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Re: Topband: Monopole Radiation Patterns, takeoff angles etc

To: <topband@contesting.com>
Subject: Re: Topband: Monopole Radiation Patterns, takeoff angles etc
From: "Richard Fry" <rfry@adams.net>
Reply-to: Richard Fry <rfry@adams.net>
Date: Tue, 8 May 2012 10:18:06 -0500
List-post: <topband@contesting.com">mailto:topband@contesting.com>
 Dave WX7G wrote:

>The program W6ELProp gives the take-off-angle needed for any path. Looking 
>at 80 meter paths (it does 801-0 meters) the angles for DX paths are in the 
>range of 3-15 degrees.

Assuming those angles are true for DX paths, note that if the NEC far-field 
elevation pattern for a 1/4-wave monopole was the only radiation leaving the 
antenna, the field at 3 degrees elevation would be about 8.9 dB below the 
field at the center of the so called take-off angle (see link below - note 
Photobucket stripped the decimal from the 3.9MHz link).

The surface wave really needs to be recognized in such evaluations.

http://i62.photobucket.com/albums/h85/rfry-100/39MHz_Elepat_6_mS.jpg

 

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