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Dongle options for FO-29 etc

Discussion in 'Satellite and Space Communications' started by KB4ZGU, Apr 19, 2017.

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  1. KB4ZGU

    KB4ZGU Ham Member QRZ Page

    Thanks, everyone. Great information. Wondering if maybe this explains some issues I've had with two Baofengs hooked up to the Arrow. I never hear myself over the satellite, even when others hear me, and one of the radios goes haywire when trying work AO-85. Perhaps not having a diplexer is contributing to front end overload (which I guess is a problem for the Baofengs in any case).

    So here's a question. Suppose the ham radio gods gifted you with a little spare cash, and you could either create an SDR-based setup (as described above) or buy a second radio, say the FT-857. What would you choose? I can see pros and cons to either option. All said and done, the price differences aren't THAT great, once you throw in the diplexer and the Windows tablet. An used FT-817MD can be found in the $500 range and FT-857s can be bought new for $850.

    Would a really cheeeeap Windows tablet (say, around $50) be sufficient for SDRplay?
     
  2. KK4FEM

    KK4FEM XML Subscriber QRZ Page

    Having tried both, I personally would spring for 2 dedicated radios vs. an SDR. However, others like Patrick might have a different opinion. Two radios just fits my portable (90% of what I do) operating style better than having to carry a tablet/laptop/SDR and all the associated accessories around with me.
     
  3. K3RLD

    K3RLD Ham Member QRZ Page

    Relating to the linear satellites, doesn't having a waterfall display (with the sdr) give you a significant advantage in finding your own downlink? I'm looking into an all mode / all band solution right now (just got my general) and am considering an 857 because of it's capability on the sats and terrestrial HF... I figured an SDR solution on the downlink would help prevent me from creating more W5PFG avatars....
     
    AD5KO and WD9EWK like this.
  4. KK4FEM

    KK4FEM XML Subscriber QRZ Page

    With a little bit of practice you'll have no trouble finding your downlink with 2 radios. There are advantages and disadvantages to both methods. There's really nothing to lose by spending ~$100 on an SDRPlay, trying it to see if it works for you. If it doesn't you can always sell it, or find other uses for the SDR (which is what I did.)

    Or you may find (like many others) that it fits your operating style! Best way is to experiment, and with the relatively low cost of the SDRplay that's easy to do.
     
    WD9EWK likes this.
  5. N4UFO

    N4UFO Ham Member QRZ Page

    My only practical thought to ad to the discussion is, that while I have never tried to use an SDR, they require a tablet, right? Well, I did use a tablet to display tracking while in the Nevada desert.... during the day... in the bright sunshine... OY! I had to 'shield it' in the car and go back and forth occasionally from rigs to tablet to get a peek. Even with the relative darkness of the car, I still had to have the tablet's brightness set to max which sucked down it's batteries much quicker. The displays on my 817s are LCD (black on light background) and plenty visible enough that I could operate in the sun. I can't imagine trying to stand out there with a tablet and figure out what was what on that screen. - Bottom line, the answer to your question needs to factor in where/how you plan to operate.

    Sometimes it's about the practical things, not just the technical ones... :)


    This is in the evening, not the bright daytime sun, but you get the idea. You can see light reflecting off the radio displays, but still able to read them.

    displays.JPG

    73, Kevin N4UFO
     
  6. NP4JV

    NP4JV Ham Member QRZ Page

    I don't have any experience with SDR dongles but I operate using a SDRPlay RSP1. My linear satellite station consists of a FT-817ND, a SDRPlay and a laptop.

    I use SDRUno as my software since I feel that the delay is shorter than with HDSDR. I have a little bit more processing power from the PC, so I also use SatPC32 for Doppler correction. SDRUno (and HDSDR) can emulate a Kenwood TS2000 receiver on SatPC32 and the FT-817ND connects to the computer via a Bluetooth dongle. That way, the operating is just a matter of click, listen and call (after a now and then calibration).

    The only disadvantage of computer control with the Yaesu is the innability to update the uplink frequency while transmitting. To work with this, just release the PTT and allow the radio to update the frequency. Not a big deal.

    As for filtering, I use two diplexers with my Arrow (only one with the Elk). One on each feedline with the unused connectors terminated with a 50 Ohm dummy. I notice no problems with the sensitivity with this setup. The SDRPlay can hear pretty well, but it's not an Icom 821, 910 or 9100! For the cost, it's a good alternative.

    IMG_20170317_164306497.jpg
     
    WD9EWK likes this.
  7. K3RLD

    K3RLD Ham Member QRZ Page

    So I ordered an RTL-SDR for experimentation, and this weekend I attempted to listen to a few linear sats. Had a 90° pass of one of the XW sats yesterday evening, and I was just able to copy a couple of QSO's. Is this the issue with the RTL-SDR? All signals were extremely faint.
     
  8. WD9EWK

    WD9EWK Ham Member QRZ Page

    The RTL-SDR dongles, in general, are not very sensitive. They were designed as TV receivers, working with kilowatts or megawatts of signals from TV transmitters. They have worked for receiving some satellite signals, but may require a preamplifier to work better. Some have reported success using them for receiving satellite downlinks, but - other than on the strongest signals - I have not had success with them. I moved on to a FUNcube Dongle Pro+, and then an SDRplay, for receiving satellite downlinks.

    73!
     

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