Ok not you have got me REALLY interested
Please tell me about your setup
Andrew
On 7 Oct 2016, at 15:28, Scott [email protected] 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} KK6OTJ-7>DE1QYT,RS0ISS*,qAS,KK6RKY:`.BJl tK>CQ CQ CQ ALL LIVE OPERATORS PLEASE REPLY = KK6OTJ-7>DE1QYT,RS0ISS*,qAS,KK6RKY:`.BJl"@K>CQ CQ CQ ALL LIVE OPERATORS PLEASE REPLY = KK6OTJ-7>DE1QYT,RS0ISS*,qAS,KK6RKY:`.BJl"cK>CQ CQ CQ ALL LIVE OPERATORS PLEASE REPLY = 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
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On Wed, Oct 5, 2016 at 6:51 PM, Robert Bruninga [email protected] 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
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb