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Re: Sound card calabration

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  • g8voip
    Hi John, As I commented before, there is no adjustment for the sound card to modify the frequency. You have not mentioned which SDR program you are running
    Message 1 of 4 , May 29, 2010
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      Hi John,

      As I commented before, there is no adjustment for the sound card to modify the frequency.

      You have not mentioned which SDR program you are running with your 20m LiteII kit, but whichever one it is, you need to go into the set-up and increase the nominal centre frequency by the required amount to correct for the error in the crystal frequency, something in the order of 4950Hz, then the displayed frequency will match what you are expecting.

      73, Bob G8VOI


      --- In softrock40@yahoogroups.com, "John T. Fleming" <john@...> wrote:
      >
      > Bob,
      >
      >
      >
      > I am using N9VV's Mercury receiver which is in Naperville, IL. I am in
      > Florida. G0ORX wrote a Java program called jmonitor which allows multiple
      > individuals to listen to anything from 15 KHz to 55 MHz. Visit www.n9vv.com.
      >
      >
      >
      > I have the Softrock 20m Lite II and the crystal circuit is definitely off on
      > the unit. I listen in my Orion and instead of hearing an oscillator on
      > 14.0475, I hear it at 14.04255.
      >
      >
      >
      > If you want to try Ken's receiver it is 24.192.100.58/rx0.html. That is
      > where I see the 50 Hz difference when listening to SSB. That is why I was
      > wondering if there was any way to adjust my sound card.
      >
      >
      >
      > 73,
      >
      > John
      >
      >
      >
      >
      >
      > From: softrock40@yahoogroups.com [mailto:softrock40@yahoogroups.com] On
      > Behalf Of g8voip
      > Sent: Saturday, May 29, 2010 10:14 AM
      > To: softrock40@yahoogroups.com
      > Subject: [softrock40] Re: Sound card calabration
      >
      >
      >
      >
      >
      > Hi John,
      >
      > You do not mention what receiver you are using, but you do not calibrate the
      > sound card to correct any error.
      >
      > If you are using one of the fixed frequency LiteII boards, then you must set
      > the correct (actual) centre frequency in the SDR program you are using.
      > Note, that actual frequency will vary a little from the marked crystal
      > frequency due to effect of the oscillator circuit.
      >
      > If you are using one of the USB controlled receivers, then it is necessary
      > to calibrate the Si570 frequency using a utility like CFGSR. That will
      > certainly be applicable with your Ensemble RX.
      >
      > Please give a little more information of what RX and SDR program you are
      > using and it will be possible to give you more specific information.
      >
      > 73, Bob G8VOI
      >
      >
      > --- In softrock40@yahoogroups.com <mailto:softrock40%40yahoogroups.com> ,
      > "John T. Fleming" <john@> wrote:
      > >
      > > Can someone point me to instructions of calibrating my sound card? When I
      > > use N9VV's jmonitor to listen to friends in the northern Midwest on 75
      > > meters, I notice that I have to tune 50 Hz off from their frequency to
      > hear
      > > them "normal." I assume that problem is with my sound card. Can this be
      > > corrected? What can I use as a standard? If my card is off, it will also
      > > affect my new Ensemble RX when I get it built. Thanks.
      > >
      > >
      > >
      > > 73,
      > >
      > > John
      > >
      >
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