Yes green light came on the LNA Filter when I connected the Bias T rtl-sdr dongle.
I managed to test the RTL-SDR dongle bias T and your L-Band LNA filter for about two minutes using Ubuntu GQRX and then it appears the RTL-SDR dongle got to hot and cut out.
I then connected it to your antenna and it spent about 10 minutes trying to get a frequency lock and then I gave up and went back to your e4000 dongle and it locked onto the satellite pretty quickly and says waiting for data.
Ah yes. Now I understand everything. There were two specific software modifications that are included in rxOS to support the v3 RTL-SDR dongle.
But this was specifically for the V3. Let me ask Carl if the same mods work for the V2.
Folks, how long have you left your devices on before they grab a file? I have had mine out for 2-3 hours, 10DB+ SNR, thousands of packets with 1 or 2 errors but have yet to get a file. Any ideas? thanks
David Saint Ruby
What version of rxOS are you running? Is this on a CHIP or Pi3?
Thanks Syed - Pi3,
Librarian v4.0post2 / rxos 2.0a1
Can you navigate to: librarian.outernet/qa/
And then tell me what build version you are using? Also, where did you obtain the image? Was it dropbox or archive.outernet.is ?
I have had the same today very little downloads.
Two days ago I got heaps of stuff. Vieos etc.
Try going to the Filecast center and sending yourself a file. I have just sent myself a 80kb grib weather file as a test.
Syed when the Outernet has nothing to send to the Inmarsat satellite, does the Satellite cut back on transmission power to save electricity or does it have a full power carrier all the time even if it is sending nothing?
Syed here you go
08/21/2016 11:00 AM 139,343,413 rxos-rpi3-image-v2.0a1-201608151712+f270bd0.zip
From here
https://archive.outernet.is/images/rxOS-Raspberry-Pi/2.0a1-201608151712/
librarian.outernet/qa/
rxOS diagnostics tools
platform:
version: 2.0a1
build: f270bd0
build time: 2016-08-15 15:11:22+00:00
ā¢ check
ā¢ mount
ā¢ net
ā¢ top
Thatās an older version, which had several download-related issues. Iām confident weāve resolved all of them in the current build:
https://archive.outernet.is/images/rxOS-Raspberry-Pi/2.0a1-201608221602/
Would you mind trying this one out?
I have not shifted the antenna or moved any wires for the last few days. Sometimes my DIY Outernet receiver is getting very low SNR readings ie 1.5 SNR
Is there a weakening of the satellite sent signal strength or is it something to do with the Ionosphere or angle of sun etc.
Should I reset the unit when I get these low SNR ratios.
Could this be caused by the download testing Outernet is doing?
Working great now. Spot on. Thanks for the feedback and congrats to your team.
@Seasalt Yes, just the day passing can have an impact on SNR. But to go from 7 to 1.5 is really extreme. Has the SNR gone back up? Have you noticed any patterns to the fluctuations?
Although the SNR is enough to close the link, we donāt have that much link margin, so any kind of anomaly can impact the signal and reduce the quality of reception. I donāt know much about all of the variables that can impact the link.
When in doubt, reset. You can almost never cause harm by resetting. But with issues related to SNR, I doubt resetting will do much good. The SNR fluctuation is independent of whatever we are bouncing off the bird.
Did you receive the 3gp video file on how to do push ups?
Syed I got the push ups video fine.
I think what would help if you guys would publish or send by satellite a forecast of what you will be test transmitting.
Are all three satellites receiving the same data or are you already breaking the transmissions into regions.
I donāt seem to get a weak SNR when data is being transmitted.
Possibly the system could be playing up when it all goes idle.
One thing, I think you need to be logging is frequency offset. Anecdotally I think possibly i get a lower SNR when the frequency offset drifts.
Rain makes a difference.
It appears to decode down to 3db.
I have stopped worrying about resetting the unit and just leave it on. As I think it can work great and once you stop sending test files and start regular service that is the time to be measuring performance.
As you accurately assumed, we are currently in test broadcast mode.
Yes, all three satellites are broadcasting the same content.
The files are on a carousel which is constantly playing out, so there is always a file being broadcast. However, you may already have those filesābut there is always something going over the air.
What do you think would be the killer app, from a content perspective? Simply sending a comprehensive set of grib files? Or something else?
For people that cross oceans then grib weather forecast files would be essential.
But sending a broadcast every 6 hrs or 12 hrs with a world wide grib file could be something like 1 - 2 mb every 6 hours Assuming you want to send out most of the world.
But if we broke the grib up into the 3 regions as defined by Inmarsat then it would be a lot less information. Mariners at sea are only interested in their geographic regions grib. Possibly this could break the grib down to .6 to 1 Mb per region or even less.
It might be possible to use a special compression algorithm and remove a lot of redundant information as the current system is sort of designed to be a one off, stand alone data file but you will be using apps that could handle date , spacing etc so this information could be removed from the data set.
It might be possible to remove grib data from a worldwide grib file where the wind data is over land. This might reduce the data size by a third.
I think this kind of thinking on reducing grib file size has been worked on.
It might be possible with the grib file forecast to have the first four 6 hour forecast and then just give 12 hour forecasts. So a 3 day forecast would have
4 X 6 hrs day one
2 X 12 hrs day two.
2 X 12 hrs day three.
This would still be very useful for mariners.
Ok putting gribs aside.
What is a killer app for Outernet.
I think a super successful Outernet will not be bound to 20 Mb a day.
I think if enough people jump on you will possibly go 40 or 60 mb a day.
So what is possible and what is needed.
For remote people News is the biggest I think.
So I would possibly like some kind of constantly updated news ticker.
I am assuming that the information data will be multiplexed with big files broken up into smaller files and small files packed in between.
Next I think RSS news-feeds would be good.
If we could have not only news stories but also analysis of news that would be good too.
I think the text news data will not be huge and I think people would be happy to read it in a basic markup language.
I think it would be good if you could re-broadcast popular HTML webpages.
Ie in London is the theGuardian.com this is an excellent newspaper. (It just one the Pulitzer prize) They also have a RSS news feed.
Do some newspaper websites let you rebroadcast there HTML pages?
Would the BBC let you rebroadcast their news site.
The test videoās you sent out, were a lot of Data. but video is very informative. Possibly a small 60 second h265 video news every hour etc might be useful. the video could be sent out in highly compressed h265 Video and then the CHIP could slowly decode it as a background task to h264 Video which most slow computers could play. This would halve your video upload size. There are already open source apps that decode X265 to x264 etc. I actually tested decoding x264 to x265 on my Orange PI it was 20 times slower than my i7 Acer, but it worked.
I think for remote people having a database schedule of what is being broadcast on shortwave radio would be very helpful.
Weāre looking for sources of world news that will allow us to broadcast their content at no cost. If you have any suggestions, please let us know. The normal sources (BBC, AP, CNN) all charge for their full story feeds.
This is creative commons: Internacional | Ćltimas hora de las noticias en el mundo | 20minutos
http://www.20minutos.es/especial/corporativo/creative-commons/
http://www.20minutos.es/rss/internacional/
Itās in Spanish, but still well worth having.
Thanks
Sam
(Being creative commons you could legally machine translate this into English and other languages too. A few glitches, but would be understandable. This should be English version Portuguese etc etc once a few new articles come through)
You can also use Radio Free Asia in various languages so long as you attribute them:
Particularly useful for those in repressive regimes there.
