Wavelength is the distance from:
wave crest to the next trough.
wave crest to wave crest.
trough to the next wave crest.
the E to the H field superimposed onto the system reactance background scatter.
The emission characteristics A3E describe:
ILS.
VHF communications.
HF communications.
VOR.
Electromagnetic waves travel at:
300 000 metres per second.
the speed of sound.
the speed of light.
162 000 miles per hour.
In radio terms, frequency means:
the speed of radio waves in metres per second.
the length of a complete waveform in metres.
the number of complete waveforms passing a spot in one second.
the number of waveforms in one hour.
According to ICAO Annex 10, in which frequency band(s) does a locator normally transmit?
HFI/VHF
MF/HF
HF
LF/MF
The Automatic Direction Finder uses the following wavelengths:
decimetric.
metric.
hectometric or kilo metric.
centimetric.
The Microwave Landing System (MLS) uses the following wavelengths:
myriametric
metric
hectometric
centimetric
Into what range does the ILS wavelength fall?
Kilometric
Metric
Nanometric
Millimetric
What is the frequency band for ADF?
Hectometric
Centimetric
Decimetric
A transmission of RF energy at a wavelength of 18 metres is in which frequency band?
MF
LF
VHF
The Instrument Landing System (ILS) uses the following wavelengths:
decimetric
The VHF direction finder uses the following wavelengths:
The Distance Measuring Equipment (DME) uses the following wavelengths:
The VHF omnirange (VOR) uses the following wavelengths:
What is the wavelength of an ILS signal?
A radio facility transmits on a wavelength of 2,22 cm. The facility could be a ___ operating on a frequency of __ •
VDF; 135 MHz
DME; 1350 MHz
doppler; 13500 MHz
radio altimeter; 13500 kHz
Frequency is defined as the:
number of complete cycles recurring in one unit of time.
distance between a crest and a crest.
number of complete cycles recurring in ten units of time.
distance from the axis to the peak value.
What is the wavelength of a VOR?
Heximetric
A radio transmitter modulator:
superimposes an audio frequency signal (AF) onto a radio frequency signal (RF).
couples the RF signal to an aerial.
tunesthe'aeria I-onl
ensures receiver compatibility.
The Marker beacons use the following wavelengths:
The secondary Surveillance Radar (SSR) uses the following wavelengths:
The Low Altitude Radio Altimeter uses the following wavelengths:
Selcal is an equipment that:
is coupled with TeAS II and is to do with TA warning systems.
automatically transmits data signals
automatically receives incoming signals.
functions as a frequency modulator.
What is the wavelength corresponding to a frequency of 375 kHz:
8m
80m
800m
8000m
The wavelength of a radio signal transmitted at the frequency of75 MHz is:
4m
40m
7,5 m
75m
A wavelength of 8,5 m~ corresponds to a frequency of:
2 833,3 MHz
35294MHz
3529,4MHz
28333 MHz
The VHF frequency band is in the:
3 to 30 kHz range.
30 to 300 kHz range.
3 to 30 MHz range.
30 to 300 MHz range.
Assuming a wavelength of 1 cm, frequency will be:
30MHz
30GHz
3,OGHz
0,3 GHz
The limits of the VHF band are:
300 - 3000 MHz.
30 - 300 MHz.
300 - 3000 kHz.
3-30 MHz.
Decimetric waves correspond to the frequency range:
3 000 to 30 000 MHz.
3 000 to 30 000 kHz.
300 to 3 000 MHz.
300 to 3 000 kHz.
The wavelength of a radio signal transmitted at the frequency 118,7 MHz is:
2,53 m
25,3 m
2,53 cm
25,3 cm
The wavelength of a radio signal with a frequency of 121.95 MHz is:
24,60m
24,60 cm
2,46 cm
2,46 m
The frequency which corresponds to a wavelength of 12 cm is:
2500 kHz
2500 MHz
360MHz
3600 MHz
A half wave dipole aerial suitable for transmitting an RF signal at 18 MHz should have an effective length of:
16,67 metres.
166,67 metres.
83,33 metres.
8,33 metres.
Assuming a frequency of 20 MHz, wavelength will be:
1,5 m
15m
150m
0,15 m
What is the wavelength of an NOB transmitting on 375 kHz?
1,25 m
12,5 m
A frequency of 2.400 kHz is equivalent to a wavelength of:
125 m
105 m
0,80em
The wavelength of a non-directional beacon (NOB) at a frequency of 300 kHz is:
1000 metres
100 metres
10 metres
1 metre
The wavelength of a radio signal is 200 metres. What is its frequency?
1,5 kHz
1,5GHz
1,5MHz
15 MHz
A radio signal has a frequency of 3 GHz. Its wave length is:
100 cm
1,O cm
10 cm
1,O m
The VHF frequency band has a wavelength limit of:
100 m to 10m.
1 m to 100c m.
10 m to 1 m.
100 cm to 10 em.
The gain of an aerial is a measure of its ability to:
focus power.
transmit intelligence.
overcome transmitter line resistance.
compensate for attenuation.
Which of the following statements is correct in respect of a RF signal:
the plane of polarisation is dictated by the oscillator unit in the transmitter.
the electrical component of the signal is parallel to the aerial.
the magnetic component of the signal is parallel to the aerial.
both the electrical and magnetic components are parra lei to the aerial.
A radio wave with a horizontal magnetic component would be best received by a ___ aerial.
magnetic
parabolic
horizontal
vertical
A horizontally polarized electromagnetic wave:
has the H field horizontal.
has the Z field horizontal.
has the E field vertical.
has the E field horizontal.
Feeder lines are of the following types:
Co-axial- up to 3000 MHz; wave guides - above 3000 MHz
Co-axial- above 3000 MHz; wave guides - up to 3000 MHz
Co-axial- up to 300 kHz; wave guides - above 300 kHz
Wave guides - up to 20 MHz; co-axial above 30 MHz
An electromagnetic wave has two types of energy field:
an H electrical field and an E magnetic field.
a Z electrical field and an H magnetic field.
an E electrical field and an H magnetic field.
an Z magnetic field and an E electrical field.
Comparing a parabolic reflector with a flat plate antenna of the same size
the parabolic reflector has a considerably smaller beam width.
the parabolic reflector generates less side lobes than the flat plate antenna.
the flat plate antenna generates less side lobes than the parabolic reflector.
the flat plate antenna has a considerably smaller beam width.
What causes the so-called night effect?
A change in the direction of the plane of polarisation due to reflection in the ionosphere.
The absence of the surface wave at distances larger than the skip distance.
Interference between the ground and the space wave.
The difference in velocity of the EM-waves over land and over sea, at night.
A Doppler shift will occur:
if a transmitter is moving during transmission to a fixed position receiver.
when the distance between a transmitter and a receiver is changing during a transmission.
if a receiver is moving during reception of transmission from a fixed position transmitter.
all answers are correct.
When a transmitter is moving towards a receiver, the correct description of Doppler effect is:
there is a decrease in apparent wavelength which is dependent on the transmitter velocity.
there is a decrease in apparent wavelength which is independent of the transmitter velocity.
there is a increase in apparent wavelength which is dependent on the transmitter velocity.
there is a increase in apparent wavelength which is independent of the transmitter velocity.
An apparent increase in the transmitted frequency which is proportional to the transmitter velocity will occur when:
the transmitter moves away from the receiver.
the transmitter moves towards the receiver.
the receiver moves towards the transmitter.
both transmitter and receiver move towards each other.
Due to Doppler effect an apparent decrease in the transmitted frequency, which is proportional to the transmitters velocity, will occur when:
the transmitter and receiver move towards each other.
the transmitter moves toward the reciever.
both transmitter and receiver move away from each other.
Refraction of an electro-magnetic radiation is:
the bending of its propagation path as it passes through or over areas of different electrical conductivity.
the loss of power as it passes through or over areas of different electrical conductivity.
bending resultant from reflection from objects.
loss of power through reflection from objects.
Which statement is true?
The attenuation of an HF ground wave is worse over the land than over ice.
The ionosphere will attenuate and refract signals up to 30 GHz.
The lower the frequency the greater the ionospheric attenuation.
None of the above.
The term Doppler shift refers to:
the change in depression angle measured at the receiver.
the change in the speed measured at the receiver.
the change in phase angle measured at the receiver.
the change in frequency measured at the receiver.
Attenuation of radio waves means:
the weakening of the radiated waves.
the atmospheric bending of the waves.
only the scattering of the waves by the tropopause.
only the absorption of radio energy by the sea.
When an LF radio wave passes over the earth's surface it:
speeds up, picks up electrons and becomes stronger.
slows down and is attenuated.
speeds up and is attenuated.
slows down, picks up electrons and becomes stronger.
To establish and maintain effective HF communications the frequency used at a given range:
should remain constant.
should be increased at night.
should be decreased at night.
should only be varied by season, decreased in summer and increased in winter.
Skip distance is the:
highest critical frequency distance.
range from the transmitter to the first sky wave.
wavelength distance of a certain frequency.
thickness of the ionosphere.
Diffraction of a RF signal is a displacement of its propagation path dueto:
reflection from the surface.
passing over or though mediums of different conductivity.
passing over obstacles with dimensions close to the wavelength.
passing through ionised regions of the upper atmosphere.
Using a medium frequency band when is fading likely to occur?
Day time and snowing.
Night time and snowing.
Day with sky and ground waves.
Night with sky and ground waves.
Complete the following statement: ___ radio signals have a __ range by ___ wave over __ than over __ •
MF; shorter; sky; sea; land
MF; greater; groLind; sea; land
VHF; shorter; sky; sea; land
MF; greater; ground; land; sea
The frequency at which sky waves should least affect reception?
VLF
The skip distance of HF-transmission will increase with:
higher frequency and higher position of the reflecting ionospheric layer.
lower frequency and higher position of the reflecting ionospheric layer.
higher frequency and lower position of the reflecting ionospheric layer.
lower frequency and lower position of the reflecting ionospheric layer.
Attenuation is a generic term for:
increase in power.
loss of power.
refraction.
loss of power but is only relevant to space waves.
Reflection from ionospheric layers is used in the following radio frequencies:
UHF
MF fading is most common:
during the day due to the reception of both sky waves and ground waves.
during the day and during heavy rain.
at night and during heavy rain.
at night due to the reception of both sky waves and ground waves.
As the frequency of a transmitter is increased, the range of the ground wave will:
increase.
decrease.
decrease only at night.
increase only over the sea.
Skip distance is longest by __ and with a __ frequency.
day;low
day; high
-night; low
night; high
Attenuation of a radio wave is the:
increase of its power by the combination of mUlti-path signals.
change of its frequency QY use of sidebands.
change of its amplitude by use of sidebands.
reduction of its power by absorption, scattering or spreading.
A radio signal looses strength as the range from the transmitter increases. This effect is called:
refraction
attenuation
amplification
ducting
In the propagation of MF waves, the phenomenon of FADING is particularly found:
by day, due to the combination of sky and ground waves.
at night due to the combination of the sky and ground waves.
at night and when raining.
by day and when raining.
Fading happens:
in daytime when ground-waves and sky-waves interfere with each other.
at night when the signal is received by ground-waves only.
at daytime when the signal is received by sky-waves only.
at night when ground-waves and sky-waves interfere with each other.
Which of the following statements is true?
A broad bandwidth gives a narrow beam width.
A narrow bandwidth improves beam width.
A transmissions bandwidth is affected by the design of the aerial.
Bandwidth must be reduced in order to reduce noise.
Diffraction is the process by which:
a space wave penetrates the ionosphere.
a ground wave is attenuated over rough ground
radio wave travel over and around obstacles.
a direct wave is bent around the form of the Earth.
An HF transmitter is tuned to a frequency that refracts from the E layer in the Ionosphere. The maximum distance of the first returning skywave is:
599 NM
599 km
1500 NM
1500 km
What is the lowest frequency where freedom from static interference can be guaranteed?
3MHz
300MHz
3 GHz
An aircraft travelling at 330 metres a second transmits a signal at 10 GHz to a stationary receiver. If the aircraft is flying directly towards the receiver and they are approximately at the same height the received frequency will be:
11 MHz
10,000011 GHz
9,999989 GHz
11 GHz
The approximate ground waves of LF and MF are (by day) __ and __ respectively, with __ suffering more from atmospheric attenuation.
1500 NM; 1000 NM; MF
1000 NM; 500 NM; LF
1000 NM; 300 NM; MF
500 NM; 100 NM; LF
The VDF class B bearing is accurate to within:
± 1°
±2°
±3°
±5°
When would VDF be used for a position fix:
when an aircraft declares an emergency on any frequency.
when first talking to a FIR on crossing an international boundary.
when joining controlled airspace from uncontrolled airspace.
when declaring an emergency on 121,5 MHz.
In which one of the following circumstances is ground direction finding (VDF) likely to be used to fix an aircraft's position?
When contacting ATe to join controlled airspace from the open FIR.
When declaring an emergency on any frequency.
When using the emergency VHF frequency 121,5 MHz.
On first contact with ATC on crossing an international FIR boundary.
What airborne equipment, if any, is required to be fitted in order that a VDF let-down may be flown?
None.
VHF radio.
VOR/DME.
What equipment does an aircraft need when carrying out a VDF letdown:
none.
The minimum airborne equipment required for operation of a VHF direction finder is a:
VHF compass operating in the 200 kHz to 1.750 kHz range.
VHF transmitter-receiver operating in the 118 MHz to 136 MHz range.
VHF receiver operating in the 118 MHz to 136 MHz range.
cathode-ray tube.
Ground direction finding at aerodromes utilises which frequencies?
VHF at civil aerodromes and VHF at military aerodromes.
UHF at civil aerodromes and UHF at military aerodromes.
VHF at civil aerodromes and UHF at military aerodromes.
UHF at civil aerodromes and VHF at military aerodromes.
The range at which you can obtain a VDF bearing can be influenced by:
time of day.
type of surface.
height of aircraft.
intensity of ionisation.
An aircraft wishing to use the VDF service must:
be equipped with a VOR indicator unit.
transmit a signal for a long enough period for the bearing to be established.
ask the controller to transmit for a long enough period to establish the bearing
be within 10 NM of the VDF aerial.
What is the role of a ground direction finder?
To aid pilot navigation .
To aid ground movements.
To map airfields.
To assist planners in the construction of airfield approaches .
If, when you are requesting a QDM from an airfield, you are offered a QGH, it means:
the bearing will only be accurate when the aircraft is flying above the QGH level.
the VDF service will be handled by a different VDF unit, operating on the same frequency.
the VDF unit is prepared to give you assistance during an approach to the airfield, based on VDF bearings.
the service will be limited to bearings, no positions will be given by the DF station.
In VDF service the report "QDR235, Class C" means:
the magnetic bearing from the aircraft to the station is 235°±10°.
the true bearing from the aircraft to the station is 235°±1 0°.
the magnetic bearing from the station to the aircraft is 235 ±15°.
the magnetic bearing from the station to the aircraft is 235°±10°.
When conducting a QGH approach responsibility for interpreting the procedure rests with __ and on a QDM approach responsibility rests with ___ •
the controller; the controller
the pilot; the pilot
the pilot; the controller
the controller; the pilot
Which of the following affects VDF range?
Coastal refraction.
The height of the transmitter and of the receiver.
Sky wave propagation.
Strength of the pilot's voice when transmitting.
Abnormal long ranges may be experienced on VDF channels, caused by:
efficient VDF antennas.
super refraction of signals in the atmosphere.
the VDF station using a relay station for communication to the aircraft.
intermodulation with signals on frequencies close to the one used by the VDF station.
You intercept a QDM with a right crosswind component. Is your intercept heading greater or smaller then without wind influence?
Greater.
Smaller.
Remains the same.
Not enough information to give an answer.
If a ground DfF controller passes a bearing thus: "your true bearing is 256°, class alpha." This means:
QTE accurate to ± 5°.
QUJ accurate to ± 3°.
QOR accurate to ± 2°.
QTE accurate to ± 2°.
With reference to a VDF bearing, the true bearing of the aircraft from the ground station is a:
QTE
QUJ
QOR
QOM
Which Q code would give a magnetic bearing from a VDF station:
Which Q code would give a magnetic heading to steer (nil wind) to a VDF station:
QDM
QDR
Which Q code would give a true track from a VDF station:
A VDF bearing can be obtained:
only on a frequency of 121,5 MHz.
on the Approach frequency
on the frequency notified for VOF services.
on the frequency agreed between the pilot and ATC but chosen from one of the available ATC frequencies.
An aeroplane requesting a VDF bearing should:
avoid banking during transmission.
not pass overhead VOF aerial.
ensure that radio silence is maintained.
transmit on 121,5 MHz.
Which of the following is an advantage of VDF?
No equipment required in the aircraft.
No special equipment required in the aircraft or onthe ground.
Only a VHF radio is needed in the aircraft.
It is pilot interpreted, so ATC is not required.
WhatisQTE?
Magnetic track from the station.
Magnetic track to the station.
True track from station.
True track to the station.
Which of the following is an advantage of GroundlDF (VDF) let-down?
It is pilot interpreted and does not require the assistance ofATC.
It only requires a VHF radio to be fitted to the aircraft.
It does not require any special equipment to be fitted to the aircraft.
It does not require any special equipment, apart from a VHF radio, to be installed in the aircraft or on the ground.
Which of the following statements regarding VHF direction finding (VDF) is most accurate?
It is simple and only requires a VHF radio on the ground.
It is simple and requires a VHF radio and OF equipment in the aircraft.
It is simple requiring only VHF radios on the ground and in the aircraft.
It uses line of sight propagation.
In the VDF system directional antennas are used:
in the aircraft.
in the aircraft and at the ground installation.
at the ground installation.
no directional antennas are used.
