The Washington herald., 1922-04-09
DIRECTION FINDER,
MARVEL OF RADIO,
BOOM TO SHIPPING
Bureau of Standards De-
vice Aids Coastal Life
Saving.
WARNS OF SHOALS
Speed of Operation Simplifies
Methods Formerly
In Use.


ship owners, radio operators and
goSefnment departments are giving
mach attention to the Importance
- pPviding on shipboard radio d.
ectls finding equipment by means
Tot which the position of a ship can
De quickly and accurately de-
termlned
| TIL matter is receiving attention
IN various foreign countries as well
as is the United states. The pro-
vision of radio direction finding
equipment on a ship may eliminate
Se3lOas delays caused by a ship be-
ing Enable to enter port during a
| log because its position or the
bearing Of lighthouses is not
known In case of wreck such
equipment NAV be the means of
saving many lives.
Not Affected by Fog.
The radio direction-fnder is a
device for determining In a simple
manner the direction of a radio
Transmitting station with reference
10 the point at which the direction
hndef is located. The direction
Under has a considerable number
I Of practical applications. of which
one Of the most important 10 its
use as an aid to navigation.
The finder is not affected by fog.
and has the further advantage that
II VIII operate over much create
distances than sound and visual
signaling devices
common type of direction
finder. which has been used for In
Sallation on shipboard. consists of
4oil of ten turns of insulated cop
ger wire wound on a wooden frame
Hour feet square, which is mounted
so that. it may be rotated about
vertical axis. Suitable radio -e-
ceiving apparatus is used in con-
: nection with the coil and in re-
cent Installations has consisted of
a variable air condenser for tuning
purposes, a balancing condenser for
increasing the accuracy OF observed
bearings, a six-tube amplifier hav-
ing three stages of radio-frequency
application. a detector. and two
stages of audio-frequency ampli-
tiCation, batteries and suitable tele-
phone receivers.
Work of Bureau of Standards.
As the coil is revolved about its
vertical axis, the intensity of the
signal which is being received from
the station, whose location is to be
determined, diminishes until a mini
mum is reached. which occurs when
position at -isht angles 10 the line
of direction to the radio trans
mitting station. At this point of
minimum signal. the radio bearing
is read on a suitable scale, which
may be either a fixed scale, or the
card of a magnetic compass.
In developing this system of di-
rection finding, the Bureau of
Standards has made a study of the
distortion effects which may result
from the presence OF adjacent OBJ
Its, such as the mast Of a ship,
and methods of eliminating errors
which such distortion may cause in
! observed radio bearings. \ particu-
1arly careful study has been made
of distortion effects on shipboard
and methods for correcting for these
effects by celebration.
Practical methods have been de-
velOped for simplifying the opera
tion of the direCtion-finder. The
finder is essentially a nautical in
strument and should be installed
on shipbOard where it may be used
directly by the navigator in taking
bearings on radio signaling stations
established on shore or on light
vessels. This can be done with the