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

THS720P measurement error

Expand Messages
  • Jon Flickinger
    All, Below is an interesting response plus an attached document that I received from the technical support folks at Tektronix that came as a final answer to my
    Message 1 of 4 , May 9, 2002
    • 0 Attachment
      All,

      Below is an interesting response plus an attached document that I received from
      the technical support folks at Tektronix that came as a final answer to my
      continued questioning about the Math channel inaccuracies of my TDS3034. Did you

      ever wonder why you couldn't make any sense of Bearden's and JLN's THS720P scope

      readings, well...........

      Jon


      Hi Jon,
      Even though our scopes allow this it turns out the RMS measurement on a math
      waveform is bogus and has no value. I have a attached a document discussing
      this.
      Best Regards
      Jurgen Krannich
      Tektronix Customer and Sales Support Center
      email jurgen.r.krannich@...
      Phone - 503-627-3713 or 1-800-835-9433, ext.7 3713
    • jnaudin509@aol.com
      Dans un e-mail daté du 10/05/2002 03:06:44 Paris, Madrid, ... Hi Jon, Thank you very much for your information, THIS IS A VERY IMPORTANT COMMENT and I shall
      Message 2 of 4 , May 9, 2002
      • 0 Attachment
        Dans un e-mail daté du 10/05/2002 03:06:44 Paris, Madrid, jonfli@... a écrit :


        All,

        Below is an interesting response plus an attached document that I received from
        the technical support folks at Tektronix that came as a final answer to my
        continued questioning about the Math channel inaccuracies of my TDS3034. Did you

        ever wonder why you couldn't make any sense of Bearden's and JLN's THS720P scope

        readings, well...........

        Jon


        Hi Jon,

        Thank you very much for your information, THIS IS A VERY IMPORTANT COMMENT and I shall update my web page dedicated to the MEG Project with this.

        Best Regards
        Jean-Louis Naudin
        Email: JNaudin509@...
        Main Web site : http://jlnlabs.org
        Site France : http://jlnlabs.multimania.com
      • jnaudin509@aol.com
        Dans un e-mail daté du 10/05/2002 03:06:44 Paris, Madrid, ... Hi Jon, This Tektronix note have been added in the MEG page at :
        Message 3 of 4 , May 9, 2002
        • 0 Attachment
          Dans un e-mail daté du 10/05/2002 03:06:44 Paris, Madrid, jonfli@... a écrit :


          Did you

          ever wonder why you couldn't make any sense of Bearden's and JLN's THS720P scope

          readings, well...........

          Jon


          Hi Jon,

          This Tektronix note have been added in the MEG page at :
          http://jnaudin.free.fr/html/ths720p.htm

          Best Regards
          Jean-Louis Naudin
          Email: JNaudin509@...
          Main Web site : http://jlnlabs.org
          Site France : http://jlnlabs.multimania.com
        • Cyril SMITH
          Jon, Hooray!! As you know I tried to make this point a long time ago, even wrote to Bearden. Interesting thing is if you look at Figures 18 and 19 of
          Message 4 of 4 , May 10, 2002
          • 0 Attachment
            Jon,

            Hooray!! As you know I tried to make this point a long time ago, even wrote
            to Bearden. Interesting thing is if you look at Figures 18 and 19 of
            Bearden's original MEG paper (the scope traces) and take the average (not
            the RMS) of the power waveforms, then Bearden's ouput power is overstated.
            On figure 19 the (wrong) stated RMS value is 12.7W whereas the (true)
            average value is about 10W.

            On the other hand, when you look at the input waveforms on figure 18, the
            stated RMS level of the power waveform is 3.588W, but the display is too
            small to accurately determine the average level. However by looking at the
            (DC) voltage and the (AC!!) current traces you can do the multiplication
            yourself and see that the power waveform is very much AC. The current
            waveform has positive peaks of about 150mA and negative peaks (ignoring the
            ringing) of about 200mA, which when multiplied by the 50V DC gives the power
            waveform swinging from + 7.5W to -10W. Its average level could
            therefore be about 1.25W which is much lower than the wrongly stated RMS
            level. Bearden should claim greater OU!!

            Cyril


            ----- Original Message -----
            From: Jon Flickinger <jonfli@...>
            To: <MEG_builders@yahoogroups.com>
            Sent: Friday, May 10, 2002 2:01 AM
            Subject: [MEG_builders] THS720P measurement error


            > All,
            >
            > Below is an interesting response plus an attached document that I received
            from
            > the technical support folks at Tektronix that came as a final answer to my
            > continued questioning about the Math channel inaccuracies of my TDS3034.
            Did you
            >
            > ever wonder why you couldn't make any sense of Bearden's and JLN's THS720P
            scope
            >
            > readings, well...........
            >
            > Jon
            >
            >
            > Hi Jon,
            > Even though our scopes allow this it turns out the RMS measurement on a
            math
            > waveform is bogus and has no value. I have a attached a document
            discussing
            > this.
            > Best Regards
            > Jurgen Krannich
            > Tektronix Customer and Sales Support Center
            > email jurgen.r.krannich@...
            > Phone - 503-627-3713 or 1-800-835-9433, ext.7 3713
          Your message has been successfully submitted and would be delivered to recipients shortly.