Evening star., 1922-09-24
BY COMMANDER STANFORD c.
HOOPER.

undoubtedly would constitute the
marvel of this age. Radio, however,
is not only the outstanding marvel OF
this age, but Of all ages.
Yet both are infant sciences-arts-
industries-the future possibilities of
which no one can foretell.
In future ages they probably Will
symbolic the beginning of the era
of universal rapid transit and instan-
taneeus communications over long
distances.
Radio will serve aircraft in fight
above the clouds as faithfully as it
serves ships at sea or points separated
by great distances on land.
Its effects are all-pervading. They
have no limits.
Theoretically. the earth moves IN a
vast ocean of ether which surrounds
and permeates all matter ana all
space in nature. By creating cleo
trical discharges in 1t. ether. or radlo
waves are set up, and these may pc
made to manifest themselves not only
on land and sea, but under ground
and under water--and in the limitiess
space above the clouds.
Hence, radio may be designated, In
literal sense, the universal medium
of communications.
May Become Universal Agency.
Future developments in the radio
art may conceivably make or II uni
versal agency for other services as
well.
Aeronautics. having been extensive
Iy developed for military purposes as
IL result of the world war. is now rec
ogniZed as an extremely important
agency for use in possible future
wars.
Aircraft may serve and aid the
forces on land or at sea, or they may
constitute force in themselves anC
act independently. Adequate facili.
ties for reliable communication would
obviously be essential in any case.
Radio will be Indispensable to arr
! craft which carry the mails in peace
| times, if the lives Of the pilots are
| to be safeguarded and avoldable de-
| lays obviated-especially If flights are
| made after nfghtfali.
With the advent of commercial avia-
| ton on a large scale, radio Will as
sumo an Importance in connection
with the protection of life ana prop
erty in the air. as it now has VITA
! respect TO the safety of passengers,
crew and cargoes of ships at sea.
| Undoubtedly II distinctive radio sig
nal denoting aircraft in distress in
| the air, similar to the $. .. 5. signal
used by ships in distress at sea, will
! eventually be found necessary.
Developing suitable apparatus for
and methods of operation and con-
! troll Of aeronau utical radio constitutes
one of the major problems in radio
| today.
| There are four principal limiting
| factors peculiar only to aeronautlcal
| radio, which hamper all efforts in this
! respect They are weight limitations.
| fire risk, wave-length limitations and
noise.
Radio TransmittinE Apparatus.
! Radio transmitting apparatus. with
! its electrical power equipment, and
also radio-receivinG apparatus. must
be made as light and compact as pos
| sible, due to limitations in the total
weight and space which the craft will
accommodate. A maximum weight
! for the radio installation is specified
for each type of craft, and TINS can
not be exceeded.
Electrical sparks" or "brushing
must not take place in any part OF
! the transmitting equipment owing to
danger to the plane from fire.
Only very short lengths of the gem
| eral order of 500 meters can be used
; for transmitting owing to the i'm
, tied capacity of the antenna system.
| Several stages of amplif1cation must
| ordinarily be used in reception due
! to propeller and other noises.
Ordinarily a single wire Is reeied
| out for one hundred or. more feet
| after a plane leaves the ground. This
! constitutes for the aircraft what is
| termed the Overhead" part of an
J ordinary shore or ship station an
| tenna system A lead weight or
| wire to keep it below the plane and
away from the propellers of the
| rapidly moving craft. The ground
part of the aeronautical antenna sys.
| tenn always consists of all the metal
parts of the craft bonded together
I al ricallv In some the large
Navy seaplanes the overhead part of
! the antenna system consists OF Few
/ wires. stretched taut and suspended
on insulatorS foot or two above the
upper framework of the plane.
Obviously the value of the cleo
| trio current such antennaS will ac-
commodate for transmitting purposes
| is very small, and consequently their
transmitting range is restricted.
Likewise the wave length used must
mensfons of an antenna largely de-
termine the length of the wave that
can be used.
Experiments and test In aeronauti-
cal radio for the Navy have been
| in progress only since our entrance
! into the world war. These have been
conducted at the aircraft radio
laboratory. at Anacostia, D. c., and on
aircraft.
notwithstanding the short period
! of time since aerOHdutlCdi TdulO mas
been inaugurated in the naval serv-
] ice, and the difficulties to be con-
tended with, very gratifying results
have already been attained.
Carried by All Naval Aircraft.
All naval aircraft carry radio in
stallations and radio operators. as do
F., also those of the Army. Communi-
| cations are now readily exchanged
between craft in fight. and between.
craft in flight and the land and sea
up to distances of not less than 100
miles under practically any condi-
tions.
Communications are readily ex-
changed by radio telegraphy between
at sea for distances of from 200 to
$50 miles.
improvements are gradually being
made in the radio teiegraphic in
stallations with a view to increasing
! this range.
by radio telephony. also. but for dis
tances considerably less than state.
in the foregoing. Special efforts are
being made to provide radio tele-
phonic equipment having similar or
greater ranges, because radio tele-
phony is far more suitable for use
with aircraft than is radio teleg-
raphy.
ments are under way at the Anacostia
laboratory with this end in view. One
of the novel features Of this work
is the concerts by the United States
Marine and Navy Yard bands, broad
casted weekly by Anacost!a (NOF).
the results of which are reported by
! radio fans located in various parts
of the country. These reports. and
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