[time-nuts] DC distribution

[Mark Spencer]

I seem to recall being involved in a project where a PEng called for certain connectors to be soldered and crimped.  I expect there were specific reasons why that was specified for that particular project.  My memory is a bit hazy about the specific details of the connectors.

Re power poles..  I'm not a huge fan of them for my hobby used but I seem to recall commenting re this a few years ago and won't take up any more bandwidth re this.  I do own some equipment that uses them, and   a number of friends of mine seem quite happy with them for amateur radio use.  

All the best
Mark S


mark at alignedsolutions.com
604 762 4099

>> On Oct 5, 2019, at 5:49 AM, jimlux <jimlux at earthlink.net> wrote:
>> 
>> On 10/4/19 1:41 PM, Poul-Henning Kamp wrote:
>> --------
>> In message <5D979AC0.80304 at rogers.com>, MLewis writes:
>>> With audio signals, a soldered crimp is one of the worst possible
>>> connections.
>> Dabbling in audio-homoepathy are we ?
>> No, don't bother responding unless you have a reference to peer-reviewed
>> scientific documentation for you claim.
> 
> 
> well..
> https://nepp.nasa.gov/files/27631/NSTD87394A.pdf
> 
> doesn't give why, and doesn't explicitly say "don't crimp and solder" but does basically say "crimp crimp connectors and solder solder connectors"
> 
> TE "Crimp Theory Fundamentals; Advanced" - explanation of what makes a good crimp, doesn't discuss solder
> https://www.youtube.com/watch?v=bAO9eCS65jw
> 
> There are actually splices designed to be crimped and soldered - but I suspect their applicability is for specific applications.
> 
> 
> On Monday, I will try to find one of the connector reliability people for some references.  One challenge is that these practices ("don't solder crimped connectors") have been around for a long time (at least 70 years), so there may not be recent published information on it. (recent papers I found on solder joint reliability are all about PWB connections - esp BGA, CGA, etc.)
> 
> And, to be honest, materials have changed.
> 
> There is *great* resistance to changing any assembly and workmanship standard - nobody wants to be the person who says "we don't need to do *that* anymore" and then a disaster happens, and one of the potential causes is "you didn't do *that*"
> 
> It is entirely possible that the original rationale and explanation is no longer valid.
> 
> There is no question that in a vibration environment, solder is deprecated (it's hard, brittle, work hardens, etc), not to mention all the issues with RoHS.  That said they do use solder joints in high reliability systems - just with attention to the support of the wire.
> 
> https://www.tandfonline.com/doi/full/10.1080/14686996.2019.1640072
> https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100029736.pdf
> 
> 
> 
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