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

RE: [wsjtgroup] Re: [DigitalOnSix] Do you think a sound card interface can make a difference?

Expand Messages
  • Randy Tipton
    SNIP: I thought it was a box... Russ take a look at the webpage... http://www.rigexpert.com/ It is much more than a box ... Randy Tipton WA5UFH (Tip)
    Message 1 of 13 , Nov 7, 2005
    • 0 Attachment
      SNIP: I thought it was a box...

      Russ take a look at the webpage... http://www.rigexpert.com/

      It is much more than a "box" ...

      Randy Tipton WA5UFH (Tip)

      > -----Original Message-----
      > From: wsjtgroup@yahoogroups.com [mailto:wsjtgroup@yahoogroups.com] On
      > Behalf Of Russ K2TXB
      > Sent: Monday, November 07, 2005 1:32 PM
      > To: wsjtgroup@yahoogroups.com
      > Subject: RE: [wsjtgroup] Re: [DigitalOnSix] Do you think a sound card
      > interface can make a difference?
      >
      > Bob, what do you mean "RigExpert will decode signals"? Is RigExpert a
      > program or an interface box? I thought it was a box...
      >
      > 73, Russ K2TXB
      >
      > > -----Original Message-----
      > > From: wsjtgroup@yahoogroups.com
      > > [mailto:wsjtgroup@yahoogroups.com] On Behalf Of Bob Poortinga
      > > Sent: Monday, November 07, 2005 2:17 PM
      > > To: DigitalOnSix@yahoogroups.com
      > > Cc: wsjtgroup@yahoogroups.com
      > > Subject: [wsjtgroup] Re: [DigitalOnSix] Do you think a sound
      > > card interface can make a difference?
      > >
      > > Howard S. White KY6LA writes (in another group):
      > >
      > > > As a result of my extensive bench testing of virtually every sound
      > > > card interface device I could get my hands on such as the MFJ 1279,
      > > > the Microham Keyer and the RigBlaster in parallel with the
      > > RigExpert,
      > > > each on a separate but identical computer but attached to the same
      > > > Radios (IC-756 Pro3, IC-2720, IC-706 MKIIG were tested), I have
      > > > observed that the RigExpert will decode signals in signal to noise
      > > > situations about 10 db better than ANY of the devices based on the
      > > > internal PC Sound Cards.. Which means that it will still
      > > give you 100%
      > > > copy when the internal Sound Card Devices no longer copy anything.
      > >
      > > So has anyone used a RigExpert (with built-in soundcard) with WSJT?
      > > Does it really exhibit a 10db increased S/N on decodes? If
      > > so, this could make a huge difference especially in JT65.
      > >
      > > --
      > > Bob Poortinga K9SQL
      > > Bloomington, Indiana US
      > >
      > >
      > > ------------------------ Yahoo! Groups Sponsor
      > > --------------------~-->
      > > Get fast access to your favorite Yahoo! Groups. Make Yahoo!
      > > your home page
      > > http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/ELTolB/TM
      > > --------------------------------------------------------------
      > > ------~->
      > >
      > > To unsubscribe, send an email to:
      > > wsjtgroup-unsubscribe@yahoogroups.com
      > >
      > > Activity Periods http://www.ykc.com/wa5ufh/
      > > NAHSMS Contest Page http://www.ykc.com/wa5ufh/Rally/NAHSMS.htm
      > >
      > >
      > >
      > >
      > > Yahoo! Groups Links
      > >
      > >
      > >
      > >
      > >
      > >
      > >
      > >
      >
      >
      >
      >
      >
      >
      > To unsubscribe, send an email to:
      > wsjtgroup-unsubscribe@yahoogroups.com
      >
      > Activity Periods http://www.ykc.com/wa5ufh/
      > NAHSMS Contest Page http://www.ykc.com/wa5ufh/Rally/NAHSMS.htm
      >
      >
      >
      >
      > Yahoo! Groups Links
      >
      >
      >
      >
      >
      >
    • Bob Poortinga
      ... RigExpert is not a program but it is more than an interface box. It contains both an interface AND an external sound card. It is this external sound card
      Message 2 of 13 , Nov 7, 2005
      • 0 Attachment
        "Russ K2TXB" <k2txb@...> writes:

        > Bob, what do you mean "RigExpert will decode signals"? Is RigExpert a
        > program or an interface box? I thought it was a box...

        RigExpert is not a program but it is more than an interface box. It
        contains both an interface AND an external sound card. It is this
        external sound card that provides a 10db S/N improvement over internal
        sound cards. There are several models of the RigExpert and the RigExpert
        Tiny does not include the sound card (it is an interface only).

        73 de
        --
        Bob Poortinga K9SQL
        Bloomington, Indiana US
      • Andrew T. Flowers, K0SM
        Bob, and group, Be skeptical of any magic box that appears to takes noise away. Both noise and signal arrive at the antenna in one stream and you can t
        Message 3 of 13 , Nov 7, 2005
        • 0 Attachment
          Bob, and group,

          Be skeptical of any magic box that appears to takes noise away. Both
          noise and signal arrive at the antenna in one stream and you can't
          separate them. If he really did an empirical test something is
          seriously wrong--you might ask what his test setup was and how he
          measured the SNR and what confounds he controlled for.

          It's a little hard to speculate not knowing anything about how this was
          measured (or even what, exactly, was being measured), but here is my
          hunch:

          It almost sounds like he used a big "Y-cable" to hook all the interfaces
          in parrallel (!) to the same radio. If all of these interfaces have a
          different input impedence then we are going to see different amounts of
          power (volume) reaching each sound card...I wouldn't be surprised if the
          AF amp in the rig started limiting too. Did he measure and control for
          this? I believe that most of these soundcards have a resistive network
          that controls how much audio passes--changing one will likely change the
          input power to all of the other interfaces. Of course, there are all
          kinds of other problems that can result from not having the inputs
          isolated from each other, but I'm not even going to go there.

          I've also found some other "reasoning" having to do with the RigExpert
          being outside the "noisy" environment of the computer. If you just
          record dead silence you can indeed hear these birdies. You will
          probably have to crank your volume up all the way to hear them, though.
          Indeed, the noise floor of most sound-card systems is limited in this
          way, at least at 16-bit resolution and higher. However, the level of
          these birdies is typically on the order of *50dB* below what the input
          signal from the radio should be. Unless you have the audio gain set
          *way* too low, this should not be an issue. That's why WSJT gives you
          the green line.

          That's my two cents.

          Andy K0SM/2

          Bob Poortinga wrote:

          >Howard S. White KY6LA writes (in another group):
          >
          >
          >
          >>As a result of my extensive bench testing of virtually every sound
          >>card interface device I could get my hands on such as the MFJ 1279,
          >>the Microham Keyer and the RigBlaster in parallel with the
          >>RigExpert, each on a separate but identical computer but attached to
          >>the same Radios (IC-756 Pro3, IC-2720, IC-706 MKIIG were tested), I
          >>have observed that the RigExpert will decode signals in signal to
          >>noise situations about 10 db better than ANY of the devices based on
          >>the internal PC Sound Cards.. Which means that it will still give
          >>you 100% copy when the internal Sound Card Devices no longer copy
          >>anything.
          >>
          >>
          >
          >So has anyone used a RigExpert (with built-in soundcard) with WSJT?
          >Does it really exhibit a 10db increased S/N on decodes? If so, this
          >could make a huge difference especially in JT65.
          >
          >
          >




          --
          No virus found in this outgoing message.
          Checked by AVG Free Edition.
          Version: 7.1.362 / Virus Database: 267.12.8/162 - Release Date: 11/5/2005
        • Russ K2TXB
          Hi Bob & Randy. Well the page Randy cited is completely different than what I found: I found http://www.mixw.net/RigExpert/. It simply says USB Transceiver
          Message 4 of 13 , Nov 7, 2005
          • 0 Attachment
            Hi Bob & Randy. Well the page Randy cited is completely different than what
            I found: I found http://www.mixw.net/RigExpert/.

            It simply says "USB Transceiver Interface". That was the first result from
            a Google search on RigExpert.

            Now I looked at the rigexpert.com page and can see that it is more than a
            simple interface, they say it has it's own sound card and does not use the
            one in the computer. How can that work for WSJT? WSJT needs to communicate
            with the sound card. Does RigExpert provide an interface via the USB
            connection that looks like a normal sound card, so that WSJT can interface?
            I cannot see on the web page where it says anything about that. It looks to
            me like it is only set up to work with CW and FSK - but not FSK as done by
            WSJT.

            Other that that, it looks like a nice product, but OH the price!

            As for low noise provided by their sound card, maybe, but if WSJT cannot
            interface to it then that benefit will be lost. Also, I suspect that many
            high end sound cards will be just as quiet. There may also be a benefit by
            having the USB interface, so that matching and ground loop problems between
            the computer and the radio are reduced - but you still have to interface the
            radio to the RigExpert... And low noise in those connections is pretty easy
            to accomplish anyway. One only has to pay attention to impedance matching
            and preventing ground loops.

            And finally, it still does not appear that RigExpert can decode anything. I
            think it is still the computer program that does the decoding. However it
            appears, Bob, that what you mean is that signals through the rig expert can
            be decoded when they are 10 db weaker than via other interfaces you have
            tested. That sounds very good, but the question becomes; how did you test
            this, and is your alternate interface set up in the best way to match
            impedances and eliminate ground loops?

            I have no way to verify it, but I think my simple home made interface will
            work as well. I can decode JT65 signals that are as weak as -30 db, and I
            do not recall anyone ever saying they have done better. I doubt I have over
            20 dollars invested.

            73, Russ K2TXB


            > -----Original Message-----
            > From: wsjtgroup@yahoogroups.com
            > [mailto:wsjtgroup@yahoogroups.com] On Behalf Of Bob Poortinga
            > Sent: Monday, November 07, 2005 2:58 PM
            > To: wsjtgroup@yahoogroups.com
            > Subject: Re: [wsjtgroup] Do you think a sound card interface
            > can make a difference?
            >
            > "Russ K2TXB" <k2txb@...> writes:
            >
            > > Bob, what do you mean "RigExpert will decode signals"? Is
            > RigExpert a
            > > program or an interface box? I thought it was a box...
            >
            > RigExpert is not a program but it is more than an interface
            > box. It contains both an interface AND an external sound
            > card. It is this external sound card that provides a 10db
            > S/N improvement over internal sound cards. There are several
            > models of the RigExpert and the RigExpert Tiny does not
            > include the sound card (it is an interface only).
            >
            > 73 de
            > --
            > Bob Poortinga K9SQL
            > Bloomington, Indiana US
            >
            >
            > ------------------------ Yahoo! Groups Sponsor
            > --------------------~-->
            > Get fast access to your favorite Yahoo! Groups. Make Yahoo!
            > your home page
            > http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/ELTolB/TM
            > --------------------------------------------------------------
            > ------~->
            >
            > To unsubscribe, send an email to:
            > wsjtgroup-unsubscribe@yahoogroups.com
            >
            > Activity Periods http://www.ykc.com/wa5ufh/
            > NAHSMS Contest Page http://www.ykc.com/wa5ufh/Rally/NAHSMS.htm
            >
            >
            >
            >
            > Yahoo! Groups Links
            >
            >
            >
            >
            >
            >
            >
            >
            >
          • Joe - WD0M
            If you re interested in an interface at a much lower price (and without an external sound card), you may want to check out the MicroHam Keyer - much like the
            Message 5 of 13 , Nov 7, 2005
            • 0 Attachment
              If you're interested in an interface at a much
              lower price (and without an external sound card),
              you may want to check out the MicroHam Keyer -
              much like the Rig Expert, and works well. The
              company provides exceptional customer support,
              and provides free firmware/software updates regularly.

              Yes, it's the computer program that does the
              decoding, not "the box". Purportedly, the
              external sound card "helps" by providing a less
              noisy signal to work with. I've been using the
              MicroHam Keyer for WSJT and it does an excellent
              job, along with all the other digital modes. It
              also features the WinKey CW chip, and lets you
              use only USB connections - no serial port issues.

              http://microham.com/

              No financial interest, just a satisfied customer.

              73,
              Joe WDØM
            • Bob Poortinga
              ... Yes. ... Yes, they are pricey. How much would you pay for an antenna that gave you 10 db better S/N? ... The person who tested it (an EE with real test
              Message 6 of 13 , Nov 7, 2005
              • 0 Attachment
                "Russ K2TXB" <k2txb@...> writes:

                > Does RigExpert provide an interface via the USB connection that looks
                > like a normal sound card, so that WSJT can interface?

                Yes.

                > Other that that, it looks like a nice product, but OH the price!

                Yes, they are pricey. How much would you pay for an antenna that gave you
                10 db better S/N?

                > Also, I suspect that many high end sound cards will be just as quiet.
                > And finally, it still does not appear that RigExpert can decode anything.
                > However it appears, Bob, that what you mean is that signals through the rig
                > expert can be decoded when they are 10 db weaker than via other interfaces
                > you have tested.

                The person who tested it (an EE with real test equipment, not me) stated that
                the RigExpert sound card codec (ADC) provides 10 db better S/N. That means
                that under 'no signal' conditions, the noise floor of the sound card is 10 db
                lower than the other tested cards.

                I'd be very interested in any comments from Joe, K1JT, on these figures.

                --
                Bob Poortinga K9SQL
                Bloomington, Indiana US
              • Joe Taylor
                Bob -- ... When something sounds too good to be true, it usually is. Specifications of sound cards that refer to the S/N of the card are completely
                Message 7 of 13 , Nov 7, 2005
                • 0 Attachment
                  Bob --

                  > RigExpert is not a program but it is more than an interface box. It
                  > contains both an interface AND an external sound card. It is this
                  > external sound card that provides a 10db S/N improvement over internal
                  > sound cards.

                  When something sounds too good to be true, it usually is.

                  Specifications of sound cards that refer to the "S/N" of the card are
                  completely irrelevant to use of the card with WSJT -- or indeed just
                  about any other ham radio software. The reason is that the
                  signal-to-noise ratio that matters for MS or EME (with WSJT), or for HF
                  use of PSK31, is determined far upstream of the device interfacing your
                  radio to your computer.

                  A sound card would have to be EXTREMELY poor -- so poor that it would be
                  unacceptable for "normal" computer uses such as recording/playing music,
                  etc. -- before its S/N rating would significantly degrade the decoding
                  ability of WSJT and similar programs.

                  The noise that the WSJT decoders must cope with is a combination of
                  cosmic noise, atmospheric noise, and receiver noise; sound card noise is
                  many tens of dBs weaker, and entirely negligible.

                  As it happens, there is one way in which poor sound cards can adversely
                  affect WSJT signals. It's not S/N, but rather inaccuracies in sampling
                  rate. WSJT uses a sample rate of 11025 Hz for both input and output.
                  All sound cards claim to support this rate, but some do it by
                  interpolating rather poorly from another sampling rate.

                  The Rig Expert may be a convenient way to do your radio-computer
                  interfacing, but it will NOT gain you 10 dB (or even 1 dB) in detecting
                  weak meteor pings or EME signals.

                  -- 73, Joe, K1JT
                • Bob Poortinga
                  ... Doesn t sampling jitter also introduce noise? Wouldn t a highly-stable sampling clock produce a lower noise floor resulting in better decodes? ...
                  Message 8 of 13 , Nov 8, 2005
                  • 0 Attachment
                    Joe Taylor K1JT <joe@...> writes:

                    > As it happens, there is one way in which poor sound cards can adversely
                    > affect WSJT signals. It's not S/N, but rather inaccuracies in sampling
                    > rate.

                    Doesn't sampling jitter also introduce noise? Wouldn't a highly-stable
                    sampling clock produce a lower noise floor resulting in better decodes?

                    > The Rig Expert may be a convenient way to do your radio-computer
                    > interfacing, but it will NOT gain you 10 dB (or even 1 dB) in detecting
                    > weak meteor pings or EME signals.

                    Thanks, Joe, I was simply looking for a definitive answer in response to
                    the claims of others.

                    73 de
                    --
                    Bob Poortinga K9SQL
                    Bloomington, Indiana US
                  • Joe Taylor
                    ... Yes, but for any plausible amount of jitter that noise will cause negligible degradation of the WSJT audio signals sent from your radio to the sound card
                    Message 9 of 13 , Nov 8, 2005
                    • 0 Attachment
                      Bob Poortinga wrote:
                      > Joe Taylor K1JT <joe@...> writes:
                      >
                      >>As it happens, there is one way in which poor sound cards can adversely
                      >>affect WSJT signals. It's not S/N, but rather inaccuracies in sampling
                      >>rate.
                      >
                      > Doesn't sampling jitter also introduce noise? Wouldn't a highly-stable
                      > sampling clock produce a lower noise floor resulting in better decodes?

                      Yes, but for any plausible amount of jitter that noise will cause
                      negligible degradation of the WSJT audio signals sent from your radio to
                      the sound card input.

                      The "inaccuracies in sampling rate" that I mentioned are not jitter, but
                      rather a sampling rate that is constant but offset from the nominal
                      value by a significant amount. WSJT always requests a sampling rate of
                      11025 samples per second. The actual sample rate can be somewhat
                      different. Some recent sound cards are "off" by as much as 75 Hz,
                      sampling at about 11100 Hz instead of 11025. If uncorrected, this means
                      that the WSJT tone spacing will be off by about 0.7% in both time and
                      frequency, causing a loss of sensitivity up to about 2 dB.

                      The next WSJT version to be released will have the ability to correct
                      for errors in sound card sample rates.

                      >>The Rig Expert may be a convenient way to do your radio-computer
                      >>interfacing, but it will NOT gain you 10 dB (or even 1 dB) in detecting
                      >>weak meteor pings or EME signals.
                      >
                      >
                      > Thanks, Joe, I was simply looking for a definitive answer in response to
                      > the claims of others.
                      >
                      > 73 de Bob, K9SQL

                      Happy to help!

                      -- 73, Joe, K1JT
                    • Paul Whatton
                      Hi Joe Do you have any examples so we know which sound cards to avoid? For example at the moment I m using a cheap OEM PCI soundcard. I also have an external
                      Message 10 of 13 , Nov 8, 2005
                      • 0 Attachment
                        Hi Joe

                        Do you have any examples so we know which sound cards to avoid? For
                        example at the moment I'm using a cheap OEM PCI soundcard. I also have
                        an external Soundblaster USB card so I wonder if there would be a real
                        advantage in using that instead?

                        Paul G4DCV

                        PS the facility to click on and decode pings & bursts in real time in
                        5.8.6 is wonderful!

                        Bob Poortinga wrote:
                        > Joe Taylor K1JT <joe@...> writes:
                        >
                        > > As it happens, there is one way in which poor sound cards can adversely
                        > > affect WSJT signals. It's not S/N, but rather inaccuracies in sampling
                        > > rate.
                        >
                      Your message has been successfully submitted and would be delivered to recipients shortly.