How it Works | The Transmitter

Question 1

The modulator combines the signals from the radio an audio amplifiers by superimposing the amplified speech signal on the _F carrier with a ___.

Answer 1

R, transformer

Question 2

Modulation is the process of imposing information onto a ___ wave by changing its characteristics.

Answer 2

carrier

Question 3

An unmodulated signal travels ___ than a modulated one for the same power.

Answer 3

further

Question 4

The Depth of Modulation is the extent to which the ___ wave is modulated by ___ ___

Answer 4

carrier, another frequency

Question 5

When a wave is amplitude modulated, the carrier has its ___/___ varied according to the strength of an audio signal which is applied to it.

Answer 5

amplitude, power

Question 6

AM suffers from ___ and lack of ___, man-made interference, and ___ static

Answer 6

noise, quality, precipitation

Question 7

The lowest frequency where freedom of static is guaranteed is __ _HZ

Answer 7

30 MHz

Question 8

When a carrier is modified by a frequency ___ than itself, a band of frequencies either side of the carrier are created. These bands are called ___bands.

Answer 8

lower, side

Question 9

Sidebands are the equivalent of the ___ and ___ of the frequencies of the carrier and the modulator

Answer 9

sum difference

Question 10

There is an ___ and a ___ sideband

Answer 10

upper lower

Question 11

Single Sideband Transmission aims to suppress the carrier and one sideband, transmitting just the other one. It requires ___ the power with the signal taking up ___ space.

Answer 11

half, less

Question 12

SSB has a ratio of _:1; __x the efficiency

Answer 12

4, 16

Question 13

Frequency modulation changes the ___, rather than the ___

Answer 13

frequency amplitude

Question 14

Frequency modulation does (not) suffer from man-made interference

Answer 14

not

Question 15

The signal:noise ratio for FM is ___ than for AM, meaning that ___ power is required for the same quality.

Answer 15

lower less

Question 16

FM receivers are ___ complex to produce

Answer 16

more

Question 17

For FM, with positive amplitude, the frequency ___ ___ the mean carrier frequency.

Answer 17

increases above

Question 18

The amount of change of frequency, for FM, is called the ___

Answer 18

deviation

Question 19

For FM, _ _Hz is the maximum limit for speech.

Answer 19

5 KHz

Question 20

Pulse Modulation is used for ___

Answer 20

radar

Question 21

Frequency key shifting is used with ___, the carrier frequency is shifted ___ and ___ the mean to represent bits of information.

Answer 21

satellites, above, below

Question 22

Radio waves must oscillate at a frequency high enough to excite the air molecules surrounding the antenna, needing ___ and ___.

Answer 22

inertia, elasticity

Question 23

Resonance, uses the concept of capacitors to release just enough extra ___ into the circuit to maintain the oscillations

Answer 23

current

Question 24

Modulation is the addition of a ___ frequency signal tone onto a ___ frequency carrier wave

Answer 24

low high