Fcc Grol Element 3G

Front 1

3-51G1

What class of amplifier is distinguished by the presence of output throughout the entire signal cycle and the input never goes into the cutoff region?

Back 1

Class A

Front 2

3-51G2

What is the distinguishing feature of a Class A amplifier?

Back 2

Output for the entire 360 degrees of the signal cycle

Front 3

3-51G3

Which class of amplifier has the highest linearity and least distortion?

Back 3

Class A

Front 4

3-51G4

Which class of amplifier provides the highest efficiency?

Back 4

Class C

Front 5

3-51G5

What class of amplifier is distinguished by the bias being set well beyond cutoff?

Back 5

Class C

Front 6

3-51G6

Which class of amplifier has an operating angle of more than 180 degrees but less than 360 degrees when driven by a sine wave signal?

Back 6

Class AB

Front 7

3-52G1

The class B amplifier output is present for what portion of the input cycle?

Back 7

180 degrees

Front 8

3-52G2

What input-amplitude parameter is most valuable in evaluating the signal-handling capability of a Class A amplifier?

Back 8

Peak voltage

Front 9

3-52G3

The class C amplifier output is present for what portion of the input cycle?

Back 9

Less than 180 degrees

Front 10

3-52G4

What is the approximate DC input power to a Class AB RF power amplifier stage in an unmodulated carrier transmitter when the PEP output power is 500 watts?

Back 10

1000 watts

Front 11

3-52G5

The class AB amplifier output is present for what portion of the input cycle?

Back 11

More than 180 but less than 360 degrees

Front 12

3-52G6

What class of amplifier is characterized by conduction for 180 degrees of the input wave?

Back 12

Class B

Front 13

3-53G1

What is the modulation index in an FM phone signal having a maximum frequency deviation of 3,000 Hz on either side of the carrier frequency when the modulating frequency is 1,000 Hz?

Back 13

3

Front 14

3-53G2

What is the modulation index of a FM phone transmitter producing a maximum carrier deviation of 6 kHz when modulated with a 2 kHz modulating frequency?

Back 14

3

Front 15

3-53G3

What is the total bandwidth of a FM phone transmission having a 5 kHz deviation and a 3 kHz modulating frequency?

Back 15

16 kHz

Front 16

3-53G4

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Back 16

It does not depend on the RF carrier frequency

Front 17

3-53G5

How can a single-sideband phone signal be generated?

Back 17

By using a balanced modulator followed by a filter

Front 18

3-53G6

What is a balanced modulator?

Back 18

A modulator that produces a double sideband, suppressed carrier signal

Front 19

3-54G1

What is an L-network?

Back 19

A network consisting of an inductor and a capacitor

Front 20

3-54G2

What is a pi-network?

Back 20

A network consisting of one inductor and two capacitors or two inductors and one capacitor

Front 21

3-54G3

What is the resonant frequency in an electrical circuit?

Back 21

The frequency at which capacitive reactance equals inductive reactance

Front 22

3-54G4

Which three network types are commonly used to match an amplifying device to a transmission line?

Back 22

L network, pi network and pi-L network

Front 23

3-54G5

What is a pi-L network?

Back 23

A network consisting of two inductors and two capacitors

Front 24

3-54G6

Which network provides the greatest harmonic suppression?

Back 24

Pi-L network

Front 25

3-55G1

What will occur when a non-linear amplifier is used with a single-sideband phone transmitter?

Back 25

Distortion

Front 26

3-55G2

To produce a single-sideband suppressed carrier transmission it is necessary to ____ the carrier and to ____ the unwanted sideband.

Back 26

Cancel, filter

Front 27

3-55G3

In a single-sideband phone signal, what determines the PEP-to-average power ratio?

Back 27

The speech characteristics

Front 28

3-55G4

What is the approximate ratio of peak envelope power to average power during normal voice modulation peak in a single-sideband phone signal?

Back 28

2.5 to 1

Front 29

3-55G5

What is the output peak envelope power from a transmitter as measured on an oscilloscope showing 200 volts peak-to-peak across a 50-ohm load resistor?

Back 29

100 watts

Front 30

3-55G6

What would be the voltage across a 50-ohm dummy load dissipating 1,200 watts?

Back 30

245 volts

Front 31

3-56G1

How can intermodulation interference between two transmitters in close proximity often be reduced or eliminated?

Back 31

By installing a terminated circulator or ferrite isolator in the feed line to the transmitter and duplexer

Front 32

3-56G2

How can parasitic oscillations be eliminated in a power amplifier?

Back 32

By neutralization

Front 33

3-56G3

What is the name of the condition that occurs when the signals of two transmitters in close proximity mix together in one or both of their final amplifiers, and unwanted signals at the sum and difference frequencies of the original transmissions are generated?

Back 33

Intermodulation interference

Front 34

3-56G4

What term describes a wide-bandwidth communications system in which the RF carrier varies according to some pre-determined sequence?

Back 34

Spread-spectrum communication

Front 35

3-56G5

How can even-order harmonics be reduced or prevented in transmitter amplifier design?

Back 35

By using a push-pull amplifier

Front 36

3-56G6

What is the modulation type that can be a frequency hopping of one carrier or multiple simultaneous carriers?

Back 36

Spread spectrum