Radiotelegraphy: U.S. Signal Corps |
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adjustments aerial alternating current amperes amplitude antenna ammeter reading antenna circuit antenna inductance armature binding post C₂ called changes charged closed circuit closed oscillating circuit connected copper cuit curve cycles per second damped desired wave length detector direct current discharge electrical electromagnetic electrostatic energy formula fundamental wave length gasket gears ground hot-wire ammeter inch inductively coupled insulated jars kilowatts loading coil logarithmic decrement loosely coupled machine mast maximum millihenry motor motor-generator natural logarithm number of turns open circuit operating chest oscillation transformer oscillations per second plates plug potential primary circuit radiation radio pack set radiotelegraphy reactance receiving circuits receiving set resistance resonance rheostat secondary circuit sections shown in figure Signal Corps spark frequency spark gap speed spiral static surface switch telephones terminals trans transformer secondary transmitting tuning variable condenser variometer voltage voltmeter volts wattmeter watts wave meter wave train wire
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Page 104 - Operating chests : 1 chest. 1 resonance transformer. 1 condenser. 1 oscillation transformer. 1 sending key. 1 spark gap. 1 hot-wire ammeter. 1 switch. 1 receiving set. 1 connecting cord for generator (4-conductor, with plugs). 1 connecting cord, with plug for antenna. 1 double-head receiver. 1 test buzzer. 1 tool kit. 1 extra section for transformer secondary. 1 extra set crystals. 1 canvas case for receiver. 1 connector, 4- wire (lower half), generator. 2 connectors, 2-wire (lower half, antenna...
Page 99 - I. and so on, finding the best combination for every 50 meters increase in wave length up to the limit of the set. LIMITATIONS OF SYSTEM OF CODING WAVE LENGTHS. It will be noted that there is one best wave for the set, namely, about 1,000 meters. From some experiments made recently at Fort Leavenworth it is concluded that it is safe to state that, up to about 75 miles over average land, the falling off of energy due to the use of the longest wave lengths will not be so great as to prevent the use...
Page 115 - FIG. 79. ondary coil within the primary — that is, the coupling — is variable, and for the sake of convenience a scale is provided so as to be able to note the different adjustments. The coupling is closest when the secondary is inside the primary, in which case the scale reading is 0, and vice versa, the coupling is loosest when the secondary is drawn outside the primary and th6 scale reading is 40.
Page 127 - The antenna is of the umbrella type, with 16 radiating wires each 75 feet long. The counterpoise is likewise of the umbrella type, laid on the ground with 8 wires, each 75 feet long. The transmitting set is of the quenched-spark type, with inductively coupled circuits adjusted to radiate waves of 600, 800, 1,000, and 1,200 meters. The receiving set is of the...
Page 86 - It is of 2-kilowatts output and is carried on a two-chest pintle wagon, one chest with the engine and generator and the other with the transmitting and the receiving apparatus. The range of these sets varies from 75 to 800 miles, depending on favorable weather conditions, time of day or night, character of the land between the sets, etc. FORT SAM HOUSTON STATION SET. The following description of the Fort Sam Houston station is given as an illustration of the type of the 8 and 10 kilowatt sets installed...
Page 72 - ... where the adjustments are made by using a variable inductance ; thus the larger the number of turns in circuit the greater the inductance and the lower the frequency or the longer the wave length of the oscillations to which it is tuned, and, vice versa, the fewer the number of turns the less the inductance and the higher the frequency or the shorter the wave length of the oscillations. In this case the detector D is in a branch circuit with the condenser S and the telephones T, which is connected...
Page 27 - ABODE, half of which is positive and half negative, is called a cycle of voltage or current, the symbol for which is often thus written ~. The number of cycles per second is called the frequency and the letter " n " or " f " is often used as its symbol. In commercial alternators used in radio telegraphy the frequencies are generally 60, 120, 480. or 500 cycles per second; that is, there are 60, 120, etc., complete sets of values, such as :B +/1 \ \ Time\ FIG.
Page 5 - BODIES sealing wax they will be attracted to it, and similarly if the rubbed sealing wax is brought near particles charged by the rubbed glass they will be attracted; but two bodies, both of which have been charged by either the glass or the wax, will repel each other. Hence like charges repel each other and unlike charges attract. The names positive (glass) and negative (sealing wax) have been given, respectively, to these charges. By...
Page 105 - Hand generator: 1 generator. 2 cranks. 1 stand. 1 speedometer (carried in operating chest). 1 cap for speedometer opening. 1 canvas hood. Mast, type F. (Type D mast has 1 top, 1 bottom, 5 intermediate, and 3 extra sections) : 1 top section. 1 bottom section. 8 intermediate sections. 4 intermediate sections, extra (3 for tent). 1 antenna. 1 counterpoise. 9 carriers, wire. 4 pins, antenna. 2 hammers. 1 set adapters for tent (4 pieces). 1 bag, antenna and counterpoise. 1 bag, accessories. Pack frames,...
Page 115 - The coil is variable only by sections, marked "100," "200," etc., the smaller numbers to be used at the shorter wave lengths and the larger ones at the longer wave lengths. The position of the secondary coil within the primary — that is, the coupling — is variable, and for the sake of convenience a scale is provided so as to be able to note the different adjustments. The coupling is closest when the secondary is inside the primary, in which case the scale reading is 0, and vice versa...