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Re: To helix or Not to helix



Neat information...thanks for sharing, Pieter.

What about a loop yagi feed for a dish??  Sounds like a fun thing....

73,

Mark

At 02:26 PM 5/30/01 -0400, Pieter Ibelings wrote:
>Hi Guys,
>
>I performed some antenna comparisons yesterday between 3 different helix
>antennas and a loop yagi. My results show that the loop yagis have a LOT
>more gain for a given length than a helix antenna. The longest helix that I
>have is about 23 turns and is about 6 inches shorter than the 21 turn
>looper. The loop yagi was consistently about 1 S unit (6dB) better. The
>linear to circular loss appeared to be inexistent.
>I was going to stack four helix antennas and now I have decided I am going
>to stack four loop yagis. I think I now need to get rid of all my 7 helix
>antennas for a good price.
>
>Here is the picture of the Loop Yagi sitting on a small vise on top of my
>window.
>
>http://ozoni.com/n4ip/DSCN0505.JPG
>
>Pieter N4IP
>
>
>----- Original Message -----
>From: "C. Martins" <martins@vega.net.dhis.org>
>To: <amsat-bb@AMSAT.Org>
>Sent: Wednesday, May 30, 2001 1:40 PM
>Subject: [amsat-bb] Helix lenght limit
>
>
> >
> > Hi all,
> >
> >   I've read several references on this list to the maximum practical
>lenght
> > limit of an helix antenna. It seems to be about 3ft at 2.4GHz, right?
> >   However, consulting the ARRL antenna book chapter on helicals I didn't
>find
> > any reference to this matter. Can anyone give some explanation or some
>link
> > about how to know/calculate this limit vs. working frequency or something
> > similar?
> >
> >   Sorry if this has been asked earlier, but couldn't read all the
>e-mails...
> >
> >  Thanks for any info. Best regards
> >
> >   Claudio
> >   CT3KD
> >
> >
> >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
>----
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



Mark L. Hammond  [N8MH]

----
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