Broadcasting (Chapter 12 Past Board: Excel)

ECE Board Exam April 2001
A type of radio station in broadcast service that converts channel frequency of one station to another channel for purposes of rebroadcasting. 
Translator

ECE Board Exam November 2000
How would you best describe an example of a pilot tonne system in commercial frequency modulation broadcast radio stations?
Stereo multiplex

ECE Board Exam April 2000
lt is an electronic instrument which can be referred to as a miniature radio transmitter and can be made to generate signals at any desired frequency normally it is used for test purposes.
Signal generator

ECE Board Exam November 1999
What is the primary purpose of an RF amplifier in a receiver?
To improve the receiver’s noise Figure.

ECE Board Exam April 1999
What is the advantage on the TV receiver audio, by employing FM audio and AM video on the television transmitter?
FM receiver is basically insensitive to amplitude modulation.

ECE Board Exam 1998
When adjusting an RF filter on a transmitter using a dummy load, how much watts dissipation should it stand to test a 150 watts transmitter?
150 watts

ECE Board Exam April 1998
The final power amplifier in an FM transmitter usually operates class ________
C

ECE Board Exam November 1997
A form of telecommunication for the transmission of transient images of fixed or moving objects.
Television

ECE Board Exam April 1997
What particular circuit that rids FM of noise?
Limiter

ECE Board Exam November 1996
What is the maximum color TV bandwidth.
1.3 MHz

ECE Board Exam March 1996
What is the purpose of a beat frequency oscillator (BFO)?
Generates a 1 kHz note to Morse reception.

ECE Board Exam April 2001
Which of the following refers to a result of an over modulated amplitude modulated radio broadcasting transmission?
Interference to adjacent channels

ECE Board Exam November 2000
What is the main reason why television picture signal uses amplitude modulation, while voice is frequency modulation'?
To minimize interference between signals at received end

ECE Board Exam April 2000
A radar-set receiver has normally a ________ mixer stage
silicon crystal

ECE Board Exam November 1999
Which of the following is a possible cause for an abrupt frequency variation in a self-excited transmitter oscilator circuits resulting a poor frequency stability to hold a constant frequency oscillation?
Power supply voltage changes

ECE Board Exam April 1999
What is the frequency separation between the visual carrier and the upper limits of its total channel bandwidth of a monochrome TV broadcast?
4.75 MHz

ECE Board Exam November 1998
When does broadcast station conduct an equipment test?
During experimental period

ECE Board Exam April 1998
In television broadcasting vivid strong colors are often referred as __________
saturation

ECE Board Exam November 1997 .
Another SEG function that allows a person to superimposed on another scene.
Chroma keying

ECE Board Exam November 1996
When was the UHF channels (14-83) of television were added?
1952

ECE Board Exam March 1996
The frequency spectrum of the stereophonic FM signal.
30 to 53 kHz
ECE Board Exam April 2001
What does a simplest radio transmitter produce when it is keyed on and off during continuous operation?
Morse code signal

ECE Board Exam November 2000
Which of the following is referred to as a disadvantage of using a squelch circuit?
Very weak signal might not be received

ECE Board Exam April 2000
One of the following processes or systems best described an example of a pilot tone sysntem normally used in commercial broadcast FM stations.
Stereo multiplex

ECE Board Exam November 1999
In television, the color with the most luminance is
yellow

ECE Board Exam April 1999
Vnlgtat is the range of an AM broadcast frequency toleranoe above or below its assigned frequency?
20 Hz

ECE Board Exam November 1998
Channel 7 of the regular television channel belongs to which band?
High VHF Band

ECE Board Exam Aprll 1998
This is referred to as a fixed radio station that broadcasts program material from studio to transmitter by radio link.
Aural broadcast STL

ECE Board Exam November 1997
A good example of a pilot tone system used in commercial frequency modulation stations.
Stereo multiplexing

ECE Board Exam April 1997
The final amplifier of either FM or AM transmitter operates as
class C.

ECE Board Exam November 1996
Which ofthe following filters block FM radio band forTV channels (2 to 13)?
Band reject filter

ECE Board Exam April 2001
Assume a simple block diagram of a radio receiver containing an antenna, detector, speaker, RF amplification and audio amplification, Which block is input to speaker?
Audio amplification

ECE Board Exam November 2000
which one referred to the reduction of receiver gain caused by strong signal from nearby transmission of adjacent frequency?
Desensitizing

ECE Board Exam April 2000
In basic transmitter such as CW transmission, the rounding off square wave emission will reduce _________
bandwidth

ECE Board Exam November 1999
What will happen, if the diplexer of a television transmitter station is removed?
Power dissipation to both video and audio transmitted power could happen due to inter-feedback.

ECE Board Exam April 1999
A term used in radio communications defining the frequnecy band from the lowest to its highest limits, designed to be passed through a component, system or a device with an acceptable attenuation.
Bandwidth

ECE Board Exam November 1998
lt is an average power of a radio transmitter supplied to the antenna transmission line taken duting a sufficient interval of time and compared with the lowest frequency encountered in the modulation, taken under the
normal operating conditions.
Mean power

ECE Board Exam April 2001
What is the frequency tolerance of a standard FM broadcast?
2 kHz

ECE Board Exam November 2000
How far is the visual carrier from the aural in a monochrome television broadcast channel?
4.5 MHz

ECE Board Exam April 2000
Determine the local oscillator frequency of a broadcast receiver using a 455 kHz, IF and is tuned at 630 kHz.




ECE Board Exam November 1999
The actual vertical resolution of broadcast TV with reference to the number of horizontal lines
525 lines

ECE Board Exam April 1998
Refer to the deviation of the operating frequency of a crystal oscillator from its nominal value due to temperature variations.
Drift

ECE Board Exam November 1997
What is the effect in over modulated amplitude radio broadcasting transmission?
Interference to adjacent channel

ECE Board Exam April 2001
Audio frequency signal generators are capable of operating at a frequency range of
20 to 20,000 cps

ECE Board Exam November 2000
What is the noise that is developed in the RFamplifier front end of a TV receiver which is indicated by a white dot in the picture?
Snow

ECE Board Exam April 2000
One of the following refers to the standard frequency band limits of AM broadcast band.
535-1605 kHz

ECE Board Exam November 1999
In basic radio transmitter, what is the main advantage of a single-tube transmitter?
Frequency instability

ECE Board Exam April 1997
T\/ channels 2, 4 and 5 are known as _________
low band VHF

ECE Board Exam April 1997
_______ is the first component of any MATV system to receive broadcast signals.
Antenna

ECE Board Exam April 2001
One of the following is not a part of RF section of a radio transmitter.
AF power amplifier

ECE Board Exam November 2000
Which type of power amplifier used in radio transmitter is biased for purposes of continuous conduction and where output is amplified linearly from its input'?
Class A

ECE Exam April 2000
What is the purpose of one or more drlver amplifiers in a radio frequency transmitter?
Increase radio frequency power level of the transmitter

ECE Board Exam April 2001
A broadcast communications equipment that receives and collects very weak signals from a broadcast satellite.
Satellite receiver

ECE Boa d Exam November 2000
Which type of power amplitier used in radio transmitter is biased for purposes of continuous conduction and where output is amplified linearly from its input?
Class A

ECE Board Exam April 1999
Kind of broadcasting system where television programs are transmitted directly to home/user receiver via satellite, thus making the reception cover not only individuals(s) in their homes but other places as well.
Direct to Home TV

ECE Board Exam November 1998
Which of the following is one of the possible causes for a slow drift of frequency in a self excited transmitter oscillator circuits resulting to poor frequency stability?
DC and RF heating, of resistors, causing them to change values

ECE Board Exam April 1998
How much is the required minimum power output of an international AM BC stations
50 kW

ECE noard Exam April I997
Mechanism or device which enables the TV camera to move in internal and tilting motion.
Pan/Tilt device

ECE Board Exam April 1997
The allowable deviation ratio of commercial FM broadcast.
5

ECE Board Exam April 2001
When an information is sent out in all directions, this process is an act of _________ in communication.
broadcasting

ECE Board Exam November 2000
What is the maximum number of lines for any building other than a one or two story residential building to be required a service entrance facility under ECE building code?
Three lines

ECE Board EXam April 2000
If a frequency of a simple transmitter having a square wave is 233 kHz, which of the following belongs to its harmonics?
699 kHz and 1631 kHz

ECE Board Exam November 1999
Which one of following is a type of an electronic circuit which is designed for an IF amplifier
Class A

ECE Board Exam Aprll 1999
Determine from the following, possible cause for a slow drift of frequency in self-excited transmitter oscillator circuits resulting to a poor frequency stability.
Heating in the oscillator device causing a change in electrical characteristics.

ECE Board Exam November 1998
Referred to an oscillator signaI "Ieak through" from a properly neutralized amplifier such as a master oscillator power ampliher.
Back wave

ECE Board Exam April 1998
Term in communications which is referred as, "to send out in all directions".
Broadcast

ECE B0ard Exam November 1997
An antenna that can only receive a television signal.
TRVO

ECE Board Exam April 1997
________ is the time duration for one horizontal trace.
52 us

ECE Board Exam April 2001
An amplifier of radio transmitter used to increase RF power level of a frequency modulation type of transmitter.
Class C

ECE Board Exam November 2000
The purpose of a final amplifier in a radio frequency transmitter is to __________
increase RF power level of the transmitter

ECE Board Exam April 2000
Which ofthe following communication receiver stage provides fidelity?
Audio stage

ECE Board Exam November 1999
Determine from the following which is not a part of RF section of a radio transmitter.
AF voltage amplifier

ECE Board Exam April I999
One ofthe following is not a probable cause of radiating spurious signal from basic transmitter.
Regulated supply

ECE Board Exam November 1998
What controls the contrast of a television cathode ray picture?
Video stage gain

ECE Board Exam April 1998
How can intermodulation interference between two transmitters in close proximity reduced or eliminated?
Through installing a band-pass filter in the antenna feed line

ECE Board Exam April 2001
The condition which occurs when the signals of two transmitters in close proximity mix together in one or both of either final amplifiers, and unwanted signals at the sum and difference frequencies of the original transmissions are generated.
Intermodulation

ECE Board Exam November 2000
Refers to the most efficient amplifier in transmitter in terms of power amplification
Class C

ECE Board Exam April 2000
Which of the following is a function of a radio transmitter when used to transmit information over the air space.
Produce carrier signal
Applies modulation

ECE Board Exam November 1999
In basic transmitter, __________ is a kind of transmitter that develops type B emission.
spark

ECE Board Exam April 1999
Section of the radio transmitter that is responsible in the conversion of sound energy into electrical energy
Microphone

ECE Board Exam November 1998
What do you call the service area of a standard AM broadcast where fading is allowed but not objectionable co-channel interference?
Secondary

ECE Board Exam April 1998
The signal to noise ratio that is required for a satisfactory television.
40 dB

ECE Board Exam NOvember 1998
What kind of receiver is used in conventional telephone handset?
Electromagnetic

Board Exam April 1999
The frequency tolerance of an AM radio broadcast station.
20 Hz

ECE Board Exam April 2001
What is the term used to refer to a reduction in receiver sensitivity caused by unwanted high-level adjacent channels signal?
Desensitizing

ECE Board Exam November 2000
Which of the following is not a part of the audio frequency section of radio transmitter'?
Master oscillator

----------- part of audio frequency section of radio transmitter --------------
AF voltage amplifier
Microphone
AF power amplifier


ECE Board Exam April 2000
Refers to the basic advantage of frequency-shift keying over on/off keying.
Improvement in the receiver's quieting

ECE Board Exam November 1999
Type of radio communication transmission utilizing frequency modulation technique.
Television audio

ECE Board Exam April 1999
What can you hear from a radio transmitting station without modulation over radio receiver tuned to the same frequency?
Nothing

ECE Board Exam November 1998
Refers to one ofthe front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled tolthe mixer.
Local oscillator

ECE Board Exam Aprll 1998
What is a frequency discriminator?
A circuit for detecting FM signals

ECE Board Exam November 1998
One of the following is a possible cause of an abrupt frequency variation in a self excited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency oscillator
Loose connections in the oscillator, amplifier, or antenna circuits

ECE Board Exam November 2000
What do you call the service area of a standard AM broadcast where fading is not allowed?
Primary

ECE Board Exam April 2000
Which of the power amplifiers is normally used in radio transmitter that has the longest conduction reference to its input signal?
Class A

ECE Board Exam November 1999
One of the very thin layers at the tube’s front surface of a vidicon TV camera which is next to the lens, is called ________
the transparent conductive film

ECE Board Exam April 1999
Whit is the number of scanning lines per field for an NTSC standard?
262 1/2

ECE Board Exam November 1998
The stability of transmitted signal from a simple Hartley oscillator single transmitter which is coupled to an antenna wire affected by ________
close coupling between the oscillator and the antenna

ECE Board Exam November 2000
Which of the following type of radio emission ic capture-effect is most prevalent?
FM

ECE Board Exam April 2000
Refers to type of radio receiver that adopts amplifier and detectors only.
TRF receiver

ECE Board Exam November 1999
What controls the brightness of a television picture tube?
CRT cathode-grid bias

ECE Board Exam April 1999
A device used in television broadcast that prevents any FM signal from entering into visual transmitter and vice versa.
Diplexer

ECE Board Exam November 1998
Which of the following refers to the video signal amplitude that determines the quality picture?
Contrast

ECE Board Exam April 2000
When a signal bandwidth of a TV broadcast over the radio is lessen, using a technique that limits the picture frequency, this is referred to as _________
interlaced scanning

ECE Board Exam November 1999
What is the advantage on video of a TV receiver, by employment of FM audio and video on the television transmitter side?
Combination of AM and FM in a TV receiver is most compatible

ECE Board Exam April 1999
What wave trap frequency is used in the video amplifier?
4.5 MHz

ECE Board Exam November 1998
Where does the AM broadcast band located in the spectrum band?
MF band

ECE Board Exam November 2000
Which of the following solution will you prescnbe to a telegraph transmitter power supply to avert a chirp?
Regulate the power supply output voltage

ECE Board Exam Aprll 2000
in broadcasting, an area characterized tc have no interference but with fading or intermittent variations in intensity is _________.
secondary service area

ECE Board Exam
How many visible horizontal lines are left due to vertical retrace interval?
525 lines

ECE Board Exam April 1999
A test method used to campre two audio systems switching inouts so that both/same recording is heard in rapid succession over one given system to the other
AB test

ECE Board Exam November 1998
In regulation of public telecommunications carrier such as in the evaluation of new entrant, the following consideration shall be given emphasis to _____
technical, legal and financial

ECE Board Exam November 2000
Service area of a broadcast station within ground wave coverage where no fading of transmitted signals ls observed.
Primary area

ECE Board Exam April 2000
Where d¤es the FM broadcast band located in the spectrum band'?
VHF band

ECE Board Exam November 1999
One of the early radio transmitter which roduced keyed carrier generating purer waveform than spark transmitter, used for high powered RF transmission and are limited to radio frequency of about 500 kHz.
Arc Transmitter

ECE Board Exam November 2000
One of the following is a part of a modulated radio transmitter where carrier frequency equal to the desired multiple of the original frequency is obtained
Frequency multiplier

ECE Board Exam April 1999
Determine a possible cause for an abrupt frequency variation in a self-excited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency oscillation.
Loose shielding.

ECE Board Exam November 1998
One ofthe following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency operation and RF amplifier stage or stages that develop a high power output. The purpose of which is to develop a good frequency stability.
MOPA

ECE Board Exam November 2000
Which of the very thin layers of the tube's front surface of the vidicon TV camera located at the middle layer and posses very high resistance when dark, while it reduces greatly when struck by photos of light?
Photo conductive mosaic

ECE Board Exam April 2000
Refers to frequency band limits of the standard FM broadcast band.
88 -108 MHz

ECE Board Exam April 1999
A test method used to compare two audio systems switching input so that both/same recording is heard in rapid succession over one given system to the other.
AB test

ECE Board Exam November 1998
What consist the front·end circuit of a VHF TV superheterodyne receiver.
Local oscillator, mixer and RF amplifier

ECE Board Exam November 1999
One of the following is referred to as the number scanning lines per frame
for NTSC standard.
525 lines

ECE Board Exam April 1999
Which part of the HF marine antenna handle the broken salary link, in case it results collision, grounding or storm?
The strong part

ECE Board Exam November 1998
One of the following prevents a transmitter form emitting a signal that interferes with other stations on frequency during test
Use of dummy antenna

ECE Board Exam November 2000
Determine the image frequency of a broadcast band receiver using a 455 kHz IF tuned at 630 kHz·DZMM.




ECE Board Exam April 1999
How you do  decrease or eliminate the slow drift of radio frequency in a transmitter oscillator?
Using crystal oscillator

ECE Board Exam November 1998
How do you eliminate radio frequency variation of an  oscillator transmitter  caused bt its supply voltage?
Use of regulated power supply

ECE Board Exam April 1999
One of the most important reason for using the peak-limiter amplifier in an AM broadcast station.
Prevents over modulation

ECE Board Exam November 2000
What is the reason why frequency modulation is used in the broadcast video recording on tape?
Low noise

ECE Board Exam Aprll 1999
In a simple Hartley oscillator single stage transrmitter which is coupled to an antenna wire, one of the following conditions will affect the generated radio frequency.
Variation or antenna height and swinging of its elements

ECE Board Exam November 1998
One of the following is a possible cause for a slow drift of frequency in a self-ecxited transmitter oscillator circuits resulting to a poor frequency stability.
Heating capacitor in the oscillator

ECE Board Exam April 1999
How many horizontal scanning line does a TV camera transmitter have, without the lost of horizontal lines caused by vertical retrace interval?
525 lines

ECE Board Exam April 1999
How many VHF televison channels do we have in the country?
12

ECE Board Exam November 2000
Which component of a super heterodyne receiver is responsible for provision of bulk of radio frequency signal amplification at fixed frequency and superior selectivity?
RF stage

ECE Board Exam April 1999
This is referred to the number of lines per second to trace a complete television picture.
Frame frequency

ECE Board Exam April 1999
What is the maximum number of years within which a mobile radio service provider must provide a local exchange service to unserved and underserved areas pursuant to R.A. 7925?
Three years

ECE Board Exam November 2000
Which of the following primary colors are used in colored television broadcast?
Red, Blue and Green

ECE Board Exam November 2000
What is the frequency separation between the aural carrier and the lower limits of the total channel band of a monochrome TV broadcast?
5.75 MHz

ECE Board Exam November 2000
Which of the foloowing is used as standard channel spacing for AM broadcast in the Philippines?
9 kHz