RHM 1 ESAT PART 3

Once the AM signal is amplified, it is fed to antenna with characteristic impedance that is ideally

With AM which of the following conveys no information?

In a frequency modulation receiver, the output of the high frequency oscillator is fed to the:

In a frequency modulation receiver, the output of the _______ is connected to the mixer.

In an FM stereo multiplex transmission, the

Interference generated by lightning, motors, automotive ignition systems, and any power line switching that produces transient signals is referred to as

One of the primary benefits of FM over AM is its

A technique that helps offset high-frequency noise interference by passing a modulating signal through a simple network that amplifies high-frequency components more than the low-frequency components is called

For a 10-MHz crystal with a temperature coefficient k=+10 Hz/MHz/°C, determine the frequency of operation if the temperature increase is 10°C and temperature decrease is 5°C.

In a frequency modulation receiver, the _______ is in between the mixer and the intermediate frequency amplifier.

In a single sideband and CW receiver, the antenna is connected to the _______.

In high-level AM, the modulator varies the voltage and power in the

The modulation index of an AM wave is changed from 0 to 1. The transmitted power is

If a class C amplifier has an input of 1000 W, the modulator must be able to deliver

In a single sideband and CW receiver, the output of the _______ is connected to the mixer.

In a single sideband and CW receiver, the _______ is in between the filter and product detector.

Which of the following is not a basic element of a phase-locked loop circuit?

When dealing with random noise calculations it must be remembered that

A receiver has a sensitivity of 0.5μV and a blocking dynamic range of 70 dB. What is the strongest signal that can be present along with a 0.5 μV signal without blocking taking place?

Circuits that make use of techniques for varying the frequency of the carrier oscillator in accordance with the modulating signal are referred to as

In a single sideband transmitter, the output of the _______ is connected to the balanced modulator.

In a single sideband transmitter, the output of the _______ is connected to the balanced modulator.

Which list of emission types is in order from the narrowest bandwidth to the widest bandwidth?

Moving towards the clockwise direction in the Smith chart implies moving

An FM Modulator has k_f= 30 kHz/V and operates at a carrier frequency of 175 MHz. Find the output frequency for an instantaneous value of the modulating signal equal to 150 mV.

The figure in a receiver's specifications which indicates its sensitivity is the:

The output stage of a television transmitter is most likely to be a

Which of the following is not a benefit of using a frequency synthesizer over a simple VFO design?

What can you do if you are told your FM hand-held or mobile transceiver is overdeviating?

What kind of emission would your FM transmitter produce if its microphone failed to work?

What is used to reduce image interference caused by crowding of the RF spectrum?

A phase modulator has kp=2rad/V. What RMS voltage of a sine wave would cause a peak phase deviation of 60°?

If two receivers of different sensitivity are compared, the less sensitive receiver will produce:

Which of the following modes of transmission is usually detected with a product detector?

A phase-locked loop has a VCO with a free-running frequency of 12 MHz. As the frequency of the reference input is gradually raised from zero, the loop locks at 10 MHz and comes out of lock again at 16 MHz. Find the capture range and lock range.

When the modulation index of an AM wave is doubled, the antenna current is also doubled. The AM system being used is

A receiver designed for SSB reception must have a BFO (beat frequency oscillator) because:

If the carrier of a 100 percent modulated AM wave is suppressed, the percentage power saving will be

The rate of change of amplitude with frequency in a filter is the

Which of the following, also known as a Thomson filter provides the desired frequency response, but has a constant time delay in the passband?

What circuit has a variable-frequency oscillator connected to a driver and a power amplifier?

What type of modulation system changes the amplitude of an RF wave for the purpose of conveying information?

The ratio of the frequency deviation to the modulating frequency is known as the

What type of filter should be connected to a TV receiver as the first step in trying to prevent RF overload from an amateur HF station transmission?

The higher the modulation index in FM

What is the term for the average power supplied to an antenna transmission line during one RF cycle, at the crest of the modulation envelope?

In a typical single-sideband phone transmitter, what circuit processes signals from the balanced modulator and sends signals to the mixer?

A low ratio of the ac to the dc load impedance of a diode detector results in

What may happen if an FM transmitter is operated with the microphone gain or deviation control set too high?

When a receiver has good blocking performance, this means that

With regard to a transmission line, which of the following statements is correct?

Why is FM voice best for local VHF/UHF radio communications?

One way to obtain selectivity while eliminating the image problem is to use

One of the following cannot be used to demodulate SSB:

A special version of the superheterodyne that converts the incoming signal directly to baseband is known as the

What is the usual bandwidth of a frequency-modulated amateur signal?

What should you do for safety if you put up a UHF transmitting antenna?

In a broadcast superheterodyne receiver, the

What is one way to tell if radio frequency interference to a receiver is caused by front-end overload?

Determine the %m for the following conditions if the unmodulated carrier is 80 V peak-to-peak, modulated carrier max is 100V and modulated carrier min is 60V.

If a neighbour reports television interference whenever you transmit, no matter what band you use, what is probably the cause of the interference?

The local oscillator of a broadcast receiver is tuned to a frequency higher than the incoming frequency

Oscillators whose frequencies are controlled by an external input voltage are generally referred to as

When the signal from a transmitter overloads the audio stages of a broadcast receiver, the transmitted signal:

A receiver has poor IF selectivity. It will therefore also have poor

What devices would you install to reduce or eliminate audio-frequency interference to home entertainment systems?

Three-point tracking is achieved with

What should be done if a properly operating amateur station is the cause of interference to a nearby telephone?

Indicate the false statement. Noting that no carrier is transmitted with J3E, we see that

How can you prevent key-clicks?

If the intermediate frequency is very high (indicate false statement)

Given a Three-stage system comprised of two amplifiers and one filter. The input power Pin=0.1 mW.The absolute power gains are A(P1)=100, A(P2)=40,and A(P3) =0.25. Determine the dB gain of each of the three stages and the total dB gain.

If someone tells you that signals from your hand-held transceiver are interfering with other signals on a frequency near yours, what may be the cause?

If your transmitter sends signals outside the band where it is transmitting, what is this called?

What problem may occur if your transmitter is operated without the cover and other shielding in place?

An AM broadcast transmitter has a carrier power output of 50 kW. What total power would be produced with 80% modulation?

The antenna current of an AM transmitter is 12 A when unmodulated but increases to 13 A when modulated. Calculate% m.

In Morse code transmission, local RF interference (key-clicks) is produced by:

Indicate which of the following statements about the advantages of the phase discriminator over the slope detector is false:

To prevent overloading of the IF amplifier in a receiver, one should use

A superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is

Two resistors, 5 kΩ and 20 KΩ are at 27°C. Calculate the thermal noise power for a 10-kHz bandwidth.

If a neighbor reports television interference on one or two channels only when you transmit on 15 meters, what is probably the cause of the interference?

A portable radio transmitter has to operate at temperatures from -5°C to 35 °C. If its signal is derived from a crystal oscillator with a temperature coefficient of +1 ppm/degree/°C and it transmits at exactly 146 MHz at 20 °C, find the transmitting frequency at the two extremes of the operating temperature range

Tinier microstrip and striplines made by using monolithic, thin-film, and hybrid techniques when combined with diodes, transistors, and other components form what are called

In a radio receiver with simple AGC

A sophisticated graph that permits visual solutions to transmission line calculations is the

What is meant by harmonic radiation?

Show which of the following statements about the amplitude limiter is untrue:

Why is harmonic radiation from an amateur station not wanted?

What type of interference may come from a multi-band antenna connected to a poorly tuned transmitter?

The signal at the input of an amplifier has an S/N of 42 dB. If the amplifier has a noise figure of 6 dB, what is the S/N at the output (in decibels)?

Why do modern HF transmitters have a built-in low pass filter in their RF output circuits?

The characteristic impedance of a transmission line is determined by the:

The equation that expresses the phase angle in terms of the sine wave modulating signal can be solved by using a complex mathematical process known as

The image frequency of a superheterodyne receiver

The primary purpose of narrowband FM is

The characteristic impedance of a 20 metre piece of transmission line is 52 ohms. If 10 metres were cut off, the impedance would be: