This leads me to think if soldering lowered the “noise floor” over just crimping that the crimp wasn’t done properly. A proper crimp doesn’t leave any space for solder to fill
Sent from my iPhone ...nr4c. bill > On Jun 17, 2019, at 4:32 AM, hawley, charles j jr <c-haw...@illinois.edu> > wrote: > > Interesting about the additional soldering and resultant noise reduction. A > chart from the Indium Corp shows 63/37 solder to be about 11% of the > conductivity of copper. I guess that's better than air though. > > https://www.microwaves101.com/encyclopedias/soldering-basics#chart > Microwaves101 | Soldering > Basics<https://www.microwaves101.com/encyclopedias/soldering-basics#chart> > Click here to go to our main page on packaging. New for February 2019: here's > a link to an update on lead-free solders, from Aerospace Corporation, from > 2011.In case you were wondering, the issues with lead-free solders have never > really gone away. To put it in perspective, 88% of lead consumed in the > United States is used in storage batteries, which are not subject to RoHS. > www.microwaves101.com > > > > Chuck Hawley > c-haw...@illinois.edu > > Amateur Radio, KE9UW > aka Jack, BMW Motorcycles > > ________________________________ > From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> on > behalf of Bob McGraw K4TAX <rmcg...@blomand.net> > Sent: Sunday, June 16, 2019 10:03 PM > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Terminal resistance > > The company for which I previously worked designed and built recording > studio consoles. In order to eek out every bit of noise, that is > achieve the lowest noise floor, it was necessary to crimp and then > solder the lugs on the power supply cables on both ends. Crimping was > only OK and was done until it was discovered that also soldering the > lugs did lower noise floor a few dB. This leads me to conclude that > crimping AND soldering is preferred, leading to a lower resistance > connection. > > For lightning grounding, joints and terminations, soldering alone is not > permitted. Crimping is required. > > Yes, lugs can not be soldered alone. They must be crimped first and > THEN soldered. At the same time, some installations of aeronautical > equipment, along with NASA procedure, I do understand does indicate > sweating solder into the lug and it thereby wicking up into the stranded > wires makes for a "stiff" connection. This connection is reported to > break under vibration conditions. I've personally never experienced > such with ham equipment, although I've never carried any into space. I > suppose there is merit to this directive. Perhaps you FAA and NASA > types can expand this thought. > > I am also aware with power distribution systems, a.k.a TVA, it is quite > common to use a crimp method to join wires. These conductors are > several thousand circular mills in size and are of many layers of > stranded conductors. When properly and completely crimped by a > hydraulic crimp machine, the joint is void of space. If fact, having cut > one of these in half just to see for myself, it appeared as a solid rod > with no voids observed. Thus the strands were compressed to that > degree. The center strand was steel as the messenger and the five > outer layers of aluminum were alternating in direction of rotation, > clockwise wound and counterclockwise wound. > > In most cases, crimping connectors with a crimping tool which has the > correct die for the connector is noted to be satisfactory. On the other > hand, I've seen many cables in various ham applications which were > installed using what ever was handy to mash the sleeve. That is NOT > crimping. Crimping does not distort the tubular diameter nor round > shape of the sleeve as the correct size die prevents distortion of the > sleeve. A correct crimping tool puts a dimple in one side of the sleeve. > > And now you know the rest of the story. > > 73 > > Bob, K4TAX > >> On 6/16/2019 7:27 PM, Nate Bargmann wrote: >> * On 2019 16 Jun 18:50 -0500, Kidder, George wrote: >>> Interesting data, Don. I wonder if there is any information about >>> resistance variations between soldered and crimped terminals. One might >>> think that, with stranded wire, even a good crimp connection might not >>> solidly involve all of the strands, and might additionally deteriorate >>> with time since oxygen could get between the strands. A good solder job >>> should wet the wire through and (additionally) exclude oxygen. This >>> wouldn't be easy to measure, for sure, but these engineers are cleaver >>> people! >> For what it is worth, the company I worked for prohibited the use of >> soldered connectors for terminating bonding or power wiring. Especially >> with regard to bonding, dissipating any lightning strike energy through >> a soldered connector could cause it to enough to melt the solder. In >> doing some microwave site upgrades I did pull out a previous generation >> of bonding wiring that was soldered and some connectors had signs of >> being heated since installation. >> >> In my shack I use crimp connectors and a quality crimping tool with no >> problems. >> >> 73, Nate, N0NB >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to c-haw...@illinois.edu > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to n...@widomaker.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
