Re: [amsat-bb] Re: Re: RE: Geo Opportunity

[Keith N6ORS <k2@xxxxxx>]

Ok, this is starting to look pretty good. All of you tech-heads
following this thread
this is your chance to build something. I think we have a good shot at
this with a 6 month timetable.
Any co-conspiritors can email me directly. MY address is on QRZ.com

Keith (N6ORS)

Bob Bruninga wrote:
> 
> But I think your downlink budget assumes a single SSB user gets the full
> 10 watts of linear downlink.  I think we need to assume that there might
> be as many as 5 simultaneous QSO's?  THus he only gets 2W of transponder
> power, losing 7 more dB.  I think that's right.  I edited your link budget
> below to this situation...
> 
> On Wed, 30 Jul 2003, Keith N6ORS wrote:
> 
> > These numbers assume 10watts of tx on the sat.
> > A 5w rig with a wire on the uplink and arrow antenna on the downlink
> > would make a nice portable psk-31/hellschriber setup. larger downlink
> > antennas would make ssb workable.
> >
> > Keith (N6ORS)
> >
> > Uplink 10m
> > TX power         10W    40 dBm
> > TX Antenna Gain          3 dBi
> > Polarization loss       -3 dB
> > Resulting EIRP          40 dBm
> >
> > Path Loss at 10m      -153 dBm
> > Receiver Antenna Gain    0 dBi
> > Received signal       -113 dBm
> > Required for 10dB SNR
> >   in 3 KHz bandwidth  -119 dBm
> > ------------------------------
> > Margin                  +6 dB
> >
> > Downlink 2m
> > TX power          2W    33 dBm  <== One of 5 users in 10W transponder
> > TX Antenna Gain          3 dBi  <== when the whip is broadside to you
> > Polarization loss       -3 dB
> > Resulting EIRP          33 dBm
> >
> > Path Loss at [2m]     -167 dBm
> > Receiver Antenna Gain   15 dBi  <== OSCAR class array
> > Received signal       -119 dBm
> > Required for 10dB SNR
> >   in 3 KHz bandwidth  -120 dBm
> > ------------------------------
> > Margin                  +1 dB
> 
> 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://ssdl.stanford.edu/mims/
----
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