Discussion in 'Software Defined Radio (SDR)' started by LB0TH, Aug 22, 2020.

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  1. LB0TH

    LB0TH Premium Subscriber QRZ Page

    Hi, I have an RTL-SDR V3 Pro that I have tested a bit. When I listen to e.g. 20 meter HF band I get no reception at all. If I tune in my TS-590 on the same frequency, I have S9 + 20dB. Same Windom antenna and feed line. On the RTL-SDR V3 Pro dongle I hear nothing. No deflection at SCOPE either. In general, it seems to have little sensitivity. I use SDR# (Airspy). Probably something I have not adjusted correctly, because it can not be so bad?
  2. VA3VF

    VA3VF Ham Member QRZ Page

    I'm not aware of a 'Pro' version, but if you mean direct sampling, it's experimental and far from comparable to your TS-590. I have 2 of them at the moment, they are good for other uses, but very limited for HF in direct sampling mode.

    Better performance is obtained by using an upconverter, but by then, cost wise, one is better off buying an RSP1A, for example.
  3. LB0TH

    LB0TH Premium Subscriber QRZ Page

    Was probably what I suspected yes, thank you very much for the answer.
  4. VA3VF

    VA3VF Ham Member QRZ Page

    I'm surprised you receive nothing at all. Are you using the correct I/Q branch? While far from 'competitive', it does work in direct sampling mode.
  5. LB0TH

    LB0TH Premium Subscriber QRZ Page

    Absolutely nothing on any HF band. Correct I / Q branch is on. Very weak signal on the 2 meter band and the air band as well, but there is at least something.
  6. K3RLD

    K3RLD Ham Member QRZ Page

    I know I'm going to ruffle some feathers here, but my RTL-SDR.com V3 dongle receives extremely well in direct sampling mode. I'd say it's almost as good as my 706MKIIG. I use GQRX as the receiver software on Ubuntu linux.

    You may have a bad dongle.
  7. K3RLD

    K3RLD Ham Member QRZ Page

    Here's a 5 minute demonstration of my meager station:

  8. VE3CGA

    VE3CGA XML Subscriber QRZ Page

    I have to agree with K3RLD
    hooked mine into the hf antennas. this is 20M just hoppinglots of dx. Antenna is a 20M dipole up 25feet using HDSDR 2.8
    and 40M with a 40M inv vee up 35feet
    and back on 20M with SDR console

    make sure you have the HF direct sampling set up for Q input and of course a fair antenna.

    Glad I read this forum, just started using sdr console for satellite listenning and with doppler is not only looks great it works great
    I might start using it to see how the HF bands are rather than calling up FT8 and seeing whats happenning on it.
    I'd say at least here it works incredibly well

    check out your setup and try again, (bias tee is off here) if your dongle works on vhf, then with Q sampling selected in the sdr setup it should work
    WW2PT likes this.
  9. N6YWU

    N6YWU Ham Member QRZ Page

    Direct-sampling HF with an RTL-SDR works well if you have a good antenna, and there are no powerful signals (AM/FM broadcast, neighbor's RFI, etc.) hitting your antenna; as large RF signals can easily overload the RTL-SDR's meager 8-bit sample range and hide any weak HF. If there is such interference, broadcast bandstop filters, plus perhaps an HF receive filter (home-brew LC, or MFJ, et.al.), possibly followed by an LNA, could greatly improve and RTL-SDR's HF signal reception.
  10. VA3VF

    VA3VF Ham Member QRZ Page

    Agree. If one already has all that, fine, otherwise the total cost easily exceeds other better alternatives. Granted that cost is not the be all in a hobby situation...

    There is an RSP1 (not RSP1A) 'clone' on eBay called MSi.SDR that costs a little more than the RTL-SDR Blog - at least when I bought mine - that performs much better.

    I like the RTL-SDR Blog sticks, just not for HF. For HF I use the mentioned MSi.SDR, an AirSpy HF+, and an AirSpy Discovery.

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