[amsat-bb] Re: EggBeater

Tue May 29 14:08:52 PDT 2012

I was actually reading up on Bob Bruninga's analysis (earlier in this
thread) of why a fixed elevation yagi would have more than adequate
performance for majority of the LEO passes, when you sent me the info
below. Thank you!

Comment: based upon what you sent in a separate message, the picture of a
"mean" looking in-service 5-element model, if the antenna is that small of
a mass, a second revolute joint for Elevation control with positioner could
be practical - if some parts from hobby robotics / class room robotics
projects were able to be used. Of course it would increase the cost
somewhat and complicate wiring - but would result in true elevation over
azimuth control.

73 de N3RDX

On Tue, May 29, 2012 at 4:49 PM, Ted <k7trkradio at charter.net> wrote:

> Hi Samudra, consider a better alternative to the 'egg beater':  Moxon
> turnstile....much better performance. I will e-mail the article from qst.
> Also, consider an Elk 2m/440 yagi at a fixed elevation and on a Radio Shack
> rotor.
>
> GL, Ted, K7TRK
>
> -----Original Message-----
> From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
> Behalf Of Samudra Haque
> Sent: Tuesday, May 29, 2012 1:18 PM
> To: Edward Cole
> Cc: amsat-bb at amsat.org
> Subject: [amsat-bb] Re: EggBeater
>
> Hello, can I ask a question related to this several-years old thread? At
> George Washington University, this fall we will be on the air and are
> buliding up an amateur radio club ground station from scratch. Currently we
> are collecting equipment, cables, etc., while we wait for the construction
> to begin on a new door in the interior of a third floor class room space to
> let us use that area as a "radio room" or something like that. At my home
> QTH, I'm testing out the radios we can use, and would like to both receive
> and transmit - with omni antennas (e.g., eggbeaters, QHA ) and later AZ-El
> yagis.
>
> Assuming an LNA is used at the antenna for the RX path,  would it be
> practical to use that same omni for uplink? What are the recommended power
> settings for such an uplink for any of the recent amsats?
>
> If there was a constraint (for the summer into fall) of operating in a
> limited visibility area, and approximately 50 sq. ft of open access (i.e.,
> 21 ft monopole mast with open  free area about 4 ft dia.) would that be
> adequate for any sort of uplink antenna? The good thing is that the
> ultimate location of the club station antenna farm is huge, but for now
> this is what we have. I'm open to AZ-El positioners but the mast loading
> limit is pretty small for now.
>
> Any suggestion welcome.
>
> Regards,
>
> Samudra N3RDX
>
> On Thu, Apr 16, 2009 at 9:50 PM, Edward Cole <kl7uw at acsalaska.net> wrote:
>
> > Drew,
> >
> > Thanks for the document on this antenna.  I was going to try resizing
> > the 2m Lindenblad design of Tony's but this will be a snap for me.  I
> > have 1/8-inch rod elements from an old Cushcraft yagi that
> > disintegrated long ago and have some 1/2-inch sched-40 aluminum pipe
> > (7/8 inch OD) that will work fine for the vertical.  I can get the
> > PVC from my local building supply.  Only need to order ferrites from
> > Mouser.  Since I will place a 432 preamp at the antenna a short run
> > of RG-58 or mini-8 will suffice.  I probably will make some variation
> > in the materials used.  I did that on the 2m Lindenblad (not assembled,
> > yet).
> >
> > 73, Ed - KL7UW
> >
> > At 08:02 AM 4/16/2009, Andrew Glasbrenner wrote:
> > >Consider trying AA2TX's excellent parasitic lindenblad design. Unlike
> the
> > >overpriced eggbeater, it puts the gain on the horizon where it is
> needed,
> > >and is circular across the pattern. The parts mostly are from your local
> > >hardware store, and in Tony's typical fashion, it is simple to assemble
> > and
> > >works well.
> > >
> > >73, Drew KO4MA
> > >
> > >----- Original Message -----
> > >From: "Bill Dzurilla" <billdz.geo at yahoo.com>
> > >To: <amsat-bb at amsat.org>
> > >Sent: Thursday, April 16, 2009 11:56 AM
> > >Subject: [amsat-bb] Re: EggBeater
> > >
> > >
> > > >
> > > > Steve,
> > > >
> > > > I have both a commercial and a homebrew Eggbeater and am disappointed
> > with
> > > > both, especially in light of its rather high price.  Connected to my
> > > > IC-7000 via an ARR mast-mounted preamp, performance is far less than
> > with
> > > > an HT and an Arrow.  Guess an omni can't cut it, at least not from my
> > QTH.
> > > >
> > > > Maybe if I could get it up higher, clear of all roofs, it would do
> > better.
> > > > I can make contacts at relatively high sat elevations, but can do
> just
> > as
> > > > well with a $10 dual band ground plane.  My friend has an Eggbeater
> and
> > > > the same preamp at a clearer QTH, and he hears substantially better,
> > down
> > > > to 10 degrees elevation in some directions.
> > > >
> > > > Good luck and 73,
> > > > Bill NZ5N
> > > >
> > > >> > Hi Steve,
> > > >> >
> > > >> > It is surprising to read that you are not hearing
> > > >> anything.  I have
> > > >> > repeatedly used a 2m and 70cm Eggbeater for the sats
> > > >> and have had no
> > > >> > problem hearing things.  No pre-amp.
> > > >> >
> > > >> > I was using a short cable (e.g. less than 10 meters).
> > > >>  The rigs I
> > > >> > used were a FT-736r (deaf) and a FT-847 (so-so).
> > > >> >
> > > >> > 73,
> > > >> >
> > > >> > Dave
> > > >
> > > >
> > > >
> > > >
> > > > _______________________________________________
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> > >_______________________________________________
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