Responding to Thomas Tindale's request for information about tin-tin vs. tin-goldcontacts. Some years back, I was working on a project that involved putting some ceramic IC quad packs in sockets, pairing tin with gold contacts. A fellow I considered a contact expert told me gold to gold was best, but the fact that half the contact was gold made it better than tin to tin. I was shocked when, much later, I learned that gold to tin was inferior to a tin to tin contact. Sorry I don't have more details or references, but this experience did make an impression on me. Louis Hart