the outside and it seems to have held up really well over the last year. I think it'll be alright. If not, I'll build something stronger again lo
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by TBYODA » Mon Sep 30, 2013 10:42 pm

v7guy wrote:
HARDTRAILZ wrote:Look cool, but wouldnt they grab shit that is sliding down the side of truck...like branches?

I may be mistaken, but dual antennas don't help much at all for our use offroad. http://cbradiomagazine.com/May%202007/D ... ything.htm


You could do a integrated flag mount on other one for use at offroad parks and such. Saw a nice idea with using quick connect air chucks for flag mount.



Truthfully I was just thinking dual antennas for the looks lol
I've read a bit that it might be helpful on the highway, but I don't know about the accuracy of the info.

I do like the idea of a flag mount, I noticed Badlands was saying it was required out there. It may be something I should consider.

I did briefly consider it might grab more stuff, but the rod loop going up to the claw mount is on the outside and it seems to have held up really well over the last year. I think it'll be alright. If not, I'll build something stronger again lo


I can say I have a lot of back ground in this area, as the article states the dual antenna are not effective since the distance between each antenna is not far enough a part. Since most of the TB owners are mounting their antennas on the back rear corner or rear side, the antenna patter or effective radiated transmit power and receive are distorted more forward and right or left of the TB since most of the ground plane is forward of antenna. Here is example of what I mean.
Image
Flip this pattern if antenna is mounted on the right side. If you move the antenna say to the front across from the am/fm antenna on the left side, the pattern is move to more on the right side of the SUV. What you are doing is effecting making a some what of a directional pattern and reducing the performance and range. In the above example the range behind the SUV is very limited compared to the right front.

Some one (who will remand nameless :finger: ) on the ride back from TECORE commend on my shitty wire whip mag mount antenna because I did not have normally used firestick. We'll I will say since my antenna is mounted more in the middle of the roofs ground plain my antenna does not have any directionality to it and is more of omni pattern and will have better performance all around the TB. Please don't misunderstand me the firestick is a awesome antenna. I considered getting a 2 or 3' version with super strong mag mount. I know most of you are going to say that the 2' or 3' is to short. But go take look at your TB and see how much of the antenna is above the roof about 2-3'. On the trail in the close grouping the placement and patterns will not really be a issue but as the group thins out it could be. Enough said.
Last edited by TBYODA on Mon Sep 30, 2013 11:10 pm, edited 1 time in total.
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by dvanbramer88 » Mon Sep 30, 2013 10:47 pm

You forgot to mention adding a dual antenna will somewhat correct the lopsided radiation pattern.

And you also forgot to mention how great the Wilson Lil Wil antenna you have is actually pretty awesome.


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by ErikSS » Mon Sep 30, 2013 10:55 pm

TBYODA wrote: Please don't misunderstand me the firestick is assume antenna.

So, um, what type of "assume antenna" do you prefer? Is the Wilson assume too?
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by TBYODA » Mon Sep 30, 2013 11:08 pm

dvanbramer88 wrote:You forgot to mention adding a dual antenna will somewhat correct the lopsided radiation pattern. :cheers:
True but not worth the extra $$ and effort (unless you pick it), just place the antenna in right location however that is tough if you have a roof basket. But could be achieved if one were to mount to the front part of the basket. Might look dumb just saying.

dvanbramer88 wrote:And you also forgot to mention how great the Wilson Lil Wil antenna you have is actually pretty awesome.:cheers:


I though I did. :finger: ROFL
Last edited by TBYODA on Mon Sep 30, 2013 11:14 pm, edited 1 time in total.
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by TBYODA » Mon Sep 30, 2013 11:13 pm

ErikSS wrote:
TBYODA wrote: Please don't misunderstand me the firestick is assume antenna.

So, um, what type of "assume antenna" do you prefer? Is the Wilson assume too?

ROFL thanks for pointing that out Erik. fixed. Read my post like three or four times before posting still read assume as awesome. Do'h.
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by Trail X » Wed Oct 09, 2013 1:07 pm

Robert, just to ensure I understand your graph and how a ground plane works - the further away the ground plane is (between you and the intended recipient), the more power transmission in that direction? Conversely, if the ground plane is behind the antenna, it actually reduces power?

Why not mount the antenna inside the vehicle? Is that possible? Or would the body of the vehicle act to totally shield the output of the antenna?
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by mikekey » Wed Oct 09, 2013 1:29 pm

An antenna must be at least 1/4 of its radio's wavelength, nearly all CB antennas have to be a compromise of either the radiator, or the GP. The only one that is not, would be an 8 ft 1/4 wave stainless steel whip mounted on a spring in the middle of the roof. That's pretty freaking ugly and not practical. You cannot place the antenna inside the car. The middle of the roof is actually the best ground plane.

If you desire maximum range and performance from your CB, then the bumper is probably the poorest location for an antenna you can find, because the body blocks too much of the radiator, and usually gives a bad SWR. Mounting it on a tire carrier or on the front of a brush guard will work okay, but isn't a good coupling to the GP. So for the best performance that only leaves the roof (best performance, but not strong enough for a 1/4 wave whip), or high on the rear quarter panel. This is probably the best compromise area.

That being said, the tail light guard antenna's are probably effecting performance of his CB negatively.

For the CB, the 8 ft stainless whip is the ultimate radiating element... bar none. The next best would be a long fiberglass unit (the longer the better). This is what most of us are already running. This is why I have a 4' firestik instead of the smaller ones you other guys are using. Best compromise in my opinion.
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by dvanbramer88 » Wed Oct 09, 2013 1:33 pm

Not to hijack, I see you asked Robert.

But basically the radio waves bounce off of and get aimed by the ground plane. The body of the truck reflects the waves. So yea, inside the truck would insulate the antenna.

Ideally for a perfect circle, You want the antenna dead center on the roof. But even than, the rectangle shape of the truck would make an oval out of the radiation pattern.

If you were to put the antenna on a lip mount from the hood/quarter panel seam, the windshield and hood would reflect most of the waves forward and out at an angle. Dictated by the side of the truck the antenna was on.

For me, my antennas are top, middle, and bottom loaded. The top portion uses the roof as a ground plane and reflects forward and out. The middle portion reflects back off the back window, and the bottom load reflects off the tool box to the rear and the sides.

Theoretically this is how it is supposed to work. In real life YMMV.

Things like roof racks and light bars and disturb the ground plane and reduce your range.

Robert probably has a more technical answer.


I see mike key beat me to it. He also adds a good point, you want to work with quarters and halves of the wave length when it comes to antenna length and separation. Mine are a little too close together for 1/4 wave length, but are 4 footers.
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by mikekey » Wed Oct 09, 2013 1:35 pm

Not to mention, a roof rack or a light bar will have a similar effect even if you mount it dead center on the roof.

edit* I see Dave mentioned this already. :thumleft:
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by HARDTRAILZ » Wed Oct 09, 2013 1:42 pm

mikekey wrote:This is why I have a 4' firestik instead of the smaller ones you other guys are using. Best compromise in my opinion.


I thought most on here ran a 4 foot Firestik...

That is generally tall enough to get a portion up and above anything on the roof and seems more than adequate for the trail usage most of us have a CB for.
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by dvanbramer88 » Wed Oct 09, 2013 1:50 pm

Yea, on the trail, you realistically only need a few hundred yards of range to be adequate. More is nice for bigger groups or if you get spread out.

Most firestick models that I know of are "Top loaded" anyway. So like Kyle said, as long as you get a good portion above the roof, the part of the antenna doing the work is un-obstructed.

I know for me, and a few others, I drive A LOT of highway miles and always have the CB on. When there is an accident or a lane closure up ahead, the truck drivers warn other truck drivers about it and give them a heads up for what lane to be in. Around here at least, they are pretty good with the "bear reports" too. And in that case, decent range is nice to have. One notable instance I can think of, the last time I went to Harrisburg for the game commission, coming home on the PA turnpike, I knew about a "bear trap" over 7 miles before I got to it.
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by mikekey » Wed Oct 09, 2013 1:57 pm

HARDTRAILZ wrote:
mikekey wrote:This is why I have a 4' firestik instead of the smaller ones you other guys are using. Best compromise in my opinion.


I thought most on here ran a 4 foot Firestik...

That is generally tall enough to get a portion up and above anything on the roof and seems more than adequate for the trail usage most of us have a CB for.



JD and a few others I saw at the spring Tecore were running 3' models. But like you pointed out, and Dave, it's about getting over the obstruction. I figured an extra foot for the roof rack.


dvanbramer88 wrote:I know for me, and a few others, I drive A LOT of highway miles and always have the CB on. When there is an accident or a lane closure up ahead, the truck drivers warn other truck drivers about it and give them a heads up for what lane to be in. Around here at least, they are pretty good with the "bear reports" too. And in that case, decent range is nice to have. One notable instance I can think of, the last time I went to Harrisburg for the game commission, coming home on the PA turnpike, I knew about a "bear trap" over 7 miles before I got to it.


Same here, smokey checks and accidents are a life saver. I find however that it's not until we get further out on the HWY that the chatter and mentions pick up. Inside our metro area it's all spanish, seriously. 8-)
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by TBYODA » Wed Oct 09, 2013 5:15 pm

JamesDowning wrote:Robert, just to ensure I understand your graph and how a ground plane works - the further away the ground plane is (between you and the intended recipient), the more power transmission in that direction? Conversely, if the ground plane is behind the antenna, it actually reduces power?

Why not mount the antenna inside the vehicle? Is that possible? Or would the body of the vehicle act to totally shield the output of the antenna?


I can say Dave & Mike really answered it excellent and as Mike said you need the extra height or so to clear the roof basket. One thing I would suggest is tune the system with the SUV fully loaded with gear up top. Reason because that how you will be running it on the trail and you want the best performance. Also when you tune the system get out in open field away from other metal objects.

Roadie has good example of this, his Wilson 1000 CB antenna looks bottom loaded and knowing him he's got some type matching network he built to "tune" with the small ground plane. But with a permanently mount you have much better RF connection.
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