Re: [volt-nuts] low emf solder

On Sat, 29 Oct 2016 20:41:48 +0200, you wrote: >On Sat, 29 Oct 2016 15:27:49 +0100 >"Dr. David Kirkby (Kirkby Microwave Ltd)" >wrote: > >> But if one could use copper as the bond wire, rather than gold which is >> quite common, then it would give you very little

Re: [volt-nuts] low emf solder

Am Sat, 29 Oct 2016 20:41:48 +0200 schrieb Attila Kinali : > On Sat, 29 Oct 2016 15:27:49 +0100 > "Dr. David Kirkby (Kirkby Microwave Ltd)" > wrote: > > > But if one could use copper as the bond wire, rather than gold > > which is quite common,

Re: [volt-nuts] low emf solder

Am Sun, 30 Oct 2016 01:05:56 -0500 schrieb David : > Sounds more like copper free copper than oxygen free copper. To be fair, one does not exclude the other. And nobody specified to what the 100% is supposed to apply to. Being oxygen free does not necessarily imply that it

Re: [volt-nuts] low emf solder

On Sat, Oct 29, 2016 at 03:27:49PM +0100, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > Perhaps the person who was making the measurements on the solder, could try > making a thermocouple by welding two bits of wire taken from different > sources. I guess the problem would be preventing any

Re: [volt-nuts] low emf solder

good one. On Sat, Oct 29, 2016 at 11:05 PM, David wrote: > Sounds more like copper free copper than oxygen free copper. > > On Sun, 30 Oct 2016 01:06:12 +, you wrote: > > >Once you get past 99.99% purity funny things begin to happen... I have > some 100% pure Cu

Re: [volt-nuts] low emf solder

Sounds more like copper free copper than oxygen free copper. On Sun, 30 Oct 2016 01:06:12 +, you wrote: >Once you get past 99.99% purity funny things begin to happen... I have some >100% pure Cu oxygen free cable (says so right on the jacket) made in China >that is magnetic! You can't do

[volt-nuts] low emf solder

Once you get past 99.99% purity funny things begin to happen... I have some 100% pure Cu oxygen free cable (says so right on the jacket) made in China that is magnetic! You can't do that with the cheap stuff, now can you? ;-) Oh, and it is so pure that it has three times the resistance of

Re: [volt-nuts] low emf solder

[volt-nuts] low emf solder I don't know if it the proper way but I used a very nice fume hood. Measured the metals (high purity), melted them in a quartz crucible, stirred with a quartz rod, and cast it in a ceramic block with a spiral pattern machined into it with a ball mill. You

Re: [volt-nuts] low emf solder

On Sat, 29 Oct 2016 15:27:49 +0100 "Dr. David Kirkby (Kirkby Microwave Ltd)" wrote: > But if one could use copper as the bond wire, rather than gold which is > quite common, then it would give you very little thermal EMF Copper is more and more used for bonding

[volt-nuts] low emf solder

When making the CdSn solder you want to avoid contamination with other metals. It doesn't require much contamination to lose its magic foo powers. So no metallic molds or tools used. And what, no shaved cadmium with a Bordeaux garlic reduction? Try it, it's delicious ;-)

Re: [volt-nuts] low emf solder

On 29 October 2016 at 14:51, NeonJohn wrote: > > > On 10/28/2016 08:39 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > > > I wonder how practical it is to weld test leads, so there's no solder or > > thermal EMF. > > > > I know that this will sound crazy, and probably

Re: [volt-nuts] low emf solder

On 10/28/2016 08:39 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > I wonder how practical it is to weld test leads, so there's no solder or > thermal EMF. > > I know that this will sound crazy, and probably is, but could one weld > components to a PCB? Yes indeed. About 20 years ago I

Re: [volt-nuts] low emf solder

probably because they drowned some lab rats with solutions of the stuff. As we say in the health-physics business, "the devil's in the dose". If I were working in a cad plating outfit, yeah, I'd check into what is behind the IARC's somewhat arbitrary designation. Making a small batch of cad

[volt-nuts] low emf solder

I don't know if it the proper way but I used a very nice fume hood. Measured the metals (high purity), melted them in a quartz crucible, stirred with a quartz rod, and cast it in a ceramic block with a spiral pattern machined into it with a ball mill. You don't want to contaminate the

Re: [volt-nuts] low emf solder

On Sat, 29 Oct 2016 01:39:12 +0100, you wrote: >On 28 Oct 2016 15:25, "Juris L" wrote: > >I wonder how practical it is to weld test leads, so there's no solder or >thermal EMF. > >I know that this will sound crazy, and probably is, but could one weld >components to a PCB? > >I

Re: [volt-nuts] low emf solder

Typing on phone... If the bond wires are gold they still are dissimilar to pcb copper, but if they were copper bond wires, thermal gradients would be less of an issue. On Friday, 28 October 2016, Scott Stobbe wrote: > "chip on board", not sure that it wouldnt help > >

Re: [volt-nuts] low emf solder

"chip on board", not sure that it wouldnt help On Friday, 28 October 2016, Dr. David Kirkby (Kirkby Microwave Ltd) < drkir...@kirkbymicrowave.co.uk> wrote: > On 28 Oct 2016 15:25, "Juris L" > wrote: > > > > Found reference to optimal emf solder composition

Re: [volt-nuts] low emf solder

: [volt-nuts] low emf solder On 28 Oct 2016 15:25, "Juris L" <juri...@gmail.com> wrote: > > Found reference to optimal emf solder composition cadmium/tin alloy > (70 %/30 %) in JJ array measurement article page 12. I wonder how practical it is to weld test leads, so

Re: [volt-nuts] low emf solder

Laser welding should work for either similar or dissimilar materials.At one time microwire PCBs  used stainless steel  wires were welded to stainless lands. Bruce  On Saturday, 29 October 2016 1:39 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: On

Re: [volt-nuts] low emf solder

On 28 Oct 2016 15:25, "Juris L" wrote: > > Found reference to optimal emf solder composition cadmium/tin alloy > (70 %/30 %) in JJ array measurement article page 12. I wonder how practical it is to weld test leads, so there's no solder or thermal EMF. I know that this will

Re: [volt-nuts] low emf solder

In message , NeonJohn writes: >Let's don't get carried away with cadmium toxicity. Yes, it is toxic is >sufficient dose but the LD50 dose for Cd is 750 mg/kg while the value >for lead is around 450mg/kg. Read how a professional

Re: [volt-nuts] low emf solder

LD50 is not the only consideration. From Wikipedia: "The International Agency for Research on Cancer has classified cadmium and cadmium compounds as carcinogenic to humans." FWIW Neville Michie > On 29 Oct 2016, at 8:09 AM, NeonJohn wrote: > > Let's don't get carried

Re: [volt-nuts] low emf solder

Let's don't get carried away with cadmium toxicity. Yes, it is toxic is sufficient dose but the LD50 dose for Cd is 750 mg/kg while the value for lead is around 450mg/kg. As far as dumping it in a solder pot, that works just fine for me. It's cheaper to buy 50/50 plumber's bar solder and then

[volt-nuts] low emf solder

A few years back I whipped up a batch of Cd/Sn solder... but I had access to the proper equipment to do it safely. And no, you can't have any! ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to

Re: [volt-nuts] low emf solder

I would recommend against trying to use cadmium - it's very toxic, which is why Cd-based solders are rare nowadays. They are probably still made, but for lab or industrial use with proper handling. If you try to alloy it with Sn yourself without proper handling, you could get poisoned. You

[volt-nuts] low emf solder

Found reference to optimal emf solder composition cadmium/tin alloy (70 %/30 %) in JJ array measurement article page 12. www.bipm.org/utils/common/pdf/rapportBIPM/2011/05.pdf Quick look at ebay show 1/4 kg of pure cadmium cost 10$ (item 111333082639), so you can make quite a lot of solder for

[volt-nuts] Low EMF solder

Please excuse me for asking this... I'm sure it's been covered before, but without an easy way to search the archives, here goes. I'm repairing a couple of old Holt 323A Audio Voltage Standards, trying to make one good one out of two. These instruments used to have small hanks of special low