301 



Questions and Answers 



This department will appear regularly in THE WORLD'S ADVANCE, subject to following 

 regulations: The questions must be legibly written with typewriter or in ink, on one side of 

 the sheet. Each question must be definite and cover but one point of the subject under con- 

 sideration, although a letter can contain more than one question. On the 10th of the second 

 month preceding the date of issue of the magazine, all the questions on hand will be consid- 

 er .? d and , those which are put in the most intelligent manner and of widest general interest 

 will be selected for publication in such issue, the number being governed by the space available 

 All other questions will be returned to the writers with a statement of the price for which 

 they will be answered by letter. Return postage must be enclosed with each letter containing 

 questions, and the letters must be addressed to the Questions and Answers Department and 

 contain nothing relative to other departments of the magazine. 



SAYVILLE RADIO STATION. 



In reply to the many requests we are re- 

 ceiving from our readers in regard to the 

 operation of the Sayville radio station on 

 Long Island, -we -will make the following state- 

 ments, which we hope will clear up the diffi- 

 culty. Sayville is intended to operate directly 

 with Nauen, Germany, and to send press to 

 the German ships. Since the war has been 

 in progress the German ships have been con- 

 spicuous on the high seas only by their ab- 

 sence, so that it would be foolishness to still 

 send press messages out to them. As there 

 is no direct cable communication with Ger- 

 many, the news has to come by wireless if it 

 is to come Direct, so that it has been found 

 more practicable to use the Sayville station 

 only for trans-Atlantic purposes, thus no press 

 messages are being sent as formerly. The 

 callPOZ called by Sayville is the Telefunken 

 station at Nauen. There are several wave 

 lengths authorized for the use of the Sayville 

 station, but in general one about 2,800 meters 

 is employed. Sayville's call is WSL. 



GENERATOR WINDING. 



(i) H. O. P., Elkhart, Ind, asks: 

 Q. i. What should be the winding for a 

 proposed dynamo having an upright bipolar 

 field magnet 6" high, 4" wide, space for wind- 

 ing being i%" thick, 2ft" wide, and 3^" long? 

 Bore is 3 1/16" in diameter and 4" long. 

 Armature is H-shaped, 4" long and 3" in 

 diameter. It is desired to get an output of 

 10 volts, speed being 500 or 1,000 rev. per min. 

 A. i. Although you did not state the ma- 

 terial of field magnet, we presume it is of 

 cast iron. It appears to be of good design, 

 differing from most designs submitted to us 

 in that it has more iron. To have the wind- 

 ing space 3" in diameter would be still better. 

 It surprises us, however, to find that you pro- 

 pose to use a Siemens shuttle armature. Even 

 if this is laminated, the operation would be 

 intolerable Sixteen-slot punchings can readily 

 be secured, and from them you can make a 



first-class drum armature. If you decide to 

 make such modifications in the design of the 

 machine as we suggest, we can then advise 

 you more accurately as to the winding. 



WINDING FOR STATOR OF 

 INDUCTION MOTOR. 



(2) C. U., Brockport, N. Y., asks: 



Q. i. What winding should be used on 

 the stator of a certain induction motor of 

 which the principal dimensions are: Outside 

 diameter of stator sheets, 7^"; inside diam- 

 eter, 4 17/64"; thickness, i^"; diameter of 

 rotor, 4 7/32", with 31 copper rods 7/32" in 

 diameter. Stator has 24 slots. It is desired 

 to wind machine for no volts and 25 cycles. 



A. i. For the 4-pole 75o-revolution machine 

 No. 18 magnet wire would appear to be about 

 the largest size that will permit the requisite 

 number of turns. You can wind the coils in 

 the manner described in Watson's recent ar- 

 ticles on alternating current motor construc- 

 tion. Of course, you are to put on all the 

 turns possible. For a 2-pole i,5oo-revolution 

 motor you might use No. 16. 



Q. 2. What is the size of a certain sample 

 of wire sent? 

 A. 2. No. 25. 



WINDING FOR AN ELECTROMAGNET. 



(3) ] E., Ardmore, Okla., asks: 



Q. i. What would be a suitable winding 

 for an electromagnet having two cores of 

 wrought iron, each I&" in diameter and 3&" 

 long, joined by a wrought iron block having 

 a section i l / 2 " x 2", the current to be taken 

 from ten or twenty dry cells? 



A. i. You do not state whether the use 

 of the coils is to be continuous or inter- 

 mittent, yet, from the fact that such batteries 

 are at best adapted for intermittent work, we 

 will propose a winding that will draw a cur- 

 rent of only about 2 amperes. If you desire 

 less strength, you can put the cells in two 



117 



