Quote:

The difference between lead, silver and copper conductivity is very small.


Err.. Silver and Copper are similar enough, at 15.9 and 17.1 nano-ohms/metre of resistivity. But lead is more than an order of magnitude greater than those, at 208 nano-ohms/metre. Tin is midway, at ~115 nano-ohms/metre, which is still not close to copper/silver.

DC resistance is not "impedance", but the two are quite related.

Using silver solder would seem to be much better than tin/lead solder, because its impedance is likely to be very close to that of copper.

It is mis-matches of impedance that will degrade a signal the most --> each time a signal passes from one material to a different one results in partial reflections back to the source. The bigger the impedance mismatch, the bigger the loss/reflections. Adding solder to a connection results in two connections rather than one (instead of wire-to-terminal, we now have wire-to-solder and solder-to-terminal), which gives more potential for signal reflections.

Mind ya, the magnitudes here are miniscule, and probably don't matter too much in the grander scheme of things. But I know the local electrical inspectors prefer crimped wiring joints over soldered joints, specifically because the latter have potential to heat up under high current (and cause fires).

For manufacturing of circuit boards, solder makes mass-production feasible, so of course it is preferred to the unwieldly wire-wrap memories of my youth.

But hey, I'm no expert. Just pointing out some obvious trivia.

Cheers