Is composed of

Using comprise, we can start our description with the blocks:

A tuner, a detector, and an AF amplifier comprise the radio.

We can describe the links between each building block using these expressions:

The tuner is connected to the detector.

Is linked to

Now look again at Fig.2. We can describe the values of the components like this:

R1 a-two-hundred-and-twenty-kilohm resistor

C2 a hundred-picofarad (puff) capacitor

Task 9. Describe the value of these components:1) R2; 2) C1; 3) R3; 4) C3; 5) P1; 6) L1.

This table provides the terms you need.

Prefix	Symbol	Multiple	Example
giga mega kilo deci milli micro nano pico	G M k d m µ n p	109 106 103 10-1 10-3 10-6 10-9 10-12	GHz gigahertz MΩ megohms kV kilovolts dB decibels mW milliwatts µH microhenries nF nanofarads pF picofarads

Looking now at the basic units of the circuit, we can describe the volume control like this:

The volume control consists of a ten-microfarad electrolytic capacitor connected in series with a five-kilohm potentiometer (pot). The positive terminal of the capacitor is connected to the output of the AF amplifier and the wiper of the pot is connected to the power amp. The third terminal of the pot is connected to the zero voltage supply rail, which is earthed.

Task 10. Fill in the gaps in this description of the tuned circuit shown in Fig.2. Each gap represents one word.

The circuit 1) … of a four hundred and seventy 2) … inductor which is connected in parallel with 3) … capacitor. The 4) … can be varied between five and sixty-five 5) … . The aerial is 6) … to the top end of the tuner. It is also connected to the positive terminal of the 7) … in the detector. The bottom end of the tuner is connected to earth via the zero voltage 8) … rail.

Task 11. With the help of the diagram, fill in the gaps in the text. Each gap represents one word. The description should answer the questions:

1. What is the diagram of? 2. What does it consist of in terms of blocks? 3. How are the blocks connected? 4. What is the function of each block?

Fig. 3

Fig.3 shows the block diagram of an amplitude-modulated (AM) radio transmitter. It 1) … of a radio frequency (RF) oscillator, a 2) …, an audio frequency (AF) amplifier, and an RF power amplifier. The RF 3) … generates an RF 4) … wave which is fed into the modulator.

The microphone converts sounds into audio frequency signals which are amplified by the AF 5) …. The modulator then uses the amplified AF 6) … to modulate the RF carrier wave.

The power of the modulated carrier wave is increased by the RF 7) … amplifier. The strong modulated output signals are fed to the 8) … which enables them to be transmitted over long distances.

TASK 12. Watch the video and decide whether the statements below are true or false. Correct the false ones.

1. According to the video, the simplest radio comprises of more than five blocks. 2. The tutor says that there is only one method to complete the exam task. 3. The basic components include: a tuned circuit, antenna, RF filter, and a demodulator as well as your headphones. 4. Antenna is the first element as it catches the signal. 5. Antenna receives the pulses which are processed by a tuned circuit to pick out the signals to need. 6. The audio signal is separated from its carrier wave with the help of the tuned circuit. 7. The RF filter comes before the headphones.