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Re: To helix or Not to helix



I've successfully fed a 1691 MHz WEFAX 4 foot dish with a four element loop 
yagi.. works well.  Probably would work fine with 2.4 GHz as well.

Fred W0FMS


>From: "Mark L. Hammond" <hammond@surrealnet.net>
>To: "Pieter Ibelings" <rfspace@yahoo.com>, <amsat-bb@AMSAT.Org>
>Subject: Re: [amsat-bb] To helix or Not to helix
>Date: Wed, 30 May 2001 15:33:43 -0400
>
>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]
>
>----
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

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