These conductive "growths" from metal plating were a
-severe- problem for early versions of GE 2-way radio's
MASTR II (sic) series of radios. The plated cavities that
held the tuned circuits for the RF front ends grew almost
invisible whiskers off the walls of the housing that were
astoundingly strong.
73! Ken Kopp - K0PP
ElecraftCovers at rfwave.net