The Washington times. [volume] (Washington [D.C.]) 1902-1939, 1924-05-17
TRA|LED.
BY SPECIAL
DEVICE
Automatic Devices Gather
Data to Be Used in Elimi-
mating Interference

Static, which has been the most
trying problem with which radio
engineers have contended since the
invention Of wireless, is the subject
Of an intensive observation and in.
vestigation by the radio engineers
Of the American Telephone ana
Telegraph Company.
Much time and energy have been
spent by inventors in the past de-.
yelcping static tanks. elinairators
and traps, but the results 90 far
have been unsuccessful. Engineers
are now devoting their time to the
study of static with the viyw of
variations from minute to minute.
day to day and season to season,
as well as the direction from which
1t comes to different stations and
relating these to other solar and
terrestrial phenomena.
Data For Solution Sought.
When the engineers have learned
these things. much win have been
done toward minimizing static inter.
ference, II not its elimination. 1t
10 only after such phennomella are
thoroughly investigated and under
stood that intelligent steps can be
taken toward elimination.
The study. being made by the
telephone company engineers, has
resulted in information, which,
though limited, disclose some very
interesting facts. These engineers
have developed special apparatus
which automatically trails static
every minute of the day, recording
It's every move. These data, 1t is
hoped, will yield information neces-
sary to solve the problem.
In the past such studies have
been made by an observer listening
to the static and by comparison or
otherwise expressing it's magnitude
In some unit of measure Inasmtich
as continuous records are desirable
and. furthermore, as human per.
ceptton is not at all times reliable,
such observations are now being
made automatically, thereby eliml.
mating the personal equation.
The automatic recorder, DEVELOPED
by the telephone engineers, requires
only occasional attention. For hours
at a time this faithful device quietly
and accurately writes out on long
strips of paper the information de.
sired.
characteristics Of Static.
Some interesting characteristics
Of static have been observed. Fur
instance, in the record for July 10,
1873, static was observed to Be
quite constant in its average in.
tensity during the early hours Of
the morning, but just before day
break it diminished rapidly, reach.
ing a minimum shortly after sun
rise.
This change in static occurs
every morning regularly at sunrise
and does not depend upon wealth
er conditions. With the receiving
loop placed IN the east and west
direction this change is most pro.
nounced and probably the reason
for this is the fact that some
rather sudden change in transmits
sion occurs between dark and day.
light. AS the earth revolves on
its axis the sun is shining on one
side, while the other is in complete
darkness.
This gives rise to a shadow wall
that separates day and night. For
radio waves and static this shadow
wall appears to act as a giant,
reflector or refractor.
Origin Not Determined.
Apparently most Of the static re.
ceived on the eastern coast OF the
United States originates in the
and as the shadow wall
passes the station 1t appears to
reflect or refract the static waves
from the southwest and acts az a
shield, greatly reducing their In.
tensity.
Records thus far taken tell very
little about the real origin Of static,
but they do give very interesting
results regarding its magnitude,
and from what localities 1t seems
to come. Though these studies
may not lead to a definite elimina.
ton of static they will provide
Information as to the power requir-
ed to maintain service through
different hours of the day and diff
ferent periods of the year.