That would be pico volts and my limit is around 20 pV/rt(Hz.) with an input impedance of under an ohm and very limited bandwidth. Besides it should come as no surprise that different connectors of the same manufacturer mate a bit differently.
Yea we knew that, scope probes are full of unnecessary junctions/connections.
Yup.
If you give Ed a megavoltmeter with 9 additional digits to the right that are displaying gps coordinates, he will report the gps coordinates as the error signal.
John
For reasons which I won't bore you with, some years ago I found myself having to assist a maths professor with a project which involved some experiments on real stuff - in this case it was a composite rubbery material containing carbon fibres. We were visiting a company which had some ultrasonic technology for looking inside things. I watched with a mixture of horror and amusement as she took a material sample out of its holder, placed it on the experimental rig and then smoothed it down with her finger. It was one of those occasions when by the time I realised what she was about to do it was too late to stop her and suggest we find some tweezers etc. I don't know how this affected the outcome, but not knowing that would have made me cautious; it obviously had the opposite effect on her.
Real stuff is messy. I would hesitate to think that I could measure nV (or aV!) at points separated in space by more than a few mm, or joined by a loop of wire - unless magnetic induction in the loop was what I was intending to measure.
Real stuff is messy. I would hesitate to think that I could measure nV (or aV!) at points separated in space by more than a few mm, or joined by a loop of wire - unless magnetic induction in the loop was what I was intending to measure.
Thus my observation above. You cannot reliably do so- that's the difference between precision and accuracy.
I wish it were a matter of confusion rather than pointing out a basic flaw in the experiment (which took several days to come to light when no sketch was provided). My question would then be, is that flaw a deliberate one?
No.
Tweezers for removing the carbon fibers that were pinned into her hand’s skin.
For the next time, I would suggest back and forth scraping with a sharp blade to remove those tiny carbon pins.
George
Do you mean you are measuring cables and attached connectors all together? If, so you have a system that is a little more complex that a cable alone. If there are directional effects, how would you know if it was cable, solder, connectors? In particular, connectors can be a problem as you seem to indicate when you say it make take a few re-connections to get them to settle down. In that case, I wonder, settle down to what? When you have metals, perhaps with some light oxidation slip-fit together it seems like an opportunity for non-linearity to occur.
No.
Tweezers for removing the carbon fibers that were pinned into her hand’s skin.
For the next time, I would suggest back and forth scraping with a sharp blade to remove those tiny carbon pins.
George
But of course, a distinction I missed, clearly.
Most of the directional effects are from the connectors and how they mate. That is why it is better to do multiple passes and see what repeats.
Demonstrated this many times.
years ago, I build a speaker cable from 10 paralleled 75 Ohm coax. Seemed to work well... low Z... and low L & R.
THx-RNMarsh
Okay, but given the connectors are always attached to the cable, how do you know it is the cables and not the connectors that eventually repeat? (edit: assuming some directional effect remains)
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You must have a lot of fun posting such stupid schematics and then watching others bite.
You've already made conclusions with no hypothesis. There are no directional effects simply interpretations of experimental artifacts.
DADiSP-
Though I/we might agree on that point of yours', it doesnt really apply to what DADiSP has done. It is more than a GUI. All the code is written or rewritten in machine language and originally for scientific computers which are optimized for number crunching. It is super fast... so fast you can have many (up to 50) windows open at the same time and all get changed in what looks like real time. With the LSI-11 family, I could input circuit and do a sweep of values on a component and in another window watch in real time the output (filter) response changing. And you can input a signal in one window and under that window type fft to another window --- fft W2 and instantly you have the fft in the other window. In that W2*W2 = W3 and you instantly have the PSD in W3. So it is like a spreadsheet but using windows.
Having many windows open at the same time and watching changes in real time on all of them is impressive in speed and usefulness in correlating it all together. Then of course you can do 2D-3D graphes as well. But the speed is amazing when you have more complex math functions in several windows. Using machine language in a new fast PC might be the next best thing to have your designing done on a super computer.
THx-RNMarsh
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We were doing that stuff a long time ago. Satellites have to be completely re-configurable from the ground. But for a power amp its a bit OTT IMO. Remote VTA adjustment on vinyl might be fun. If only strain gauge carts were more widespread you could do VTF on the fly as well. But I don't want my things connected to the cloud. Flood sensors etc yes. My stuff NO.
Me too. I can still play CDs in the fancy blu-ray player but its soo slow compared to my old marantz CD80 I do often wish I still had that.I'm all for that , but would still want everything to be backwards compatible with
the 20'th century (just in case)
Not sure it would work for me. I jump genres waaay too much. I might try it at some point, but for now I want my music player to do as its damned well told and not get clever.
Aside: was called a heretic by a friend today as mentioned I preferred the original demo of Lynerd Skynerd 'freebird' to the album version as was missing the 4 minute gratuitous guitar solo, which although is good, doesn't really add to the song other than doubling its length.
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