With reference to local experimental wireless telephony, there is undoubtedly a great "opening for useful work among the enthusinats, provided the essential coeration is maintained. At preent, however, there, seems to be ttle opportunity for discussion ind the inter-change of ideas, although the inclination for, and value of such ce-operation is evident, Five watts is ample power for this local work, and some excellent results have been obtained with this low output, The same -dificulty concerning supply of apparatus still og, but of all the essentials for n-transmitter of this type, high tension D. C. si tolly the most cliff Several methods are in regular wse, and these may he vided into. three _classes:—the for-generator unit, which is robshiy. the best but the most sponsive—the storage battery thod, and the rectification of ternating current supply from the public mains after trans. formation up.to the desired method th the highest capital outlay, it is the least expensive in upkeep costa and ives very lite trouble.
SXPRRIMENT Witt FAN MoTORD, In this connexion the writer has been investigating the possibility of utilizing two electric fan motors, one A.C., and. one! D.C.
for the construction of a motor-generator set for small-power transmission, The fan motors arranged to run off A.C. supply are usually of the squirrel-cage synchronous typo, and may be employed as motor of the unit with The: D.C. course, have to be as Generator, and while this is not a dificult job, yet it important that, the number of turns of wire of the gauge for both' fold windings and armature should be correctly calculated first.
The writer has had no opporti ity yet of carrying out a practical test on generator so. arranged, but. hopes to. do a in the. sory] Rear future," when figures will Bindly be furnished to those who Are interested, With ard to the storage battery an rectifier methods of chaining the high tension suppl it may be possible in the next future to publish details of the manner in which these means are employed, but so both aystoms are relatively more complicated than the motor-generator, prover, description of each cannot in' the space here available,
Text read from the printed page and cleaned; old type leaves the occasional error.