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JK CB & HAM Radios Bulletin board forum regarding all topics concerning CB and HAM radios, the installation of them in your Jeep JK Wrangler. This would include antenna mounts, wiring, tuning and usage.

Antenna height

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Old Mar 25, 2012 | 08:03 PM
  #1  
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Default Antenna height

Hi I'm changing the way my antenna mounts on the bumper and it's now going to be about 3 feet higher, on the tire carrier now instead of on the bumper. If I go from a 6' to a 3' antenna will that effect the performance much? It will still be at about the same over all height above the jeep.
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Old Mar 26, 2012 | 05:53 PM
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Default High Enough

- How does your first antenna perform? What type is it? Is the mount grounded? What were your SWR readings? Need this basic data to provide a fair answer.

- Generally speaking, if you have a hard top, the installation should have about one third of the antenna above the hard top.

- With any rear bumper antenna mount, you risk having most of the transmitted signal being reflected by the tub and hard top, especially if none of the antenna is above the top. Very poor performance ahead of your JK will usually result.
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Old Mar 26, 2012 | 05:56 PM
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I had an 8' whip on my 'ol YJ rag top.
If I transfer it over to my new JKU hard top,
will i get just as good a performance out of it?
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Old Mar 27, 2012 | 05:49 PM
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The Antenna I had worked great, it was a fire stick I believe. The location I had it mounted before is now where my tire carrier stop is sitting and the next best place is to move it up onto the top of the swing out tire carrier itself. I'm really just wondering is the length of the antenna important or is the overall height above the jeep what is important.
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Old Mar 27, 2012 | 06:16 PM
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Originally Posted by Summiteer
The Antenna I had worked great, it was a fire stick I believe. The location I had it mounted before is now where my tire carrier stop is sitting and the next best place is to move it up onto the top of the swing out tire carrier itself. I'm really just wondering is the length of the antenna important or is the overall height above the jeep what is important.
I'm thinking the answer you & I seek is; the amount of antenna that clears
the hard body points of the vehicle.
I know you need a "clear" window around the antenna in order to both receive and
transmit a clear signal. The Newer "Hot Stick" antennas are SWR tuned so there's no
need to have a huge whip,(such as I have.)

I just always liked the look of a huge whip, with a flag near the top....
Like a bicycle would have. It's great to have when your wheeling in some high grass
and all you can see is the flag sticking out of the grasses.......
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Old Mar 27, 2012 | 07:04 PM
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Default 18 inches

Your long wire whip and the 4' Firestik have the same electrical length. On the Firestik this accomplished by winding wire up the shaft of the antenna mast. You will notice that as the wire gets closer to the top, it is wound much closer together for about the last 18". That is because the Firestik is "top loaded" which means that's where most of the radio's signal power is transmitted from. So the answer to your question is, install the antenna so that at the top of the antenna mast is at least 18" above the hard top, 24" would be better. but it makes driving into the garage difficult.
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Old Mar 28, 2012 | 01:37 AM
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Originally Posted by Desert Fox
Your long wire whip and the 4' Firestik have the same electrical length. On the Firestik this accomplished by winding wire up the shaft of the antenna mast. You will notice that as the wire gets closer to the top, it is wound much closer together for about the last 18". That is because the Firestik is "top loaded" which means that's where most of the radio's signal power is transmitted from. So the answer to your question is, install the antenna so that at the top of the antenna mast is at least 18" above the hard top, 24" would be better. but it makes driving into the garage difficult.
I'm guessing the Wilson ez tune antennas are designed like the fire stick as well. They have a tunable top, and the wire looks as if its wrapped around the mast. I'm getting a 2ft and 4ft mast with a quick release. 2 ft around town and swap to the 4 ft in the woods wth my friends for range.
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Old Mar 28, 2012 | 03:06 AM
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I've got 3 and 4 foot k40 top loads, the 4' definitely gets out better and has a quieter receive, but the 3' clears the garage and still gets the job done.

The k40's have an inductance coil about 2/3's of the way up, with the 4' it's clear if the roof.
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Old Mar 29, 2012 | 04:26 PM
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Great, thanks for the replys, that's what I was wanting to know. Hoping to get one this weekend and get it installed. Thanks
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Old Mar 30, 2012 | 07:23 PM
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i'm looking to mount a firestick to my spare tire holder...i occasionally park at a public parking garage with low ceilings and a foot or so of the firestick will stick up past my softop, how durable are the firesticks?

do i need to unscrew it and take it off on the occasions i park in these garages or is it flexible/durable or is that too much to ask of an antenna?

matthew

Last edited by Matthewd5; Mar 30, 2012 at 07:26 PM.
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