In the early days of aviation,
flying was done primarily during daylight by visual reference such as
highways, railroad tracks and rivers. Communication was done by signal
lights and wing waggling.
As the reliability of aircraft
improved, flying under all conditions became practical, creating demands
for improved communications and navigation systems. However, during the
early use of these systems, pilots quickly became aware of a form of
severe radio interference, which hampered the performance of the
existing navigation and communication systems.
Experience showed a correlation
between RF noise and flight through rain, snow and clouds. Hence, pilots
became very concerned because the conditions which caused the most
"precipitation static" (P-Stat) occurred when navigation and
communication instruments needs were greatest.
During WW II, it was necessary to have
navigation and communication systems that were reliable in all weather
conditions. To address the interference problem the Naval Air
Development Center (NADC) sponsored a program to develop methods to
reduce noise created by P-Stat. As a result of this program,
Dayton-Granger invented and patented the first static dischargers.
Continued research and development in the 1950's led
to a static discharger which adopted a new concept that was far superior
in noise suppression than anything else. This patented device, designed
by Granger Associated (later to be part of Dayton-Granger) was the
Nullified Discharger, which is still the industry standard today.