“Call signs “are used
To identify the transmitting stations
Word “Roger” signifies,
The last transmission received
The best way to orient your antenna when making the long distance communication are to your
Great Circle Map
In RTTY (Radio teletype) transmission, frequency shift shall not exceed,
850 Hz
The calling frequency in the 40m band in the Philippines is,
7.045 MHz
The six most basic parts of the telephone set are,
Switch
Dialing (dual tone or rotary)
Ringer
Microphone
Speaker
Hybrid coil
Another name for a hookflash that is rented by the PBX system to telephone company central office switches that signals a request for dial tone or another services.
Wink
When replying a call made on calling frequency, reply by called station made preparatory to traffic shall be made on
Where calling station keep watching unless a specific frequency was inducted by calling station.
Frequency of signal is 15MHz, the wavelength is
200 m
Grounded antennas are known as
Marconi Antenna
Feedhorn is a part of what type of antenna.
Parabolic
Quarter wavelength of signal using 150 MHz operating frequency
0.5 m
Emission designation of SSB suppressed carrier, voice telephony.
J3E
Bending of radio waves over terrain like mountains and hills.
Diffraction
Telephone line installers sued test tone (installer’s tone) to place RF signal on a pair of wires so that they can locate that pair of the other of the feed.
Tone probe/Banana
USB is an external bus standard that emerges in 1996. Its supports data transmission rates of ______and can connect as many as ______peripheral devices.
12 Mbps, 127
Frequency ranges of FM radio broadcasting.
VHF (30-300 MHz)
The Q word for “I am acknowledging receipt” is
QSL
Grounded grid amplifier are often used at very high frequency because
Usually do not require neutralization
The alpha cut off frequency of a transmitter is defined as
High frequency at which current gain becomes unity
In the Q code “I am listening to” is
QSX
“Beyond the horizon” is also called
Troposcatter propagation
The approximate bandwidth of A3 voice modulation receiver
6 kHz
Ideal value of signal to noise ratio is
Infinity
The energy dissipated from 100 W radio transmitters for 10 hrs continuous
1 kW hr
Which is not a Hertz type antenna?
AM Broadcast Tower Antenna
The term referring to the space orientation of electromagnetic wave of a radiating transmission system.
Polarization
A sensor used to measure the change in resistance of extrinsic silicon with temperature.
Spreading Resistance Sensor
Half power points are also known as
- 3 dB point
The most ideal SWR on VHF communication.
Unity SWR or 1:1 WSR
Second Harmonic of 500 kHz is
1000 kHz
A radio telephony signal used to indicate a very urgent message to transmit concerning safety of a ship or aircraft for safety of a person.
PAN
What permit is required if a transmitter is to be shipped from Manila to Davao City?
Permit to Transport
In the International call sign series, the Philippines is allocated the three-letter
from
DUA to DZZ
Responsibility for proper operation of radio station fall on
License Radio Operator on Duty
What determines the frequency of the crystal oscillator?
Thickness of the crystal
What are the requirements for the circuit to oscillate?
Gain must be high
Feedback must be positive
Coupling from the output to the input must be good
What circuit provides two complementary signals to a puss-pull circuit?
Phase splitter
The no signal area between the ends of the mobile groundwave signal and the reflected skywave in the high frequency propagation
Skip Zone
One of these may cause ionic disturbance characterized by rapid fluttering sound, hence voice communications is poor.
Aurora Borealis
If circumstances permit, immediately before crash of forced landing, radio apparatus must
Set for continues emission
A coil of wire that filters out high frequency
RF Splitter
The practice of taking a bit her and there in the beginning and end of a digital transmission for use in the overhead of the transmission equipment
Bit-robbing of robbed bit signaling
Roaming means
The cellular/PCs telephone travels outside of its calling area but still continues to send and received a signal
At three digit code or shortened phone number that has the specific purpose, such as 911
Service Code
Is a harmonic radio frequency that is a result of modulation on an AM carrier and is a transmission characteristic of an FM carrier.
Sideband
SIM stands for
Single Interface Module
The illegal practice of charging a customer telecommunications carrier without their consent.
Slamming
A standard interchange format used by e-mail applications to exchange message with each other
Simple Mail Transfer Protocol (SMTP)
A device that is used to maintain a minimum bend radius for installed fiber optic cable.
Snowshoe
A plot of the relative strength or intensity of the antenna radiation as the function of the orientation in a given plane is called ______.
Radiation Pattern
What is the unit of magnetic field intensity?
Ampere per meter
What is the parameter that compares the concentration of the power of the given antenna to that of some reference antenna?
Gain of the antenna
The most usable layer for long distance communication in HF propagation using ionosphere is
F2
In propagation in space waves, the most practical frequency band to used is
VHF (30 – 300 MHz)
Frequency used for submarine/power
EHF (3 – 30 Hz)
Frequency range used for ultraviolet light
3 PHz to 30 PHz
Frequency range used for terrestrial microwave/satellite
SHF (3 – 30 GHz) and EHF (30 – 300 GHz)
Frequency range used in broadcasting TV
UHF (300 – 3000 MHz)
Video TV signals are transmitted using this kind of modulation
Amplitude Modulation
For uniformity in international communication the time reference standard used at present is
UTC
What condition exist when there is no potential across the detector in a bride circuit
Null condition
What is the process of balancing an arc bridge circuit that consists of making successive adjustments of two parameters until a null is obtained in the detector?
Balance Convergence
The television Standards used for color system in the Philippines.
American National Television Standards Committee
The number of lines per frame of TV transmission in the Philippines
525 lines per frame
How much will crystal frequency change by means of inductor and capacitor in parallel?
0.1 %
Highest audio frequency transmitted in FM broadcast stations
15 kHz
The product of the power fed to the antenna and the antenna power gain minus the transmission losses equals
Effected Radiated Power (ERP)
How long before expiration date must radio station file a renewal at NTC?
60 days
The logbook and file copies of message handled by radio station shall be preserved and retained for a period of
2 years
The silent is observed at least half an hour of operation. If the first silent period of is done at 10:15 AM, the second period shall be observable at ______.
10:45 AM
The band of frequency which is usually affected by solar cycle
HF Band
Approximate height of geosynchronous satellite above the earth surface
36,000 km
Q code are used to
Shorten message
When it is 12:30 in the Philippines, in UTC it is
0430 UTC
A LAN connector that crimps into the outside a coax cable
Vampire trap
Wide bandwidth amplifier has
Poor Selectivity
Class A is ideal for single transistor audio amplifier because
It produces minimum distortion
The velocity of light divided by the frequency
Radio Wavelength
A device that was engineered to a make a microwave antenna systems that allows to transmit and receive signals on the same antenna
Directional Coupler
A variable error in GPS latitude and longitudinal signals. It is purposely integrated in the positioning system to prevent anyone other than the government from having an absolute precise positioning position.
Dithering
An executable subroutine store as a file that is separate from the programs that could use it.
Dynamic Link Library (DLL)
A closure containing a cellular\PC transmission line. It comes with a heater/air conditioner units and its size of a doghouse.
Doghouse
What is the kind of power that comes directly from the power company? It is not a pure 220 V AC power because as it travels on the power line, it collects all kinds of EMI (Electromagnetic Interference) of all frequencies.
Dirty Power
What operates in the intermediate frequency of MTI – Radar?
The Coho
What is the major advantage of a cross-field amplifier?
High Frequency
What is the reception of emission from a space station in the broadcasting satellite service by the receiving equipment which in some cases may be complex and having antennas larger than those used in individual receptions?
Community Receptions
What antenna using a mean beam from an earth station with respect to the satellite that illuminates a given area on the surface of the earth of the rotating communications satellite?
Despun
Why is CDMA ideally for military use?
Because of its immune in interference (Jamming)
What is the term otherwise known as CDMA?
Spread Spectrum multiple Access
It is previously known as single sideband reduced carrier.
A3A
Bit–Robbing is also known as
In- Band Signaling
The maximum commercial load outside Metro Manila is
17 minutes
The purpose of RF Amplifier to receiver
To improved noise figure.
Used to increase battery voltage and extend signaling range.
Loop Extender
What kind of receiver does the radar used?
Super Heterodyne
What is the radiation of the end fire array?
Bi-directional
Range of LORAN
One quarter wavelength absolute, less than 100 ft relative
Two types of manufacturing IC
Bipolar and MOS
What is the maximum transmitter power of the mobile nit for CDMA?
300 mW
What is the wavelength of deep red?
700 nm
Zero dispersion wavelengths
Wavelength at about 1300 nm
What is the most popular plug for RG-56U coax?
F Connector
How wide is the spectrum bandwidth of a single HF carrier?
200 kHz
What is the effect of light controlling dark current of a detector?
Photoconductive
Why coax cable is is not used above 6 GHz?
High Attenuation
3 Communications color codes:
Twisted pair cable color code (PIC)
Fiber optic color code
Resistor color code
What is a propagation effect that results when phase difference between radio wave components of the same transmission are experience at the recovery station?
Selective Fading
Telemetry by using radio waves
Radio Telemetry
The frequency range of FM
88-108 MHz
The frequency range of AM
535-1605 kHz
A device use to amplify the output of fiber optic reflector.
BJT
If the antenna is too low, the directivity gain and the radiation resistance will also be too low ______is used to overcome this problem.
Top Loading
A test telephone set used by telephone installer and repair personnel.
Butt Set
It is an effect that last for 10 minutes or several hours wherein the electromagnetic wave disappears rapidly as a result of the increased ionization of the ionosphere caused by increase in noise from solar storms.
Dellinger Effect
A frequency band whose frequency ranges from 0.46 – 0.5 kHz, what emission uses these frequencies?
NBDP/SITOR
Time difference between the transmitted signal and received signal in LORAN
Time Delay
The most important specification in fiber optic communication
Data Rate
Number of electrons produced by incident phones
Quantum Efficiency
Provide better selectivity
High Q tuned circuit
GMDSS
Provide automated and improved emergency communication in marine transportation.
Antenna which can be used on more than one band due to the used of parallel LC network
Trap Antenna
Common used of DSB in broadcast and communication.
FM/TV stereo
What is the primary purpose of an RF amplifier in a receiver?
To improve the receiver’s noise figure
What ferrite receiver can be used instead of a duplex to isolate a microwave transmitter and receiver when both are connected to the same antenna?
Circulator
TACS cellular system has how many channels?
1000
What is the transmit frequency of TACS?935 – 960 MHz
What is the received frequency of TACS?
890 – 915 MHz
What is the minimum size of telephone conduit used for hospitals, hotels, residential, condominiums and apartments?
12.7 mm diameter
Maximum number of turns of a typical helical antenna
20 turns
What is the typical dithering error in a civilian-purchased GPS unit?
±0 – 50 ft
What microwave device is used as an oscillator and amplifier?
Klystron
It is the circuit whose purpose is to keep the receiver audio tuned off until an RF signal appears at the receiver input.
Squelch circuit
What cable has a solid center conductor which is then covered by and insulator such as Teflon?
Coax or Coaxial cable
What is the area between the point where the ground wave is completely dissipated and the point where the first sky wave returns, where no signal is receive?
Skip Zone/ Quiet Zone
______is a large telephone device which has keyed on-off circuit which functions as the main controller in the PBX
Console
The minimum output power for cordless telephone and telephone line extenders operating beyond 300 ft.
10 Watts
The radiation pattern of the vertical/whip antenna
Circle
The varactor is used as a ______in microwave devices.
Frequency Multiplier
Underwater communications in which audible baseband signals use water as the transmission medium
SONAR
What is the frequency range of high frequency?
3 – 30 MHz
What is the time for a satellite to complete 1 orbit?
Sidereal period
The study of light transmission in solid material
Fiber Optics
Known as the electromagnetic signal.
Radio Frequency (RF) waves
What is the other term of longitudinal wave?
Compressional or Irrotational wave
What are the types of linear transponder?
Inverting and non-inverting
What call is most prioritized?
Distress call
The beamwidth of the Yagi-Uda antenna ranges from
20° - 40°
The wavelength range of ultraviolet.
10 – 390 nm
The circuit used to create a dibit.
Bit Splitter
The frequency assigned to VOR.
115.05 MHz
Which circuit provides channelization is transponder?
Bandpass filter
Wavetrap frequency used in video amplifier
4.5 MHz
The measurement for metrological aid that is placed on an aircraft, balloon, or kite that provides meteorological measurement.
Radiosonde
A device use to measure the height above surface with reference to a surface place in an aircraft or wavecraft.
Altimeter
What type of IC determines a short distance one way optic communication system?
Opto-isolator
What is the advantage of FET over BJT?
Higher input impedance
Philippines belong to what region?
Region 3
The resistance characteristic of a microwave diode where when voltage is increased, the current decreases
Negative Resistance
The maximum power utilized by short range radio service?
3 Watts
What refers to as a converge entity of the telecommunication system by congress which authorizing that entity to be engage to that telecommunication service?
Franchise
SITOR stands for
Single Telex On Radio
An impedance matching transformer with impedance ranging from 50 to 75
Baum
The data rate of DVD
1.3 Mbps
Peak wavelength of sunlight
500 nm
Wavelength of sunlight
300 – 2000 nm
The current threshold of an ILD
70 nA
What occurs when the threshold voltage of the ILD is reached?
Lasing
A parabolic reflector has an efficiency of 55%
A director is _____shorter than the driven element.
5%
A reflector is _____longer than the driven element.
5%
The component used to produce AM in very high frequencies
PIN diode
How many SITOR signals can occupy one voice band channel?
6
What best describes demodulation?
Removing information signal from the carrier
What best describes amplitude modulation?
The information signal changes the amplitude but does not change the carrier frequency
Percentage of modulation is also known as
Modulation Index of Modulation Factor
What separates the sound and video signals in TV receiver?
Video Detector
What refers to the privilege given upon the telecommunications entity by congress, authorizing that entity to engage in a certain type of telecom service?
Franchise
The magneto-optic effect that has a polarization plane of electromagnetic wave is rotated under the influence of a magnetic field parallel to the direction of propagation.
Faraday Effect
Multiple Cable TV RF signals fed in different inputs and taken from one output alone
Combiner
Sideband present in J3E?
Upper Side band
Sideband present in AM?
2
What is FM?
Information varies the frequency while its amplitude remains constant
What is AM?
Information varies the amplitude while the frequency remains constant
Refers to the path that crosses private property and enters the building?
Service Entrance
A location where the riser cable terminate from further distribution throughout the floor structure
Riser Conduit
The diameter of a single mode fiber cable
10 m
It is a flat conductor separated from a large conducting ground plane by an insulating dielectric
Microstrip
Highest frequency that can be used for sky wave propagation between two given points on earth
MUF (Maximum Useable Frequency)
An echo completely out of control
Singing
Thermal detector that changes its resistance in response to thermal energy resultant from impinging radiant energy
Bolometer
Radiation of a collinear or broadside antenna
Bidirectional
Spectrum bandwidth of a GSM HF carrier
200 kHz
Has a wavelength of 455 – 492 nm
Blue
Widely used Balance Modulator
Lattice Modulator
Previous emission designation of a single sideband reduce carrier
A3E
Emission designation with the least bandwidth utilization
F3E
Least effective radius of operation
VHF DSC
What is critical angle?
Angle in which a wavefront is at incidence with the ionosphere
What is a Wavefront?
A fixed point in an electromagnetic wave
What rays are beyond visible light?
Gamma rays, X-rays, Cosmic Rays
Cause of too intense color signal
High Chroma
The constant in Path Loss where distance is in Nautical Mile and frequency is in MHz
37.8
Approximately what is the gain of RF, IF Receiver?
100 dB (typical value)
The direction of the of the satellite is opposing the direction of the rotation of the earth
Retrograde
A hollow tube used in microwave to transfer signal from one place to another
Waveguide