SDR Receivers - Difference in Performance between cheap and sophisticated?

  • Hi there,

    I have optimised my QO-100 setup to a degree where I am happy with it for the time being. My signal with 2W into a 70cm dish is about 6dB below beacon level and fine fo QSOs in CW and SSB.

    While I'm enjoying QSOs with that setup, I'm already thinking ahead for the next possible improvements: The S/N of my setup with a cheap Chinese RTL-SDR stick is obviously not as good as the various WEB SDRs, i.e. signals which are barely audible in my setup are better on the WEB SDRs. While my possibilities to increase the dish size are a bit limited, I wonder whether there are other possible improvements.

    In order to get a feeling if it's worth investing in that part of the RX chain: Has anybody made a performance comparison between different SDR receivers? Is it worth investing in a more sophisticated SDR RX, to have a better reception than the Chinese RTL-SDR clone? Are there other SDR X with a significantly better performance? How does the RTL-SDR perform in comparison with a downconverter and a conventional HF or VHF RX?

    73 Jens HB9EKO

  • HI

    I’m using FuncubePro + with 1.1m dish and I’m very pleased with it. I can adjust every stage individually and it is an advantage. For the second QTH I have a RTL-SDR with 85 dish with a wider reception bandwidth but les pleasant reception, by the way SDRconsole is a fantastic sortware and the audio is better compared with the classic receiver-converter approach.

    73 Alex

  • A cheap Newgen.RTL.2832SDR and the way more expensive SDRplay RSPdx are showing no difference in SNR on the NB&WB.

    Checked that some weeks ago.

    Thanks a lot, that's what I was interested in.

    With regards to the SNR. the crucial factor is the size of the dish and - to a smaller amount - the noisefigure of the LNB. The output of the LNB is way above the reception threshold of all SDRs. Goonhilly WebSDR runs a 1.3m dish.

    Thanks Jean, that makes the audible difference plausible. Looks like an increase of dish size is the best option, if feasible.

    by the way SDRconsole is a fantastic sortware and the audio is better compared with the classic receiver-converter approach.

    Hi Alex, thanks for the info. I am running GQRX native on Linux, and SDRconsole in a Windows VM. I have not encountered major difference in audio quality between the two programmes. (maybe I should try to play with filter settings). So it looks like it's not worth investing in a downconverter. I was considering a conversion to 28 or 50 MHz in order to make use of the DSP filtering capabilities of my FT-891, but rather stick to what I've got.

    Thanks for all the info, and hope to talk to you on the sat soon.

    73 Jens, HB9EKO