[Elecraft] OT: Keying contacts - Clairification

[Stuart Rohre]

Keys almost universally would have silver contacts.  Silver is one metal 
whose oxide is conductive.

The contact area is a high stress point of pressure, Gold is a soft metal 
and actually can develop films that inhibit good conduction, unless the 
contact "wipes" so as to be self cleaning.

Bronze is not as yellow as gold, visually.  Bronze is not suited to switch 
contacts.  Brass is sometimes used as cheap switch contacts, but alloys are 
often what you see that have a yellow color.

Brass lends itself to having the silver contact welded or riveted to the 
brass base piece. The war surplus J38 keys were an example of brass 
conductors for the electrical paths to the contacts and a harder metal for 
the contact points.

-Stuart
K5KVH