1. . . .
Vocabulary
to convert - ,
to interrupt - ,
converter tube
wave range
interrupted circuit
carrier wave ,
direct communication - ,
RADIOTELEGRAPH
The function of radiotelegraphy is sound broadcasting. Radiotelegraph transmits coded messages, for example, in Morse code by radio. Its essential parts are radio transmitters, radio receivers, and teleprinter apparatus. These parts are usually located in the radio service centre. The equipment of the service centre includes high-speed Morse and music apparatus. The function of the radio transmitters is to convert mechanical movements into electrical currents. Transmitters may be directly controlled by telegraph in a frequency-modulated or amplitude-modulated systems.
Amplitude modulation is the method of transmitting information by radio waves. As for frequency modulation, it is radio transmission in which the frequency of a carrier wave is modulated and not its amplitude.
Transmitters in the system may also be controlled by a number of telegraph channels in AM or FM systems.
The amplitude keying of the system may be of two different types: one of them consists in interrupting the radio carrier. In the other amplitude-modulated voice frequency is carried by radio waves.
Questions
What functions does radiotelegraphy perform?
What are the essential parts of radiotelegraphy systems?
What are the functions of transmitters?
By what means are transmitters controlled?
What do amplitude- and frequency-modulation differ hi?
What are the two different types of the amplitude keying in the systems?
Task 2. Translate and write down the following words and word combinations in your workbooks. Make up a short plan of the text "RADIOTELEGRAPH" and write it down in your workbooks, summarize the text in short.
2. . Ի , .
Short theoretical information and a sample of implementation
( )
Word Formation ()
() in-, il-, im-, ir , , .
in - :
: accurate inaccurate ( ); active inactive ( ). HO unacceptable .
: coherent incoherent ( ); capable incapable ( ).
|
|
|
: informal ; inarticulate .
il - , l:
Logical illogical ( ); legible illegible ( ).
im - , :
Polite impolite ( ); personal impersonal ( ).
ir - , r:
Responsible irresponsible ( ); replaceable irreplaceable ( ).
Translate the following words in written form.
.
Words
1. irregular ____________________
2. impossible __________________
3. independence ________________
4. inconvertible ________________
5. inseparable __________________
6. inconsiderable ________________
Words
indicator__________________
index_____________________
interval___________________
inspect____________________
Fill in the table. Follow the model.
.
(Model):
| process () | action () |
| interaction - | to interact |
| interrelation - | |
| interruption - | |
| conversion - | |
| reception - | |
| direction - |
Task 3. Prepare a presentation of the topic RADIOTELEGRAPH: make up slides about the topic RADIOTELEGRAPH, write down the material of the slides in your workbooks, prepare your report (presentation) for the demonstration it in the lecture-room.
3. Ի: Ի, , () .
5. 5. Unit 1.5. RADIO TRANSMITTER
1.5.
