Evening star., 1936-05-24

ner music moguls have decided to give
convention bands carte blanche to
perform their numbers. Moreover,
they have made known that they will
not hold networks or stations liable
for any of their music which may be
performed even though these stations
hold no licenses. This, it was re-
ported, was done on the theory that
convention broadcastS constitute a
public service of the nature that
should not make necessary payment
of royalties to copyright owners.
THE way of the criminal trans
= gressor is getting harder and
harder as radio scientists learn more
and more about how to apply their
discoveries to the relentless efforts OF
police to make the Nation safe for
living.
One of the newer tricks in radio
sleuthing is new way of changing
of one-way systems into two-way COM
muniCation so that cruising patrol
men can talk back to their superior,
as well as take orders for them. The
two-way transmission makes the COM
munication similar to ordinary tele-
phone communication. The chief of
police or the dispatcher can cut into
the conversation without any switch
ing operations under this new duplex
system.
Under the so-called simplex system
of two-way conversation it is neces-
sary to wait until the party at the
other end is through talking. Even
the chief himself must wait patiently
until the policeman is through saying
his piece before he can give him
| orders.
A 'talk-back" receiver Is the gadget
that does the trick. 1t has a filter
that allows simultaneous transmission
and reception at headquarters yet
uses only one transmission line and
one antenna. Higher frequencies are
used for this reception.
| A N IMPORTANT step in raising the
power of radio to sweep criminals
off the map and into damp cells
was taken last week by the Federal
Communications Commission when it
assigned number Of frequencies for
intercity police use. Along about
Autumn the International Associa-
ton of Police Chiefs will hold their
annual get-together, and they will
have before them complete plans to
set up a radio code system tieing In
cities all over the Nation.
The F. C. c. weaned nine choice
frequencies used by group of early
television experimenters to provide
police with air room to set up their
code system. In recent years tele-
| vision experimenters have turned to
the ultra-high frequencies for their
sight transmission efforts, most of
them now using cathode ray tubes
instead of the earlier scanning disc
systems.
A radio telegraph system will be set
up by the police and perhaps in a
year or two it will be used to carry
facsimiles of portraits and finger
prints. At first, however, it will be
used mainly to supplement the auto
matte teletypewriter systems that
many States have.
For exampe, police message in
New York could be sent by radio
to adjoining States, which in turn
could relay it to other States, and
these could continue the relays until
the entire 48 States had been reached,
all within matter of minutes. At
the same time the New York police
would be sending the message on the
present teletype system, which links
five and other nearby States.
A LITTLE farther in the future Is
the plan nursed by ]. Edgar
Hoover the Department of Justices
ace director of the kidnaper- -exterm-
mating G-Men. Hoover has been
tinkering since last November with a
plan to set up a powerful broadcast
transmitter in Washington. He sends
out regular messages from a Bureau
of Standards station and is checking
reports from listeners who pick up the
test broadcasts.
One of Hoover's fondest dreams Is
radio communication system by
which he will be in constant ear-and-
eye communications with the whole
Nation, whether he be in his air.
! cooled Washington Office or cruising
in his bullet-proof limousine. This
dream envisions the day when he can
| apply televiSion and facsimile and
broadcast communication to his drive
20 rid the country of professional
criminals.