"N Cook" wrote in message
...

I have hundreds of Germanium OC71's , now useless although perfectly
alright when bought perhaps 20 years ago, stored indoors in normal
human comfortable conditions.
Looking under a microscope and probing it would appear the
C-E shorts are due to metalisation creeping over the die.
Over the years I've found a few times that those, usually 3 lead, ceramic
resonators can fail by going resistive over the edge of the thin element
as
though the metalisation has crept around the edge.
Is this a recognized failure mode and anyone know the proper term or where
I
could research it ? Whether silver or Al or both have this effect ?

Interesting, but OC71's are surely just a collectible now?

N