Hi,
N6LF did a very comprehensive study on radials setup and layout effect on
verticale efficiency and radiation.
It was published on QEX but is available online for free.
To make it short from what I remember:
- elevated radials are great
- you don't need full 1/4 wl radials to achieve good efficiency, but very short
radials are no good
- the more the better
- mixing various lengths is good especially if you plan to use your antenna on
several bands
- radials distribution has an effect (verticale with 1 radial or all radials in
the same direction will be directive) albeit not usually that important
73,
Yan.
---
Yannick DEVOS - XV4Y
http://www.qscope.org/
http://xv4y.radioclub.asia/
Le 16 mars 2015 à 09:06, towertalk-request@contesting.com a écrit :
> Message: 2
> Date: Sun, 15 Mar 2015 13:45:30 -0400
> From: <john@kk9a.com>
> To: "'StellarCAT'" <rxdesign@ssvecnet.com>, <towertalk@contesting.com>
> Subject: Re: [TowerTalk] modeling compare: 80M, 2EL vs 4SQ
> Message-ID: <00e301d05f47$d53213d0$7f963b70$@com>
> Content-Type: text/plain; charset="us-ascii"
>
> NEC-2 will not accurately model ground radials. I am certainly not a
> vertical expert but I am thinking that the far field is what effects the
> radiation pattern and unless your redials are wavelengths long they will
> have little effect other than to minimize ground losses. For ease of
> maintenance and the ability to easily switch from CW to SSB band segments, I
> would pick the 4 square over a Yagi. From a gain standpoint they are
> probably pretty close in an average installation.
>
> John KK9A
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