SDR MK1.5 Radio 'Andrus' Shortwave Receiver with Network Interface 

Its finally here! After being on a drawing-board for way longer than I would have wanted, the MK1.5 'Andrus'  receiver is ready!

The prototype batch of 10 units was all spoken for for the time I got the units assembled, so I have to apologize that this listing is once again a pre-sale for the batch of ten units arriving on the end of January. However, as the design is ready and the units are finally in production, this is a opportunity to get one secured from that lot. The shipping and handling time is therefore 30 days as well.

However, as a compensation for the wait, all pre-order purchases will receive a neat production-run aluminium enclosure for the unit for free! (I am not guaranteeing that the enclosures will arrive together with the radio tho, as it takes a while to get them done!) 

The receiver is really a long step forward from MK1 units I designed on 2011. The major difference in usability is, that the MK1.5 unit has now a 10/100base Ethernet adapter built-in, what allows using up to 400kHz IF bandwidth over the network! This is really an improvement, as it is now fully utilizing a good-quality radio circuit what was used already for MK1, but was not able to perform to full capacity because of the processor on the old unit being too slow. 

If the above sounded too cryptic, then in simple terms it means that on your SDR software screen you are now able to see a 400kHz wide chunk of radio spectrum at once, given that the software supports it of course. This is almost 10 times wider than MK1 was! Please note, that while the radios do have NetSDR for networking support and SDR-IQ for serial communication implemented, they do not identify themselves as RFspace radios (for a very good reason that this would violate their rights!), so I will not give out any promises that they will be working with the proprietary software RFspace may have. However, to keep the software developers life a little easier, I did adapt existing protocols.

The second serious improvement over the MK1 unit is the internal clocking system, what is now all synchronous with the output sample rate. Thanks to this approach, there is significantly less noise on the received signal once it reaches your computer and this is well visible (or absent thereof) on the SDR software screen!

The full (long!) list of improvements can be found here: http://files.uvb-76.net/SDR_MK1.5/SDR_MK1.5_changelog.pdf

But enough about the comparison with the MK1 - here be info about SDR MK1.5 'Andrus':

The radio itself is a fully digital design with two identical RF frontends possible to use simultaneously, so you can have one channel available for monitoring something, while another one can be used for scanning around the band. The presence of two channels also enables combining the two signals, so in urban areas it is possible to use the second channel for noise cancelling! This feature makes the MK1.5 a unique design at least for now, as I have no knowledge that there would be any other amateur/consumer SDR radios available what would allow that!

Please check blog post at http://uvb-76.blogspot.com/2011/06/sdr-mk1-radio-has-now-diversity-mode.html for more information. (This is for MK1, but is also valid for MK1.5)

The in-depth specifications, as well as the full description of the design and schematic can be found from the http://uvb-76.net website at the SDR MK1 section. Some technical details hereby:

• 5kHz to 30MHz frequency range
• 0.02Hz tuning resolution
• 123dB total dynamic range with AGC (80dB with AGC off)
• 64MHz internal sampling rate
• User Programmable AGC (automatic gain control) with enhanced Power Detector
• 48kHz/16-bit Ch A and Ch B simultaneous USB audio output, 196kHz output sample rate for single channel (A or B or diversity) in SDR-IQ protocol mode
• 10/100Base Ethernet interface for 400kHz sample rate through network (NetSDR protocol mode)
• 128MHz to 160MHz band add-on card option (using ADC undersampling) and up to 1.7GHz downconverter option cards (sold separately, available on Q2 2012).
• Compatible with most free SDR software, such as SDR-Radio, Winrad, Linrad, HDSDR, CuteSDR etc.
• On-board RS232TTL compatible serial port and I2C interface for driving external peripheral
• Powered from USB port (requires Y cable for drawing power from two USB sockets simultaneously) or external 6VDC adapter (not included). (custom PoE can be fitted) 
• 2x BNC Antenna connectors (Mfg: Rosenberger)
• Max current consumption 800mA
• Open software and hardware design for DIY development, filter upgrades etc.