Recently the Outernet project transitioned from using RTL-SDR dongles and C.H.I.P single board computers to using their Dreamcatcher board, which is an RTL-SDR and computing board all in one. In between the transition they also produced a number of ‘SDRx’ dongles. These were custom RTL-SDR dongles with a built in L-band LNA and filter. As they no longer need the SDRx they have them on clearance at their store.
The clearance price is $15 USD which is an excellent deal. Remember though, that the SDRx is limited in frequency range – it is designed for receiving L-band satellites between 1525 – 1559 MHz and the filter will cut off all other frequencies.
Just add a simple L-band tuned antenna to the port and you should be able to receive Inmarsat and a signal like STD-C, AERO or the Outernet signal. A suitable antenna might be a homebrew patch, helix, cooking pot antenna or even a small tuned V-dipole antenna can work for the stronger AERO signals.
We also see that the price of their L-band Outernet active ceramic patch antenna has been dropped down slightly to $25 USD. This antenna is bias tee powered and can be used with a V3 dongle or their Dreamcatcher hardware. The Dreamcatcher itself is also now reduced in price to $59 USD.
We have a review of the Dreamcatcher and active ceramic patch antenna available here.
We also now list Outernet products in our store. These are commission sales so we receive a little bit per purchase which supports the blog, and the items are shipped by Outernet within the USA.
If you were unaware, Outernet is a free L-band based satellite service that provides content such as news, weather data, APRS repeats and more. Currently you can get about 20MB of data a day. Outernet receivers are also all based around the RTL-SDR, allowing for very cheap receivers to be built
Back in June we tested Outernet’s new Dreamcatcher which is an ARM based computing board with RTL-SDR and L-band LNA built in. The $99 USD kit also included an external active L-band patch antenna. The Dreamcatcher full kit has now been reduced to $89 USD, and the active L-band patch antenna can also now be purchased by itself for $29 USD. The active patch antenna is also compatible with the bias tee on our V3 dongles and is a good low cost option for exploring most L-band satellite signals like Outernet, Inmarsat STD-C and AERO around 1542 MHz. The filter does unfortunately cut off the higher Iridium frequencies though.
They are also selling off their older L-band SDRx RTL-SDR boards at a reduced price of $20 USD. The SDRx is a RTL-SDR PCB with a built in L-band LNA and filter, but unlike the Dreamcatcher does not have built in computing hardware. They also have a limited $25 USD edition version of their active patch antenna which includes a built in RTL-SDR. This version is a bit more noisy compared to the standard active patch, but may be an interesting experimental antenna for some.
Recently the Outernet team sent us a prototype of their L-Band tuned RTL-SDR which is called the SDRx for testing. This is an RTL-SDR with RTL2832U and R820T2 chips together with an L-band LNA and filter on the same PCB. It is designed for their Outernet system which transmits from geostationary L-Band satellites.
Outernet is an L-band satellite service that hopes to be a library in the sky. Currently it is broadcasting down about 20 MB of data a day, with data like weather updates, books, pictures, wikipedia pages, APRS repeats and more.
For their DIY Outernet kit they have been using E4000 or our RTL-SDR V3 dongles, so we speculate that this SDRx is going to be used in the “Lantern” which will be their fully assembled Outernet receiver product. The Lantern looks like it will be a single unit, with patch antenna, battery pack, solar panel, RTL-SDR radio and CHIP built into a plastic enclosure.
The SDRx connects to the computer via a micro USB port. It also has a USB repeater and two USB expansion ports on board. This is useful as Outernet is designed to be used with the CHIP portable computer which only has one USB port. The expansion USB ports can be used for plugging in a portable hard drive which can be used as the storage for downloaded Outernet files.
We’ve been running a version of the SDRx prototype on an Outernet receiver for a number of weeks without issue. The SNR on Outernet signals is about identical to the V3 dongles combined with the external Outernet LNA and no L-band heat problems are observed.
A new UK designed and manufactured upconverter that goes by the name SDR(X) has recently become available for purchase. This upconverter connects to a RTL-SDR dongle and allows it to receive from 100 kHz up till 1850 MHz. Some of its features include:
Four user selectable HF pre-filters (0-2, 2-6, 6-11 and 11 to 30MHz) or single 0-30MHz pre-filter.
Band pass filter after mixer and band pass filter after Oscillator
User selectable MMIC 18db amplifier external to RTL chip set (lower noise level, than RTL chip and compensates for pre-filters).
User selectable HF and VHF/UHF mode (HF 0-30MHz, VHF/UHF mode 24MHz to 1850MHz).
Microchip PIC controller for above.
Diode protection on RF input.
The board comes as a prebuilt kit which is currently selling for 79.95 GBP which includes an RTL-SDR dongle. The device also comes with complete documentation. The SDR(X) can be purchased from 6v6.co.uk.