Evening star., 1928-12-26
COUNTRIES SPE|T
OVER SHORT WAVES
Canada, Cuba and Mexico
Want Share of LoW-:Fre-
quenCy Channels.
BY MARTIN CODEL.

Discussions are still in progress with
Canada, Cuba and Mexico relative to
the division of the radio channels in
the band from 1900 to 5000 kilocycles
1900 to so meters). These are the short
waves pioneered and developed largely
mand among commercial interests for
continental communications purposes.
An agreement is believed to be in
sight with Canada, which refused some
time ago to negotiate for division of
the spectrum until assured so per cent
of the available channels.
DR.. j. H. Dellinger, chief engineer OF
the Federal Radio Commission, esti-
mates that there are 639 communica-
ton channels in this band in the pres
ent state of the art.
The Federal Radio Commission this
week will undertake to allot groups OF
the channels, but not specific channels,
to various American enterprises. The
use of these waves, however, will neces-
Sarily be contingent upon an agreement
with the other North American coun-
tries. One country failing to ratify
the division can wrack havoc with the
by pre-empting the channels.
Works Both Ways.
Such course would be mutually dis
advantageous, for the evil works both
ways. This makes imperative an agree
ment with Canada, and the State De-
partment is pressing to that end.
1t is likely that the next conferences
will be held in Ottawa. Efforts will be
snade to avoid the necessity of a for
NAL treaty or of carrying disputes to an
arbitration board of diSintereSted coun-
ETieS, such as the International Radio
Telegraph Convention preScribes.
The primary point of difference with
Canada may be the principle of dupli-
eating land wires with radio. Canadian
radio officials propose to utilize their
channels for communicating with the
sparsely settled regions of the Domin-
ion not now reached by land lines and
for necessary and emergency services.
Radio-telegraph network in the United
States, which is in effect a repudiation
by this country of the Canadian prin-
ciple, is problematical.
DR.. Dellinger has prepared a report
for issuance today which he aptly titles
Standing Room Only in Radio" and
in which he discusses the scramble for
the short and long waves among Amer
Scan interests.
In connection with the channels to be
divided on this continent DR. Dellinger
points out that these frequencieS are
continental rather than worldwide in
their effects. They can all be used on
this continent, because in general they
will not interfere abroad or be inter-
fered with from abroad.
has had about $50 applications for the
continental freQuencies. These are for
such uses as ship telephone and tele-
graph, airplafe telephone and telegraph,
freight train signaling, geophysical ex-
ploration, power-line emergency Serv-
ice, television transmission, point-to-
point commercial message service,
broadcasting pickup, relay broadcast
Ing, police signaling and general expert
mentation.
The commission will necessarily re-
ject many Of the applications because of
the priority that obviously must be
given certain services and because of
the scarcity Of channels. There stiH re-
main something like 1900 channels in
the band from 5000 to %, 900 kilocycles
(50 to Is meters) inzwalich signals may
be heard throughout the world These
are the extreme short waves, those be-
low 13 meters being still the subject of
experiment.
But there are already some 2,400
stations in the world operating on these
channels, an average of about two per
channel" Dr. Dellinger states. This
frequency band is therefore already fully
occupied. Whenever more than one
station operates on channel there is
. potential source of-interference. Ad-
ditions can be made only in special
cases by consideration of the areas af-
1ected time OF operation, differing ca
pacities of the various freuuencies at
different parts of the diurnal period,
and engineering expediencies like direc-
tional reception or transmission"
copyright, 1928, by North American
NeWSOaDPr Alliance \