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Re: [softrock40] Re: What might be the cause of this HDSDR display please?

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  • Alan
    ... Subject: Re: [softrock40] Re: What might be the cause of this HDSDR display please? ... Chris, I think I ve seen people say that the USB can cause this.
    Message 1 of 10 , Feb 18 11:04 AM
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      ----- Original Message -----
      Subject: Re: [softrock40] Re: What might be the cause of this HDSDR display please?


      >
      > Yes, it must be local, but what gives exact 1 kHz signals? I have done
      > nothing at all, the Softrock's been powered up all the time since that
      > screen shot, here's a current one, same band, all looks fine...
      >

      Chris,

      I think I've seen people say that the USB can cause this. Maybe an intermittent?
      But, yes, find out where it is coming in, check local equipment.

      I'm not sure about Mike's advice to increase gain. I have good results with that sort of noise floor, maybe you have calibrated
      HDSDR? If so then leave it. Yes, it is possible to cover up signals not coming in through the antenna but I'd say get rid of them if
      you can.

      73 Alan G4ZFQ

      > http://www.chriswilson.tv/hdsdr2.jpg
      >
      > Next time it does it I'll disconnect, then ground the antenna socket.
      > Just disconnecting it from my 590, and connecting straight to the
      > antenna doesn't change things. I thought it might be something
      > generated inside the TS-590 where it acts as a second receiver cum
      > panadaptor. Will try what you suggest next time, but suspect it's
      > actually pulling this from the air waves round here.
      >
    • warrenallgyer
      Chris I am guessing you are suffering overload from a very strong local signal that is in the filter bandpass of the receiver. I see a very similar display on
      Message 2 of 10 , Feb 18 2:28 PM
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        Chris

        I am guessing you are suffering overload from a very strong local signal that is in the filter bandpass of the receiver. I see a very similar display on 40 meters when the local shortwave broadcaster comes on the air on 7280 KHz and I can measure his signal on my antenna at -10 dBm. That equates to 60+ dB over S9.

        I have to disagree strongly with the advice that you increase your sound card gain. If this is indeed overload then you will make the problem worse by increasing the gain. I recommend running the sound card with minimum gain in order to minimize exactly this problem.

        Warren Allgyer - W8TOD

        --- In softrock40@yahoogroups.com, Chris Wilson <chris@...> wrote:
        >
        >
        >
        > 17/02/2013 15:53
        >
        > Sometimes on 15 meters my bandscope shows the vertical lines in the
        > link to the screenshot of HDSDR The white outline shows the display
        > when I change to 12 and 17 meters. It sometimes suddenly appears, for
        > several hours. Closing and re opening the app, or CFGSR makes no
        > difference. It's displaying from my Softrock Ensemble II receiver. Thanks.
        >
        > http://www.chriswilson.tv/hdsdr.jpg
        >
        > --
        > Best Regards,
        > Chris Wilson. 2E0ILY
        > mailto: chris@...
        >
      • warrenallgyer
        Chris One additional thought that came shortly after hitting SEND .... If it is overload, and if you have a scope, you can probe the crossover jumpers on the
        Message 3 of 10 , Feb 18 2:39 PM
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          Chris

          One additional thought that came shortly after hitting "SEND"....

          If it is overload, and if you have a scope, you can probe the crossover jumpers on the IQ audio output. If the receiver is overloading you will see peak to peak audio signals in the range of 4-5 V P-P. These signals can be well outside the displayed frequencies on HDSDR. You can also flip up and down the band, 100 KHz at a time, to find the offender. I would look +- at least 5 MHz. I am betting you will find something hitting the peg on your S meter in that range.

          Warren Allgyer - W8TOD
          --- In softrock40@yahoogroups.com, "warrenallgyer" <allgyer@...> wrote:
          >
          > Chris
          >
          > I am guessing you are suffering overload from a very strong local signal that is in the filter bandpass of the receiver. I see a very similar display on 40 meters when the local shortwave broadcaster comes on the air on 7280 KHz and I can measure his signal on my antenna at -10 dBm. That equates to 60+ dB over S9.
          >
          > I have to disagree strongly with the advice that you increase your sound card gain. If this is indeed overload then you will make the problem worse by increasing the gain. I recommend running the sound card with minimum gain in order to minimize exactly this problem.
          >
          > Warren Allgyer - W8TOD
          >
          > --- In softrock40@yahoogroups.com, Chris Wilson <chris@> wrote:
          > >
          > >
          > >
          > > 17/02/2013 15:53
          > >
          > > Sometimes on 15 meters my bandscope shows the vertical lines in the
          > > link to the screenshot of HDSDR The white outline shows the display
          > > when I change to 12 and 17 meters. It sometimes suddenly appears, for
          > > several hours. Closing and re opening the app, or CFGSR makes no
          > > difference. It's displaying from my Softrock Ensemble II receiver. Thanks.
          > >
          > > http://www.chriswilson.tv/hdsdr.jpg
          > >
          > > --
          > > Best Regards,
          > > Chris Wilson. 2E0ILY
          > > mailto: chris@
          > >
          >
        • Chris Wilson
          ... 18/02/2013 22:36 I need to do some more testing. I got a similar signal on 10 meters this afternoon. Disconnecting the antenna at the Softrock antenna
          Message 4 of 10 , Feb 18 2:41 PM
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            >
            > Chris

            > I am guessing you are suffering overload from a very strong local
            > signal that is in the filter bandpass of the receiver. I see a very
            > similar display on 40 meters when the local shortwave broadcaster
            > comes on the air on 7280 KHz and I can measure his signal on my
            > antenna at -10 dBm. That equates to 60+ dB over S9.

            > I have to disagree strongly with the advice that you increase your
            > sound card gain. If this is indeed overload then you will make the
            > problem worse by increasing the gain. I recommend running the sound
            > card with minimum gain in order to minimize exactly this problem.

            > Warren Allgyer - W8TOD


            18/02/2013 22:36

            I need to do some more testing. I got a similar signal on 10 meters
            this afternoon. Disconnecting the antenna at the Softrock antenna
            connector made no difference. Nor did grounding the centre pin of the
            connector to the outer sleeve. Fiddling with the USB connectors did
            make a difference. I believe it may be a further grounding issue. I
            connected my TS-590 case to the case of my PC and fixed a very
            annoying tocking noise that my ACLog software caused whilst polling
            the 5090's frequency for automatic frequency and band logging. I
            suspect a further ground loop may be occurring, something related to
            the USB stuff. I will see if I can add a further ground next time I
            see this. I am now pretty sure it is NOT a local signal. There are no
            broadcast TX's for many many miles. Thanks Warren, Alan and Mike.

            --
            Best Regards,
            Chris Wilson. 2E0ILY
          • edingraham
            When operating at Full Speed, USB sends a Start Of Frame each millisecond. With light buss traffic (and poor USB shielding) this might be visible. Try a new
            Message 5 of 10 , Feb 18 4:58 PM
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              When operating at Full Speed, USB sends a Start Of Frame each millisecond. With light buss traffic (and poor USB shielding) this might be visible. Try a new USB cable.

              73, Ed WX4S (who is reading USB Complete in his spare moments)

              --- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
              >
              >
              > ----- Original Message -----
              > Subject: Re: [softrock40] Re: What might be the cause of this HDSDR display please?
              >
              >
              > >
              > > Yes, it must be local, but what gives exact 1 kHz signals? I have done
              > > nothing at all, the Softrock's been powered up all the time since that
              > > screen shot, here's a current one, same band, all looks fine...
              > >
              >
              > Chris,
              >
              > I think I've seen people say that the USB can cause this. Maybe an intermittent?
              > But, yes, find out where it is coming in, check local equipment.
              >
              > I'm not sure about Mike's advice to increase gain. I have good results with that sort of noise floor, maybe you have calibrated
              > HDSDR? If so then leave it. Yes, it is possible to cover up signals not coming in through the antenna but I'd say get rid of them if
              > you can.
              >
              > 73 Alan G4ZFQ
              >
              > > http://www.chriswilson.tv/hdsdr2.jpg
              > >
              > > Next time it does it I'll disconnect, then ground the antenna socket.
              > > Just disconnecting it from my 590, and connecting straight to the
              > > antenna doesn't change things. I thought it might be something
              > > generated inside the TS-590 where it acts as a second receiver cum
              > > panadaptor. Will try what you suggest next time, but suspect it's
              > > actually pulling this from the air waves round here.
              > >
              >
            • Alex
              I also figured out that using a poor audio cable [from rxtx to soundcard] for the input from the rxtx to soundcard will cause a problem. I replaced both tx and
              Message 6 of 10 , Feb 18 6:35 PM
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                I also figured out that using a poor audio cable [from rxtx to soundcard] for the input from the rxtx to soundcard will cause a problem. I replaced both tx and rx 3.5m audio cables, and it really cleaned up my panadapter.

                73's

                --- In softrock40@yahoogroups.com, "edingraham" <edingraham@...> wrote:
                >
                > When operating at Full Speed, USB sends a Start Of Frame each millisecond. With light buss traffic (and poor USB shielding) this might be visible. Try a new USB cable.
                >
                > 73, Ed WX4S (who is reading USB Complete in his spare moments)
                >
                > --- In softrock40@yahoogroups.com, "Alan" <alan4alan@> wrote:
                > >
                > >
                > > ----- Original Message -----
                > > Subject: Re: [softrock40] Re: What might be the cause of this HDSDR display please?
                > >
                > >
                > > >
                > > > Yes, it must be local, but what gives exact 1 kHz signals? I have done
                > > > nothing at all, the Softrock's been powered up all the time since that
                > > > screen shot, here's a current one, same band, all looks fine...
                > > >
                > >
                > > Chris,
                > >
                > > I think I've seen people say that the USB can cause this. Maybe an intermittent?
                > > But, yes, find out where it is coming in, check local equipment.
                > >
                > > I'm not sure about Mike's advice to increase gain. I have good results with that sort of noise floor, maybe you have calibrated
                > > HDSDR? If so then leave it. Yes, it is possible to cover up signals not coming in through the antenna but I'd say get rid of them if
                > > you can.
                > >
                > > 73 Alan G4ZFQ
                > >
                > > > http://www.chriswilson.tv/hdsdr2.jpg
                > > >
                > > > Next time it does it I'll disconnect, then ground the antenna socket.
                > > > Just disconnecting it from my 590, and connecting straight to the
                > > > antenna doesn't change things. I thought it might be something
                > > > generated inside the TS-590 where it acts as a second receiver cum
                > > > panadaptor. Will try what you suggest next time, but suspect it's
                > > > actually pulling this from the air waves round here.
                > > >
                > >
                >
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