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Re: VHF Spherical Antenna Designer wanted!



On Thu, 19 Sep 2002, 3.1415926535897932384626433832795028 wrote:

> What's the capacity of the satellite's 8Kg monster battery?

   5 KWH at 12 volts using lithium Ion "D" cells... enough to run it for 2
years consisdering the TNC/RX will sleep 90% of the time when not over
populated areas.  It wakes up when it hears the first packet. (though it
will miss it).  THen it stays awake for 1 minute or as long as there is
activity...  Bob


 > > Pieter >
> ----- Original Message -----
> From: "Bob Bruninga" <bruninga@usna.edu>
> To: <amsat-bb@amsat.org>
> Cc: "TAPR APRS SIG" <aprssig@lists.tapr.org>
> Sent: Thursday, September 19, 2002 5:03 PM
> Subject: [amsat-bb] VHF Spherical Antenna Designer wanted!
>
>
> > Antenna designer needed:
> >
> > We have a funded Launch opportunity for the next PCsat in less than a year
> > and need a good RF designer and antenna modeler to help out.
> >
> > The free ride is because we can go inside of a perfectly spherical but
> > totally passive mirror surfaced 18" diameter ball.  The antenna must be
> > totally internal and have absoultely zero externals.  Last year we built a
> > "split-sphere" model and EZNEC and our full size model showed that with a
> > 1" insulated gap between the upper and lower hemispheres we can get the
> > thing pretty close to a good match for 145.825 MHz with the whole thing
> > pretty much acting like a dipole.
> >
> > But with 3 other satellites under design and construction, and me being
> > the only HAM/Comm guy, I just dont have time to do all that I want to to
> > make sure this split-sphere design will tune up.
> >
> > Design to date:    http://www.ew.usna.edu/~bruninga/ande.html
> >
> > The PCsat style digipeater will run for 2 years with 8Kg of Lithium
> > primary cells (no external solar power possible)...
> >
> > What I need is someone (who really knows what he is doing) that is willing
> > to give their "life" to this antenna design over the next 9 months... for
> > the sake of getting another UI packet digipeater into space...
> >
> > Just thought I'd ask...
> >
> > de WB4APR, Bob
> >
> >
> >
> >
> >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
>

de WB4APR@amsat.org, Bob

PCsat WEB  page     http://www.ew.usna.edu/~bruninga/pcsat.html
ISS-APRS FAQ:       http://www.ew.usna.edu/~bruninga/iss-faq.html
CUBESAT Designs     http://www.ew.usna.edu/~bruninga/cubesat.html
APRS LIVE pages     http://www.ew.usna.edu/~bruninga/aprs.html
APRS SATELLITES     http://www.ew.usna.edu/~bruninga/astars.html
MIM/Mic-E/Mic-Lite  http://www.toad.net/~wclement/bruninga/mic-lite.html

----
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