[EST] Frenzel Q&A - Chapter 3: Amplitude Modulation Circuits

Analog multiplication

Amplitude modulation is the same as __________.

Tuned circuit

In a diode modulator, the negative half of the AM wave is supplied by a(n) __________.

Having the carrier vary a resistance

Amplitude modulation can be produced by __________.

Variable resistance

Amplitude modulators that vary the carrier amplitude with the modulating signal by passing it through an attenuator work on the principle of __________.

Variable resistor

In Fig. 3-4, D1 is a __________.

Varactor

The component used to produce AM at very high frequencies is a __________.

Low-level modulation

Amplitude modulation generated at a very low voltage or power amplitude is known as __________.

96 V

A collector modulator has a supply voltage of 48 V. The peak-to-peak amplitude of the modulating signal for 100 percent modulation is __________.

12 W

A collector modulated transmitter has a supply voltage of 24 V and a collector current of 0.5 A. The modulator power for 100 percent modulation is __________.

Demodulator

The circuit that recovers the original modulating information from an AM signal is known as a __________.

Envelope detector

The most commonly used amplitude demodulator is the __________.

Balanced modulator

A circuit that generates the upper and lower sidebands but no carrier is called a(a) __________.

500 kHz and 2.5 MHz

The inputs to a balanced modulator are 1 MHz and a carrier of 1.5 MHz. The outputs are __________.

Lattice modulator

A widely used balanced modulator is called the __________.

Switches

In a diode ring modulator, the diodes act like __________.

DSB

The output of a balanced modulator is __________.

Differential amplifier

The principal circuit in the popular 1496/1596 IC balanced modulator is a __________.

RC networks and op-amps

The most commonly used filter in SSB generator uses __________.

Series resonant circuit and parallel resonant circuit

The equivalent circuit of a quartz crystal is a __________.

2 kHz

A crystal lattice filter has crystal frequencies of 27.5 and 27.502 MHz. The bandwidth is approximately __________.

2997 and 3003 kHz

An SSB generator has a sideband filter centered at 3.0 MHz. The modulating signal is 3 kHz. To produce both upper and lower sidebands, the following carrier frequencies must be produced: __________.

Phase shift

In the phasing method of SSB generation, one sideband is canceled out due to __________.

Converter

A balanced modulator used to demodulate a SSB signal is called a(n) __________.

Mixer

Frequency translation is done with a circuit called a __________.

f_o - f_m

The inputs to a mixer are fo and fm. In down conversion, which of the following mixer output signals is selected?

Liner summing

Mixing for frequency conversion is the same as __________.

Balanced modulator, FET and Diode modulator

Which of the following can be used as a mixer __________.

Crystal filter

The desired output from a mixer is usually selected with a __________.

Local oscillator

The two main inputs to a mixer are the signal to be translated and a signal from a(n) __________.

157.5 MHz

An NE602 mixer IC has a difference output of 10.7 MHz. The input is 146.8 MHz. The local oscillator frequency is __________.