Evening star., 1934-08-05
AMATEURS SEEK
KEY TO ECHOES
Scientists and Owners OF
Short-Wave Sets to Take
Part in Tests.

In their explorations Of uncharted
areas Of that indehnable something
called the ether" radio scientists
have collided with a new and most
baffiing phenomenon which they have
dubbed radio echoes" Believing
long sought data about the aurora
borealis or Northern lights, magnetic
storms and sunspots and their rela-
ton to radio transmission may be In
volved In the solution of this puzxling
development. engineers and listeners
in all corners Of the globe have been
enlisted In scientific attack upon It.
The first step has been that Of de-
failing two European radio stations.
one in England and one In Switzer-
land. to broadcast special signals at
regular intervals TO allow radio enGi-
neers and fans In remote corners Of
the earth to check and measure the
long delay echoes" The object Is to
ascertain why. after the signal or
program Of q distant station is picked
up. there should be an echo" or re-
production Of the precise signal from
/ 10 80 seconds later.
Amateurs Are Enlisted.
To make the investigation as far
reaching as possible, listeners with
short-wave receiving sets are being
enlisted to aid. The signals from the
two European stations and the whole
undertaking, It Is stated by the
Bureau OF Standards, which Is con-
Quoting the American phase Of the
study, are adapted to short-wave re-
ceivers all over the world. DR.. J. H.
Dellinger, chief Of the Bureaus radio
laboratory, has asked listeners who
receive long-delay echoes in the
United States 10 report TO him. He
in turn will relay the information to
the British radio authorities who are
co-ordinatinW the investigation for
the world as whole.
Observers, Or. Dellinger said. should
give the identifying letter OF the Sig
nal observed, the time to the nearest
second at which the direct signal was
heard, the time to the nearest second
at which th. echo was heard. an
estimate of the relative intensities Of
direct signal and echo, a description
Of the sharpness or apparent shape
of the echo and any pertinent In
formation on interference, fading or
other conditions.
The worldwide campaign has been
inaugurated by the British Broad
casting Corporation, In corporation
with many scientists. Listeners IN
all parts OF. the world have been en-
rolled, more than 10000 Of them In
Great Britain.
Transmission Explained.
The stations transmitting the spe-
cial signals are GSB, Daventry, Eng
land, and HBL, Geneva, the latter
operated by the League OF Nations.
GSB signals are transmitted on 9,5f0
kilocycles. with q tone Of modulation
Of 1000 cycles per second, each sun
day, Tuesday and Thursday, from
3:25 to 1855 am, Eastern standard
time. The HBL signals are on 6.675
kilocycles unmodulated continuous
waves, each Sunday, Wednesday and
Friday, from to $3.50 am. Eastern
standard time. Each transmission
consists of q 5-minute adjusting Pc
riod (GSB using phonograph music
and HBL using It's call letters In
Morse code repeated) followed by the
letters Of the alphabet In Morse code,
spaced q minute apart.
Thus for instance. GsB transmits
the letter "A" In Morse code at $3.50
and after q minute Of silence the
letter "B" at 3:Sl; then the letter
&C" at 3:32, etc, finishing with the
letter ~" at 3:55. During the l.
minute intervals, the observers listen
for echoes and observe the elapsed
time in seconds with a watch having
a second hand. The GSB signals, 1t
Is pointed out, are receivable with a
receiving set used for broadcast pro-
grams. but the HBL signals. the more
technical Of the two, are unmodulated
continuous wave, and therefore re-
quire an oscillating receiver.