RF linear Amplifier

RF power amplification is done here and this stage is coupled to the antenna system through antenna impedance matching circuitry. Care is taken at this stage so that no harmonic frequency is generated which will cause interference in adjacent band (splatter) on other bands.

Post-text exercises:

1. Find the English equivalents for the following Russian words and] word combinations:

a) апаратура; точнiсть; удосконалення;канавка; відтворююча система; голка; розділ каналів; за часовою стрілкою; проти часової стрілки; коливання; джерело; записи на пленках та дисках;

b) fidelity; refinement; clockwise; counter clock-wise; hardware configurations; software configurations; groove; source; undulation; playback system; stylus; channel separation.

2. Arrange antonyms in pairs and translate them:

a) large, minimize, left, complex, frequently, variable, benefit, equality, wide, important;

b) constant, simple, seldom, maximize, inequality, small, narrow, right, unimportant, disadvantage

3. Put the words in order:

1. A, amplitude, frequency, current, radio, has, a, of, in, constant, absence, modulation. 2. amplitude, side, modulation, band, two, produced, during, frequencies, are, also. 3. the, degree, of, of, in, an, modulation AM, is, expressed, by %ge, maximum, wave, deviation. 4. at, full, modulation, carrier, in, two, the, requires, thirds, of, the power but, conveys, no, information.

4. Fill in the blanks with the following words:

frequency, wave, modulation, power, frequencies,

1.A radio.......current has a constant amplitude. 2. During amplitude modulation, two side band......are also produced.3. At full modulation the carrier in an AM signal requires two thirds of the......but conveys no information. 4. The degree of.......in an AM wave is expressed by %ge of maximum deviation from the normal amplitude of the carrier RF wave. 5. In it the Morse key for keying out carrier continuous.... can be accommodated.

5. Complete the following sentences, using active vocabulary:

1. Amplitude Modulation (AM) is a process in which the amplitude of a …… 2. At full modulation the carrier in an AM signal requires two ……3. Power may be saved and the band occupied by an AM signal in the frequency ……4. During amplitude modulation, two side band …… 5. The amplitude modulated carrier occupies a space in frequency spectrum, the width of which is equal to …… 6. Side bands are the sum and difference frequencies produced at the transmitter by the ……

6. Which of the following statements are true or false? If the statement is wrong, correct it:

1. Amplitude Modulation (AM) is a process in which the amplitude of a radio frequency current is made to vary and modify by impressing an audio frequency current on it. 2. This results in the carrier having three outlines of the audio signal. 3. The high power RF carrier output from the RF oscillator is amplified in this portion. 4. At full modulation the carrier in an AM signal requires one thirds of the power but conveys no information. 5. Modulator, while the audio information (voice) is impressed upon the carrier frequency.

7. Answer the following questions:

1. What is the difference between quadrasonic and stereo music? 2. What kinds of matrix systems are known to leading hardware manufacturers? 3. What type of record groove is used in matrix quadrasonic systems? 4. Why cannot the crosstalk be eliminated without the use of elaborate circuitry? 5. What are the names of the first pure discrete systems? 6. Are there many advantages in using discrete systems? 7. In what way is it.possible to make an existing stereo amplifier suitable for quadrasonic?

8. Translate the following definitions and memorize the terms:

AM (amplitude modulation). The most common form of radio broadcasting, provides only limited frequency response and is sensitive to interference.

Source. That which supplies signal power to a transducer or system.

9. Translate the following sentences paying attention to the attributive clauses:

1. A tuner is used to select a radio broadcasting signal and convert this signal into a form that may be handled by the amplifier. 2. Each model of a tape recorder that we study has its own merits. 3. Among meters there are two "LED" (light emission diode) indicators — one that glows red when the machine is in the recording mode and one that glows green when the pause button is pressed. 4. There is an easily remembered method for finding the relative directions of the current and the magnetic field it sets up. 5. It is by the agency of radio we receive most of the information the satellites are collecting at the borders of space.

10. Translate the following sentences paving attention to the adverbial clauses:

1. As the tape grew in popularity many changes were introduced into both the tape equipment and the tape itself. 2. His technique effectively extends the useful frequency range of the recorder, while at the same time it improves its signal-to-noise ratio. 3. There have been various forms of the tape cartridge, some of them designed for professional use in broadcast work where their capability for long continuous playing often is required.4.A tape head is a core electromagnet forming almost a circle so that a very narrow gap exists between the two poles of this magnet.5.Since two tracks are needed for stereo the quarter-track configuration permits stereo cross the same length of tape twice.6.On condition that more amplification is needed, amplifiers can be connected in tandem.