. Practical wireless telegraphy; a complete text book for students of radio communication . AMERICAN MARCONI CO. 247 tion of both the coupling and flexible connection. The circuits are in resonance when theaerial ammeter shows the highest possible reading. With the average ships aerial it is possible to locate the correctnumber of turns at thesecondary winding of the oscillation transformer so that the radiated wave can be changedfrom 600 meters to 300 meters by simply throwing the changeover switch to the proper posi-tion. When this switch is in the 300 meter position, the short wave condense
. Practical wireless telegraphy; a complete text book for students of radio communication . AMERICAN MARCONI CO. 247 tion of both the coupling and flexible connection. The circuits are in resonance when theaerial ammeter shows the highest possible reading. With the average ships aerial it is possible to locate the correctnumber of turns at thesecondary winding of the oscillation transformer so that the radiated wave can be changedfrom 600 meters to 300 meters by simply throwing the changeover switch to the proper posi-tion. When this switch is in the 300 meter position, the short wave condenser which is placedin series with the earth lead must have its short-circuiting strap removed. Generally speak-ing, the aerial tuning inductance tap is placed at a fixed point for either the 600 meter or 300meter wave. (c) Adjustment of the Spark Note. Either a receiver or a wavemeter may be used to indi-cate the quality of the note. If the note is not clear vary the generator voltage, the numberof gaps and the transformer coupling, until it is clear or has a pitch of about 240 sparks per. Fig. 266a—2 K. W. 240 Cycle Motor Generator With Synchronous Disc Discharger. second. If the generator voltage is too high or too low, the note will either be rough orelse have the wrong pitch. The note may also be judged by the tone of the brush dischargeof the condensers. Maximum antenna current does not indicate maximum efficiency. The note must also bekept clear and the gap not worked above the antenna current at which the clearness is notmaintained. The wattmeter should indicate about 500 watts and the number of gaps used should bebetween eight and twelve. The power of the set varies in the square of the number of gaps; that is, if the ten gapsrepresent full power the power would be 10 = 100. The set is designed to carry a load of SCO watts. Any overload is liable to develop volt-ages that may break down the condensers or cause trouble elsewhere in the set. (d) Adjustment of the Quenched
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
