I want to build a generic multi-antenna switch using relays. Many projects on the web have done this but the relays have silver contacts. This would be fine if I were to transmit to all antennas so the slowly forming silver oxide would be removed but this is not possible. I know I could use gold contacts or even a weird phasing scheme with two relays (gold and silver) so the gold contacts engage after the silver for "make" and before the silver for "break". In practice, how is this problem solved? This device will be in an attic so humidity and heat will be a factor. The desired frequency range is 3 to 30MHz.
Silver contact relay examples: RT314F12 in relay switch (https://www.hamradioworkbench.com/4-port-coax-relay.html) or G2R-1-E-T130 DC12 (http://www.ad5x.com/images/Articles/AntSwitch.pdf).
A QEX project (http://www.arrl.org/files/file/QEX_Next_Issue/2014/Mar-Apr_2014/Dzado.pdf) uses G6RN-1 relays that are gold plating on silver but I imagine the gold plating will not hold up to 1500W (I'm happy to be wrong about this because these relays are cheap.)