An FM receiver whose intermediate frequency is 10.7 MHz, is experiencing image channel interference from a station transmitting on 121.1 MHz. If the local oscillator is tracking above, the receiver is tuned to A. 131.8 MHz B. 110.4 MHz C. 142.5 MHz D. 99.7 MHz

An FM receiver whose intermediate frequency is 10.7 MHz, is experiencing image channel
interference from a station transmitting on 121.1 MHz. If the local oscillator is tracking above,
the receiver is tuned to
A. 131.8 MHz
B. 110.4 MHz
C. 142.5 MHz
D. 99.7 MHz
by

1 Answer

Answer :

D. 99.7 MHz
by

Related questions

A superhet receiver has an IF of 455 kHz and is experiencing image-channel interference on a frequency of 1570 kHz. The receiver is tuned to A. 1115 kHz B. 660 kHz C. 2025 kHz D. 910 kHz

Description : A superhet receiver has an IF of 455 kHz and is experiencing image-channel interference on a frequency of 1570 kHz. The receiver is tuned to A. 1115 kHz B. 660 kHz C. 2025 kHz D. 910 kHz

Last Answer : B. 660 kHz

What is the channel number of an FM station with a carrier frequency of 99.5 MHz? A. 256 B. 258 C. 257 D. 259

Description : What is the channel number of an FM station with a carrier frequency of 99.5 MHz? A. 256 B. 258 C. 257 D. 259

Last Answer : B. 258

A super heterodyne AM receiver is tuned to a station operating at 1200 KHz .Find local oscillator frequency and image frequency.

Description : A super heterodyne AM receiver is tuned to a station operating at 1200 KHz .Find local oscillator frequency and image frequency.

Last Answer : A super heterodyne AM receiver is tuned to a station operating at 1200 KHz Intermediate frequency is 455KHz. IF frequency=f0-fs Local oscillator frequency is f0=IF +fs=455K+1200K=1655kHz The image frequency which gives the same IF is f0+2*IF=2110KHz

After the IF stages have been aligned, the next stage to align in FM receiver is. A. local oscillator B. limiter stage C. RF amplifier D. mixer stage

Description : After the IF stages have been aligned, the next stage to align in FM receiver is. A. local oscillator B. limiter stage C. RF amplifier D. mixer stage

Last Answer : A. local oscillator

What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band? A. 3500 MHz B. 4500 MHz C. 2225 MHz D. 2555 MHz

Description : What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band? A. 3500 MHz B. 4500 MHz C. 2225 MHz D. 2555 MHz

Last Answer : C. 2225 MHz

ECE Board Exam March 1996 What is the purpose of a beat frequency oscillator (BFO)? A. Aid in the reception of weak voice-modulated signals B. Generates a signal, whose frequency is the same as that of the intermediate frequency C. Generates a 1kHz note for Morse code reception D. Generates an output, whose frequency differs from that of the intermediate frequency by 1 kHz

Description : ECE Board Exam March 1996 What is the purpose of a beat frequency oscillator (BFO)? A. Aid in the reception of weak voice-modulated signals B. Generates a signal, whose frequency is the ... reception D. Generates an output, whose frequency differs from that of the intermediate frequency by 1 kHz

Last Answer : C. Generates a 1kHz note for Morse code reception

A superheterodyne radio receiver with an IF of 455KHZ is turned to 1000KHZ. Find: (i) Image frequency (ii) Local oscillator frequency

Description : A superheterodyne radio receiver with an IF of 455KHZ is turned to 1000KHZ. Find: (i) Image frequency (ii) Local oscillator frequency

Last Answer : Given Intermediate Frequency fi=455KHz Signal frequency =fs=1000KHz Local oscillator frequency fo=fs+fi  Fo=1000KHz+455KHz  =1455KHz Image frequency is the input frequency which produces the same intermediate frequency fsi=fs+2fi  =1000KHz+2*455KHz  =1910KHz 

When the elevation angle of a geostationary satellite is 23˚ and the transmitting frequency is 3840 MHz, what is the free space loss in dB? A. 196 dB B. 200 dB C. 150 dB D. 100 dB

Description : When the elevation angle of a geostationary satellite is 23˚ and the transmitting frequency is 3840 MHz, what is the free space loss in dB? A. 196 dB B. 200 dB C. 150 dB D. 100 dB

Last Answer : A. 196 dB

What establishes the receiver bandwidth? A. RF amplifier B. Mixer C. Local oscillator D. IF amplifier

Description : What establishes the receiver bandwidth? A. RF amplifier B. Mixer C. Local oscillator D. IF amplifier

Last Answer : D. IF amplifier

What consists the front-end circuit of a VHF TV superheterodyne receiver? A. Mixer, RF amplifier and AFC? B. RF amplifier, Band pass filter and mixer C. Local oscillator, mixer and RF amplifier D. Local oscillator, AGC and antenna

Description : What consists the front-end circuit of a VHF TV superheterodyne receiver? A. Mixer, RF amplifier and AFC? B. RF amplifier, Band pass filter and mixer C. Local oscillator, mixer and RF amplifier D. Local oscillator, AGC and antenna

Last Answer : C. Local oscillator, mixer and RF amplifier

Refers to one of the front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled to the mixer. A. Antenna feed B. AGC C. RF amplifier D. Local oscillator

Description : Refers to one of the front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled to the mixer. A. Antenna feed B. AGC C. RF amplifier D. Local oscillator

Last Answer : D. Local oscillator

What is the refractive index of an ionospheric layer with 100x105 free electrons per m3 ? Assume frequency to be at 20 MHz. A. 0.99 B. 0.15 C. 0.78 D. 0.85

Description : What is the refractive index of an ionospheric layer with 100x105 free electrons per m3 ? Assume frequency to be at 20 MHz. A. 0.99 B. 0.15 C. 0.78 D. 0.85

Last Answer : A. 0.99

When measuring a transmitter’s frequency against a suitable standard, the frequency to be measured is taken from the A. oscillator stage B. intermediate amplifier C. buffer stage D. final RF stage

Description : When measuring a transmitter’s frequency against a suitable standard, the frequency to be measured is taken from the A. oscillator stage B. intermediate amplifier C. buffer stage D. final RF stage

Last Answer : D. final RF stage

What is the most commonly used intermediate frequency of radar receivers? A. 40 MHz B. 60 MHz C. 70 MHz D. 30 MHz

Description : What is the most commonly used intermediate frequency of radar receivers? A. 40 MHz B. 60 MHz C. 70 MHz D. 30 MHz

Last Answer : D. 30 MHz

nif stands for A. Non-intrinsic figure B. Noise improvement factor C. Narrow intermediate frequency D. Noise interference figure

Description : nif stands for A. Non-intrinsic figure B. Noise improvement factor C. Narrow intermediate frequency D. Noise interference figure

Last Answer : B. Noise improvement factor

Nif stands for A. Narrow intermediate frequency B. Noise interference figure C. Noise improvement factor D. Non-intrinsic fugure

Description : Nif stands for A. Narrow intermediate frequency B. Noise interference figure C. Noise improvement factor D. Non-intrinsic fugure

Last Answer : C. Noise improvement factor

Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high

Description : Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high

Last Answer : D. high

In an Ethernet local area network, which one of the following statements is TRUE ? a. A station stops to sense the channel once it starts transmitting a frame. b. The purpose of the jamming signal is to pad the frames that are smaller than the minimum frame size. c. A station continues to transmit the packet even after the collision is detected. d. The exponential backoff mechanism reduces the probability of collision on retransmissions

Description : In an Ethernet local area network, which one of the following statements is TRUE ? a. A station stops to sense the channel once it starts transmitting a frame. b. The purpose ... collision is detected. d. The exponential backoff mechanism reduces the probability of collision on retransmissions

Last Answer : The exponential backoff mechanism reduces the probability of collision on retransmissions

How far is the visual carrier from the lowest frequency in the spectrum of a monochrome TV broadcast channel following the NTSC standard? A. 1.5 MHz B. 1.25 MHz C. 4.5 MHz D. 0.25 MHz

Description : How far is the visual carrier from the lowest frequency in the spectrum of a monochrome TV broadcast channel following the NTSC standard? A. 1.5 MHz B. 1.25 MHz C. 4.5 MHz D. 0.25 MHz

Last Answer : B. 1.25 MHz

Which of the following systems uses frequency band 870-885 MHz as a transmit band of its base station? A. TACS B. NTT C. NMT D. AMPS

Description : Which of the following systems uses frequency band 870-885 MHz as a transmit band of its base station? A. TACS B. NTT C. NMT D. AMPS

Last Answer : B. NTT

A satellite receives an uplink frequency of _______ MHz from a ground station of 3700 MHz. A. 8150 MHz B. 1475 MHz C. 2225 MHz D. 5925 MHz

Description : A satellite receives an uplink frequency of _______ MHz from a ground station of 3700 MHz. A. 8150 MHz B. 1475 MHz C. 2225 MHz D. 5925 MHz

Last Answer : D. 5925 MHz

Assume a frequency range of 405.0125 MHz to 405.0875 MHz and 25 kHz channeling plan, determine the center frequency of the second channel from the lower limit. A. 405.030 MHz B. 405.025 MHz C. 405.050 MHz D. 405.075 MHz

Description : Assume a frequency range of 405.0125 MHz to 405.0875 MHz and 25 kHz channeling plan, determine the center frequency of the second channel from the lower limit. A. 405.030 MHz B. 405.025 MHz C. 405.050 MHz D. 405.075 MHz

Last Answer : C. 405.050 MHz

Assume a frequency range of 401.000 MHz to 401.050 MHz, if you apply 25 kHz channeling plan, determine the center frequency of the first channel from the lower limit. A. 401.010 MHz B. 401.0125 MHz C. 401.025 MHz D. 401.00625 MHz

Description : Assume a frequency range of 401.000 MHz to 401.050 MHz, if you apply 25 kHz channeling plan, determine the center frequency of the first channel from the lower limit. A. 401.010 MHz B. 401.0125 MHz C. 401.025 MHz D. 401.00625 MHz

Last Answer : B. 401.0125 MHz

What is the local oscillator frequency range commercial AM broadcast if it is equal to 455 KHz. A. 540 to 1600 KHz B. 0 to 1600 KHz C. 995 to 2055 KHz D. 0 to 455 KHz

Description : What is the local oscillator frequency range commercial AM broadcast if it is equal to 455 KHz. A. 540 to 1600 KHz B. 0 to 1600 KHz C. 995 to 2055 KHz D. 0 to 455 KHz

Last Answer : C. 995 to 2055 KHz

Why should local oscillator frequency be greater than signal frequency in AM receiver? Also explain why IF has constant value?

Description : Why should local oscillator frequency be greater than signal frequency in AM receiver? Also explain why IF has constant value?

Last Answer : Reason for LO frequency to be greater than signal frequency The local oscillator frequency (f0) is made greater than signal frequency (Fs) in radio receiver: Local oscillator frequency range is 995 ... frequency of desired signal because the IF is constant and same for all the incoming RF signal.

A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna. A. 36 meters high B. 64 meters high C. 100 meters high D. 182.25 meters high

Description : A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna. A. 36 meters high B. 64 meters high C. 100 meters high D. 182.25 meters high

Last Answer : A. 36 meters high

ECE Board Exam March 1996 It is a spacecraft placed in orbit around the earth carrying onboard microwave receiver and transmitting equipments. A. Fiber optic equipment B. Communications satellite C. Wireless radio system D. Coaxial cable syste

Description : ECE Board Exam March 1996 It is a spacecraft placed in orbit around the earth carrying onboard microwave receiver and transmitting equipments. A. Fiber optic equipment B. Communications satellite C. Wireless radio system D. Coaxial cable syste

Last Answer : B. Communications satellite

What is the spectrum of stereophonic FM signal? A. 19 to 38 kHz B. 30 to 53 kHz C. 59.5 to 74.5 kHz D. 88 to 108 MHz

Description : What is the spectrum of stereophonic FM signal? A. 19 to 38 kHz B. 30 to 53 kHz C. 59.5 to 74.5 kHz D. 88 to 108 MHz

Last Answer : B. 30 to 53 kHz

One of the FM signal generator control which varies the phase of the modulating voltage applied to the oscillator of the sweep generator A. Band control B. Phase control C. Marker amplitude control D. Sweep output control

Description : One of the FM signal generator control which varies the phase of the modulating voltage applied to the oscillator of the sweep generator A. Band control B. Phase control C. Marker amplitude control D. Sweep output control

Last Answer : B. Phase control

The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz

Description : The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz

Last Answer : D. 300 – 3000 MHz

What is the uplink receiver frequency if the downlink transmitter is on channel 4 (3.84 Ghz)? A. 6.065 GHz B. 6.84 GHz C. 6.65 GHz D. 6.05 GHz

Description : What is the uplink receiver frequency if the downlink transmitter is on channel 4 (3.84 Ghz)? A. 6.065 GHz B. 6.84 GHz C. 6.65 GHz D. 6.05 GHz

Last Answer : A. 6.065 GHz

Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150 MHz) marine-band receiver? A. In the ionosphere B. In the receiver rear end C. In the receiver front end D. In the atmosphere

Description : Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150 MHz) marine-band receiver? A. In the ionosphere B. In the receiver rear end C. In the receiver front end D. In the atmosphere

Last Answer : C. In the receiver front end

A box contains 15bolts of which 5 are defective. If 5 bolts are selected at random from the box, what is the probability that at least one of them is defective? a) 91/143 b) 101/143 c) 111/143 d) 121/143 e) 131/143

Description : A box contains 15bolts of which 5 are defective. If 5 bolts are selected at random from the box, what is the probability that at least one of them is defective? a) 91/143 b) 101/143 c) 111/143 d) 121/143 e) 131/143

Last Answer : Probability that at least one is defective = 1 – probability that none is defective Probability that none is defective = 10C5 / 15C5 = 12/143 Required Probability = 1-12/143 = 131/143 Answer: e)

Designed to receive a signal from a transmitting station on the ground and retransmit it to a receiving station located elsewhere A. Communication satellite B. Repeater C. Relay station D. Transponder

Description : Designed to receive a signal from a transmitting station on the ground and retransmit it to a receiving station located elsewhere A. Communication satellite B. Repeater C. Relay station D. Transponder

Last Answer : A. Communication satellite

What is a selective fading effect? A. A fading effect caused by small changes in beam heading at the receiving station. B. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station. C. A fading effect caused by large changes in the height of the ionosphere, as experienced at the receiving station D. A fading effect caused by time differences between the receiving and transmitting stations.

Description : What is a selective fading effect? A. A fading effect caused by small changes in beam heading at the receiving station. B. A fading effect caused by phase differences between radio wave ... station D. A fading effect caused by time differences between the receiving and transmitting stations.

Last Answer : B. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station.

What is the major cause of selective fading? A. Small changes in the beam heading at the receiving station. B. Large changes in the height of the ionosphere, as experience at the receiving station. C. Time differences between the receiving and transmitting stations. D. Phase differences between radio wave components of the same transmission, as experienced at the receiving station.

Description : What is the major cause of selective fading? A. Small changes in the beam heading at the receiving station. B. Large changes in the height of the ionosphere, as experience at the ... Phase differences between radio wave components of the same transmission, as experienced at the receiving station.

Last Answer : D. Phase differences between radio wave components of the same transmission, as experienced at the receiving station.

Refers to an effect of selective fading. A. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station. B. A fading effect caused by small changes in beam heading at the receiving station. C. A fading effect caused by the time differences between the receiving and transmitting stations. D. A fading effect caused by large changes in the height of the ionosphere, as experienced at the receiving station.

Description : Refers to an effect of selective fading. A. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station. B. A fading ... caused by large changes in the height of the ionosphere, as experienced at the receiving station.

Last Answer : A. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station.

Production of radiation by a radio transmitting station A. Monitoring B. Emission C. Radiation D. Transmission

Description : Production of radiation by a radio transmitting station A. Monitoring B. Emission C. Radiation D. Transmission

Last Answer : B. Emission

In an FM receiver, which circuit removes amplitude variations? A. Exciter B. Mixer C. Discriminator D. Limiter

Description : In an FM receiver, which circuit removes amplitude variations? A. Exciter B. Mixer C. Discriminator D. Limiter

Last Answer : D. Limiter

In the event of an act of unlawful interference, which of the following is the correct procedure to be taken by the pilot in command? a. Squawk 7700 if the situation requires and continue the flight as per the ATC clearance received if possible b. Squawk 7500 and broadcast a warning to ATC other traffic on 121.500MHz or the frequency in use whilst maintaining the flight as cleared c. Squawk 7500 (or 7700 if required) and broadcast a warning if the situation forces deviation from the cleared flight plan d. If forced to deviate from the flight plan, climb or descend to altitudes that differ from the normal cruising altitudes by 1000ft

Description : In the event of an act of unlawful interference, which of the following is the correct procedure to be taken by the pilot in command? a. Squawk 7700 if the situation requires and continue ... the flight plan, climb or descend to altitudes that differ from the normal cruising altitudes by 1000ft

Last Answer : c. Squawk 7500 (or 7700 if required) and broadcast a warning if the situation forces deviation from the cleared flight plan

A radio communications link is to be established via the ionosphere. The maximum virtual height of the layer is 100 km at the midpoint of the path and the critical frequency is 2 MHz. The distance between stations is 600 km. determine the optimum working frequency? A. 6.32 MHz B. 2.1 MHz C. 5.4 MHz D. 1.8 MHz

Description : A radio communications link is to be established via the ionosphere. The maximum virtual height of the layer is 100 km at the midpoint of the path and the critical frequency is 2 MHz. The distance between stations is 600 ... optimum working frequency? A. 6.32 MHz B. 2.1 MHz C. 5.4 MHz D. 1.8 MHz

Last Answer : C. 5.4 MHz

Which of the following is designated as the international distress, safety and calling frequency for radio telephony for stations of the maritime mobile service when using frequencies in the authorized bands between 156 and 174 MHz? A. 165.8 MHz B. 156.8 MHz C. 158.6 MHz D. 168.5 MHz

Description : Which of the following is designated as the international distress, safety and calling frequency for radio telephony for stations of the maritime mobile service when using frequencies in the authorized bands between 156 and 174 MHz? A. 165.8 MHz B. 156.8 MHz C. 158.6 MHz D. 168.5 MHz

Last Answer : B. 156.8 MHz

What would happen if you plugged an FM transmitter into a radio's headphone jack and set the radio to the transmitter's transmitting frequency?

Description : What would happen if you plugged an FM transmitter into a radio's headphone jack and set the radio to the transmitter's transmitting frequency?

Last Answer : You would get a positive feedback loop, probably resulting in an audible tone. The amplitude would be limited by the transmitter’s modulation limiter, so all you’d have is a very ordinary oscillator.

What ionospheric layer has a daytime approximate critical frequency of 8 MHz? A. F2 layer B. F1 layer C. E layer D. D layer

Description : What ionospheric layer has a daytime approximate critical frequency of 8 MHz? A. F2 layer B. F1 layer C. E layer D. D layer

Last Answer : A. F2 layer

What ionospheric layer has a daytime approximate critical frequency of 8 MHz? A. F2 layer B. F1 layer C. E layer D. D layer

Description : What ionospheric layer has a daytime approximate critical frequency of 8 MHz? A. F2 layer B. F1 layer C. E layer D. D layer

Last Answer : A. F2 layer

Which of the following fall under the high frequency band of the radio spectrum? A. 8.2345 MHz B. 150.50 MHz C. 2.4555 MHz D. 35.535 MHz

Description : Which of the following fall under the high frequency band of the radio spectrum? A. 8.2345 MHz B. 150.50 MHz C. 2.4555 MHz D. 35.535 MHz

Last Answer : A. 8.2345 MHz

Six (6) MHz crystal oscillator has a stability of 1 part in 106. The largest frequency error expected of this crystals A) 0.06 Hz B) 0.6 Hz C) 6 Hz D) 60 Hz.

Description : Six (6) MHz crystal oscillator has a stability of 1 part in 106. The largest frequency error expected of this crystals A) 0.06 Hz B) 0.6 Hz C) 6 Hz D) 60 Hz.

Last Answer : C) 6 Hz

What is the phase coefficient in radians per unit length of a transmission line at the frequency of 10 MHz if the velocity of propagation is 2.5x108 m/s? A. 0.25 B. 2.5 C. 0.35 D. 3.5

Description : What is the phase coefficient in radians per unit length of a transmission line at the frequency of 10 MHz if the velocity of propagation is 2.5x108 m/s? A. 0.25 B. 2.5 C. 0.35 D. 3.5

Last Answer : A. 0.25

Determine the lower half-power frequency of a class-C amplifier having upper half-power frequency of 10.025 MHz, a resonant frequency 5 MHz and a circuit Q of 10. A. 1.0025 MHz B. 10.525 MHz C. 0.5 MHz D. 10 MHz

Description : Determine the lower half-power frequency of a class-C amplifier having upper half-power frequency of 10.025 MHz, a resonant frequency 5 MHz and a circuit Q of 10. A. 1.0025 MHz B. 10.525 MHz C. 0.5 MHz D. 10 MHz

Last Answer : A. 1.0025 MHz

Not a reason for the use of an antenna coupler. A. To make the antenna look resistive B. To provide the output amplifier with the correct load impedance C. To discriminate against harmonics D. To prevent re-radiation of the local oscillator

Description : Not a reason for the use of an antenna coupler. A. To make the antenna look resistive B. To provide the output amplifier with the correct load impedance C. To discriminate against harmonics D. To prevent re-radiation of the local oscillator

Last Answer : D. To prevent re-radiation of the local oscillator