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Re: [TowerTalk] 160 dipole?

To: towertalk@contesting.com
Subject: Re: [TowerTalk] 160 dipole?
From: K4SAV <RadioIR@charter.net>
Date: Mon, 12 Jan 2009 02:14:24 -0600
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WB5OXQ wrote:
1. Is a 1/2 wave wire dipole the best antenna for the band considering 
there is room for it.

Wrong question.  There is no best antenna for 160.  I can give you a 
link to a construction project for a three element 160 meter Yagi if 
that would interest you.  You would then need a four element Yagi to be 
better.  What you need to put up depends on what you want to do with the 
antenna.  No, everything is not the correct answer to that.  If you want 
to work USA and have a KW amp, a low inverted vee or dipole will work 
just fine.  If you want something better for DX, you will probably want 
something vertical.  You may even want more than one antenna, and you 
may want a receiving antenna as well.
Read the thread just posted "160m project".   Read W4VZ's comment about 
an inverted L.   An inverted L is a good all purpose antenna for 160 but 
is significantly more trouble to put up than an inverted vee or dipole.

2. Is 80' high enough for the center of the inverted V?

Depends on the answer to #1.  Most people that use inverted vees at that 
height say they work pretty good.  (That really nails it down.)

3 How high do the ends need to be off of the ground?

For performance as high as possible.  For practical reasons, certainly 
not touching the ground and not low enough for someone to touch it.  In 
between that, is a gray area depending on how good you want the antenna 
to be.

4 Should I feed it with coax or ladder line to the 10' level (or other) 
then a balun to coax to the tuner (coax is the only acceptable line into 
the shack)?  The shack is a metal building 30X60' and directly below the 
tower.  There is no way to get ladder line to the operating position 
since all cables have to run through a 3" conduit for at least 30'.

Read the thread just posted "160m project".  For single band operation 
it is a lot easier to feed it direct with coax (no ladder line).

Here is a clue.  Most casual rag chewers on 160 use dipoles at 50 to 80 
feet or maybe inverted vees and a KW amp.  Most DXers on 160 use very 
high inverted vees or inverted L's.  The really serious DXers use full 
size verticals or phased verticals, or maybe even four squares.  
Everyone wants something better than he now has.

The best option is to purchase a copy of ON4UN's Low Band DXing Book and 
read about the many ways to build 160 antennas and what works best for 
what situations.

Jerry, K4SAV

Jim Miller WB5OXQ in Waco wrote:

>I am considering building a 160 meter antenna at our clubhouse because there 
>is a 80' tower there and over an acre of land to spread out a 1/2 wave dipole. 
> Question is;
>1 Is a 1/2 wave wire dipole the best antenna for the band considering there is 
>room for it.
>2 Is 80' high enough for the center of the inverted V?
>3 How high do the ends need to be off of the ground?
>4 Should I feed it with coax or ladder line to the 10' level (or other) then a 
>balun to coax to the tuner (coax is the only acceptable line into the shack)?  
>The shack is a metal building 30X60' and directly below the tower.  There is 
>no way to get ladder line to the operating position since all cables have to 
>run through a 3" conduit for at least 30'.
>
>The tower is a free standing commercial tower made of 4 20' sections bolted 
>together with a 2 meter and a 440mhz antenna at the top, all ham antennas.
>
>Thanks for any advice.  Jim wb5oxq
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