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Author Topic: "Verticalness" of trunk mount?  (Read 403 times)
N0XJO
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Posts: 34




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« on: September 14, 2004, 10:57:42 AM »

Okay, I've clamped a trunk mounted duel band antenna, but the way the trunk lid is, the antenna is tilting 5-10 degrees. (non-adjustable mount)

I got into debate about whether or not this is going to degrade the signal by not being 100% vertical.

What is everyone else’s opinion on this?  Serious degradation or not too noticeable?  
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WB2WIK
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Posts: 20406




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« Reply #1 on: September 14, 2004, 11:26:39 AM »

The trunk mount itself provides more loss and overall degradation of performance than the tilted vertical possibly could.

If your vertical whip was 100% vertical when you're parked, is it still 100% vertical when you're zipping down the freeway at 70 mph?  I doubt it; mine sure aren't.

Forget about the "verticalness," it's silly; however, if you want an overall performance boost, move the whip from the trunk lip mount to the center of the trunk lid, or better still to the center of the vehicle roof, and you'll pick up some performance for certain.

WB2WIK/6
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KB1LKR
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Posts: 1895




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« Reply #2 on: September 14, 2004, 11:27:58 PM »

Could bend the whip slightly 'till vertical, though as WB2WIK points out it will bend back slightly at speed anyway.
 
Unless it is a long axially cophased array (say a 5' +/- 5/8 & 3*5/8 wave, not a basic 19" +/- 1/4 & 3/4 wave) the vertical pattern should be wide enough it wouldn't matter a lot anyway I'd suppose. You only said it was a dual bander.

For sake of experiment, if time permits some day, tie the trunk lid down slightly open so the antenna's vertical and compare to trunk latched, and try hitting a distant repeater or simplex receiver at low power and compare (turn the car to face toward, perpendicular, then away from the repeater/receiver, whip vertical and tilted, in the interest of rigor) and see if it matters.
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