Loading ...
Sorry, an error occurred while loading the content.

Re: SRv5 - 1/2 actual soundcard bandwidth - confusion ?!?

Expand Messages
  • n3hkn
    I had two QSD modules that only had one channel working. One eventually developed a short from pin-1 of the LT1719 (U3) 2ohms to ground. Very hot regulator.
    Message 1 of 14 , Mar 2, 2006
    • 0 Attachment
      I had two QSD modules that only had one channel working. One
      eventually developed a short from pin-1 of the LT1719 (U3) 2ohms to
      ground. Very hot regulator. Real pain to isolate. Easy to fix.

      The other was a visually undetectable metallic bridge from an
      "old-fashioned" resistor to ground. It occurred on one of the outputs
      of the FST switch IC. It was by accident that I must have bumped the
      junk from the solder point on the IC side of the board and it began to
      work. Under magnification I could not see it. Lesson - get a small
      brush and sweep the board. The gap from a solder point to the ground
      plane is very tiny and should be insulated but nothing is perfect. If
      a very small sliver of wire (from shield of the audio cable for
      example) gets on the board trouble may occur.

      When initially building I found that I could easily solder the ICs to
      the board without using "my" solder. Just used the stuff that was
      there as tinning. Seemed to work since the IC was stuck to the board
      and resistance checks looked good. However, very soon one of these
      connections came loose. Lesson - use .015 2%silver solder from Radio
      Shack for all of the IC pins despite appearances. Buy two roles since
      RS may scale back on components or disappear. Walmart is unlikely to
      carry silver solder! .015 super small solder is not easy to find.

      Have not tried baking since now have confidence in soldering the
      really small stuff such as the DDS chips on the AMQRP project boards.
      Capacitors & resistors are still a pain! Tough to keep them from
      moving during soldering. The paste form of solder is very handy here.
      Use the Weller el-cheapo soldering "station" ($50) with a .03 conical tip.

      Dick N3HKN






      --- In softrock40@yahoogroups.com, "wrlabs" <pmudmap5@...> wrote:
      >
      > Hello Jean-Claude,
      >
      > Thanks VERY much for the reply!
      >
      > --- In softrock40@yahoogroups.com, "jabauzit" <jabauzit@> wrote:
      > > [ ... ]
      > > Search the messages for "Mirror Image" and you will likely find the
      > > solution (bad solder, solder bridge, ...).
      >
      > Did so and will check everything again very closely tomorrow.
      >
      > This problem occurs on both the 40 and 20m LO/BPF boards so I wonder
      > if my onboard AC97 might not be dealing with stereo input. May end up
      > with the spare SB Live in there after all :-).
      >
      > Much to check out.
      >
      > Thanks & take care es 73, Vikki (WV9K/7)
      >
    • jabauzit
      ... up ... Hi Vikki, This would confirm that the problem is on the QSD board. Jean-Claude PJ2BVU
      Message 2 of 14 , Mar 2, 2006
      • 0 Attachment
        --- In softrock40@yahoogroups.com, "wrlabs" <pmudmap5@...> wrote:
        >
        .....................
        > This problem occurs on both the 40 and 20m LO/BPF boards so I wonder
        > if my onboard AC97 might not be dealing with stereo input. May end
        up
        > with the spare SB Live in there after all :-).
        >
        Hi Vikki,

        This would confirm that the problem is on the QSD board.

        Jean-Claude PJ2BVU
      • wrlabs
        Hi Jean-Claude, ... Thanks again! That does make sense, but the QSD was the last place I would have looked as the QSD board was built and tested and then
        Message 3 of 14 , Mar 2, 2006
        • 0 Attachment
          Hi Jean-Claude,

          > [ ... ]
          > > This problem occurs on both the 40 and 20m LO/BPF boards so I
          > [ ... ]
          > This would confirm that the problem is on the QSD board.

          Thanks again!

          That does make sense, but the QSD was the last place I would have
          looked as the QSD board was built and tested and then shipped to me,
          maybe something got knocked loose in shipping ?!?

          I mostly suspected the LO/BPF boards as I built those myself :).

          Especially the 20m module where I broke off the 2N3904 during assembly
          and for a while had it replaced with a 2N3906 before I caught that and
          replaced it with a 2N3904 as it should have been. Funny that it
          doesn't work at all with a PNP in place of an NPN :).

          I took the LO/BPF schematic and drew it up in gschem for the 20m
          module specifically just to make troubleshooting easier. I'll check
          that today and put it up on my SoftRock page, might make things a bit
          easier for someone else. Plan on doing the same with the 40m module
          just so I don't have to look through the data lines for each bands values.

          I did look at the 20m board under a magnifier last night and it looked
          good, I am going to verify values today while I am at it today.

          This gets more exciting!

          Thanks & take care es 73, Vikki (WV9K/7)
        • Tony Parks
          Hi Vikki, Any place in the SoftRock circuit or connection to the soundcard that seriously affects one of the audio channels will result in little or no image
          Message 4 of 14 , Mar 2, 2006
          • 0 Attachment
            Hi Vikki,

            Any place in the SoftRock circuit or connection to the soundcard that
            seriously affects one of the audio channels will result in little or no
            image rejection. This can include items on the OSC/BPF board, the QSD board
            or even the soundcard input. Some things to check wold include the
            following:

            1. R25 and C25 values on each of the OSC/BPF boards.
            In a number of cases the OSC/BPF kits were shipped with a 100k resistor for
            R25 rather than the correct value of 1k. Measure the resistance between
            pins 5 and 6 on the 15-pin header to make sure R25 is 1k. Read the value
            code on C25 to be 151 (150pF) for 40m and 470 (47pF) for 20m.

            2. Wiring on secondary of T21.
            The resistance between pin 9 and 10 on the 15-pin header should read about
            zero. Also the resistance between pins 9 and 11 should read about zero.
            Along with the correct resistance readings the wires connected to via 6 and
            via 3 on the T21 mounting position should come out of opposite side of the
            T21 core, one out of the top and one out of the bottom.

            3. If you have a scope then view the waveforms on pins 5 and 8 of the
            15-pin header. Both should be fairly symmetic square waves with the
            waveform on pin 8 lagging 90 degrees compared to the waveform on pin 5.
            (Circuit ground is at pin 12 of the header.)

            4. The DC voltage at pin 9 of the 15-pin header should be close to 2.5 VDC.

            5. The DC voltage at the + wire on C13 and C14 should both be close to 2.5
            VDC.

            6. Make sure you really are plugged into the line-in on your soundcard and
            the soundcard is selected by the SDR program in use.

            Hope the above make sense and will help a bit.

            73,
            Tony KB9YIG

            ----- Original Message -----
            From: "wrlabs" <pmudmap5@...>
            To: <softrock40@yahoogroups.com>
            Sent: Thursday, March 02, 2006 2:25 PM
            Subject: [softrock40] Re: SRv5 - 1/2 actual soundcard bandwidth - confusion
            ?!?


            > Hi Jean-Claude,
            >
            >> [ ... ]
            >> > This problem occurs on both the 40 and 20m LO/BPF boards so I
            >> [ ... ]
            >> This would confirm that the problem is on the QSD board.
            >
            > Thanks again!
            >
            > That does make sense, but the QSD was the last place I would have
            > looked as the QSD board was built and tested and then shipped to me,
            > maybe something got knocked loose in shipping ?!?
            >
            > I mostly suspected the LO/BPF boards as I built those myself :).
            >
            > Especially the 20m module where I broke off the 2N3904 during assembly
            > and for a while had it replaced with a 2N3906 before I caught that and
            > replaced it with a 2N3904 as it should have been. Funny that it
            > doesn't work at all with a PNP in place of an NPN :).
            >
            > I took the LO/BPF schematic and drew it up in gschem for the 20m
            > module specifically just to make troubleshooting easier. I'll check
            > that today and put it up on my SoftRock page, might make things a bit
            > easier for someone else. Plan on doing the same with the 40m module
            > just so I don't have to look through the data lines for each bands values.
            >
            > I did look at the 20m board under a magnifier last night and it looked
            > good, I am going to verify values today while I am at it today.
            >
            > This gets more exciting!
            >
            > Thanks & take care es 73, Vikki (WV9K/7)
            >
            >
            >
            >
            >
            >
            > Yahoo! Groups Links
            >
            >
            >
            >
            >
            >
            >
          • John Melton
            Some other things to check: 1. the values of R25 and C25 are the correct values. 2. you are using the line-in on the soundcard and it is stereo. 3. any shorts
            Message 5 of 14 , Mar 2, 2006
            • 0 Attachment
              Some other things to check:

              1. the values of R25 and C25 are the correct values.
              2. you are using the line-in on the soundcard and it is stereo.
              3. any shorts on the I and Q audio cable to the sound card.

              Regards,

              John g0orx/n6lyt

              wrlabs wrote:
              > Hi Jean-Claude,
              >
              > > [ ... ]
              > > > This problem occurs on both the 40 and 20m LO/BPF boards so I
              > > [ ... ]
              > > This would confirm that the problem is on the QSD board.
              >
              > Thanks again!
              >
              > That does make sense, but the QSD was the last place I would have
              > looked as the QSD board was built and tested and then shipped to me,
              > maybe something got knocked loose in shipping ?!?
              >
              > I mostly suspected the LO/BPF boards as I built those myself :).
              >
              > Especially the 20m module where I broke off the 2N3904 during assembly
              > and for a while had it replaced with a 2N3906 before I caught that and
              > replaced it with a 2N3904 as it should have been. Funny that it
              > doesn't work at all with a PNP in place of an NPN :).
              >
              > I took the LO/BPF schematic and drew it up in gschem for the 20m
              > module specifically just to make troubleshooting easier. I'll check
              > that today and put it up on my SoftRock page, might make things a bit
              > easier for someone else. Plan on doing the same with the 40m module
              > just so I don't have to look through the data lines for each bands values.
              >
              > I did look at the 20m board under a magnifier last night and it looked
              > good, I am going to verify values today while I am at it today.
              >
              > This gets more exciting!
              >
              > Thanks & take care es 73, Vikki (WV9K/7)
              >
              >
              >
              >
              >
              > SPONSORED LINKS
              > Shortwave receivers
              > <http://groups.yahoo.com/gads?t=ms&k=Shortwave+receivers&w1=Shortwave+receivers&w2=Ham+radio&c=2&s=40&.sig=MB4yUGINw9tizVKS3Upr0w>
              > Ham radio
              > <http://groups.yahoo.com/gads?t=ms&k=Ham+radio&w1=Shortwave+receivers&w2=Ham+radio&c=2&s=40&.sig=XNtLoznpXE_hqNE4dvfaHA>
              >
              >
              >
              > ------------------------------------------------------------------------
              > YAHOO! GROUPS LINKS
              >
              > * Visit your group "softrock40
              > <http://groups.yahoo.com/group/softrock40>" on the web.
              >
              > * To unsubscribe from this group, send an email to:
              > softrock40-unsubscribe@yahoogroups.com
              > <mailto:softrock40-unsubscribe@yahoogroups.com?subject=Unsubscribe>
              >
              > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
              > Service <http://docs.yahoo.com/info/terms/>.
              >
              >
              > ------------------------------------------------------------------------
              >
            • Guido
              Hi Vikki, The noise problem, could be due to a bad crystal. My 20m crystal behaves bad and causes about 20db noise over the whole band compared to another
              Message 6 of 14 , Mar 2, 2006
              • 0 Attachment
                Hi Vikki,

                The noise problem, could be due to a bad crystal. My 20m crystal behaves bad and causes about 20db noise over the whole band compared to another crystal or LC replacement.

                What also can cause the noise, is that the mixer input setting is not preserved in de soundcard driver. Selecting again the input port line-in will solve. I do not recommend to use mic input port.

                Guido


                On 3/1/06, wrlabs <pmudmap5@...> wrote:
                Hi folks,

                  I'm real confused here and I have not found and answer for this, so
                please let me pester all the experts out here :-).

                  I have the SRv5 with the 40m and 20m LO/BPF modules.  On the
                computer I (reluctantly :) put windoz on to deal with this (old
                Thunderbird 1100 / 512M RAM / MSI-K7T-PRO2-A motherboard) I am using
                the built in AC97 sound.

                Using Rocky and M0KGK I see the same thing.

                  I ***APPEARS*** to me that only half of the banwidth shown is real,
                the other half is a mirror?!?

                  I have NOISE problems here and am lucky when a signal gets through,
                but I finally got enough of a good day here to get several signals
                going through the 20m module.  This time long enough to do some checking.

                  There is a central spike in the display corresponding to the LO
                crystal frequency and a couple smaller spikes very close to that one.

                  Signals are mirrored on the opposite side of the central spike, or
                so it certainly seems to be here.

                  A couple pix of this for reference:

                http://wrlabs.shacknet.nu/~vw/hamradio/SoftRockV5/

                  I wander back and forth between this is right (mix products) and
                maybe I have something wrong? Yes, confuzed-r-us :-).

                  One last question, I have a spare SB Live! floating around, would
                that be any better than the onboard AC97 (Delta is not in the budget :)?

                  Any thoughts appreciated!

                Thanks & take care es 73, Vikki.








                Yahoo! Groups Links

                <*> To visit your group on the web, go to:
                    http://groups.yahoo.com/group/softrock40/

                <*> To unsubscribe from this group, send an email to:
                    softrock40-unsubscribe@yahoogroups.com

                <*> Your use of Yahoo! Groups is subject to:
                    http://docs.yahoo.com/info/terms/




              • wrlabs
                Thanks **VERY** much to all who responded to this. Thanks to your gracious efforts I good idea of where to go from here. I did finish up the schematics for the
                Message 7 of 14 , Mar 2, 2006
                • 0 Attachment
                  Thanks **VERY** much to all who responded to this.

                  Thanks to your gracious efforts I good idea of where to go from here.

                  I did finish up the schematics for the 20m and 40m LO/BPF boards, you
                  can find them at:

                  http://wrlabs.shacknet.nu/~vw/hamradio/SoftRockV5/

                  Hopefully they will help in some way.

                  Again, thanks!

                  Take care es 73, Vikki (WV9K/7)
                • John Seager
                  Vikki I am not an expert but have had a similar problem with mirror image response on either side of the midline when using SRv 5.0 with Rocky and an onboard
                  Message 8 of 14 , Mar 3, 2006
                  • 0 Attachment
                    Vikki
                    I am not an expert but have had a similar problem with mirror image response on either side of the midline when using SRv 5.0 with Rocky and an onboard AC97 soundcard. Using the I2PHD SDRadio programme the unwanted images to the left of the midline disappear almost completely if the sound card channel skew calibration is set to give a delay of about -14 microseconds. Because of this I have assumed that the problem lies in the AC97 sound card and that an M-Audio Delta 44 would eliminate the problem. Of course it might not... John  G0UCP
                  • wrlabs
                    Hi Folks, After going over the boards and finding no problems, I tracked back down the cables and the one to the soundcard had pulled about halfway out of the
                    Message 9 of 14 , Mar 4, 2006
                    • 0 Attachment
                      Hi Folks,

                      After going over the boards and finding no problems, I tracked back
                      down the cables and the one to the soundcard had pulled about halfway
                      out of the extension cable.

                      Rule One still applies :-) Make sure it is plugged in! LOL.

                      To all who responded, again, thanks MUCH!

                      Is there any point to replacing the AC97 with an SB Live! ?

                      Thanks & take care es 73, Vikki (WV9k/7)
                    • KD5NWA
                      On many of my PC s the built in AC97 card work quite well, some of them are very quiet in terms of noise and hum pickup. But the Sound Blaster Live 24 PCI has
                      Message 10 of 14 , Mar 4, 2006
                      • 0 Attachment
                        On many of my PC's the built in AC97 card work quite well, some of
                        them are very quiet in terms of noise and hum pickup. But the Sound
                        Blaster Live 24 PCI has the advantage of 24 bit resolution, which you
                        can notice when there are weak signals, and it's less than $30 in most places.

                        I would say if you can afford it go for it, but beware some of the
                        higher price SB cards don't give you enough increased performance
                        compared to their cost increase. Also their USB versions take a much
                        heavier toll in terms of increases CPU usage compared to their PCI
                        cousins, that is specially important if you don't have a top end computer.

                        Have fun.:-)


                        At 11:45 AM 3/4/2006, you wrote:

                        >Hi Folks,
                        >
                        >After going over the boards and finding no problems, I tracked back
                        >down the cables and the one to the soundcard had pulled about halfway
                        >out of the extension cable.
                        >
                        >Rule One still applies :-) Make sure it is plugged in! LOL.
                        >
                        >To all who responded, again, thanks MUCH!
                        >
                        >Is there any point to replacing the AC97 with an SB Live! ?
                        >
                        >Thanks & take care es 73, Vikki (WV9k/7)
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >Yahoo! Groups Links
                        >
                        >
                        >
                        >


                        Cecil Bayona
                        KD5NWA
                        www.qrpradio.com

                        "Windows the worlds most successful software virus"
                      • wrlabs
                        Hello Cecil, Thanks for the info here, it sure clears up a number of questions I had! Much appreciated! I found one at NewEgg and will probably go ahead and
                        Message 11 of 14 , Mar 5, 2006
                        • 0 Attachment
                          Hello Cecil,

                          Thanks for the info here, it sure clears up a number of questions I
                          had! Much appreciated!

                          I found one at NewEgg and will probably go ahead and order it.

                          Thanks & take care es 73, Vikki (WV9K/7)



                          --- In softrock40@yahoogroups.com, KD5NWA <KD5NWA@...> wrote:
                          >
                          > On many of my PC's the built in AC97 card work quite well, some of
                          > them are very quiet in terms of noise and hum pickup. But the Sound
                          > Blaster Live 24 PCI has the advantage of 24 bit resolution, which you
                          > can notice when there are weak signals, and it's less than $30 in
                          most places.
                          >
                          > I would say if you can afford it go for it, but beware some of the
                          > higher price SB cards don't give you enough increased performance
                          > compared to their cost increase. Also their USB versions take a much
                          > heavier toll in terms of increases CPU usage compared to their PCI
                          > cousins, that is specially important if you don't have a top end
                          computer.
                          >
                          > Have fun.:-)
                          >
                          > Cecil Bayona
                          > KD5NWA
                          > www.qrpradio.com
                          >
                          > "Windows the worlds most successful software virus"
                        Your message has been successfully submitted and would be delivered to recipients shortly.