Great Falls tribune. [volume] (Great Falls, Mont.) 1921-current, 1922-08-13
SAVED 100000
in %REDESIGNING
OLD APPARATUS
United States Naval Subs to
Have Long Range Radio
Sets.
BY CARL n, BUTMAN

Washington. Aug. 12.-Radio engi-
neers of the navy department have
been so successful in the development
of a special radio Geographic transmit
ting and receiving set for submarines
that 80 new sets have been ordered.
They will be improvements on the ex-
perlmental set installed on the $50
which paid a visit to Washington re-
Gently and was said then to be one of
the best equipped submarines in the
world, The sets will be constructed
on confidential specifications drawn up
by the radio section of the bureau of
engineering. based on experimental
sets building at the Washington navy
yard.
Approximately 100000 has been
because the navy did not have the
perts accomplished. however. is a re-
markable saving, because virtually new
and very excellent long distance sets
will be available for all the big subs at
a very small cost. BY redesigning and
remodeling old apparatus. barring a
few small innovations and parts. the
naval radio experts have built up an
entirely new standard submarine radio
set, better than that on the $50.
Radius Increased
The results in radius of action. Rear
Admiral Robson. chief Of the bureau
of engineering, says, are twice what
the radio men hoped for when they
began the experiments some months
ago. In other words. instead of a ra-
dius of about 100 miles. the United
States navy subs will have a radius of
radio transmission better than two or
three times that distance in ordinary
daytime communication.
The first set was installed on the
R-22 and the resulting experiments
proved that an excellent practical sub
marine set had been evolved by reInod-
cling surplus apparatus and 8 ADS Of
present equipment. New apparatus
manufactured by commercial concerns
along the lines of the perfected speci-
fications would have cost the navy IN
the neighborhood of $500 Il get. in
stead of $500, the estimated cost of
~remodeling and assembly. Fifty nine
times the difference is S295.000-
saved.
Another remarkable feat accom-
plished by the nav was the perfection
of the details of the set within six
months. The original submarine set
developed and built by a commercial
concern required two and a half years,
it is said. or five times as long. When
all of the subs are equipped. naval ex-
perts believe that these craft of the
Am navy will be just a bit bet
ter equipped than those of any other
navy in the world.
Submarine Radio
Very few details of the new sets
are revealed. but il is known that they
are vacuum-tube sets developed along
original American lines. Late in the
war. German submarines lying on the
surface succeeded in sending messages
during the night as far as 800 or 1000
miles to their bases by using short
wave lengths of about 300 meters.
Spark sets were used until the last
few months of the war. when vacuum
tubes were introduced in sending. al
though they had been used in receiv-
ing for about a year. The German
spark was operated on a 5OO-cycle
frequency about 2 k. W. capacity. Much
of their equipmen emit they considered
very confidential and after an unsuc-
cessful engagement they threw the i'm
portant parts overheard or into the
bilges.
Although arc transmitting sets are
said to be dangerous for submarine
use on account of the gases given off
by the many electrical storage batter
les. 2 k. W. arc sets were used in Brit
ish subs successfully. In American
submarine practice a grounded loop is
used. This aerial is very efficient and
of a highly insulated wire
grounded at the extremities of the hull
and running to a mast amidships. Two
down leads of the loop pass through
watertight insulators into the hull,
where the primary of the circuit is
in series. The loop is ron
nected with the standard naval radio
equipment by the ordinary means. ex-
cept that a condenser in series is used
transmitting.
Owing to the ability of the undersea
to submerge with the serial in
place, it is possible to receive long
signals under water to a depth
of about 20 feet. and short wave sig !
nails to a lesser depth. In 1919. Il sub
marine 10 feet under water off New
York picked up signals sent out from
Arlington. 200 miles away md while
at eight feet. heard Nauen.
Germany, 1000 miles distant, and also
San Diego.
On underwater transmission little Is
available for publication. but it g I'M
derstood that transmission as well as