Testing a Prototype of the SDRx: A Custom Outernet L-Band RTL-SDR

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 upcoming RTL-SDR base Lantern Outernet Receiver.
The upcoming RTL-SDR base Lantern Outernet Receiver.

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.

The SDRx Prototype
The SDRx Prototype
Under the shield. SAW Filter, R820T2. LNA top left.
Under the shield. SAW Filter, R820T2. LNA top left.

Post a comment

You may use the following HTML:
<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>