Evening star., 1933-06-11
Behind the Microphone
IN EAMCASTING" or the
* transmission by radio Of
BY THE RADIO EDITOR.

.nD EAMCASTING" or the
X transmission by radio Of
l. voices and music over
fractional meter : wave
lengths, as demonstrated by West
inghouse engineers at their ex-
hibit at the Century of Progress
Exposition in Chicago, has opened
up an almost limitleSs field Of
speculation regarding the future
possibilities of radio in voice,
music, facsimile and television
broadcasting.
At the Chicago demonstrations
ultra-short wave lengths of the
order of 3,300,000 kilocycles, or
nine centimeters, are used to
transmit clearly reproducible
speech and music distance of
several hundred feet. However,
the same apparatus has been
tested at the company's Pittsburgh
plant between points more than a
mile apart, and the engineers say
there is every indication that it
can successfully be used between
points located 20 miles and more
apart" 81
The nine centimeter wave length
is one of the shortest radio waves
ever "harnessed," measuring less
than 4 inches from crest to crest
and representing fluctuations of
current some 55,000,000 times
faster than ordinary household
current. What is even more amaz-
ing is the fact that power of only
one watt is used, and that the
waves can penetrate rain, snow,
sleet and fog without distortion.
The primary drawback to the
immediate practical application
of such short wave lengths to
broadcasting, television and other
general reception services is the
fact that they shoot their impulses
in a straight line. They are re-
flected off a fiat sheet of material
just as light rays are reflected by
fiat mirror or shiny surface.
They can be DETECTED, and it is
the detection downward in all di-
rectionS from high radiating
points that may ultimately make
them highly important to future
radio services.
This straight line characteristic,
of course, can be a distinct advan-
tage, too, permitting of secret
commercial and military COM
munication between fixed points.
The big advantage Is that there
are untold channels available in
the ultra short wave spectrum, be-
cause the separations between
channels become less as the higher
TfrequencieS are used.
Engineers have freely predicted
that television, with accompany
ing sound, will ultimately be
lodged in these extremely short
wave lengths, which will mean
that entirely new types Of receiv-
ing equipment, both visual and
audible, will be used in the future.
Fractional meter wave lengths
have already been harneSsed for
use in point-to-point communica-
tionS services abroad, the out
standing experiments having been
the Marconi ultra-short wave
length installation at the Vatican
and the International Telephone
& Telegraph Co.'s ultra short wave
length experiments across the
English Channel.
In this country, In addition to
the Westinghouse experiments,
the Radio Corporation of America
has promised when economic con-
ditionS warrant to install aNation-
wide facsimile service for convey
ing messages by picture on waves
of the order Of 500, 900 kilocycles
or three-fifth of a meter. This
company'S teleyiSion experiments
are also largely being conducted
on the ultra-Si1ort wave lengths
from transmitting apparatus in
stalled at the top of the Empire
State Building in New York and
at the r. c. A. Victor factory at
Camden, N. j.
EORECASTING the day when the
1 policeman walking his beat
carries diminutive radio set on
his person to enable him to talk
back and forth with headquarters,
Warden Lewis Lawes of Sing Sing
Prison has applied to the Federal
Radio Commission for a set of
ultra-short wave lengths with
which to experiment with portable
radio equipment to be carried by
prison guards.
Warden LaweS proposes to ex-
pertinent with lightweight radio
tranSmitterS and receivers, so COM
pact that they can be strapped to
the backs Of the guards, with
which the guards can talk to one
another while at guardhouse sta
tionS or while on foot. The radio
equipment would also be particu-
larly useful during prison riots or
breaks.
Sing Sing is the first prison to
seek wave lengths of its own for
this purpose, and its application
emphasizes that the plant Is as
yet experimental. Radio Commits
sion records reveal that there are
,r1 &he. I'M ~>~I;~~ -.