Lesson 4. 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

2. 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.

3. Answer the following questions:

1. What does the radio compass determine?

2. The radio compass is basically a radio receiver fitted with a loop antenna, isn’t it?

3. Where was a loop antenna mounted?

4. How could bearings of radio stations off the line of flight be obtained?

5. What did a rotatable loop dominate?

4. Paraphrase the following sentences, using the following words and word combinations: to head, deflection of the needle, to determine bearings, antenna, dial, fuselage

1. The radio compass helped to find out the direction or angle to a radio station.

2. The aircraft traveled towards a radio station.

3) Headings to the right of left of the station resulted in a corresponding degree to

which the needle on a measuring instrument moved away from zero.

3. The loop aerial itself is very directional.

4) The loop is usually mounted on the main part of a plane, in which people sit or

goods are carried.

5) The bearing to the station was read from a graduated round part that showed you the

measurements.

5. Translate from English into Russian, paying special attention to the “Complex Object” construction:

1. Everybody knows the radio compass to be basically a radio receiver fitted with a loop aerial.

2. We heard the loop aerial be very directional.

3. We want the research to be continued.

4. Scientists found the replacing the fixed loop antenna with a rotatable loop to have eliminated the cumbersome maneuver.

5. Observations show the bearing to the radio station to be read from a dial.

6. Find the equivalents:

Луч надежды, определение местоположения, рамочная антенна, визуальный индикатор, соответствующее отклонение стрелки, устанавливать антенну, указывать на радиомаяк, силы сигнала, сводить друг друга на нет, повернуть самолет к станции, магнитный компасный курс, вращать антенну, градуированная механическая круговая шкала.