Measures for Progress: A History of the National Bureau of Standards

The submarine at New London,
Conn., equipped by the Bureau
with special antenna for underwater
radio reception and transmission.
In place of the large antenna
used in his original direction
finder, Kolster found that with
the more sensitive amplifiers
that had become available, a
simple coil aerial was equally
effective for receiving and transmitting
radio waves.
Neither here nor abroad had
navies developed a successful
radio system for underwater use
when late in 1917 one of
Koister' s direction finder coils
was tested, first under water,
then in a submerged submarine,
and in both instances picked up
clear signals from as far away
as Europe and our own west
coast.
'0
V.,