[Elecraft] Solder - In General

[Ron D'Eau Claire]

Tom, W3QS, asked:
I bought Silver-Bearing Solder at Radio Shack (.022 dia, 62/36/2, #64-013E)
and now, after reading so much on what I used to think was a pretty simple
subject, Rosin Core:  Good, Acid Core: Bad, I wonder if what I bought is OK?

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Some years ago Elecraft suggested silver-bearing solder as an alternative.
As I understand the issue, it was dropped because of its somewhat higher
melting temperature. That makes removing parts to fix building errors, etc.,
without damaging the boards more difficult. Since there is no other benefit
for using silver solder in Elecraft rigs and conventional solder is readily
available, it was decided the potential for board damage wasn't worth
recommending silver-bearing solder.

Some builders have the idea that silver solder is better for RF circuits.
That's true in some special cases in circuits that operate at very high RF
currents and temperatures. For example, some of the 900 MHz transmitters I
have serviced require its use when repairing the power amplifier stages. 

The current lineup of Elecraft rigs don't have those conditions or needs.

The flux issue isn't as simple as rosin vs acid any longer. You have rosin.
That's good. That's always good in Elecraft rigs. There are now other fluxes
sold for use in electronics that are not good. Some are even "water
soluble", which leads some builders to think they must be less corrosive.
Just the opposite is true. These fluxes, including the water soluble ones,
are designed ONLY for very tightly controlled use, usually where the board
is soldered and then very thoroughly cleaned by machine. These fluxes are
highly corrosive and must be completely and thoroughly removed to avoid the
same sort of long term destruction of the connections and the board that any
acid-flux solder will cause. 

Ron AC7AC