[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: loop yagis



Hmmm, slight point of confusion...  just how long is this puppy?  Their 
catalog says it's 144" (12'), their data sheet says 6' (boom length), and 
you reference 9'.  Maybe the boom length is really the turning radius?  That 
would make sense.

Then, it's too big.

Greg  KO6TH.


----Original Message Follows----
From: Steve Raas <sraas@optonline.net>
To: 'Edward Cole' <kl7uw@acsalaska.net>, "'Greg D.'" 
<ko6th_greg@hotmail.com>, kc6uqh@cox.net, amsat-bb@amsat.org
Subject: RE: [amsat-bb] Re: loop yagis
Date: Mon, 07 May 2007 07:52:43 -0400

I to, am considering one of the directive systems loop yagis, their antennas
are top notch in my opinion, and quite popular. There is a 9' long 1268
looper 45 element '2445LY'  that claims 20 db of gain. Here is the link -

http://www.directivesystems.com/PDF/2445LY.PDF

At $120 + shipping and that's the pre built model.. save 20 and build it
yourself.

I have been using their products for many many years.. and I've always been
very pleased with performance.

You can see my directivesystems 2/435 yagis's on my webpage @

http://n2jdq2007.tripod.com/



-Steve Raas
N2JDQ
FN20vg



-----Original Message-----
From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On
Behalf Of Edward Cole
Sent: Monday, May 07, 2007 3:59 AM
To: Greg D.; kc6uqh@cox.net; amsat-bb@amsat.org
Subject: [amsat-bb] Re: loop yagis

For what is worth, my two 45-element loop-yagis give gain of 23
dBi.  They are 12-foot long and spaced about 16-inches apart.  They
are sold by Directive Systems.

A loop fed element in front of  a 32-inch BBQ dish will not have
anywhere near this gain and have many large side lobes.  A dish needs
to be >10 wavelength to exhibit nice clean beam pattern (23cm *10 =
230 cm or about 7.5 feet).  I know many satellite folks are using a
4-foot dish so on transmit only this  may be sufficient, though the
beam will not be nice and waste much radiation in other than the
desired direction.

I used one of the loop-yagis (20-dBi) on AO-40 with 9.5w with a
marginal uplink signal.  Either 15w or more antenna gain was
indicated to produce an SSB signal comparable to mode US.  of course
P3E and Eagle requirements  may not be the same as AO-40.  This is
the best we can do without precise knowledge of the satellite parameters.

At 03:50 PM 5/6/2007, Greg D. wrote:
 >I need a good uplink antenna for the new birds, and have no real
 >space on the boom to add a yagi.  This sounds like what I need; do
 >you have any pictures?  Also, more details on how you do the
 >filtering to keep from frying the 2.4 preamp!
 >
 >I have a screen-lined grill dish, with a canned helix feed to a
 >Khune preamp.  See:  http://home.jps.net/~gregd/Dsc00201.jpg.  Would
 >I just put a single 1-wavelength loop around the outside of the
 >helix at about the focal point?  That would be right at the front of the
can...
 >
 >Greg  KO6TH
 >
 >
 >
 >----Original Message Follows----
 >From: "kc6uqh" <kc6uqh@cox.net>
 >Reply-To: kc6uqh <kc6uqh@cox.net>
 >To: <w7lrd@comcast.net>, <amsat-bb@amsat.org>
 >Subject: [amsat-bb] Re: loop yagis
 >Date: Sat, 5 May 2007 23:19:29 -0700
 >
 >Bob,
 >For ATV I have used a Conifer BBQ grill type 2.4 GHz antenna with a Loop
for
 >1.2 GHz in front of the 2.4 GHz feed. The 1.2 side has plenty of return
 >signal in the order of 18 dBi for ATV work. I haven't seen a loop yagi 
that
 >will touch it in performance. I run full duplex with filters on both
 >frequencies 1253.25 receive and 2441.5 transmit with 10 W. I am able to
work
 >the W6ATN repeater from 40 + miles.
 >
 >Art
 >KC6UQH
 >----- Original Message -----
 >From: <w7lrd@comcast.net>
 >To: <amsat-bb@amsat.org>
 >Sent: Saturday, May 05, 2007 4:13 PM
 >Subject: [amsat-bb] loop yagis
 >
 >
 > > Hello
 > > What is the consensus regarding loop yagi antennas for L band uplink.  
I
 > > have 10 watts available from an IC1271 before the coax.
 > >
 > > --
 > > 73 Bob W7LRD
 > > AMSAT member 28498
 > > Seattle
 > > _______________________________________________
 > > Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the 
author.
 > > Not an AMSAT-NA member? Join now to support the amateur satellite
program!
 > > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
 > >
 >
 >
 >_______________________________________________
 >Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
 >Not an AMSAT-NA member? Join now to support the amateur satellite program!
 >Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
 >
 >_________________________________________________________________
 >Download Messenger. Join the i'm Initiative. Help make a difference
 >today. http://im.live.com/messenger/im/home/?source=TAGHM_APR07
 >
 >
 >
 >_______________________________________________
 >Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
 >Not an AMSAT-NA member? Join now to support the amateur satellite program!
 >Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

73,
Ed - KL7UW
======================================
   BP40IQ   50-MHz - 10-GHz   www.kl7uw.com
144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w
DUBUS Magazine USA Rep dubususa@hotmail.com
======================================

_______________________________________________
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

_________________________________________________________________
Make every IM count. Download Messenger and join the iím Initiative now. 
Itís free. http://im.live.com/messenger/im/home/?source=TAGHM_MAY07

_______________________________________________
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb


AMSAT Top AMSAT Home