Слова учить wireless telegraphy

Answer the following questions:

1. 
   What are the radio direction finders used for?
   
2. 
   Who was the inventor of the earliest radio direction finder?
   
3. 
   What elements did the radiogoniometer consist of?
   
4. 
   How did the radiogoniometer work?
   
5. 
   What is ADF?
   
6. 
   Why did GPS system remove ADF and VOR systems?
   

Lesson 3. Radio compass

1. Read the new words:

radio compass радиокомпас
glimmer мерцание, слабый проблеск
to determine определять устанавливать
bearing направление; азимут, пеленг, месторасположение
fixed loop antenna стационарная рамочная антенна
needle стрелка (прибора)
heading курс, линия курса, маршрут
deflection отклонение стрелки ( приборов )
to mount монтировать, устанавливать
cancel out сокращать, уравновесить, свести на нет
null нулевой
amplifier усилитель
homing device приводное устройство; радиокомпас
rotatable вращаемый
to eliminate устранять, исключать
cumbersome громоздкий
fuselage корпус, обшивка, фюзеляж
cockpit кокпит, кабина экипажа
triangulation триангуляция
dial циферблат, круговая шкала , градуированный диск
flight chart карта полетная

1. 
   Read the text and translate it:
   

The Radio Compass was the first glimmer of hope in determining bearings to a radio station. It added a fixed loop antenna and visual indicator to the receiver system. With this system, as long as the aircraft was headed directly toward a radio station the needle of the indicator remained centered; headings to the right or left of the station resulted in a corresponding deflection of the needle.
A loop antenna was mounted on the back of an aircraft. If the plane of this antenna pointed to a radio beacon, the signal strength was a maximum, while a signal facing the loop induced voltages that cancelled each other out, resulting in a weak or null signal. The loop antenna was connected to an amplifier, which drove an indicator on the cockpit's control panel.
The radio compass was chiefly used as a "homing" device, and bearings of radio stations off the line of flight could be obtained only by turning the aircraft toward the station and noting the magnetic compass heading when the needle was centered.
Replacing the fixed loop antenna with a rotatable loop eliminated this cumbersome maneuver. With the rotatable loop, bearings could now be obtained without turning the airplane itself. The pilot or navigator would rotate the loop, usually mounted on the fuselage below the cockpit, to the position of minimum signal strength, or "null." The bearing to the radio station was then read from a graduated, mechanical dial.
By repeating this procedure with a second beacon an aircraft's position could be determined by triangulation after locating the two stations on the flight chart.

1.