[TowerTalk] Solder For Connectors

[Al Kozakiewicz]

By the way, the last generation of tube based Tektronix test equipment used a point-to-point wiring system that consisted of leaded components soldered to ceramic standoffs (think terminal strips with ceramic instead of bakelite as the insulator) that had some kind of solderable metal terminals bonded to the ceramic. These pieces of equipment had to use a silver based solder else the metal would separate from the ceramic. The equipment had a small roll of silver solder clipped on the chassis so that a repair technician had the right stuff at hand.

Al
AB2ZY

-----Original Message-----
From: Al Kozakiewicz 
Sent: Tuesday, November 03, 2015 8:27 PM
To: 'John Reilly'; towertalk at contesting.com
Subject: RE: [TowerTalk] Solder For Connectors

For the ham, virtually no advantages and one major disadvantage.

RoHS is a regulatory environment specific to the EU that regulates the amount of lead that can be used in electronics that might end up in a landfill.  IMO, it has the same scientific basis as the anti-GMO movement (also peculiar to the EU) in that it consists more of worry than facts.

The main disadvantage to a ham is the higher melting point of the Sn/Ag and Sn/Ag/Cu solders, typically 40-80 degrees Fahrenheit higher than 63/37 or 60/40 Sn/Pb solder. An inconvenience when soldering something with a large thermal mass (like the shell of a connector) or attempting a "toaster oven" assembly of SMD parts on a circuit board as the melting point is right at the temperature limit of your average Walmart toaster oven.

The big issue with RoHS when first introduced 12 years ago was the sudden increase in tin whiskers causing the failure of highly miniaturized systems.  I, for one, would not want to have been one of the first patients to receive a RoHS compliant pacemaker. Which, by the way, wasn't going to end up in a landfill anyway unless you want to start calling cemeteries landfills! A lot of high-tech work has been done to mitigate this risk, but then it is not a problem that would affect anything a ham could solder without a microscope.

Al
AB2ZY

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of John Reilly
Sent: Tuesday, November 03, 2015 7:53 PM
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Solder For Connectors

What are the advantages/disadvantages of using silver solder? I never have gotten a clear understanding when silver solder is appropriate.
   - 73, John, N0TA
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