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  1. S

    Smallest EMWIN antenna

    Here are two wav files I recorded with the hackrf and a lna I build myself. Do you think the signals are strong enough to be decoded? I have no experience in demodulation oqpsk, viterbi and reed solomon using gnuradio. Is there anyone out there that could guide me? These are 2Msp wav files...
  2. S

    Smallest EMWIN antenna

    Just in case any one is wondering, I am still working on this project. Here are some pics on dropbox of what I've got so far. I did a total redesign, sorta basing it on the BladeRF. The flow is something like this: Antenna -> rf switch -> LMS6002D -> OMAP-l138 -> PC. Due to some design errors I...
  3. S

    Smallest EMWIN antenna

    Yeah I've had some thing going on too. But I still haven't given it up. I am looking at the TMS320C6746 and ADS4222 to replace the microcontroller, fpga and adc. (Plus! Free samples of those.)
  4. S

    Smallest EMWIN antenna

    Sorry to hear that. I'm still slowly working on the pcb layout. Here are some screenshots of my work. any comments or suggestions would be welcome.
  5. S

    Smallest EMWIN antenna

    "What is it going to take to get some prototype pcb's out of this schematic?" I am working on creating footprint drawings for kiCad, then I will make a board layout. I might use https://oshpark.com/ "What kind of driver or software is going to need to be running on the host OS?" I will...
  6. S

    Smallest EMWIN antenna

    Just an update. Corrected current limiting resistor sizes for debugging leds. adjusted DC blocking cap for 1.69 GHz RF input small typos.
  7. S

    Smallest EMWIN antenna

    Ok. I'm back! Here is my "finished" schematic for my 1-2 ghz sdr. Please point out any thing missing/stupid/that won't work in my design. Here is a simple block diagram of the process. Note: The micro controller will be able to program the fpga boot flash.
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    Smallest EMWIN antenna

    Just an update of my current schematic.
  9. S

    Smallest EMWIN antenna

    I just noticed the EV schematic has 50ohm to 75ohm matching circuitry.
  10. S

    Smallest EMWIN antenna

    The max2120 has 75ohm impedance and the antenna 50ohm. Should I include a 50ohm-75ohm balun or ignore the mismatch, which would create the greatest loss?
  11. S

    Smallest EMWIN antenna

    Thank for the Max2021 evaluation kit info, one would still have to build the USB interface. I am working on a new schematic (With Ki-cad, on Linux(of course)) as soon as I get a decent scketch I'll post it.
  12. S

    Smallest EMWIN antenna

    For 1 PCB it would probably be cheaper doing it yourself although I'm not sure if we would need more than one layer(and everything will be surface mount so it will be really tiny). For more than 50 some places it's as cheap as $4-$7 a board, not a bad price. Also I think the FPGA I have in my...
  13. S

    Smallest EMWIN antenna

    I haven't found any sdrs that do what I want. The hackrf, bladerf or usrp seem a bit overkill(And expensive) for me and the prototype board on the goes website uses a lot of obsolete parts. My current design still looks like it will cost approximately $150-$200 for a one-off board. Since I am...
  14. S

    Smallest EMWIN antenna

    Dunno? Works for me. Here is the part number MAX2120CTI+
  15. S

    Smallest EMWIN antenna

    Found this, look's pretty promising. It's a lot cheaper than the ADRF2820. It has a built in LNA and VCO. http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=155639557&uq=635439602159738791
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    Smallest EMWIN antenna

    Yeah that's the conclusion I'm getting. There is the Hackrf, but I don't need the transmitting....
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    Smallest EMWIN antenna

    Yeah. no amp.
  18. S

    Smallest EMWIN antenna

    Last night I tried the dish again. This time pointing it Inmarsat 4F3. This is what I got, the signals looks fairly strong, it gives me courage to keep trying for the goes 13 signals!
  19. S

    Smallest EMWIN antenna

    This is the design I've got so far.(Yes I know I don't have any filtering circuitry, this is just a rough sketch). It still needs the adc, fpga, power supplies and usb micro controller(Probably a cypress chip)
  20. S

    Smallest EMWIN antenna

    No, I was not successful. I don't think the RTL-SRD is sensitive enough at that frequency. I have no LNA yet... What LNA did you get?
  21. S

    Smallest EMWIN antenna

    Nice I will have to check into that. As soon as you test your LNA let me know what the results are. I am leaning toward building my own receiver for 1.6-1.7 Ghz using this design "antenna -> LNA -> I/Q Demodulator (ADRF2820) -> BPSK Demodulator (FPGA)-> USB controller"
  22. S

    Smallest EMWIN antenna

    Still slowly trying to wrap my head around everything. I found the ADRF6820 (http://www.analog.com/static/imported-files/data_sheets/ADRF6820.pdf) and the STV0299B (http://pdf.datasheetcatalog.com/datasheet_pdf/sgs-thomson-microelectronics/STV0299B.pdf). Would using these two together work and...
  23. S

    Smallest EMWIN antenna

    FYI. Here is the response I got from NOAA regarding the Telestar 5 EMWIN up-link. EMWIN is no longer uplinked on Telestar 5. Sorry for the confusion, we'll have to remove that from our web pages. The broadcast on Telestar 5 was a rebroadcast from the EMWIN broadcast on the GOES I...
  24. S

    Smallest EMWIN antenna

    I am using a cheap RTL2832U based sdr but I am not sure if it has enough bandwidth (3.2 Msps) to receive BPSK @ 400Kbps. I am still trying to wrap my head around the concept of i/q demodulators... I think I am slowly getting the drift :)
  25. S

    Smallest EMWIN antenna

    Looks like it has a dipole antenna with about 1.25 inches per side. According to http://www.csgnetwork.com/antennaedcalc.html each side should be 1.6875 inches @ 1692 Mhz. Could/should I solder on extensions to get the correct length?
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