metalman said:
How in the name of sam hill are you going to prepare the sample??? Isn't it going to smear? Can you etch down below the smear? Or, are you gonna mill it at 77K?
OH, almost forgot...can you look for sulfides?. Methinks maybe they store the spools in cardboard boxes. Chlorides as well, just for kicks.
Peter Daniel said:
Hope you can get to it. I've accused many (you included) of wiring practices consistent with a bowl of spaghetti, and I believe proper harnesses designed with good low impedance e/m practices will affect the audible outcome. It would be great if you could find the time to try it.
If you don't think you'll get around to it, maybe you could send the wire to Brian.
Cheers, John
John Curl ... You've got mail.
AndrewT ... quad does indeed mean four elements, and a eutectic alloy is one that solidifies from a pure liquid phase to a pure solid phase at a single point of temperature. It only occurs for very specific elemental ratios, and identifying the correct ratios for four elements is a bit of a trick.
jneutron ... bwahahah! ... Environmental cracking of PILC (paper insulated lead sheath cable) cable in electric power transmission and distribution industry is a problem I've been working on for a while. We've had to develop special metallographic polishing techniques that involve a continuous feed fresh abrasive slurry while polishing at room temperature at very low speed. Not smearing is the easy part. It is preventing embedment of the abrasive that is the real tricky part. I'll use the same technique for the solder. Sulfides? No problem! Anything below Carbon on the periodic table gets sketchy, although theoretically with the light element detector I can go down to Beryllium.
AndrewT ... quad does indeed mean four elements, and a eutectic alloy is one that solidifies from a pure liquid phase to a pure solid phase at a single point of temperature. It only occurs for very specific elemental ratios, and identifying the correct ratios for four elements is a bit of a trick.
jneutron ... bwahahah! ... Environmental cracking of PILC (paper insulated lead sheath cable) cable in electric power transmission and distribution industry is a problem I've been working on for a while. We've had to develop special metallographic polishing techniques that involve a continuous feed fresh abrasive slurry while polishing at room temperature at very low speed. Not smearing is the easy part. It is preventing embedment of the abrasive that is the real tricky part. I'll use the same technique for the solder. Sulfides? No problem! Anything below Carbon on the periodic table gets sketchy, although theoretically with the light element detector I can go down to Beryllium.
metalman said:
Sheesh, you sound more like a mad scientist than me..(and that's bad)..
metalman said:
paper......lead.....and what, copper??? When are you guys gonna get wit it???hmmm?
You should be using the 2G wire from american superconductor..get rid of all those metal wires and their losses..
For goodness sakes, your ambient temperature is almost 77K, you don't need to go much lower..
I painfully recall Mt. Tremblant at 40 below with 50 kph winds...holy mackeral..Peter Daniel said:
When your ready, e-mail me some pix of the layout you decided on, we can discuss the best harness arrangement and wire type..if more types are needed, they can be designed easily.
BTW, pic's of proprietary stuff will remain undisclosed, you control the horizontal and vertical..
Cheers, John
No Cleans are best used where the components are very "fresh". That is, the packing, storage, and handling has always been in controlled environments.
For the average DIY'er, your components may be years old, and handled extensively before they hit your circuit. In the course of this they pick up a lot of filth and oxides that put the no-cleans at a disadvatage.
You might try using the water-based fluxes. They are quite nearly as good as the rosins. You can throw your whole project in the dishwasher when you are done. For high-Z/ low leakage circuitry, be sure to give your boards a final dip in store bought distilled water. Do this only if you know that all your parts are "process sealed".
For the average DIY'er, your components may be years old, and handled extensively before they hit your circuit. In the course of this they pick up a lot of filth and oxides that put the no-cleans at a disadvatage.
You might try using the water-based fluxes. They are quite nearly as good as the rosins. You can throw your whole project in the dishwasher when you are done. For high-Z/ low leakage circuitry, be sure to give your boards a final dip in store bought distilled water. Do this only if you know that all your parts are "process sealed".
Hi excetara2,
It's always best to clean any flux off. I always do.
Water based fluxes can be (or become) slightly conductive. Not what you want. I have not had good luck with this type of flux at all, even with new parts and board. I have a large container of unused water soluable flux. It doesn't work well.
-Chris
It's always best to clean any flux off. I always do.
Water based fluxes can be (or become) slightly conductive. Not what you want. I have not had good luck with this type of flux at all, even with new parts and board. I have a large container of unused water soluable flux. It doesn't work well.
-Chris
Oops,
Chris is totally right... but he's kind of a weanie (just kiddin' bud). Water based fluxes are conductive as hell. You MUST wash off every bit of them. They are also corrosive and will eat your parts if left on them.
All my boards have to be coated... so flux removal is not an option for me... it all has to come off.
Thanks Chris!
Stay with your "44". And don't use that Pb-free garbage unless there are guns pointed at you.
Chris is totally right... but he's kind of a weanie (just kiddin' bud). Water based fluxes are conductive as hell. You MUST wash off every bit of them. They are also corrosive and will eat your parts if left on them.
All my boards have to be coated... so flux removal is not an option for me... it all has to come off.
Thanks Chris!
Stay with your "44". And don't use that Pb-free garbage unless there are guns pointed at you.
We first hand clean the obvious flux deposits with dental picks and toothbrushes, until virtually all the visible flux is gone. In previous years, I used Freon for the final rinse, then air dry, but today I use isopropyl alcohol as an intermediate rinse, and then a final rinse with Freon. This is impractical for many, as it is time consuming and expensive, but I still use polystyrene caps which will be destroyed with normal solvents. Also, I don't like just smearing the flux into the rest of the board, so that is why I physically remove it first, as much as possible. If we had available, like we did 30 years ago, an automatic board cleaner with lots of available Freon, then that would be preferred and it would save time and trouble.
However, the results today are adequate.
However, the results today are adequate.
Brake cleaner from an auto parts store works very well and it is cheap.
Something you want to do outside though... causes cancer in California I'm sure.
It will destroy acrylics... but these aren't used in electronics...
Never used it with polystyrenes though... those things are soooo tender.
Something you want to do outside though... causes cancer in California I'm sure.
It will destroy acrylics... but these aren't used in electronics...
Never used it with polystyrenes though... those things are soooo tender.
This goes with any of these solvents.
Actually,
I haven't many problems. I don't think lexan is used that often. Not to say by any means that I tested everything though. Alcohol is nice... it just takes forever. What's in that electrowash stuff? Or is it a secret? I bet it's $20 a can... right?
For the most part, I stick with the water based-stuff. I realize, you can't put all transformers in the dishwasher; but nearly everything we buy these days is "process-sealed".
I haven't many problems. I don't think lexan is used that often. Not to say by any means that I tested everything though. Alcohol is nice... it just takes forever. What's in that electrowash stuff? Or is it a secret? I bet it's $20 a can... right?
For the most part, I stick with the water based-stuff. I realize, you can't put all transformers in the dishwasher; but nearly everything we buy these days is "process-sealed".
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