THE WORLD'S ADVANCE 



123 



contacts are polished and lacquered. 



SWITCHES: The materials for the 

 switches are: 



4 ft. spring, brass or copper. 

 2" x 3/&" x 8" hard rubber. 



Type A. Cut and bend the copper to 

 the size indicated, and solder the strips 

 together at the point P. Drill and tap 

 the brass support on top and bottom for 

 8-32 screws. The slots in the rubber 

 handle should be no deeper than is neces- 

 sary to make the blades come flush with 

 the under surface. Drill holes in the 

 blades to clear 4-36 screws at points 

 shown, and in the rubber to tap for the 

 4-36 screws. Before assembling, sand- 

 paper the brass parts to remove all tool 

 marks, using oil with the sandpaper as 

 in making the contacts. Polish and re- 

 move all traces of oil before lacquering. 



Type B. The construction is similar 

 to Type A, save that it is a single arm 

 switch, and that the arm has a 3/16" 

 hole through center. Slot the handle as 

 before. The metal arc can be made by 



filing from stock or turning a ring to 

 size. (See Fig. 6.) 



Type C. In Type C the switch arm 

 is snorter than in Type B, as is shown 

 in Fig. 6, and carries a piece of phosphor- 

 bronze spring soldered to it. The metal 

 ring should be made of %" brass, turned 

 or filed to size. It is best to support it 

 with brass pieces (approximately the 

 diameter of the contacts and held to the 

 case in a similar manner), sufficiently 

 thick to bring the ring to the same level 

 as the contacts. This, however, is not 

 necessary, as the ring may be fastened 

 by drilling and tapping for an 8-32 screw, 

 holding it directly to the case. If this 

 is done, the phosphor-bronze spring will 

 have a deeper bend. (See drawing.) 



In place of Type D a telephone switch 

 may be used, known as a ringing and list- 

 ening key. This will eliminate the double 

 pole, double throw switch necessary to 

 change from crystal to audion detector, 

 although it adds considerably to the cost 

 of the outfit. 



CHICAGO RADIO CLUB 



It is announced that the Chicago Radio 

 Club has recently been formed and will 

 hold its meetings every other Thursday 

 night at the clubrooms in Hamlin Park, 

 Wellington and Robey streets, at 8 P. 

 M. The organization charges no dues. 

 The Business Manager of the club states 

 that he will be pleased to have new 

 members join, in and around Chicago. 

 The main object of the club is to de- 

 crease unnecessary interference as well 

 as to increase interest in the art of radio 

 communication. 



The officers of the Chicago Radio Club 

 at present are: L. J. Healy, President; 

 Harry Lagodzinski, Vice-President ; R. 

 T. Strom, Secretary ; Fred Fletcher, Ser- 

 geant-at-Arms, and Edw. T. Markowski, 

 Business Agent. 



THE MANCHESTER RADIO RE- 

 SEARCH CLUB 



There has recently been organized for 

 the purpose of advancing radio science 

 the Manchester Radio Research Club of 

 Connecticut. 



The following officers have been elect- 

 ed: C. W. Hpllister, President; Wm. 

 McGonigal, Vice-President ; Raymond 

 Carrier, Treasurer; E. F. Ball, Secre- 

 tary, and Edward L. Root, Electrician. 



Wireless amateurs in the vicinity of 

 Buckland, Conn., are requested to cor- 

 respond with the Secretary, E. F. Ball, 

 of that town. 



PITTSFIELD RADIO CLUB 



At a meeting held Saturday evening, 

 April 1 7th, at the home of Allan W. 

 Burke, the Pittsfield Radio Club was 

 formed, with an initial membership 

 of twenty-five. The following officers 

 were elected: President, Allan W. 

 Burke ; Vice-President and Chief Opera- 

 tor, Vincent St. James; Secretary, John 

 S. Nichols, and Treasurer, F. Hemp- 

 stead. 



Several of the members of the club 

 have efficient stations and are in com- 

 munication with other amateurs through- 

 out Massachusetts, Connecticut and New 

 York State. 



