Evening star., 1942-02-02
Automatic Devices
To Give Raid Alarms
By Radio Studied
.AIerts' Could Be Attached
To Regular Broodeostins
Systems, Bockers Ciuim
BY WILLIAM J. WHEATLEY.

BY WILLIAM j. WHEATLEY.
Radio apparatus known as radio
alerts," which can be used for the
mobilization OF civilian defense
forces or for warning the general
public in time of emergency. are
being studied by the engineering
department Of the Federal Com
munications Commission and the
ONCE of Civilian Defense. o. c. D.
officials said. however, it would take
some time to determine whether the
device is practical. and If finally
approved. whether the public will
be permitted to use it.
Two working models Of the ap-
paratus have been demonstrated to
F. c. c. and o. c. D. of1cials.
One of the radio alerts can be
attached to regular broadcast re-
ceiving sets. 1t will give warning
even II the circuit Is broken, its
hackers claim. The alerts will turn
on radios automatically and would
be useful in awakening sleeping per-
sons in event of a raid. it was said.
The apparatus will permit con-
troll stations to hold radios from
regular programs as long as neces-
Sary, to reaSsure civilians during an
air raid, or to give instructions to
relief crews.
On the question of the alerts'
practically when regular broadcast
stations are ordered OF the air, It's
proponents claim the control sta
ton need use the device from one to
five seconds to give warning, and
that the controlling frequencies may
range from the extremely low sub
audibles to the highest super-audi-
bles 1t Is possible to broadcast.
Flyers need more than five seconds
to get a Elk" on their positions
from cross-bearings of radio beams.
those favoring the alerts declare.
There are several other systems
under consideration. one Of which
uses regular electric transmission
lines for warning signals sent to
receiving apparatus in homes or
afraid wardens' offices. This sys-
tenn would not work where electric
transmission lines were damaged, 1t
was said, while the device using low
frequency radio impulses would not
be so endangered.
Materials Are Question.
Of1cials are seeking to determine
whether manufacture Of the alerts
would take materials needed to sup
ply the services with radio appara-
tus. In the case of the radio trans
mission device, 1t was said broad
cast stations could install 1t with
out great pressure on material stock
piles. The receiving apparatus in
practically all of the devices uses
the regular tubes and coils that are
manufactured in great volume. Pro-
duction Of the sets, it was explained,
Is largely an assembly job and there
are many plants now idle with for
mer employees jobless, which could
be put to work Immediately in as
sembling the sets.
Backers have urged o. c. D. to
give the alerts q test In which
enough sets are constructed to
equip q tpNn the sStss At Whining
ton, Del II the expefi1hentsis b sue
ceSsfil, plans then could be de-
yelOped for squipping other defense
areaX providing first for towns be-
Neved most likely to be bombed.
Backers OF the device estimate It
would take two weeks from the time
Of approval to begin installations
In the town selected, two or more
weeks to complete the task. and
another week to demonstrate ef-
fectiveneSs d the system.