New-York tribune., 1922-05-21
Nations Time
Governed by
Radio Daily
Swinging Pendulum of Clock
in Arlington, Va, Surges
Through Ether Nightly,
Giving Exact Local Time
Ticks Sent Every Second
Broadcas, Stations Receive
and Send at Same Time
to Reproduce Signals

'''A'S' eVsIy evening In half
million homes the ticking of
distant clock is now heard, and the
time OF as many citizens is daily reeu-
lated by it. The ticks come from the
clock in the Naval Observatory and
are transmitted through the famous
long-distancc station at Arlington, Va.
Not only do these ticks regulate
Tho nations clocks throughout the
Eastern section of the country, but
they also figure very materially in the
navigation Of practically every steam
ship plowing its way across the waters
Of the Atlantic.
How arc these signals sent out so
regularly and consistently, and how
are they reproduced from the broad
casting stations? That is the question
that is Of the greatest interest to the
radio fan.
In the first place, the signals them
selves are produced by the clock in
the Naval Observatory in very novel
manner. The pendulum on the clock.
sA"S eN@ioSo 1tS arc OF travel,
makes contact with a piece Of metal
every time it passes through its per-
pendicular position, and it is so ar
ranged that it make. one complete
swing every second.
Pendulum Operates Transmitter
/ AS the pendulum passes acros. the
contact it closes local circuit, which
in turn operates the transmitting ap-
paratus at Arlington and thus sends
out the brief dashes that are 80 ia
| nliar
Now, as is well known, these signals
are sent out on a wave Of $500 meters
IN length, while the broadcastinR sta
tlons ere operating on $50 meters. The
| consequence is that the broadcastins
stations which reproduce them must
actually receive and transmit at the
same time.
This fact is not generally appro-
ciated by the average radio fan, and
/ it offered very serious problem to
! solve, especially IS it was desired to
reproduce in all faithfulness the exact
note Of the Arlington station. It must
be realized that in the case Of the
broadcasting station the receiving
aerial is not more than few feet
away from the transmitting aerial
The problem, therefore. was to elimi-
nate the inductive and radiation effect
of the transmitting aerial from the
receiving aerial SO that it would not
interfere with the true note of Airing
ton.
Another difficulty that had to be
overcome vas the ampli6cation of the
weak signals received from Arlington
without dstorting them or changing
their characteristics, because as re-
ceived they were too weak to operate
upon the transmitting apparatus Of
the broadcasting station.
[ have listened several times on sets
30 arranged that it was possible to
change quickly over from the $50
meter wave length to the $500 meter
wave of Arlington, and the astonish-
| ing thing was the wonderful exactitude
Of the reproduction from the station
broadcasting.
Radio Amplifcation Used
Al the broadcasting station radio
amplifcntion is used to build up the
current received in the antenna there
before it is passed FOR rectihcation
I through the detector tube. The audible
frequency of tho Arlington ouenched
spark is then passed through audio-
frequency amplifers, and finally de-
! livered into a special telephone rs
cciver.
This receiver is attached to a tee-
phone microphone transmitter Of spc-
cial design. and then placed into the
moGulator tubes of the transmitting
apparatus and re radiated Oh the $50
meter wave, so that all os the radio
fans listening on their short wave re-
ceivers can obtain the correct Official
| time every evening.
The remarkable thing about the
whole transaction is that there is ab-
solutely no loss of time in the trans
ference from Ole waye-length to the
other, and this is a very important
factor to those who desire TO set
chronometers by means Of the short
wave reproduction OF the time sig
nails.
The manner in which the signals are
! transmitted from Arlington is as fol
lows: The ticks are reproduced, start
ing from 9:56, Eastern standard time
every evening. Each second Is sent out
as a short dash, which is reproduced
in the telephones. The tick Of the
twenty-nnth second of every minute i,
skipped, Leaving quite distinctive
space. At the end Of each minute the
signals are omitted for several sec
onds, making a longer pause. Al the
end Of the fiftyninth minute after
o'clock the signals are omitted for ter
complete seconds, which, of course, i.
much more noticeable. This longcl
pause also permits the operator Of tnt
broa adcasting station to announce ove1
the $50 meter wave his famous: "HAt
next dash will be 10 o'clock"
One Of the officials of a broadcast
ing station made the following sugges
ton:
"A convenient way to check you.
watch is to follow the second han.
during the first part of the signals
thus noting the position of the secons
hand relative to the end of the min
ute. The minute hand should be OBJ
served during the fifty-ninth minute
and checked with the signal for II
o'clock. In this way you can tell exact
ly how many minutes and seconds you
watch needs to be changed In order t,
absolutely correct time"
Radio Cuts Message Cost
1t is estimated that By using radi,
to keep in touch with various arm.