Tagged: outernet

August 19, 2016

Review: Outernet LNA and Patch Antenna

Recently we posted news that Outernet had released their 1.5 GHz LNA, Patch Antenna and E4000 Elonics RTL-SDR + E4000/LNA Bundle. When used together, the products can be used to receive the Outernet L-band satellite signal, as well as other decodable L-band satellite signals like AERO and Inmarsat STD-C EGC. Outernet is a new satellite service that aims to be a free “library in the sky”. They continuously broadcast services such as news, weather, videos and other files from satellites.

EDIT: For international buyers the Outernet store has now started selling these products at http://store.outernet.is.

A few days ago we received the LNA and patch antenna for review. The patch antenna is similar to the one we received a while ago when writing our STD-C EGC tutorial, although this one is now slightly larger. It is roughly 12 x 12 cm in size, 100g heavy and comes with about 13 cm of high quality RG316 coax cable with a right angled SMA male connector on the end. The coax cable is clamped on the back for effective strain relief.

The LNA is manufactured by NooElec for Outernet. It amplifies with 34 dB gain from 1525 – 1559 MHz, with its center frequency at 1542 MHz. It must be powered via a 3 – 5.5V bias tee and draws 25 mA. The package consists of a 5 x 2.5 cm PCB board with one female and one male SMA connector. The components are protected by a shielding can. Inside the shielding can we see a MAX12000 LNA chip along with a TA1405A SAW filter. The MAX12000 (datasheet here) is an LNA designed for GPS applications and has a NF of 1 dB. It has a design where there are two amplifiers embedded within the chip, and it allows you to connect a SAW filter in between them. The TA1405A SAW filter appears to be produced by Golledge (datasheet here), and it has about a 3 dB insertion loss.

We tested the patch and LNA together with one of our V3 RTL-SDR Blog dongles, with the bias tee turned on. The LNA was connected directly to the dongle, with no coax in between. The patch antenna was angled to point towards the Inmarsat satellite. A 5 meter USB extension cord was then used to interface with a PC. The images below demonstrate the performance we were able to get.

The Outernet team writes that a SNR level of only 2 dB is needed for decoding to work on their signal. With the patch and LNA we were able to get at least 12 dB so this is more than good enough. Other signals such as AERO and STD-C EGC also came in very strongly. Even when not angled at the satellite and placed flat on a table it was able to receive the signal with about 5 dB’s of SNR.

In conclusion the patch and LNA worked very well at receiving the Outernet signal as well as AERO and STD-C EGC. We think these products are great value for money if you are interested in these L-Band signals, and they make it very easy to receive. The only minor problem with the patch antenna is that there is no stand for it, which makes it difficult to mount in a way that faces the satellite. However this issue can easily be fixed with some sellotape and your own mount.

In the future once the Outernet Rpi3 OS and decoder image is released we hope to show a demonstration and tutorial on receiving Outernet data.

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August 19, 2016

Review: Outernet LNA and Patch Antenna

EDIT: For international buyers the Outernet store has now started selling these products at http://store.outernet.is.

In the future once the Outernet Rpi3 OS and decoder image is released we hope to show a demonstration and tutorial on receiving Outernet data.

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August 12, 2016

New Outernet Products For Sale: E4000 RTL-SDR, L-Band Patch Antenna, L-Band LNA

Outernet is a new satellite service that aims to be a free “library in the sky”. They continuously broadcast services such as news, weather, videos and other files from satellites. Their aim is to provide up to date information to users in locations with little to no internet (rural, third world and sea), or in countries with censored internet. It may also be of interest to disaster preppers. Currently they have an active Ku (12 – 18 GHz, though due to be discontinued shortly) and C-band (4 – 8 GHz) satellite service, and now recently have their L-band (1.5 GHz) service active. The L-band signal is currently broadcasting at 1539.8725 MHz over the Americas, 1545.525 MHz over Europe/Africa/India and 1545.9525 MHz over Asia/Pacific.

To receive their L-Band service you will need an RTL-SDR capable of receiving 1.5 GHz, like a R820T/2 RTL-SDR (preferably at least passively cooled like our RTL-SDR Blog models as some R820T/2 units tend to fail at 1.5 GHz without cooling) or an E4000 dongle. You will also need an appropriate L-Band antenna and L-Band amplifier.

To help with these hardware requirements, Outernet have just released for sale an E4000 RTL-SDR with bias tee enabled ($39), an L-band satellite patch antenna ($24) and an L-Band LNA ($19). There is also a E4000 + LNA bundle ($49) available. The E4000 comes in a metal case, and has the bias tee always on. The LNA requires bias tee power and is also compatible with our RTL-SDR Blog units that have the bias tee. The patch antenna is tuned for 1525 – 1559 MHz and is the production version of the prototype antenna we used in our Inmarsat STD-C tutorial. Combined with an LNA we found that the patch antenna gives good performance and can also be used to receive other services such as Inmarsat STD-C and AERO. Currently shipping is only available within the USA, but they write that they will have international shipping available shortly.

EDIT: For international buyers the Outernet store is now started selling these products at http://store.outernet.is.

The L-Band Outernet signal decoders aren’t finalized yet, but we expect them to be released in a matter of days to weeks. They will have decoders available for the $9 CHIP computer and Raspberry Pi 3 platforms. They way it works is that you plug your RTL-SDR with L-band LNA and patch antenna connected into the CHIP or Raspberry Pi 3 which is running their customized image. The CHIP/Pi3 then broadcasts a WiFi access point which you can then connect to with any device, and access the files as they are downloaded. Once these decoders are released we’ll do a full tutorial on receiving the Outernet L-Band service with an RTL-SDR.

The Outnernet L-Band LNA — The Outernet L-Band LNA

The Outernet E4000 RTL-SDR in metal case with bias tee.

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May 29, 2016

Testing a Prototype of the Outernet L-Band Downconverter

Outernet are a startup company that hope to revolutionize the way people in regions with no, poor or censored internet connectivity receive information. Their service is downlink only, and runs on C and L-band satellite signals, beaming up to date news as well as other information like books, educational videos and files daily. To receive it you will need one of their official or homemade versions of the Lighthouse or Lantern receivers (the latter of which is still to be released), or an RTL-SDR or similar SDR. Recently they began test broadcasts of their new 5 kHz 1539.8725 MHz L-band signal on Inmarsat I4F3 located at 98W (covers the Americas), and they hope to begin broadcasts in more regions soon too.

The typical RTL-SDR is known to often have poor or failing performance above 1.5 GHz (though this can be fixed to some extent), so Outernet have been working on an L-band downconverter. A downconverter works by receiving signals, and shifting them down to a lower frequency. This is advantageous because the RTL-SDR is more sensitive and does not fail at lower frequencies, and if used close to the antenna, the lower frequency allows longer runs of cheap coax cable to be used without significant signal loss.

Earlier this week we received in the mail a prototype of their downconverter. The downconverter uses a 1.750 GHz LO signal, so any signal input into it will be subtracted from this frequency. For example the STD-C frequency of 1.541450 GHz will be reduced to 1750 MHz – 1541.450 MHz = 208.55 MHz. This also means that the spectrum will appear reversed, but this can be corrected by selecting “Swap I & Q” in SDR#. The downconverter also amplifies the signal with an LNA, and has a filter to remove interfering out of band signals.

The Outernet downconverter circuit board. — The prototype Outernet downconverter circuit board.

We tested the downconverter using their patch antenna which they had sent to us at an earlier date (the patch antenna is used and shown in this Inmarsat STD-C reception tutorial). Our testing found that overall the downconverter works extremely well, giving us much better signal levels. Previously, we had used the patch + LNA4ALL and were able to get reception good enough to decode STD-C and AERO signals, but with the requirement that the patch be carefully pointed at the satellite for maximum signal. With the downconverter the signals come in much stronger, and accurate pointing of the patch is no longer required to get a signal strong enough to decode STD-C or AERO.

The downconverter can be powered by a bias tee connection, and this works well with our bias tee enabled RTL-SDR dongles. We also tested with the bias tee on the Airspy R2 and Mini and had no problems. It can also be powered with a direct 5V connection to a header, and they note that the header will be replaced by a USB connector in the production version.

The release date and exact price that these will be sold at is not confirmed, but we believe that it will be priced similarly to upconverters at around $50 USD or less. A good low cost downconverter should help RTL-SDR and other SDR users receive not only the Outernet signal better, but also other satellite signals such as STD-C and AERO. Although the input is filtered and the RF frequency is specified at 1525 to 1559 MHz, we had no trouble receiving signals up to GPS frequencies of 1575 MHz, and even up to Iridium signals at 1.626 GHz, though reception was much weaker up that high.

Below are some screenshots of reception. Here we used the Outernet patch antenna sitting in a windowsill with the downconverter directly after the antenna, and then 10 meters of RG6 coax cable to the PC and bias tee enabled RTL-SDR. We found that with the downconverted ~200 MHz signal the loss in the RG6 coax was negligible. Better reception could be obtained by putting the patch outdoors. In some screenshots we used Vasilli’s R820T driver with the decimation feature, which allows you to zoom into narrowband signals much more clearly.

Some AERO Signals Zoomed in with the Decimation feature in SDR#. Received with the Outernet downconverter and patch antenna.

Some AERO and other Signals Zoomed in with the Decimation feature in SDR#. Received with the Outernet downconverter and patch antenna.

Signals zoomed out. Received with the Outernet downconverter and patch antenna.

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August 7, 2015

Outernet “Lighthouse” Receiver now for sale

Although this isn’t directly SDR related, this story may still be of interest to some readers. The Outernet project have just put on sale their first receiver which is called the Lighthouse. The standard Lighthouse consists of custom hardware, but there is also a DIY option in the store which consists of a HDStar DVB-S2 receiver board and a Raspberry Pi with custom software. You also need a satellite dish antenna and LNB which can be bought from their store, or found locally.

The Outernet project aims to be a “library in the sky” satellite based service that will provide free one-way access to daily downloads of data such as books, news, videos and other information. Its goal is to provide people who may not have easy physical or uncensored access to the internet an easy way to access daily information.

The currently available Outernet services cover almost the entire globe and use Ku-band (12 – 18 GHz) and C-band (4 – 8 GHz) geostationary satellite links, which is what the Lighthouse is capable of receiving when used with an appropriate dish antenna (the Ku-band service requires a 90cm dish, while the C-band service requires a much larger dish). The Lighthouse receives data from the satellites and then allows users to view the downloaded data by connecting to it via a WiFi enabled device such as a PC or smartphone. They currently broadcast 1 GB of data per day to most of the world, and 100 GB per day to sub-saharan African countries.

In the future Outernet is hoping to release their “Lantern” receiver, of which one prototype is based on a modified RTL-SDR design. The Lantern will receive their upcoming L-band (1-2 GHz) transmissions which will only require a small patch antenna and LNA’s to receive. A standard RTL-SDR with appropriate antenna and LNA’s should also be capable of receiving this service when it is released.

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June 10, 2015

Lantern: A New 925 MHz to 2175 MHz RTL2832U Based SDR for Satellite Reception

Over on Reddit we’ve seen news about a new 925 MHz to 2175 MHz RTL2832U based software defined radio which is currently under development. It is called the “Lantern” and is being developed for the Outernet project.

The Outernet project aims to be a “library in the sky” satellite based service that will provide free access to daily downloads of data such as books, news, videos and other information. It’s goal is to provide people who may not have easy physical or uncensored access to the internet an easy way to access daily information.

To achieve this goal the Outernet project needs a good low cost satellite receiver. The RTL-SDR is a good candidate, but it’s performance at about 1.5 GHz isn’t great, and this appears to be the frequency Outernet wants to use. To improve the performance for satellite reception at these frequencies they have redesigned the RTL-SDR by replacing the R820T2 tuner with a MAX2120 tuner chip which tunes from 925 MHz to 2175 MHz. They have also improved the components used and the PCB layout. The regular RTL2832U chip is used as the ADC and USB interface, so the maximum bandwidth and ADC bit depth remain the same.

The Lantern is currently being prototyped and there is a discussion about it on Reddit. They are aiming for a price point below $20, but note that it will take time to get to that low price as mass production will be required.

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