Top vs base-loaded antennas

Discussion in 'CB Radio Forum' started by sundown556, Apr 2, 2011.

  1. sundown556

    sundown556 Bobtail Member

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    Apr 2, 2011
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    I'm looking to mount an antenna on the roof of my Toyota 4Runner and would like some advice. Primary use would be at highway speeds on camping trips so a flimsy whip is not what I'm looking for. Would like an antenna setup that either 1) allows quick disconnect of the whip when not in use and parking in the garage or 2) short enough antenna length where it would not get damaged by any overhead garage parts. I think realistically it's probably going the #1 route, but if you've got any great ideas, I'm willing to listen.

    I've read that top-loaded antennas are more efficient that center or base-loaded antennas. If you had a top and base-loaded antenna of approximately the same length (e.g. 36" Lil Wil vs 36" Firestik II FS or 62" Wilson 5000 vs 5 foot Firestik II FS) and the radio, coax, roof center mount location, and SWR were the same, which antenna would have the longer clean xmit/receive range?

    Is the difference in performance between a 2 ft, 3ft, 4ft, and 5ft whip antenna linear? If not, at what point does the decrease in length resemble falling off a cliff?

    Can anyone give some actual data or real world experience switching between top and the other two types of antennas?

    Just in case it matters to your recommendation, I'm looking at installing a Cobra 19 DX IV or Cobra 75 WX ST. I'm flexible with either a magnetic mount antenna or a permanent mount that has a quick detach feature like the K40 base mount antenna.

    One last question; once you get an antenna like the K40 tuned, does it gradually get out of tune with repeated attach/detach of the coil and whip?
     
    Last edited: Apr 2, 2011
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  3. jessejamesdallas

    jessejamesdallas Road Train Member

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  4. josh.c

    josh.c Road Train Member

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    After trying basically every popular antenna made, my personal preference is using the longest practical top-loaded antenna practical. That's partially aesthetics, not just performance, I hated the "please break into my truck and see what else I have worth stealing" look of the Predator 10K when I ran it, although it did perform very well. I'm currently running a pair of 5' Skipshooters on my big truck, and I'd put their performance up against the 10K on anything except absolute maximum power-handling ability, which probably isn't an issue for you. I'd rate them better than the Wilson 2k and 5ks I've had.

    My personal experience has been that performance drops off considerably when you go with an antenna shorter than 4', I wouldn't go any shorter than that. As for quick disconnects, don't go cheap here, the ones you see at truck stops and CB shops usually are pretty fragile and don't last long (again, personal experience). I bought a quick-disconnect from this guy for the antenna on my pickup, and it was expensive, but you only have to buy it once. His fold-over mounts look great too, and that might be ideal for your situation.
     
  5. jessejamesdallas

    jessejamesdallas Road Train Member

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    Can't beat Hank Breedloves Mounts. Thats all I will run...Your right too, they are a bit more expensive than what you will find at Truck Stops and most CB Shops, but you get what you pay for.
     
  6. josh.c

    josh.c Road Train Member

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    Yep, but they're only more expensive once, the truckstop stuff is expensive over and over, especially if you loose an antenna. (I did)
     
  7. Rat

    Rat Road Train Member

    I have gone back and forth between stainless whips and fiberglass top loaded models. I perfer the stainless whip because it can take more abuse then the fiberglass. Currently running Wilson 5000s. They hit branches all day long and keep doing what they are supposed to do. Had to replace the fiberglass Wilsons because of tree hits and after awhile it got expensive.

    I would have loved to go for 10Ks but I like to hold something in my hands before opening the wallet which means, I am not up on buying too much over the net.
     
  8. jessejamesdallas

    jessejamesdallas Road Train Member

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    Makes perfect sense to me! I'm the same way, I always want to put my hands on something at least once before ordering over the Internet...Least that way I know what to expect...

    But once you use a Predator 10K, it's hard to go back to using anything else...

    I guess if you can't find one in your local CB Shop...Just look around at Open Coiled Antenna's on Rigs when your at Truck Stops and look for the Predator sticker located at the bottom of the lower shaft right above the antenna mount, and at least you'll be able to get a good look at one!
    [​IMG]
     
  9. Rat

    Rat Road Train Member

    I don't get out of North Dakota much these days and if I do it might be to around St cloud Minnesota. Not much for CB shops around these parts.


    I have been thinking about 10Ks pretty seriously though. My only problem is height. I am not into bull horning antennas and my 5000s already hit alot of trees at our loading sights ie farmers warehouses in their yards. That and we have to back into some warehouses were my stacks just barely clear. I have actually had to dump my rear airbags to get into some of them.
     
  10. jessejamesdallas

    jessejamesdallas Road Train Member

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    Good thing about Cowtown Antennas...Kale has several versions of the Predator 10K.

    In your case what you would want to go with if you mount your antenna on the mirror bracket, is the "SW" Dual Coil Predator 10K. This antenna was designed mainly for use on Big Rigs for mirror mounting. (trying not to sound like a "Info-Commercial" this is the 10K most mount on Big Rigs)

    Once tuned it's about 58" in total height from base to tip of stinger. So you may-not need to "Bull Horn" mounting.

    Here is a Pic of a "SW" Dual Coil 10K mounted on mirror bracket.
    [​IMG]

    Sorta hard to see just how high the antenna is in the pic, but it tuned at 58" if that helps...

    "SW" just stands for "Short Whip"...The regular Predator 10K with a single coil tunes at over 72" in total height, so this dual coil version is about a foot and a half shorter.

    The one in the Pic also has a 12" lower shaft. (which is what I would recommend...the 12" shaft just seems to tune better) It is also available with a 6" 9" and 17" shaft, but like I said, the 12" seems to tune better on mirror bracket mounting.

    Regardless of which lower shaft is used, the total height after tuned remains the same. (longer shafts end up having shorter stingers once tuned and visa-versa on shorter shafts)

    Like I said, I don't want this to turn into a info-commercial for the 10K, but I can answer just about any question on these antenna's, since I have been dealing with the builder now for over 10 years, and have installed more than I care to admit to!
     
    Last edited: Apr 4, 2011
  11. josh.c

    josh.c Road Train Member

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    Pretty hard to beat a Wilson for that reason alone-if you hit something hard, you buy a new whip, and if you REALLY hit something hard you can buy a new antenna anywhere.
     
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