The Birmingham age-herald., 1922-05-21
News And Comment
TIME GOVERNED BY RADIO DAILY
Swinging Pendulum of Clock in Arlington, Va, Surges
 Through Ether Nightly

Shortly before 10 o'clock eastern
 standard time every evening in halt
 million homes, the ticking or
 distant clock is now heard, and the
 time of as many citizens Is daily regu- lated hyit. The ticks come From the
 clock in the Naval Observatory, and
 are transmitted through the famous Virginia,
 Not only do these ticks regulate
 the nations clocks throughout the eastern section of the country. but they also figure very materially in the navigation of practically every steam ship pioughing it's way across the waters of the Atlantic. How are 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.
 Tn the first place the signals them
 Naval Observatory in a very novel
 manner. The pendulum on the clock swinging across It's arc of travel makes contact with piece of metal | every time 1t passes through its per pendicular position. and 1t Is so ar- ranged that it makes one complete I swing every second.
 Pendulum Operates Trnnsmitter As the pendulum passes across the | contact it closes local circuit. which | in turn operates tho transmitting ap- paratus at Arlington. and thus sends | out the brief dashes that are so fa-
 miliar.
 Now, as Is we'll known. these sig
 nals are sent out on wave of 2,600 meters in length. while the broads
 casting stations are operating on S60
 meters. The consequence is that the
 broadcasting stations which reproduce them must actually receive and trans
 init at the same time.
 This fact is not generally appre-
 ciated by the average radio fan, and it offered a very serious problem to
 solve, especially as 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 that 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 effec; of the transmitting aerial from tho 1 receiving aerial so that It would not 1 interfere with the true note of Arling l ton.
 Another difficulty that had to be overcome was tHe Ampn1lCbIlon or InC weak received signals from Arlington without distorting 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 | so arranged that it was possible to l change quickly over from the 380
 meter wave length. to the 2,6oo meter
 wave of Arlington. and the astonish- l ing thing was the wonderful exacti-
 tude of the reproduction from the station broadcasting.
 Radio Republication Used | At the broadcasting station radio l amplification Is used to build up the
 current received in the antenna there,
 before 1t is passed for rectification | through the dector tube, The audible frequency of the Arlington quenched | spark is then passed through audio- | frequency amplifiers, and finally de- livered Into special telephone re- | ceiver
 This receiver Is attached to tele- phone microphone transmitter of spe- 1 cial design. and then placed into the ] incubator tubes of the transmitting | apparatus and re-radiate6 on the 300- meter wave. so that all of the radio
 fans listening on their short wave re- l ceivers can obtain the correct official l time every evening.
 The remarkable thing about the