Hi jneutron,
What I said was that measuring milliohm quantities of resistance accurately is not trivial. In other words, how correct is that number on the meter? What effects come into play concerning the test current, element heating and internal connections of the black box here.
Is the internal resistor 25 milliohms, or is the total resistance as seen from the external terminals 25 milliohms? What is the accuracy of the meter on this range, kelvin connections being a minimum requirement to even talk about it?
Since we are talking about measuring this value, what range of acceptable readings are we going to accept? This will depend on both the instrument and materials used in the test leads. What instrument was used to determine this value to begin with?
For example, I have a couple 3478A meters in operation, and a 3457A as well as a 34401A. Let's just say that I normally use the 3457A for accurate measurements, or I may use the 34401A. A 3458A would be far more accurate of course, but only if the connections were properly made and the leads and wire were copper.
I'm not trying to be picky John, but low resistance measurements were difficult tests to make as they involved more things to watch for. That included cleaning the terminals and leads just before beginning the tests. So while measuring this value may be easy for you to do, and anyone else who has done this before, the average person with a multimeter will not get a meaningful number except by chance. Getting a repeatable number on a different day is even more difficult. I'm just trying to make our members aware of some limitations there are. After all, we are expecting some numbers from those who are performing tests on these Bybee devices. In order for someone else to be able to reproduce these numbers themselves, they should be aware of some of the pitfalls. Also, in the event that the results that SY (or anyone else) gets do not agree with the ones Mr. Bybee has (he must have limits for quality control), there should be enough information available to be able to explain those variations before any accusations fly.
Casual testing is one thing. Publishing numbers requires more.
-Chris
Okay. Yes it is trivial to measure a number in the milliohm region. This I'll accept without argument.
What I said was that measuring milliohm quantities of resistance accurately is not trivial. In other words, how correct is that number on the meter? What effects come into play concerning the test current, element heating and internal connections of the black box here.
Is the internal resistor 25 milliohms, or is the total resistance as seen from the external terminals 25 milliohms? What is the accuracy of the meter on this range, kelvin connections being a minimum requirement to even talk about it?
Since we are talking about measuring this value, what range of acceptable readings are we going to accept? This will depend on both the instrument and materials used in the test leads. What instrument was used to determine this value to begin with?
For example, I have a couple 3478A meters in operation, and a 3457A as well as a 34401A. Let's just say that I normally use the 3457A for accurate measurements, or I may use the 34401A. A 3458A would be far more accurate of course, but only if the connections were properly made and the leads and wire were copper.
I'm not trying to be picky John, but low resistance measurements were difficult tests to make as they involved more things to watch for. That included cleaning the terminals and leads just before beginning the tests. So while measuring this value may be easy for you to do, and anyone else who has done this before, the average person with a multimeter will not get a meaningful number except by chance. Getting a repeatable number on a different day is even more difficult. I'm just trying to make our members aware of some limitations there are. After all, we are expecting some numbers from those who are performing tests on these Bybee devices. In order for someone else to be able to reproduce these numbers themselves, they should be aware of some of the pitfalls. Also, in the event that the results that SY (or anyone else) gets do not agree with the ones Mr. Bybee has (he must have limits for quality control), there should be enough information available to be able to explain those variations before any accusations fly.
Casual testing is one thing. Publishing numbers requires more.
-Chris
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25 milliohms and one ampere is 1/4 the rating. Many meters are easily capable of microvolt resolution. Given a current source and a 34401, the error will be based entirely on the current source accuracy, as the 34401 is accurate at .003% range scale plus .003% reading. 100 mv range is 3 microvolts plus .003% of reading... Indeed, the 34401 can actually read the current to .05% of reading plus .006% of scale at one amp scale. Values of current that are not exactly 1 ampere can be normalized.
#18 is 7 milliohms per foot, or .58 milliohms per inch. If the voltage probes are 3/8 inch from the ends, 3/4 inch is .435 milliohms introduced by #18awg copper leads. To control this, I'd make a test fixture that uses a pair of razor blades for the v probes, and lock them dimensionally such that they are one fixed distance apart, with the current clips outboard of the blades.
Strange, who would think otherwise???
For micro and nano resistances, I use needle probes for the v leads as the location placement of the v probe can cause errors that far exceed nano-ohm measurements, even some micro-ohm ones.
The test is not pass/fail. It is value only.
For some perhaps. Not for me. And, I have confidence that Sy will get accurate values given his propensity towards rigorous methods..I would never believe he would 2 probe it...
Your message is certainly good and accurate.
I believe he does not exercise QA on resistor tolerance for purchased devices. At most, he only specifies nominal and tolerance, and just uses them out of the box. 1% is trivial to buy.
I've heard that...
Publishing numbers requires more.-Chris
Agreed.
Cheers, John
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That could be the 'secret' PMA. If a microwave resonant cavity exists, all else follows. First things first. I can't measure it with MY test equipment. Perhaps, someone, somewhere, can at least TRY to measure a 'glitch' at some microwave frequency. That would be VERY interesting to me. Please trust me on this, although I cannot promise anything. It is MY presumption, nobody has told me it is so.
Exeric, no bias from measurement tools. I believe SY knows well the proper methodology to carry out these tests; however, if he can't measure a difference but can hear one he probably wouldn't feel too satisfied - it goes again his philosophy. But he wouldn't lie about it. He would do more measurements. He would do more listening tests. I can't imagine him giving up that easily.
Well stalker,
I like to think the best of everyone also. And in general I've always though Sy has handled himself in an exemplary manor, knows his stuff, and has contributed a huge amount to DIY audio. Who's disputing that? Not me. I'm talking about the fact that he has dug himself in pretty deep on the subject of the bybee's. He's gone on record here, there and everywhere that this is pure pseudoscience. And he's done that without actually ever listening to them. Everyone knows that he has said these things.
The other thing is that his technical expertise and broad general knowledge does not let him off the hook for being so cocksure about these things and condemning so many who have direct experience with them. Why are you and so many others so willing to let his broad contributions in so many other areas blind you to this one failing.
The whole thing is silly that I even have to bring it up. He will have to do enormous retrenching and apologizing to people he has accused of fuzzy thinking and believing in pseudoscience if he finds these work. Yes, you are exactly right: I don't trust him that he wants to be so heavily involved in testing them. Call me an idiot but a neutral person is what the tests need. Sins of ommission in testing are just as valid as being honest about the results you do test for. It needs someone with a driving, searching curiosity, that will go the extra mile. However his dug in position on this question will have the opposite effect of making him want to go the extra mile. He knows what he has said over and over again about how the Bybees don't work. And he has said that without ever trying them.
I'll be happy to do that. If the results show no effects on signals and circuits, and no-one is able to demonstrate audibility, are you willing to do the same?
Why are we referring to him as Sy? His initials are S.Y.
Well Exeric, I think he has been on the planet long enough to smell a rat. There's a few in this field. Let's call them psuedowhatevers.
If you think that his instincts and training are a failing then perhaps it time to reconsider who is blind.
Personally, I am not expecting much so if I hear any difference, I'm libel to be ecstatic and throw a party.
Well Exeric, I think he has been on the planet long enough to smell a rat. There's a few in this field. Let's call them psuedowhatevers.
If you think that his instincts and training are a failing then perhaps it time to reconsider who is blind.
Personally, I am not expecting much so if I hear any difference, I'm libel to be ecstatic and throw a party.
Sure, as long as it is a neutral person conducting the tests. Do you want to have negative results questioned by me and others because the impartiality of the tests were questioned. If you are so sure that the tests can be done in an impartial way then why not let someone else do the testing? Then if it turns out in favor or you and against me all the better for you. I and others will not be able to complain. And I assure you I would in the first situation and I wouldn't in the second. That's a promise.
My recollection is that he has (rightly so) been very critical of the claims of "near-superconductivity", and the ability of any material to selectively remove "bad electrons" from the stream, to wit..even the existence of bad electrons.
He asks all to put your money where your mouth is....prove your assertions via controlled methods. Anecdotes are not valid proof.
Are you saying that your use of such devices renders you an expert in near-superconductivity?
Cheers, John
Cal, I can't see any periods on his moniker. I think this may require I purchase a much bigger monitor..yah, that's it...I'm missing out on all the details...
Sheesh..
Cheers, John
Oh, almost forgot...
What about a ground loop coupling/susceptibility test? Inclusion of a lumped element anything into the haversine stream will alter the loop currents.
I assume the end use system design will be code compliant and single ended drives..
I'd recommend running a swept sine 1 ampere current out to 50 Khz through the line cord, terminated at short at the male, and monitoring of the loop currents on an external ground loop using either a hall transducer, or a Danfysik Ultrastab DCCT.
Cheers, John
ps..personal??? You want personal??? OK... (old guy)
What about a ground loop coupling/susceptibility test? Inclusion of a lumped element anything into the haversine stream will alter the loop currents.
I assume the end use system design will be code compliant and single ended drives..
I'd recommend running a swept sine 1 ampere current out to 50 Khz through the line cord, terminated at short at the male, and monitoring of the loop currents on an external ground loop using either a hall transducer, or a Danfysik Ultrastab DCCT.
Cheers, John
ps..personal??? You want personal??? OK... (old guy)
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Exeric, you have found the reality of the situation. I have known SY for many years, he, in person, is a great guy. But, when it comes to Bybee, he had plenty of input potential from me, including real devices. No sale. That is OK, until he turns on Bybee, without even testing the devices, especially listening through them.
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