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Author Topic: Get higher angle of radiation with a vertical?  (Read 3988 times)
WB6BYU
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Posts: 13017




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« Reply #15 on: November 28, 2012, 08:19:16 AM »

Height above ground isn't the important factor for such high angles.

The problem is that you have a vertical radiator, and any such linear element
will have a null off the end.  That null points straight up, and regardless of the
length of the element or the height above ground, it will always have a null
overhead.  If you make it long enough (in wavelengths) then you can get
more radiation at angles closer to the end of the wire, but that isn't practical
for 40m and 80m.

With a single radial you add a horizontal radiator that will help to fill in the
null.  A horizontal dipole or inverted vee is even better because more of the
antenna is horizontal.  But by itself a vertical conductor isn't going to radiate
at high angles, no matter what you do to it.
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K6SCA
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Posts: 2




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« Reply #16 on: November 28, 2012, 09:45:45 AM »

For what KE6TDT is wanting to accomplish I'm a little surprise no one has suggested he try a dipole in NVIS configuration. While it may not be a vertical, it would fill the bill for the distance he's looking for.
« Last Edit: November 28, 2012, 09:49:24 AM by K6SCA » Logged
KE3WD
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Posts: 5694




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« Reply #17 on: November 28, 2012, 10:25:30 AM »

For what KE6TDT is wanting to accomplish I'm a little surprise no one has suggested he try a dipole in NVIS configuration. While it may not be a vertical, it would fill the bill for the distance he's looking for.


Because we recommended the Inverted Vee config, which is really a dipole, but the Vee will usually raise the radiation angle over the flat dipole's. 

There also will be a change in pattern lobes that can help out, especially when crossbanding with a tuner. 


73
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KE6TDT
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Posts: 73




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« Reply #18 on: November 29, 2012, 09:42:37 PM »

Thanks for all contributions/suggestions here.

Trying to absorb the seemingly endless antenna configurations and details  which can obviously be somewhat time consuming and complicated to those of us without formal educations or substantial experience in this field. 

To be honest after reading the manufacturer HF Wire/Vertical antenna reviews an all the boasts and claims, I will likely build my own inverted V.  hihi...

I actually built and used one simple insulated 18 gage inverted V a few years ago, fed with 300 ohm twin lead, (yes, TV type) no balun, using Radio Shack foam cored 20 gauge,  300 ohm feedline- part #15-1175, with each leg being 61 feet, a total of 122'. It was only about 26' above the ground on a roof mounted aluminum mast strapped to a chimney.  Operated only 100 watts, with a non-pro 746 and first contact was Tasmania from S. CA., on twin lead.... I think it was 20meters.  What a kick.   No balun and was fed straight into the balanced wire connections of a basic inexpensive MFJ 949D tuner.   

I have the HF6Vx which I've owned and used for well over 20 years, but is currently disassembled on it's side, not in use. I'll get it back up one day.  I took everything down, and I am now nearly antenna-less. 

In fact I'm listening to 75 meters right now hooked up to a mobile mag mounted 2 meter whip inside the home, fed to an old Kenwood R-1000.  Still have to work to eat, so unfortunately I have not a lot of time to devote to research etc. Sometimes I get a mental block trying to visualize what people are describing regarding antennas, and find I need to read things 2 or 3 times and it still doesn't sink in fully. Then I read it a 4th time...lol 

But it's all fun. Thanks all. 

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WB6BYU
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Posts: 13017




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« Reply #19 on: November 30, 2012, 09:47:56 AM »

For working 75m around the Southwest, a simple dipole or inverted vee is
a good choice.  You can use it on 40m also by adding a second element
for 40m to the same feedpoint (if using coax feed) or by feeding it with
twinlead to a tuner in the shack.

You can get more elaborate than that, but it won't improve your
performance much.

Height above ground will help to improve your signal at longer distances,
but getting sufficient height may be impractical on 75m.
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KB5UBI
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Posts: 97




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« Reply #20 on: December 03, 2012, 02:01:57 PM »

I have two doublets and a ground mounted Butternut HF6V for 75 meters. At my QTH, (night time) the vertical seems to be my best 75 meter antenna for 100 miles plus. Inside 100 miles, it's a toss-up between the vertical and a doublet. Close in, I would think a horizontal full wave loop would be in order.
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W5DXP
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Posts: 3543


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« Reply #21 on: December 04, 2012, 04:42:55 AM »

Trying to absorb the seemingly endless antenna configurations and details  which can obviously be somewhat time consuming and complicated to those of us without formal educations or substantial experience in this field.

Don't know if anyone else has suggested it, but turning a 1/4WL ground-mounted vertical into a 3/4WL inverted-L will raise the Take-Off-Angle from 26 degrees to 89 degrees turning the vertical into an NVIS antenna.
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73, Cecil, www.w5dxp.com
The purpose of an antenna tuner is to increase the current through the radiation resistance at the antenna to the maximum available magnitude resulting in a radiated power of I2(RRAD) from the antenna.
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