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I await even one answer..

""There is absolutely nothing unusual about the tests as, other than level,""RC

Bob, it's the level that concerns me..-120dB from 30 mV is what? 30 nanovolts?

Do you even have, or have seen, a piece of equipment capable of measuring that low with any accuracy?

AC, or even DC..

I work with equipment to accurately find DC levels in the hundreds of nanovolts, on a site where 5 Megawatt loads are being pulsed, and that is a very finiky beast...To measure accurately in the low nanovolts...cannot be done by simply "turning up the gain", or dropping in a different IC.

Has the primary oscillator been characterized to 1 ppm waveform accuracy? Has the notch filter? The simple act of running a cable from an IA plus input to the negative input, to test CMMR, is wrought with problems at the 1ppm level..The loops formed by the wire and ground do all kinds of strange things, like picking up primary oscillator harmonics off the unintentional ground loops..ground loops which change with different cables.

Equipment designed for that level of operation does not look anything like the ST1700 in layout..Because, from experience, they had to eliminate the layout contributed errors that were insignificant for 100 ppm testing, but bite them at the 1 ppm level.

""so just do it rather than spending two and half years telling John that his tests are flawed""RC

I've spent some time asking what his test actually is, and asking if he has eliminated any possible error sources which are being altered by the construction and materials of the test..I've not stated that the tests are flawed..I'm asking what has been done to verify that the tests are in fact, seeing what is desired..

All I'm getting back in return for my well thought out, simple but technical questions, is blank stares..and simple statements like "get off your butt", do the tests yourself..But, I must note, I've still seen no technical responses to any of my questions. And my questions and observations are EXTREMELY relevant to the correct and accurate testing of 1ppm level issues..

You seem to be simply defending JC, without regard to any of the technical issues..

If you so desired, you could look up some HP or Tektronix manuals for some of their ten digit accuracy/resolution equipment which detail the error sources I am speaking of, and the amazing amount of detail required to measure 1ppm stuff, and how simply "upgrading" a 20 year old design can be wrought with errors...And you wouldn't even have to believe me...unless, of course, you also choose to not believe either HP or Tek... But given the flavor of your posts, I don't think you will, as that is technical details you've not spoken of..

My questions are simple, and can be easily addressed..Why do they go unanswered?

TTFN, John

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