[amsat-bb] Global Geo SATCOM system?

Andrew Rich vk4tec at tech-software.net
Fri Oct 7 07:21:29 UTC 2016

Ok not you have got me REALLY interested 

Please tell me about your setup


> On 7 Oct 2016, at 15:28, Scott <scott23192 at gmail.com> wrote:
> I have a couple of additional pieces of information to pass along on this
> topic as of tonight.
> As many are aware, the Outernet hardware "package" consists of a patch
> antenna, LNA, and unmarked SDR with bias-T enabled.
> Tonight I remembered that some time ago I could not resist buying a couple
> of the second (?) generation metal-case RTL-SDR dongles from rtl-sdr.com.
> I have been using one on my linux computer but the other one was unused.
> Remembering that these rtl-sdr dongles had 5v bias-T as an option, I took
> the unused one apart and soldered the appropriate pins to enable the
> bias-T.  That allowed me to do a comparison with the unmarked SDR that came
> with the other Outernet items.
> Setting Outernet aside for a moment, I did an apples to apples comparison
> of the L-Band AERO signals coming from Inmarsat 4-F3.  The difference in
> signal strength was obvious and substantial.  The rtl-sdr gave me over 10db
> more SNR, so in addition to the 600 & 1200 AERO data streams, I could now
> easily decode the 10k AERO signals where there is a lot more (and more
> interesting) traffic.
> So with that test complete and fairly conclusive, I reconnected everything
> to the Raspberry Pi but with the rtl-sdr dongle this time.  Not
> surprisingly, the L-Band Outernet signal was also greatly improved.  Where
> my SNR figure had been around 3, with the rtl-sdr dongle it was varying
> between 6 & 8.  Please keep in mind that I do not have a clear sky view, so
> take all of these findings with that in mind.
> A few minutes after powering up the Pi and seeing the improved SNR figure,
> content from the satellite started downloading.  As you might expect, the
> rate seemed to be noticeably quicker than before.
> Imagine my surprise to see the first file arrive as a .tgz compressed
> archive that, when extracted, contained some amateur radio content!  Here
> are the first few lines from the file that just arrived:
> ==========================
> OUTERNET>APRS:>OUTERNET file created Fri Oct  7 05:00:19 UTC 2016
> VI50CC>APRS,RS0ISS*,qAR,ZL4JL-6::RS0ISS   :Hello ZL   James G/day Mate
> RS0ISS>CQ,qAS,ZL1KM-H:>ARISS - International Space Station
> K6PKL>CQ,RS0ISS*,qAS,KK6RKY:=3748.51N/12112.44W-Solar powered, 20 watts
> j-pole {UIV32N}
> RS0ISS>CQ,qAS,KK6RKY:>ARISS - International Space Station
> ==========================
> ... and it continued with similar APRS type traffic.
> So, if my finding is any example, if anyone would like to optimize their
> Outernet reception, or for that matter ANY L-band reception, you can do it
> without dedicating one of the expensive SDR's to this function.  The
> metal-case rtl-sdr dongle with bias-T enabled was an excellent step up in
> performance for me.
> -Scott,  K4KDR
> =============
> =============
> On Wed, Oct 5, 2016 at 6:51 PM, Robert Bruninga <bruninga at usna.edu> wrote:
>> AMSAT tinkerers?
>> OUTERNET is a free worldwide Geostationary Satellite downlink system
>> designed to bring content to remote areas all over the globe.  They have
>> six geostationary birds covering the entire globe EVERYWHERE.  All you need
>> is a small 18” (or 36” in some very remote areas) to receive content via
>> your own home-made receiver based on a TV dongle and Rasberry Pi.
>> Is there anyone on AMSAT-bb that is already receiving this content?  We’d
>> like to hear about how easy it is to set up a receiver.
>> We have some ideas on how this can be used to augment Ham radio in our
>> Emergency Response and remote operations missions.  See
>> http://aprs.org/outnet.html
>> Bob, WB4APR
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