New-York tribune., 1922-08-20
Sub w ater Loop
Antenna Cuts
Down Static
New System of Buried Loop
Devised by Radio Section
of the Postoffice Gives
Very Successful Results
Used on Air Mail Route
Tests Show Ii Cnls Static
Interference Fifty Per
Cent From Usual Aerial

outstanding problem how to limit
static interference ir receiving has
been made, it has just been disclosed
through a series of experiments con-
ducted by the radio service of the
Postoffice Department. The results are
declared by government radio experts
to have proven that the aerial antenna
FOR receiving is about to be placed
among the relics of early radio history.
static the one big fly in the oiflt-
ment of all operators, is about to sue
cunab before comparatively simple
device. an underwater loop, according
to the predictions, which are based
upon a report just made 20 James G..
Edgerton, superintendent of the Post
Office Radio Service, by his station at
Bryan, Ohio. Comparative tests were
made there Under the direction of Nh.
j. Y. Maresca, who was formerly con-
nected with the Radio Corporation,
with three antenna systems, the
straight aerial, which was the same as
is used for transpfanting. the pole loop
and the underwater loop. The report
shows the approximate signal static
iatio OF the three systems used at
Bryan are as follows:
Ratio-------
Anterlaa- Signals. Static.
! Straight aerial
Pole loop.-..
Underwater loop ....
Single Turn Loop
"Thjs underwater loop, which has
been in use Only two weeks. 9at is now
being used regularly in preference, OF
course, to any other aatenaa for the
routine work of the station, is a single
turn, horizontal, lao feet by $50 feet,
with the lead-in to the station 30 feet
long. The wire used is no. i2, rubber
covered. The wire is placed app1s3xi-
inately three feet under water ard Che
leads from the pond to the station are
buried in the ground about six inches
deep From the grousd TO the receiv-
lead sheathing, the sheathiag being
grounded.
..The following description OF the
tests conducted has been made by
James c. Edgerton, superintendent Of
she radio section:
"The air mail radio section has
eliminated the use of regular trans.
hitting antenna for receiving pur-
peees altogether, as it has been found
that the severe static conditions nseva-
lent, especially in the Middle West,
made receiving impossible Very good
receiving conditions with favorable
aignai static radio has been obtained,
however through the use of three diff
farent methods of receiving, wlIeh are.
ee'ected 10 conform TO local condf-
tions. They arc, first, LARGE versicle
outside multiple turn loops; second.
underground horizontal buried loops,
end, lagtlg, underground .antennaes.
The best results are obtained with
ths underground antenna when it can
be laid in damp soil with a straight
away Of LOCO feet. The horizontal
buried loop is more or less of new
departure and has been very success
fEl when well insulated and buried in
water or very damp earth.
lightning Effect Reduced
In actual use well constructed
underground antenna such as is used
in the majority of the fifteen stations
in the air mail circuit the results are
rather unusual Communication has
been carried on in the Middle West be-
tween air mail stations when lightning
was actually striking near by AS a
matter Of fact, it has been possible to
carry on communication when the cur
rents induced in the <antenna from
near by lightning discharges blew out
the are Receiving on an ordinary
antenna would fae, Of course, been
impossible long before the storm
isached the vicinity"
lnasmuch as the postoffice stations,
which have the primary duty of con-
trolling the transcontinental air mail
service flyers, have not been able to
transmit through moderate lightning
it has been necessary to devise a
method of reception through such a
condition and not burn up the receiv-
ing sets.
Each one Of the twelve stations is
equipped with FIVE kilowatt arc trans
'nitter. During the winter time and
approximately eight months out of the
wear stations as far west as Salt Lake
City are able to intercept traffic trans
mitted by WWX, the Washington sta
tion Likewise. during the absence of
local Interference this station is able
TO copy as far west as Salt Lake and
has intercepted Elko, New, all during
the daytime.
Summer Range Low
However, during July, August and
September the receiving range is cut
down so that the maximum working
range of wireless as a rule is with
Bryan, Ohio, distance Of 400 miles,
during the daytime. During the months
of July, August and September static
interference starts in at about noon
time and continues until generally
or O'Clock the next morning.
The aim of this development is to en-
able all stations to work throughout
tho twenty-four hours.
The same form of loop as the BRYAN
loop has been used at Hazelhurst. L.,
l., with considerable success. That
wire, however, was not buried under
water, but was used as a ground loop.
Inasmuch as this is horizontal form
Of loop and is probably not as direc-
tionaa as the vertical loops it enables
stations away from the center Of inter-
ference, such as we have near New
York and San Francisco, to get the
traffic through. 1t must be understood
that the department realizes that there
have been developed receiving systems
by such comDanies as the Radio Cor
peratlon which eliminate static to b
grea. degree, but the air mail stations
work with other stations at a variety
OF wave lengths that makes it necessary
to have 3 orick change available from
one wave length to- the other. The
adjustments also must be taken care,
Of by an operator and not by corps
Of radio engineers and must be as IN
extensive as possible
s. The postoffice stations have aIwags
been able to receive on vertical looms.
either multiple or single turns, when
no work could pc done on the ordinary
arstenna This, of course.
s,leaIss getting the traffic through under
bad conditions, work which promises
10 be settled completely by the use OF
the underwater, horizontal aatenna. a