I purchased the setup from Amazon and used the Raspberry Pi 3 board. Its only been running for about a day and its downloaded some of the WX info, APRS Lists, Pics, News. and Wiki lists. I am looking for a more suitable enclosure for outdoors.
Its setup on a shelf about a foot in front of the window with Vertical plastic blinds closed and plastic window screen on the outside and it manages to get enough of a signal to download the packets.
I do see a problem once my computer and monitor are powered up and possibly with the TV as well. I am powering it from the Raspberry PI wall wart for now but after a few days I want to try out my portable power pack and outdoor locations.
The patch antenna is mounted on a plastic sheet with the L-Band Amp, SDR dongle, and Pi-3 on the other side. I have a tablet stand from the 99 cent store to tilt and aim the board for now.
I was wondering what other users are seeing signal wise from their setup. Mine shows a SNR of only 2.8 and signal quality of around 3 to 4 on their setup screen but appears to do the job.
Mike
N6IMF
Mike, my SNR values are not very representative of what someone might see because I have partial tree cover in that direction.
But generally speaking, my SNR's have been as follows:
patch antenna: 2's with an occasional 3
TP-link 2.4GHz wi-fi dish: 6 to 8
1m dish w/ helical feed: 11 to 12
I'm using the Outernet LNA as well. FYI, my signal improved dramatically when I switched from the Outernet dongle to a metal-case rtl-sdr.com TXCO dongle (please note that the bias-T will have to be enabled if you try one of those).
-Scott, K4KDR
==============================================================
-----Original Message----- From: Mike Hoblinski Sent: Saturday, October 15, 2016 10:35 PM To: amsat-bb@amsat.org Subject: [amsat-bb] Outernet L-Band Service
I purchased the setup from Amazon and used the Raspberry Pi 3 board. Its only been running for about a day and its downloaded some of the WX info, APRS Lists, Pics, News. and Wiki lists. I am looking for a more suitable enclosure for outdoors.
Its setup on a shelf about a foot in front of the window with Vertical plastic blinds closed and plastic window screen on the outside and it manages to get enough of a signal to download the packets.
I do see a problem once my computer and monitor are powered up and possibly with the TV as well. I am powering it from the Raspberry PI wall wart for now but after a few days I want to try out my portable power pack and outdoor locations.
The patch antenna is mounted on a plastic sheet with the L-Band Amp, SDR dongle, and Pi-3 on the other side. I have a tablet stand from the 99 cent store to tilt and aim the board for now.
I was wondering what other users are seeing signal wise from their setup. Mine shows a SNR of only 2.8 and signal quality of around 3 to 4 on their setup screen but appears to do the job.
Mike
N6IMF
Scott,
I moved the patch inside to a much less optimum location. It looks through my thermopane glass past a post, and some leafy trees. SNR dropped to 2-3, and I am now seeing some packet loss. However, data is still flowing as before. One thing to try is rotating the patch antenna 90 degrees. I see a solid, reproducible 0.7 dB difference, which matters with suboptimal locations.
73s,
Alan WA4SCA
<-----Original Message----- <From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Scott <Sent: Saturday, October 15, 2016 10:12 PM <To: amsat-bb@amsat.org <Subject: Re: [amsat-bb] Outernet L-Band Service < <Mike, my SNR values are not very representative of what someone might see <because I have partial tree cover in that direction. < <But generally speaking, my SNR's have been as follows: < <> patch antenna: 2's with an occasional 3 < <> TP-link 2.4GHz wi-fi dish: 6 to 8 < <> 1m dish w/ helical feed: 11 to 12 < <I'm using the Outernet LNA as well. FYI, my signal improved dramatically <when I switched from the Outernet dongle to a metal-case rtl-sdr.com TXCO <dongle (please note that the bias-T will have to be enabled if you try one <of those). < <-Scott, K4KDR < < <============================================================== < <-----Original Message----- <From: Mike Hoblinski <Sent: Saturday, October 15, 2016 10:35 PM <To: amsat-bb@amsat.org <Subject: [amsat-bb] Outernet L-Band Service < <I purchased the setup from Amazon and used the Raspberry Pi 3 board. <Its only been running for about a day and its downloaded some of the WX <info, APRS Lists, Pics, News. and Wiki lists. I am looking for a more <suitable <enclosure for outdoors. < <Its setup on a shelf about a foot in front of the window with Vertical <plastic <blinds closed and plastic window screen on the outside and it manages to <get enough of a signal to download the packets. < <I do see a problem once my computer and monitor are powered up and possibly <with the TV as well. I am powering it from the Raspberry PI wall wart for <now but <after a few days I want to try out my portable power pack and outdoor <locations. < <The patch antenna is mounted on a plastic sheet with the L-Band Amp, SDR <dongle, and Pi-3 on the other side. I have a tablet stand from the 99 cent <store <to tilt and aim the board for now. < <I was wondering what other users are seeing signal wise from their setup. <Mine shows <a SNR of only 2.8 and signal quality of around 3 to 4 on their setup screen <but appears <to do the job. < <Mike < <N6IMF < <_______________________________________________ <Sent via AMSAT-BB@amsat.org. 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
Interesting stuff. I should get a station up today...
So, a question to the group: what is the main area of interest?
APRS? Weather info? General Interest? tinkering?
On Sun, Oct 16, 2016 at 6:48 AM, Alan wa4sca@gmail.com wrote:
Scott,
I moved the patch inside to a much less optimum location. It looks through my thermopane glass past a post, and some leafy trees. SNR dropped to 2-3, and I am now seeing some packet loss. However, data is still flowing as before. One thing to try is rotating the patch antenna 90 degrees. I see a solid, reproducible 0.7 dB difference, which matters with suboptimal locations.
73s,
Alan WA4SCA
<-----Original Message----- <From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Scott <Sent: Saturday, October 15, 2016 10:12 PM <To: amsat-bb@amsat.org <Subject: Re: [amsat-bb] Outernet L-Band Service < <Mike, my SNR values are not very representative of what someone might see <because I have partial tree cover in that direction. < <But generally speaking, my SNR's have been as follows: < <> patch antenna: 2's with an occasional 3 < <> TP-link 2.4GHz wi-fi dish: 6 to 8 < <> 1m dish w/ helical feed: 11 to 12 < <I'm using the Outernet LNA as well. FYI, my signal improved dramatically <when I switched from the Outernet dongle to a metal-case rtl-sdr.com TXCO <dongle (please note that the bias-T will have to be enabled if you try one <of those). < <-Scott, K4KDR < < <============================================================== < <-----Original Message----- <From: Mike Hoblinski <Sent: Saturday, October 15, 2016 10:35 PM <To: amsat-bb@amsat.org <Subject: [amsat-bb] Outernet L-Band Service < <I purchased the setup from Amazon and used the Raspberry Pi 3 board. <Its only been running for about a day and its downloaded some of the WX <info, APRS Lists, Pics, News. and Wiki lists. I am looking for a more <suitable <enclosure for outdoors. < <Its setup on a shelf about a foot in front of the window with Vertical <plastic <blinds closed and plastic window screen on the outside and it manages to <get enough of a signal to download the packets. < <I do see a problem once my computer and monitor are powered up and possibly <with the TV as well. I am powering it from the Raspberry PI wall wart for <now but <after a few days I want to try out my portable power pack and outdoor <locations. < <The patch antenna is mounted on a plastic sheet with the L-Band Amp, SDR <dongle, and Pi-3 on the other side. I have a tablet stand from the 99 cent <store <to tilt and aim the board for now. < <I was wondering what other users are seeing signal wise from their setup. <Mine shows <a SNR of only 2.8 and signal quality of around 3 to 4 on their setup screen <but appears <to do the job. < <Mike < <N6IMF < <_______________________________________________ <Sent via AMSAT-BB@amsat.org. 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
Sent via AMSAT-BB@amsat.org. 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
Mike,
I got their kit, being in a hurry, and have been running it on the front deck with a battery pack. It has a clear shot at the satellite, and I see SNR of 8-10 or so. The downlink isn't all that interesting right now, but at some point I need to come up with a weatherproof mount for the electronics. There are relatively long periods between data, so checking it when I bring it in for the night is adequate. They have a fairly active support forum, and there are reports/conjecture that the LNA may be a bit sensitive to ESD.
I found these a useful source of azimuth and elevation information:
http://www.csgnetwork.com/geosatposcalc.html
http://www.csgnetwork.com/antennasatelazposcalc.html
The US satellite is at 98W.
Thanks for the suggestion for a mount. Turns out I had one on the shelf, and it gives me exactly the right tilt.
73s,
Alan WA4SCA
Our bird is very strong lots of signals here in Australia
I was amazed what a difference the AMP made.
I just need to decode now
Beamwidth about 45 degrees
Andrew
On 16 Oct. 2016, at 4:14 pm, Alan wa4sca@gmail.com wrote:
Mike,
I got their kit, being in a hurry, and have been running it on the front deck with a battery pack. It has a clear shot at the satellite, and I see SNR of 8-10 or so. The downlink isn't all that interesting right now, but at some point I need to come up with a weatherproof mount for the electronics. There are relatively long periods between data, so checking it when I bring it in for the night is adequate. They have a fairly active support forum, and there are reports/conjecture that the LNA may be a bit sensitive to ESD.
I found these a useful source of azimuth and elevation information:
http://www.csgnetwork.com/geosatposcalc.html
http://www.csgnetwork.com/antennasatelazposcalc.html
The US satellite is at 98W.
Thanks for the suggestion for a mount. Turns out I had one on the shelf, and it gives me exactly the right tilt.
73s,
Alan WA4SCA
Sent via AMSAT-BB@amsat.org. 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
Hi All,
Been meaning to try it. Hopefully this week when I'm off from work.
Can't wait to see what this project does.
73 Frank kb1qzh
On Sun, Oct 16, 2016 at 2:22 AM Andrew Rich vk4tec@tech-software.net wrote:
Our bird is very strong lots of signals here in Australia
I was amazed what a difference the AMP made.
I just need to decode now
Beamwidth about 45 degrees
Andrew
On 16 Oct. 2016, at 4:14 pm, Alan wa4sca@gmail.com wrote:
Mike,
I got their kit, being in a hurry, and have been running it on the front
deck with a battery pack. It
has a clear shot at the satellite, and I see SNR of 8-10 or so. The
downlink isn't all that
interesting right now, but at some point I need to come up with a
weatherproof mount for the
electronics. There are relatively long periods between data, so checking
it when I bring it in for the
night is adequate. They have a fairly active support forum, and there
are reports/conjecture that the
LNA may be a bit sensitive to ESD.
I found these a useful source of azimuth and elevation information:
http://www.csgnetwork.com/geosatposcalc.html
http://www.csgnetwork.com/antennasatelazposcalc.html
The US satellite is at 98W.
Thanks for the suggestion for a mount. Turns out I had one on the shelf,
and it gives me exactly the
right tilt.
73s,
Alan WA4SCA
Sent via AMSAT-BB@amsat.org. 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
Sent via AMSAT-BB@amsat.org. 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
Feel like a kid again
Andrew
----------------------------- Sent from my iPhone Andrew Rich e vk4tec@tech-software.net w www.tech-software.net m 0419 738 223
On 16 Oct. 2016, at 16:37, Franklyn A. Ballentine, Jr art.ballentine@gmail.com wrote:
Hi All,
Been meaning to try it. Hopefully this week when I'm off from work.
Can't wait to see what this project does.
73 Frank kb1qzh
On Sun, Oct 16, 2016 at 2:22 AM Andrew Rich vk4tec@tech-software.net wrote: Our bird is very strong lots of signals here in Australia
I was amazed what a difference the AMP made.
I just need to decode now
Beamwidth about 45 degrees
Andrew
On 16 Oct. 2016, at 4:14 pm, Alan wa4sca@gmail.com wrote:
Mike,
I got their kit, being in a hurry, and have been running it on the front deck with a battery pack. It has a clear shot at the satellite, and I see SNR of 8-10 or so. The downlink isn't all that interesting right now, but at some point I need to come up with a weatherproof mount for the electronics. There are relatively long periods between data, so checking it when I bring it in for the night is adequate. They have a fairly active support forum, and there are reports/conjecture that the LNA may be a bit sensitive to ESD.
I found these a useful source of azimuth and elevation information:
http://www.csgnetwork.com/geosatposcalc.html
http://www.csgnetwork.com/antennasatelazposcalc.html
The US satellite is at 98W.
Thanks for the suggestion for a mount. Turns out I had one on the shelf, and it gives me exactly the right tilt.
73s,
Alan WA4SCA
Sent via AMSAT-BB@amsat.org. 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
Sent via AMSAT-BB@amsat.org. 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
Since reading about the Outernet, I am becoming more curious. I have a Funcube Dongle Pro + connected to my discone antenna going into my windows 7 laptop, running SDR Console. I am hearing a signal that sounds like data with about 2-3 second breaks every so often. The frequency is 1,539.793 MHz and I have the decode in Data USB 24 KHz bandwidth. The signal is -60 dBM on the signal strength meter. Is it possible I am hearing this signal from the bird or could it be a local source? I already have 4 versions of the Raspberry Pi but figured this would be a reason to purchase the version 3! We all need a good excuse to present to the XYL.
When using the programs to calculate my pointing direction for the bird, I get two different numbers for the azimuth with two different programs. The elevation is the same. I wish all the programs would accept E or W longitude instead of the 0 to 360 degrees. I guess that makes it easier for the programmer but they usually allow you to give N or S latitude.
Finally, I keep thinking if I get all the components to grab this data, is it really worth it other than to say I did it? Thanks for any guidance or comments. Rick - WB3CSY
Sent from Rick's iPhone 6S "Great spirits have always encountered violent opposition from mediocre minds" - Albert Einstein
"Any sufficiently advanced technology is indistinguishable from magic" - Arthur C. Clarke
El 19/10/16 a las 18:03, Rick Walter escribió:
Since reading about the Outernet, I am becoming more curious. I have a Funcube Dongle Pro + connected to my discone antenna going into my windows 7 laptop, running SDR Console. I am hearing a signal that sounds like data with about 2-3 second breaks every so often. The frequency is 1,539.793 MHz and I have the decode in Data USB 24 KHz bandwidth. The signal is -60 dBM on the signal strength meter. Is it possible I am hearing this signal from the bird or could it be a local source? I already have 4 versions of the Raspberry Pi but figured this would be a reason to purchase the version 3! We all need a good excuse to present to the XYL.
Hi Rick,
The signal you describe doesn't seem to me like Outernet's signal. Outernet's signal is a bit more than 4kHz wide and it doesn't have any breaks in it.
-60dBm on your SDR software doesn't really mean anything unless you have calibrated your signal meter (and -60dBm would be way too high for Outernet's signal). What is strength of the noise floor?
Some 10's of kHz above Outernet you have 2 other signals from the same Inmarsat satellite. They are a bit narrower than Outernet and much more stronger (perhaps 10dB even). I would use those to check if you hear the bird.
I haven't run the numbers, but I wouldn't expect that you'll be able to hear Outernet with a discone and no LNA. In my experience the FUNcube Dongle Pro+ is not very good at 1.5GHz (but I haven't done any serious tests), and if you have a long cable run from the antenna to the dongle, then you definitely need an LNA.
By the way, Outernet's software doesn't support the FUNcube dongle, only the RTL-SDR or MiriSDR. You may want to look at https://github.com/daniestevez/gr-outernet which supports any SDR that works in GNUradio.
Finally, I keep thinking if I get all the components to grab this data, is it really worth it other than to say I did it? Thanks for any guidance or comments. Rick - WB3CSY
That's something you'll have to decide for yourself. What you currently get is:
* An hourly small file with a listing of all APRS packets sent through satellites or the ISS and all APRS packets containing the word OUTNET. * Some grib files with the weather (most useful to sailors) * Some other weather data * Random (most popular) wikipedia pages
Most of the bandwidth is spent with wikipedia pages, and the bandwidth is not so high: you can only get about 15MB worth of files per day.
Of course you could get the same content on the internet.
If you just want to see how it looks like, I have several brief SDR recordings and recordings of Outernet frames that can be used with https://github.com/daniestevez/free-outernet/
One reason to get the hardware for Outernet (LNA and perhaps patch antenna) is that it can be used used not only to receive Outernet but many other things on the L-band.
73,
Dani EA4GPZ.
I'm interested in the Outernet L-Band service, so today I decided to see if I could at least detect the signal. I really don't have any optimized antenna or preamp but I had an idea.
I have an old Trimble 41556 bullet GPS antenna that has a bad output connector on it. GPS is up around 1575 MHz. Depending on the type of antenna used, there can be really tight bandpass filtering that won't pass the ~1539 MHz Outernet signal.
So I opened up the antenna and removed the two bandpass filters in the unit. Here are two pics of the parts and the simple bypass I did. This is real meatball surgery <grin>
Here are the filters. https://www.dropbox.com/s/t9r9pwitjzjjgxq/filters.jpg?dl=0
Here is the LNA with red arrows showing where I removed the filters. https://www.dropbox.com/s/3w6q78kocvzvw3m/Trimble.jpg?dl=0
The patch antenna used for GPS is designed to look at a large portion of the sky at once, so I knew the directional gain wouldn't be great, but what the heck! This is an experiment.
I used my FUNcube Dongle as a receiver. This is one of the original ones, but it does have a switchable 5v bias tee on the input. I used this 5 volts to power the GPS antenna.
Just pointing the patch out the window, I see this signal: https://www.dropbox.com/s/48fhr38vwhylozz/Outernet.JPG?dl=0
So I have something. I assume it's the Outernet signal? It definitely peaks at the correct AZ/EL for Inmarsat 4-F3 from my location. I do need to check the frequency calibration of my FUNcube as the signal is higher than I expected.
The next step will be to use my RTL dongle with appropriate software to see if I decode anything. I could easily use a better/more directional (more gain) antenna connected to the GPS LNA by simply disconnecting the patch.
This is fun!
Mike
It is fun, Mike. If you'd told me a year ago that I would be receiving something from geosynchronous orbit, or anything at all above 1GHz, I would have asked what you were drinking!
But, thanks to a lot of talented & generous programmers in the amateur community, not only can we receive satellite data streams but many of them can be decoded.
As for L-band transmissions from Inmarsat 4-F3 (my only point of reference), it's become apparent to me that there is considerable variation in both bandwidth and signal strength across the spectrum. As luck would have it, the Outernet signal is weaker & more narrow than most of what you see up there. I guess it's safe to assume that you get what you pay for!
Still, it's a completely receivable signal.
I'd like to offer a couple of screen shots that might help you get familiar with what to expect. You can best spot the Outernet signal because there are two stronger signals to the right of it. If you'd like to look at these images, you can see what to expect. (Outernet data stream is on the left)
http://k4kdr.github.io/files/outernet/2016-10-06--Outernet-HDSDR.png
-and-
http://k4kdr.github.io/files/outernet/2016-10-14--Outernet-GQRX.png
... finally, if you'd like to see a broader view of what is coming down from Inmarsat 4-F3, I posted a screen shot from SDRSharp the other day as one of several images in a Tweet:
https://twitter.com/scott23192/status/786804580625428482
Hope some of that might help!
-Scott, K4KDR
-------------------------------------------------------------------------------- --------------------------------------------------------------------------------
-----Original Message----- From: Mike Seguin Sent: Saturday, October 22, 2016 12:12 PM To: amsat-bb@amsat.org Subject: Re: [amsat-bb] Outernet L-Band Service
I'm interested in the Outernet L-Band service, so today I decided to see if I could at least detect the signal. I really don't have any optimized antenna or preamp but I had an idea.
I have an old Trimble 41556 bullet GPS antenna that has a bad output connector on it. GPS is up around 1575 MHz. Depending on the type of antenna used, there can be really tight bandpass filtering that won't pass the ~1539 MHz Outernet signal.
So I opened up the antenna and removed the two bandpass filters in the unit. Here are two pics of the parts and the simple bypass I did. This is real meatball surgery <grin>
Here are the filters. https://www.dropbox.com/s/t9r9pwitjzjjgxq/filters.jpg?dl=0
Here is the LNA with red arrows showing where I removed the filters. https://www.dropbox.com/s/3w6q78kocvzvw3m/Trimble.jpg?dl=0
The patch antenna used for GPS is designed to look at a large portion of the sky at once, so I knew the directional gain wouldn't be great, but what the heck! This is an experiment.
I used my FUNcube Dongle as a receiver. This is one of the original ones, but it does have a switchable 5v bias tee on the input. I used this 5 volts to power the GPS antenna.
Just pointing the patch out the window, I see this signal: https://www.dropbox.com/s/48fhr38vwhylozz/Outernet.JPG?dl=0
So I have something. I assume it's the Outernet signal? It definitely peaks at the correct AZ/EL for Inmarsat 4-F3 from my location. I do need to check the frequency calibration of my FUNcube as the signal is higher than I expected.
The next step will be to use my RTL dongle with appropriate software to see if I decode anything. I could easily use a better/more directional (more gain) antenna connected to the GPS LNA by simply disconnecting the patch.
This is fun!
Mike
Hi Scott,
Tnx for the images. Big help! So I am seeing Inmarsat, but I need more gain. Time to dig out a WA5VJB log periodic and AD6IW preamp I have here and see what that does.
Mike
On 10/22/2016 4:09 PM, Scott wrote:
It is fun, Mike. If you'd told me a year ago that I would be receiving something from geosynchronous orbit, or anything at all above 1GHz, I would have asked what you were drinking!
But, thanks to a lot of talented & generous programmers in the amateur community, not only can we receive satellite data streams but many of them can be decoded.
As for L-band transmissions from Inmarsat 4-F3 (my only point of reference), it's become apparent to me that there is considerable variation in both bandwidth and signal strength across the spectrum. As luck would have it, the Outernet signal is weaker & more narrow than most of what you see up there. I guess it's safe to assume that you get what you pay for!
Still, it's a completely receivable signal.
I'd like to offer a couple of screen shots that might help you get familiar with what to expect. You can best spot the Outernet signal because there are two stronger signals to the right of it. If you'd like to look at these images, you can see what to expect. (Outernet data stream is on the left)
http://k4kdr.github.io/files/outernet/2016-10-06--Outernet-HDSDR.png
-and-
http://k4kdr.github.io/files/outernet/2016-10-14--Outernet-GQRX.png
... finally, if you'd like to see a broader view of what is coming down from Inmarsat 4-F3, I posted a screen shot from SDRSharp the other day as one of several images in a Tweet:
https://twitter.com/scott23192/status/786804580625428482
Hope some of that might help!
-Scott, K4KDR
-----Original Message----- From: Mike Seguin Sent: Saturday, October 22, 2016 12:12 PM To: amsat-bb@amsat.org Subject: Re: [amsat-bb] Outernet L-Band Service
I'm interested in the Outernet L-Band service, so today I decided to see if I could at least detect the signal. I really don't have any optimized antenna or preamp but I had an idea.
I have an old Trimble 41556 bullet GPS antenna that has a bad output connector on it. GPS is up around 1575 MHz. Depending on the type of antenna used, there can be really tight bandpass filtering that won't pass the ~1539 MHz Outernet signal.
So I opened up the antenna and removed the two bandpass filters in the unit. Here are two pics of the parts and the simple bypass I did. This is real meatball surgery <grin>
Here are the filters. https://www.dropbox.com/s/t9r9pwitjzjjgxq/filters.jpg?dl=0
Here is the LNA with red arrows showing where I removed the filters. https://www.dropbox.com/s/3w6q78kocvzvw3m/Trimble.jpg?dl=0
The patch antenna used for GPS is designed to look at a large portion of the sky at once, so I knew the directional gain wouldn't be great, but what the heck! This is an experiment.
I used my FUNcube Dongle as a receiver. This is one of the original ones, but it does have a switchable 5v bias tee on the input. I used this 5 volts to power the GPS antenna.
Just pointing the patch out the window, I see this signal: https://www.dropbox.com/s/48fhr38vwhylozz/Outernet.JPG?dl=0
So I have something. I assume it's the Outernet signal? It definitely peaks at the correct AZ/EL for Inmarsat 4-F3 from my location. I do need to check the frequency calibration of my FUNcube as the signal is higher than I expected.
The next step will be to use my RTL dongle with appropriate software to see if I decode anything. I could easily use a better/more directional (more gain) antenna connected to the GPS LNA by simply disconnecting the patch.
This is fun!
Mike
Thank you for the replies to my questions from a couple of people. The azimuth aiming difference between the two programs is more than my magnetic declination but i'll look at the math again.
I really did not expect to hear the bird with a simple discone antenna without a pre-amp but was surprised to see a fairly strong signal using the Funcube Dongle Pro plus. A friend who lives about 3 miles away checked the frequency with his equipment and hears nothing. I figured it had to be local. It may be coming from my Comcast Gateway or telemetry from a local water pumping station. I realize you need the SDR mentioned by the outernet docs but thought I would try the FCD for the fun of it.
As always, there are great threads on this bb. Some may say this has nothing to do with amateur radio satellites but I say wait until we get that geosynchronous bird in orbit! This experience will help us in the end.
Please keep the outernet info flowing. I know it will help many of us. 73, Rick WB3CSY
Sent from Rick's iPhone 6S "Great spirits have always encountered violent opposition from mediocre minds" - Albert Einstein
"Any sufficiently advanced technology is indistinguishable from magic" - Arthur C. Clarke
On Oct 19, 2016, at 5:40 PM, Dani EA4GPZ daniel@destevez.net wrote:
El 19/10/16 a las 18:03, Rick Walter escribió: Since reading about the Outernet, I am becoming more curious. I have a Funcube Dongle Pro + connected to my discone antenna going into my windows 7 laptop, running SDR Console. I am hearing a signal that sounds like data with about 2-3 second breaks every so often. The frequency is 1,539.793 MHz and I have the decode in Data USB 24 KHz bandwidth. The signal is -60 dBM on the signal strength meter. Is it possible I am hearing this signal from the bird or could it be a local source? I already have 4 versions of the Raspberry Pi but figured this would be a reason to purchase the version 3! We all need a good excuse to present to the XYL.
Hi Rick,
The signal you describe doesn't seem to me like Outernet's signal. Outernet's signal is a bit more than 4kHz wide and it doesn't have any breaks in it.
-60dBm on your SDR software doesn't really mean anything unless you have calibrated your signal meter (and -60dBm would be way too high for Outernet's signal). What is strength of the noise floor?
Some 10's of kHz above Outernet you have 2 other signals from the same Inmarsat satellite. They are a bit narrower than Outernet and much more stronger (perhaps 10dB even). I would use those to check if you hear the bird.
I haven't run the numbers, but I wouldn't expect that you'll be able to hear Outernet with a discone and no LNA. In my experience the FUNcube Dongle Pro+ is not very good at 1.5GHz (but I haven't done any serious tests), and if you have a long cable run from the antenna to the dongle, then you definitely need an LNA.
By the way, Outernet's software doesn't support the FUNcube dongle, only the RTL-SDR or MiriSDR. You may want to look at https://github.com/daniestevez/gr-outernet which supports any SDR that works in GNUradio.
Finally, I keep thinking if I get all the components to grab this data, is it really worth it other than to say I did it? Thanks for any guidance or comments. Rick - WB3CSY
That's something you'll have to decide for yourself. What you currently get is:
- An hourly small file with a listing of all APRS packets sent through
satellites or the ISS and all APRS packets containing the word OUTNET.
- Some grib files with the weather (most useful to sailors)
- Some other weather data
- Random (most popular) wikipedia pages
Most of the bandwidth is spent with wikipedia pages, and the bandwidth is not so high: you can only get about 15MB worth of files per day.
Of course you could get the same content on the internet.
If you just want to see how it looks like, I have several brief SDR recordings and recordings of Outernet frames that can be used with https://github.com/daniestevez/free-outernet/
One reason to get the hardware for Outernet (LNA and perhaps patch antenna) is that it can be used used not only to receive Outernet but many other things on the L-band.
73,
Dani EA4GPZ. _______________________________________________ Sent via AMSAT-BB@amsat.org. 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
participants (9)
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Alan
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Andrew Rich
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Dani EA4GPZ
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Dave Hartzell
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Franklyn A. Ballentine, Jr
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Mike Hoblinski
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Mike Seguin
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Rick Walter
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Scott