Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-07-04
RADIO CHANNEL
INCREASE |SSEEN
IS Per Cent More Waves viii
Be Available in Five Years,
Craven Believes.

Scientific progress within the neZt
five wears will make possible at least q
rs per cent increase in the number OF
radio channels available for telegraph
use to the United States and materially
increase those for all other nations
This is the prediction Of Lieut.. Comdr:
T A. NJ. Craven, recognized as one OF
the worlds foremost radio communlca-
ton authorities.
Corndr. Craven estimates the actual
increase in the number of channels In
ali of the communication bands will be
from 2,24o to 1922. Thus the lamented
congestion in the ether will be allevlated
to some extent, although the demand
sluavs will greatly exceed the supply OF
natures facilities The estimates are
included in q comprehensive statlstlcai
statement Comdr. Craven has prepared
for submission to the Senate interstate
Commerce committee. Testi1ylng oeioIe
this committee recently on world radio.
telerrauh communications. the naval
oficer was asked TO draft such state
nent dividing up the ether into its cate
rories of uses and detailing other peril
uent information
Must Narrow Channels.
The ofacer makes no prophecy as 70
Hhe rossibility of an increase In tns
number of broadcast channels available
the nrobleHn closest to the heart OF
the American people. It Is not ms par
ticular line. Moreover, the question OF
transmitting sound, voice and music Is
Altogether different from that, OF cooe
transmission. In the oroaocasG oan1
The present width Of channel is ~
l,ilocvcles, whereas If telegrapny was
used In this band the channel "loIh
would be only 2 kilocycles.
The secret Of increasing the rumcer
of radioteleeraph channels Is IN narrow
inr the width Of channels and the sepa-
ration hetween channels without cauS-
irc interference or jumbling OF signals
Tyen now that is possible In certain
portions Of the ether. BY 1nternatlonaI
egrecnert, however, the standard sepa-
ration between communication cnannels
is tvo-tenths Of one per cent. Wnereas
cornparies In some instances are operat-
inr successfully with only half this sep
Grafton. making possible virtual douo.
ling IF the number Of channels allocateo
then1 n tfev are adjacent. But IN allo-
eating channels. the licensing author
ities must recognize the figure OF two
tenths per cent separation until the
international agreement Is modmeo 70
conform with this engineering progress.
In the low and medium IrequeneS
bands, ranging from 10 KuocyCles 70 ~ ~
kll0EVcleS.
INCREASE In the number Of channels VIII
he 147 There are 500 standard width
channels in these bands now. Ihese
ara the channels used In international
communication, mobile, ship to snip
rooint IN roint, aircraft and radio beacon
oneratiorls, and are the very hrst OF tne
radio channels to be employed In COM
munlcation.
High Frequency Increase Seen.
The greatest increase, In Comdr
eraven's opinion. will be In the h1gn
Frequency bands, both continental ana
transoceanic, where the number OF
channels should be more than doubled
bv the Tightening UP Of operations, ana
through use Of improved equipment.
IN the transoceanic high frequency
hena ranrinr from 5000 to $4,000 kills
cycles. there are now SPA standard
width channels. This number should
he increased to about an even 400 ac-
cordine to the radio expert. II Is N
fhis band where the international con-
troversv centers, for these channels are
available TO al nations Of the Torlo on
a priority basis. 1t will be the cnle!
problem for the next 1nternationai
radiotelegraph conference 70 De neto III
The Hague in 1882.
In the continental high frequency
band. covering the area from 1,5O0 TO
& moo kilocvcles the channels Of which
are adapted for use only over The North
American continent, the increase shoulo
he from 639 channels to 1898, says the
Commander, The continental band, to
the United States. is destined TO be Of
tremendous importance. First It u IN
this pand that the point to point radio
telegraph communication In companion n
With wire lines will be carried on. ms
is now the basis of a court action that
is to be perhaps the most important
radio case yet in litigation. Also to
operate in this band will be telev1sion,
when IL finally arrives, for particular
blocks have been reserved for byoad-
casting. Then airplane, communication:
general communication, amateurs ana
experimenters go into this ethereal
space, az. we'll as the hundreds OF other
uses found for short waves In conmunl-
caticn with the United States and its
North American territories.
(Copyrisht, 1929, By the Consolidated Press)