Uses of radio

Today, radio takes many forms, including wireless networks, mobile communications of all types, as well as radio broadcasting.

Before the advent of television, commercial radio broadcasts included not only news and music, but dramas, comedies, variety shows, and many other forms of entertainment. Radio was unique among dramatic presentation that it used only sound.

Aviation voice radios use VHF AM. Aircraft fly high enough that their transmitters can be received hundreds of miles away, even though they are using VHF.

Marine voice radios can use AM in the shortwave High Frequency—3 MHz to 30 MHz. Government, police, fire and commercial voice services use narrowband FM on special frequencies. Civil and military HF (high frequency) voice services use shortwave radio to contact ships at sea, aircraft and isolated settlements.

Mobile phones transmit to a local cell site that ultimately connects to the public switched telephone network through an optic fiber or microwave radio and other network elements. When the mobile phone nears the edge of the cell site's radio coverage area, the central computer switches the phone to a new cell. Cell phones originally used FM, but now most use various digital modulation schemes. Satellite phones come in two types: INMARSAT and Iridium. Both types provide world-wide coverage. INMARSAT uses geosynchronous satellites, with aimed high-gain antennas on the vehicles. Iridium uses 66 Low Earth Orbit satellites as the cells.

Television sends the picture as AM and the sound as FM, with the sound carrier at fixed frequency (4.5 MHz in the NTSC system) away from the video carrier. Analog television also uses a vestigial sideband on the video carrier to reduce the bandwidth required.

Radio-frequency energy can be used for heating of objects. Microwave ovens use intense radio waves to heat food. Diathermy equipment is used in surgery for sealing of blood vessels. Induction furnaces are used for melting metal for casting.

Tractor beams can use radio waves which exert small electrostatic and magnetic forces. These are enough to perform station-keeping in microgravity environments.

Radiation pressure from intense radio waves has been proposed as a propulsion method for an interstellar probe called Starwisp. Since the waves are long, the probe could be a very light metal mesh, and thus achieve higher accelerations than if it were a solar sail.

Radio remote control use radio waves to transmit control data to a remote object as in some early forms of guided missile, some early TV remotes and a range of model boats, cars and airplanes. Large industrial remote-controlled equipment such as cranes and switching locomotives now usually use digital radio techniques to ensure safety and reliability.

Energy autarkic radio technology consists of a small radio transmitter powered by environmental energy (push of a button, temperature differences, light, vibrations, etc.). This technology includes, for example, solar power stations in orbit beaming energy down to terrestrial users.

EXERCISE 10

Find in the text suitable nouns for adjectives given below and translate word combinations

Wireless, mobile, unique, optic, shortwave, geosynchronous, high-gain, vestigial, intense, electrostatic and magnetic, interstellar, solar, remote, autarkic, environmental, terrestrial.

EXERCISE 11

Make up word combinations which have the construction ‘noun + noun’. Find in the text another element to each noun below and translate the expression. There could be more then one noun added.

Radio broadcasting, …services, … network, … area, …sight, …carrier, …energy, …equipment, …vessels, … furnaces, …beams, …environment, …pressure, … method, …sail, …differences, …boat, …mesh, …station

EXERCISE12

Answer the questions. Add information from the text to your answer

1. What forms does radio take nowadays? (wireless networks, mobile communications, radio broadcasting)

2. What kind of amplitude modulation do aviation voice radios use? ( VHF AM)

3. What services use narrowband FM on special frequencies? (Government, police, fire and commercial voice services)

4. What types do satellite phones come in? (INMARSAT and Iridium)

5. What is the radio frequency energy used for? (for heating objects)

6. What was proposed as propulsion method for an interstellar probe? (Radiation pressure from intense radio waves)

7. What does energy autarkic radio technology consist of? (a small radio transmitter).

EXERCISE 13

Make a sentence out of the two parts from the table

Radio was unique amongdramatic presentation	in the shortwave High Frequency
Aircraft fly high enough that their transmitters	that it used only sound.
Marine voice radios can use AM	now usually use digital radio techniques to ensure safety and reliability.
Electrostatic and magnetic forces of radio waves	can be received hundreds of miles away
Radiation pressure from intense radio waves has been proposed	solar power stations in orbit beaming energy down to terrestrial users.
Large industrial remote-controlled equipment such as cranes and switching locomotives	are enough to perform station-keeping in microgravity environments.
Energy autarkic radio technology includes	as a propulsion method for an interstellar probe called Starwisp.

EXERCISE 14

What significance do the following names have in relation to the text‘Uses of radio’? Look at the example:

Radio broadcast – Before the advent of television, commercial radio broadcasts included news and music, dramas, comedies, variety shows, and many other forms of entertainment.

1. VHF AM

2. 3 MHz to 30 MHz.

3. narrowband FM

4. INMARSAT and Iridium

5. geosynchronous satellites

6. 66 Low Earth Orbit satellites

7. 4.5 MHz in the NTSC system

8. a vestigial sideband

9. heating of objects

10. microgravity environments

11. radiation pressure

12. radio remote control

13. energy autarkic radio technology

14. Starwisp