NEW CB Attenna

[darkoverlift]

Well I ordered this for my 96 Cherokee: (4 FT Black Antenna too. I have the Cobra 29 LTD Classic CB)

http://www.rightchannelradios.com/f...de-mount-kit-firestik-cb-antenna-kit-300.html


This kit provides an ideal solution when a quality CB antenna installation is needed where a good vehicle chassis ground isn't available. Whether it be on a RV, trailer, motorhome or boat, this kit will provide superior CB performance in a no-ground environment. All kit components are high-quality parts manufactured by Firestik.
The antennas used in these kits are extremely similar to Firestik's Firefly series, but are specially modified for NGP applications. They include a tunable tip, which makes adjusting for peak performance and minimal SWR as simple as turning a screw on top of the antenna.
The kits uses Firestik's molded M-2 "teardrop" side mount. The black plastic shell has a textured finish to give the installation a professional look. All hardware and coax connections are hidden in the inner wall of the vehicle to maintain visual integrity and prevent weather exposure. The actual mounting surface is approximately 3.125" (79mm) x 1.675" (43mm). Outward protrusion is about 1.875" (48mm). This mount comes complete with all of the required mounting hardware, rubber gasket, metal reinforcement plate, nylon insulator and ground terminal lug and can be mounted to surfaces up to 0.28 inches (7mm) thick.
The 17' coaxial cable used in these kits is of the highest quality. The NGP cable assembly that comes with this kit utilizes a custom manufactured coaxial cable available only through Firestik. This NGP cable can only be directly attached to Firestik NGP antennas. If a longer cable length is required, the user may add standard RG-58 A/U cable between the radio and NGP cable, preferably in lengths that are multiples of nine feet. Because it is a tuned circuit, the length cannot be reduced without causing non-repairable damage.


Only wish they were 30 watts not FCC limited

 

[T3hk1w1]

Why a no ground plane antenna? The cherokee has plenty of sheet metal to work with.

 

[darkoverlift]

Fiberglass Hatch.....

 

[kastein]

The antenna shouldn't really limit your power output until you're putting WAY more than legal limit out - Looking at that antenna, I'd bet on it handling at least 50 or 100 watts, though VSWR will be horrible without a pi or pi-L impedance matching network. Ideally, of course, your antenna would have an electrical length of 7 meters, which gives a feed point impedance closer to 50 ohms than a true resonant half wave or quarter wave antenna will give.

As tehkiwi said though, why no ground plane? Making use of the vehicle as your ground plane will greatly improve the antenna's radiating efficiency.

 

[darkoverlift]

I wanted to match it in t he rear hatch like I seen on a XJ here. So since the hatch is glass I had to have a no ground plane.

 

[T3hk1w1]

That will work, but you will get a much better signal if you mount just about anywhere else. I'd save a no-ground-plane setup for a last resort.

 

[rehberg79]

thats the mount im running on my xj, works and looks good. I'm pleased with it.

 

[RCP Phx]

I wanted to match it in t he rear hatch like I seen on a XJ here. So since the hatch is glass I had to have a no ground plane.

Just because the hatch is fiberglass doesnt mean you have no ground plane.Boats are all glass thats why they need a NGP ant,but the sheetmetal of your body is still grounded thru the radio itself.

 

[darkoverlift]

So am I FUBAR or will this work still...

 

[kastein]

Just because the hatch is fiberglass doesnt mean you have no ground plane.Boats are all glass thats why they need a NGP ant,but the sheetmetal of your body is still grounded thru the radio itself.

The problem with this idea is that when you use a quarter wave (or other length) whip with a ground plane, the ground plane is approximating the other half of a dipole as far as the radio is concerned. If you leave the ground shield of the coax ungrounded at the point where the antenna is connected, the system is left unbalanced and strong common mode RF currents will develop along the coax shield, which reduces the effectiveness of the antenna. So ideally you connect the coax braid to the sheetmetal as close as you can to the base of the antenna. You could remove the sheathing and clamp the braid to the frame right where the coax leaves the unibody and crosses onto the hatch, but it's not ideal and will also open you up to water getting inside the shield and increasing cable loss. Personally if I wanted an antenna as far back as I could for appearance sake, I'd mount it using a bracket on the upper taillight mounting bolt and space the hatch out a little bit to keep it from squashing the cable.

 

[T3hk1w1]

It should work. It's not ideal, but offroadable CB setups rarely are from what I've seen.

 

[95XJ_Cbiscuit70]

This is the mount I came up with after seeing a few similar ones online. First guy said it should be aluminum for maximum conductivity but when I went back to the radio shop, second guy thought the mount as nice yet thought it should be steel. Radio seems to work either way.
I did the cutting and had a guy I do work for weld the top plate on.
Took a little bit of time yet I think it was worth the effort.

 

[kastein]

Looks great. With a piece of metal that short I doubt the metal particularly matters.

 

[kentuckytwostep]

So ideally you connect the coax braid to the sheetmetal as close as you can to the base of the antenna

So the coax doesn't ground through the connector? If that is the case why don't the coax makers leave the brade terminated with a spade terminal, in which case there wouldn't be a water concern.

 

[kastein]

the coax grounds through the connector - but that's a DC ground. It does not get a proper RF ground there, and technically speaking it's not a ground at the antenna end of the cable, it's the phantom side of a dipole antenna (the whip of your CB antenna is the other, non-phantom side)

it's a little hard to explain without some EE gobbledegook... and sadly I'm not much of a teacher.

 

[RCP Phx]

As already stated,a "ground plane" is there based on the radio connection.The "working" portion is still based on the antenna location and the sheetmetal!

 

[gbyrnes]

FWIW, and to add my own two cents, I put my antenna on an isolated tire carrier and I ran a 10 gauge ground cable from the mount to the vehicle. No problems at all.