I'm having difficulty following this thread due to huge amounts of quoting.. And my recent post disappeared, so here it is again: >From what I've read the best thing is to use no plating, but you need to make sure you don't get problems from copper oxide build up which has a very high thermal emf against copper. I think you're likely to puncture any thin oxide layer when making a connection, so I'm not sure this is really a problem in practice. An application of something like Deoxit would hopefully solve it anyway. With gold plating I presume the temperatures either side of the plating at the point of contact will so similar that very little emf will be generated independent of what plating material is used. Tables of thermal emf vs. copper show brass produces quite a low voltage. I've never seen the figure for tellurium copper quoted. Alan