Radio age (Jan 1927-Jan 1928)

RADIO AGE for April, 1927 Ancient Wooden Clock Still Keeps Excellent Time P r3 • J^k T^ "''^jel hit^ £}Jm r W^lIWa *^/k ^SaMsfH NHpExli LB a\ 47 Carved by hand out of wood, this strange clock of ancient origin is keeping very good time for its owner, Hans A. Bergstrand, of St. Paul, Minn. The 'works" are composed of four wooden wheels and the pendulum is at the top of the timepiece, or perhaps, more properly should be called the governor of the clock. Small metal pins driven into the wheels constitute the escapement action. The clock has only the hour hand, the spaces between the numbers being divided into quarter hours. The timepiece is motivated by a weight which is lifted once every 24 hours. Photo shows Mr. Bergstrand with his ancient clock Hissing Sounds Made By Northern Lights HUNTERS and others who frequent the northern forests of Canada have often reported hearing hissing or crackling sounds accompanying the Aurora Borealis or Northern Lights. Scientists have been skeptical of these reports, for the aurora is known to be an electrical discharge high up in the air; never less than fifty miles above the ground and usually higher. Even if the aurora does produce a noise, which is doubtful, the sound could not reach the earth from so great a height. Nevertheless, the controversy now appears to be settled in favor of the unscientific observers, who reported merely what they heard. A scientist of distinction, the Norwegian meterologist, Dr. Hans Jelstrup, has heard the sound himself. On the night of October 15, 1926, Dr. Jelstrup and an assistant were observing the aurora from a hill-top near the city of Oslo. Suddenly the often-described hissing sound was noticed. It seemed to rise and fall in intensity, keeping time with the changes of intensity in the light of the aurora. Inexpensive Eliminator For Home Constructor (Continued from page 6) to forestall rapid evaporation it is a good idea to pour a layer of paraffin oil over the surface of the liquid in each cell, to a depth of about onequarter inch. It sometimes happens that when a chemical rectifier is first attached to a receiving set, rectification will not immediately take place. This is because the plates of the rectifier have not had a chance to form which usually takes several minutes. Do not become alarmed if this should happen but lift the electrodes up out of the jars and then immerse them again slowly. This operation will enable the necessary film to form more quickly on the aluminum plates and when this is accomplished the cells will function properly and further attention will be unnecessary. The various voltages necessary to take care of the average receiving set are obtained by the use of variable resistances, as illustrated. While the approximate output of the described eliminator is forty milliamperes at 150 volts, a greater output can be readily obtained by increasing the depth of the electrodes in the rectifying solution and increasing the capacities of condensers C-l and C-2. Do not, however, cut down on the specified capacities of either the condensers or choke coils shown if you expect secure satisfactory results. Before closing this article it would perhaps be well to call the reader's attention to the fact that while the grid leak used in the average receiving set functions quite efficiently when regular "B" batteries are used, it will usually be found too high in value when an eliminator is employed to furnish plate current and produces a hum in the loud speaker unit. This condition can be easily remedied by inserting a leak of lower value, or what will prove more satisfactory, a variable leak, which can be accurately adjusted until all trace of hum is eliminated. When the proper value is once determined further adjusting will be unnecessary. SUBSCRIBE NOW! RADIO AGE $2.50 a Year HARTER PARTS as usual specified for Madison Moore Circuit as in all the other really popular circuits including Hammarlund Roberts Hi-Q L. C. 27 (Popular Radio) Worlds Record Silver Marshall Shielded Six B-T Counterphase Power 6 and others Any dealer can tell you why In Canada: CARTER RADIO CO., Ltd., Toronto u arter Radio Co. CHICAGO 105& MAKE YOUR OWN CONE OR ROLL SPEAKER GENUINE ENSCO KIT Only $10 The Sensation of 1926-27 MAKE YOUB OWN THREE FOOT CONK SPEAKER IN LESS THAN AN HOUR. Complete put! furnished Id kit form. We guarantee toll speaker the equil of any manufactured tone speaker at any price. With this THREE FOOT CONE SPEAKXR T*s near all the tones. It brings out the trie depth and beauty of orchestral and Instrumental musle. Can be operated softly for living Room Music or Full rolume for dancing, and without trace of distortion. 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