Hi SY,
I'm glad you're poking around in it. And I do agree that these do things that are unique. A great thing to have around when the need arises.
As for that low noise IC, it only performs at that level once everything else has been looked after. It's extremely easy to end up with a noisier system if you aren't careful.
Too bad it wasn't something easy.
Hey, was there anything at all on the switch contacts? There was once a contact enhancing polymer that an audio company came out with. Anyway, I found that equipment with this applied ended up with open connections until you cleaned it all off. It's also possible for you to have an open finger type contact, ot one that just makes contact and now almost does. I have to get into mine at some point. Let's hope yours is working by then.
-Chris
I'm glad you're poking around in it. And I do agree that these do things that are unique. A great thing to have around when the need arises.
As for that low noise IC, it only performs at that level once everything else has been looked after. It's extremely easy to end up with a noisier system if you aren't careful.
Too bad it wasn't something easy.
Hey, was there anything at all on the switch contacts? There was once a contact enhancing polymer that an audio company came out with. Anyway, I found that equipment with this applied ended up with open connections until you cleaned it all off. It's also possible for you to have an open finger type contact, ot one that just makes contact and now almost does. I have to get into mine at some point. Let's hope yours is working by then.
-Chris
SEM, not STM.
Actually, an old friend of mine built one of the first STMs outside of IBM when he was at Columbia. Turns out that (according to him) it was easier and simpler than an SEM. Most of it was constructed with surplus parts, yet it still allowed him to characterize some nanofabrication he was doing on graphite surfaces.
Building something like this from scratch out of surplus is very impressive.
Should be fine, but of course 22 gauge five 9's silver wire with a pure virgin teflon jacket sounds best, ask anyone with too much money. (Surprisingly it also measure fairly well!)
Of course be sure to wind the coil under the light of a new moon, two turns clockwise then turn it around and put on other two... so on until done.
I just assume you know to put on white cotton gloves after you wash your hands with Jeweler's soap before you begin. I don't think a silk mask will be needed as you are using insulated wire.
Then of course you should rest the coil at an elevated temperature while it is aligned North - South. The North end should become the input end ... of course for those in the southern hemisphere it goes the other way around.
Break in will be required, but if you don't twist the wire as you wind it a week should be enough. Being cheap I use a solar powered radio for this.
Have fun, or if not keep on drinking...
Sorry to suggest the blindingly obvious, but ...
Have you tried a Bybee Quantum Purifier? Apparently they're ideal for this sort of thing. Just one connected in series with the 'hot' wire of the power cord ought to do the trick.
Hey - if it works, you've fixed your meter and got a positive test result all in one go.
ps: If the problem persists, you may need to connect a second QP pigtail-style (one lead only) to a convenient earth point near the input socket.
First here I am providing serious guidance to the newbies who actually might learn something. Have you ever compared a coil wound under those conditions with one just crudely wound? Oh yeah these rules work best for input inductors, for output inductors they should be wound under a full moon and used South to North. Just because something seems silly don't knock it unless you have tried it! Please know when to be serious!
The actual problem seems to be transient RF cause the chips to "squeeg" or do a damped oscillation after a trigger. That is why shielding doesn't help. You actually want to unload the chip input from the outside world. That is also why the bypass capacitor needs to be very small. A coil will have lower noise than a resistor. The problem shows up as excess noise. If you try to measure it the load from the probe is enough to prevent the problem!
Gotcha!
I am glad that you learned something SY. This is an old problem, first shown to me by Dean Jensen, and explained in a book by a designer at Burr-Brown. Perhaps the really serious designers here who do op amp design or the equivalent could explain it more thoroughly. Ed and I compared notes about it, months ago, but we are not IC designers.
I'm aiming to have the measurements all wrapped up by the time Panomaniac gets here (the 21st). I have most of them at this point and I have to say that John Curl was right- no real difference between one of these and an ordinary 0R025 resistor. I can't see anything like the ripple/noise spectra that he posted.
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