Re: [amsat-bb] New amateur satellite ideas

[Emily Clarke <w0eec@xxxxxxxxx>]

Hi John,

Please. please - this is not critical.....

As much as you are very close to the alphabet soup (and you shoud be) 
perhaps you should explain to the masses what a "TDM bent pipe" is, and 
what you mean by (ADC/DAC/FPGA/MSU/USB) is.  I think I know all the 
acronyms except USRP, but perhaps we can get them entered into the AMSAT 
glossary (http://www.amsat.org/amsat-new/information/glossary.php) so us 
mere mortals can figure it out?

Thanks,

Emily

PS - Send it to me - I'll be happy to be the clerk.





At 04:33 AM 8/2/2004 +0000, John B. Stephensen wrote:
>Development projects with engineers geographically dispersed are especially
>difficult to manage and 20 MBPS is ambitious for an amateur HEO satellite.  If
>this is still the TDM bent pipe approach, acheiving the necessary EIRP at low
>cost at the ground station will be a challenge. I had a few email 
>exchanges with
>Phil a year or more ago about accomodating small earth stations and TDM vs FDM
>on the uplink.
>
>The DCP-1 is very similar to the USRP -- the main difference is a 32-bit MCU
>rather than an 8-bit MCU. My goal was to get the cost as low as possible 
>so that
>more people could afford to duplicate it. The sampling rate is 24.576 MBPS
>adjustable +/-90 PPM and the maximum bandwidth of the analog front end 
>board is
>5.8 MHz. The lower sampling rate means that the basic chip set
>(ADC/DAC/FPGA/MCU/USB) is $50 in small quantities.
>
>I'll look into attending the meeting.
>
>73,
>
>John
>KD6OZH
>
>----- Original Message -----
>From: "Robert McGwier" <rwmcgwier@comcast.net>
>To: "John B. Stephensen" <kd6ozh@amsat.org>; <amsat-bb@amsat.org>
>Sent: Monday, 02 August, 2004 01:26 UTC
>Subject: RE: [amsat-bb] New amateur satellite ideas
>
>
> > Without going into a tremendous amount of detail why, etc., for the
> > time being,  I am in charge of transponders for Eagle.  Others are
> > holding positions or have positions of project technical leadership,
> > and project management and I for one hope that all shakes out and
> > settles down before the annual meeting.  Phil, Tom Clark, Rick
> > Hambly, and I presented a top level view of what we might do for
> > a useful digital transponder for C band and what it might ental.  There is
> > a lot of work to be done on the ground elements as well as the
> > spacecraft elements.  The reasons for my being shoved forward
> > with a electric cattle prod in my back for the transponders will
> > become clearer as the project leadership tells the story of where
> > we are headed for now, and that is likely to be at the annual
> > meeting.  Suffice it to say, it is ambitious, it is forward looking,
> > and the team appears to be excellent with new faces, old faces,
> > and I encourage others to become involved.  If few Mbps >= 20,
> > then your hardware might be interesting and we would certainly
> > look at it.  If we cannot achieve what we want at 20 Mbps,
> > then we might drop back in speed but that is the design goal.
> > I am using the USRP (which is remarkably similar to what you
> > have proposed and talked about on this forum earlier) as a slower
> > speed version to do experimentation and development.  Even the
> > DC and AM broadcast band experiments (2m, 70cm, etc.) have a
> > very interesting twist.  Come to the ANNUAL MEETING and if you cannot,
> > order copies of the proceedings.
> >
> > Caveat:
> > AMSAT-NA is an equal opportunity exploiter ;-) and the more warm
> > bodies there are to exploit the better.
> >
> > Bob
> > N4HY
> >
> >
> > -----Original Message-----
> > From: John B. Stephensen [mailto:kd6ozh@verizon.net]
> > Sent: Sunday, August 01, 2004 7:04 AM
> > To: Robert McGwier; amsat-bb@AMSAT.Org
> > Subject: Re: [amsat-bb] New amateur satellite ideas
> >
> >
> > Its good to hear that work is proceeeding. I was worried after checking 
> Phil
> > Karn's web site and seeing that it hadn't been updated in two years.
> >
> > A few months ago I volunteered as the ARRL HSMM RMAN UHF project leader and
> > am
> > busy with the development a DSP-based transceiver for high-speed digital
> > communication. The design will be published in QEX starting in the
> > November/December issue. For terrestrial links, an OFDM modem will be
> > implemented. However the hardware is completely programmable and could be
> > used
> > to implement a PSK or FSK link at a few MBPS. It would be nice if hams
> > interested in satellites and HSMM could have interoperable hardware.
> >
> > I let my AMSAT membership lapse so I haven't received the AMSAT Journal in
> > the
> > past year and I couldn't find much information on the current web site. Who
> > is
> > the best person to contact to talk about coordinating efforts?
> >
> > 73,
> >
> > John
> > KD6OZH
>----
>Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
>Not an AMSAT member? Join now to support the amateur satellite program!
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---------------------------------
W0EEC - CM87tm
AMSAT Area Coordinator - San Francisco Bay Area
http://www.projectoscar.net    http://www.PlanetEmily.com 
http://www.emilyshouse.com/experthams/ao7/

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