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> Further to Prawlin's post: a question for the q.c. engineers present.

> In the long long ago this writer, doing bench repairs of high end transceivers for a big company, had imposed upon him the use of lead free solder. That lead to bitter complaints until, a couple of months later, the same "little man" who had confiscated our good old eutectic solder had come around again with his cart and had taken back the lead free solder and replaced that with rolls of the lead containing eutectic solder that we knew so well. The arrogant V.P. of Q.C., who would not listen, had been forced to climb down!

> Lead free solder had become "fashionable" in his professional circle and he was going to thrust it upon us. He had probably never made a quick, competent and shiny solder joint in his life; a degree is not enough. Fortunately, some of the very senior engineers in the company, one a ham of the old school, "had dirt under their finger nails" and knew a good solder joint when they saw it.

> Now many of us on this list will know the nuisance lead free solder was in earlier days. From Prawlin's post it appears that the problems have not all been resolved. The stuff might be alright for equipment down at the consumer level. The question that arises is what high end users specify today. What does the N.A.S.A. the European Space Agency and any operation engaged in making man rated systems do to ensure reliable joints? Should we ordinary mortals, soured by early experience, be attempting to use lead free solder? Is it today as good as Kester 44 eutectic and similar?

> Those of us in the know about lead free solder in its early days would not care to board a space vehicle or even a commercial aircraft relying on what we knew at the time as lead free solder. The passengers on the "Gimli Glider" and others involved learned about solder joints that come apart.

> John,

> at radio station VE7AOV.

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On 2024-02-10 08:35, Prawlin via wrote:

Thanks Erik. Just sending pic again hopefully at better resolution. If you zoom a little, you can clearly see the places where the connector legs originally were. I had only used the connector a few times and had not knowingly exerted any excessive forces. Some insertion force is unavoidable with that particular Jack design. I wonder if gentle twisting of the Jack plug whilst inserting might reduce the risk? Then again, it might increase the chances of the blobs fracturing by twisting forces? Maybe adding a tiny dab of contact lube or silicon grease might allow easier Jack insertion/removal? I’ve considered carefully adding a tiny amount of thin cyano to bond the connector to the PCB. It is unlikely to ever need replacing in the future (though I can hear some groaning now as I write this)

I still blame the lead free solder. I’m retired now but in my career we lived through the introduction of lead free and it caused no end of similar joint fracture problems.?

I’m glad the same didn’t happen with the USB C as that would likely result in hard to fix or even unrepairable PCB (delaminating of those tiny close pitch pins)!?

On 10 Feb 2024, at 15:05, Erik Kaashoek <erik@...> wrote:

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