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Decimetric waves correspond to the frequency range:
Decimetric waves correspond to the frequency range:
An aircraft traveling at 330 meters per 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:
An aircraft traveling at 330 meters per 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:
A half-wave dipole aerial suitable for transmitting an RF signal at 18 MHz should have an effective length of:
A half-wave dipole aerial suitable for transmitting an RF signal at 18 MHz should have an effective length of:
Which of the following statements is true?
Which of the following statements is true?
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With regards to radio waves, which statement is true?
With regards to radio waves, which statement is true?
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You are at an altitude of 9,000 feet. At a range of 200 nm from a VHF communications transmitter, and you are receiving a good signal.
You are at an altitude of 9,000 feet. At a range of 200 nm from a VHF communications transmitter, and you are receiving a good signal.
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Refer to figure. In the following diagram, the phase difference between the two signals is:
Refer to figure. In the following diagram, the phase difference between the two signals is:
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The emission characteristics A3E describe:
The emission characteristics A3E describe:
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The gain of an aerial is a measure of its ability to:
The gain of an aerial is a measure of its ability to:
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What is the lowest frequency where freedom from static interference can be guaranteed?
What is the lowest frequency where freedom from static interference can be guaranteed?
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The VHF frequency band has a wavelength limit of:
The VHF frequency band has a wavelength limit of:
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The wavelength of a radio signal is 200 meters. What is the frequency?
The wavelength of a radio signal is 200 meters. What is the frequency?
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The approximate ground waves of LF and MF are (by day) ______ and ______ respectively, with _______ suffering more from atmospheric attenuation.
The approximate ground waves of LF and MF are (by day) ______ and ______ respectively, with _______ suffering more from atmospheric attenuation.
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As the frequency of a transmitter is increased, the range of the ground wave will:
As the frequency of a transmitter is increased, the range of the ground wave will:
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An RMI indicates aircraft heading. To convert the RMI bearings of NDBs and VORs to true bearings the correct combination for the application of magnetic variation is:
An RMI indicates aircraft heading. To convert the RMI bearings of NDBs and VORs to true bearings the correct combination for the application of magnetic variation is:
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Doppler navigation systems use ______ to determine aircraft ground speed and drift:
Doppler navigation systems use ______ to determine aircraft ground speed and drift:
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In day-to-day use, the greatest cause of error in Doppler is:
In day-to-day use, the greatest cause of error in Doppler is:
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The largest error and source of error on a Doppler-derived position is:
The largest error and source of error on a Doppler-derived position is:
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Updating Doppler is undertaken when:
Updating Doppler is undertaken when:
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After a long period in memory, Doppler:
After a long period in memory, Doppler:
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Sea bias error:
Sea bias error:
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With regard to Doppler navigation systems:
With regard to Doppler navigation systems:
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What frequencies are allocated to Doppler Navigation systems?
What frequencies are allocated to Doppler Navigation systems?
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A radio facility transmits on a wavelength of 2.22 cm. The facility could be a:
A radio facility transmits on a wavelength of 2.22 cm. The facility could be a:
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The 4-beam moving Janus array aligns with the aircraft center line by:
The 4-beam moving Janus array aligns with the aircraft center line by:
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Which of the following statements is correct when considering a Doppler navigation system?
Which of the following statements is correct when considering a Doppler navigation system?
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Doppler may unlock over
Doppler may unlock over
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Which of the following statements is TRUE in respect of Doppler?
Which of the following statements is TRUE in respect of Doppler?
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The maximum theoretical range at which an aircraft at FL80 can obtain bearings from a ground VDF facility sited 325 FT above MSL is:
The maximum theoretical range at which an aircraft at FL80 can obtain bearings from a ground VDF facility sited 325 FT above MSL is:
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What is the maximum range at which a VDF station at 325 ft can provide a service to an aircraft at FL080?
What is the maximum range at which a VDF station at 325 ft can provide a service to an aircraft at FL080?
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When conducting a QGH approach responsibility for interpreting the _______ on a VDF approach responsibility rests with _______ and ______ procedure rests with _______.
When conducting a QGH approach responsibility for interpreting the _______ on a VDF approach responsibility rests with _______ and ______ procedure rests with _______.
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If, when you are requesting a QDM from an airfield, you are offered a QGH, it means:
If, when you are requesting a QDM from an airfield, you are offered a QGH, it means:
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Ground DME responders respond at a frequency:
Ground DME responders respond at a frequency:
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The phase difference between the reference and variable signals on QDM 0500 (VAR 100W) for a conventional vor is:
The phase difference between the reference and variable signals on QDM 0500 (VAR 100W) for a conventional vor is:
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A VDF bearing can be obtained:
A VDF bearing can be obtained:
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Which of the following does NOT affect the accuracy of VDF bearings:
Which of the following does NOT affect the accuracy of VDF bearings:
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The range at which you can obtain a VDF bearing can be influenced by:
The range at which you can obtain a VDF bearing can be influenced by:
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At a height of 5,000 feet you might expect to receive a VHF signal, from a transmitter at sea level, at a range of
At a height of 5,000 feet you might expect to receive a VHF signal, from a transmitter at sea level, at a range of
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Study Notes
BASICS
- Decimetric waves correspond to the frequency range of 3000 to 30000 MHz.
- An aircraft traveling at 330 meters per second transmitting a 10 GHz signal to a stationary receiver, flying directly towards the receiver at the same height, will result in a received frequency of 10,0011 GHz.
- A half-wave dipole aerial suitable for transmitting an 18 MHz signal should have an effective length of 8.33 meters.
- A broad bandwidth results in a narrow beam width; a narrow bandwidth improves beam width.
- Radio waves reflect off metallic objects with sizes comparable to their wavelength. The longer the wavelength, the less surface attenuation. Radio waves travel at 186,000 miles per second in a vacuum.
- High frequencies require large antennas.
DOPPLER
- Doppler navigation systems use frequency shift in signals reflected from the ground to determine aircraft ground speed and drift.
- In day-to-day use, the greatest cause of error in Doppler systems is sea movement error.
- The largest error source in Doppler-derived position is cross-track errors due to compass errors.
- Doppler updating is undertaken when a new database is loaded, equipment is initialized with the date and time, and the atomic clock is actuated.
GROUND DIRECTION FINDER
- The maximum theoretical range for an aircraft at FL80 to obtain bearings from a ground VDF facility sited 325 ft above MSL is 134 NM.
- The maximum range at which a VDF station at 325 ft can provide service to an aircraft at FL080 is 107 nm.
- Responsibility for interpreting the procedure on a VHF approach rests with the controller, not the pilot in a QGH approach.
ADF
- Coastal refraction, timing errors, and night effects can contribute to errors in ADF bearing measurements.
- In ADF, static interference from thunderstorms contributes to error.
- Station interference, mountain effect, and site errors can cause ADF bearing inaccuracies.
- Coastal refraction, slant range, and night effect are factors that can cause inaccuracies in ADF bearings.
- A signal from an NDB aerial suffers from magnetic horizontal and vertical polarisation.
- In ADF, the BFO can be selected off for tone signals on NONA1A or NONA2A.
- The most pronounced night effect in ADF transmissions is at dusk and dawn.
- The ADF signal, when crossing from land to sea, bends and speeds up.
- When the loop aerial is in line with incoming signals from an NDB, the aerial is correctly aligned.
- With normal operation of ADF, the accuracy by day is ±5°.
- An aircraft heading 3150M receiving an NDB bearing of 1800 on the RMI experiences zero quadrantal errors.
- Short range NDBs transmit at 200 KHz.
- An aircraft wanting to use VDF assistance needs a VOR indicator unit.
VOR
- The phase difference between the reference and variable signals in a conventional VOR for QDM 0500 (VAR 100W) is 2300.
- VDF bearings are obtained from the Approach frequency.
- VDF bearings are the best if they are obtained on the ATC frequency agreed between the pilot and ATC.
- Skywaves, duct propagation, and ground reflections may affect the accuracy of VDF bearings, without synchronous transmission.
- A VDF bearing is influenced by time of day, type of surface, and height of the aircraft.
- VHF signal range for a transmitter at sea level to a receiver of 5000 feet is approximately 200 km.
ILS
- The maximum theoretical range an aircraft at FL 150 can receive signals from a 609 ft above MSL VOR is 184 NM.
- The glide slope and localizer centerlines have an angular coverage of ±10°.
- Coastal refraction is likely to cause the greatest inaccuracy in ADF bearings.
MLS
- MLS operates in the SHF band.
- The primary factor affecting the maximum range of a pulse radar is pulse repetition frequency.
- The main advantage of a slotted scanner is to reduce side lobes and get more energy into the main beam.
Other
- The pulse recurrence frequency a signal having a pulse interval of 5 microseconds is 200 KHz.
- In a cathode ray tube, the grid potential is negative with respect to the cathode, the same as the second anode.
- The size of a target on a primary radar screen depends on beam width for azimuth, and pulse length for range.
- Short range aerodrome radars will use millimetric or centimetric wave lengths.
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Description
This quiz covers fundamental concepts of decimetric waves and the Doppler effect, focusing on their applications in aviation. It explores topics such as frequency ranges, transmission principles, and how Doppler navigation systems function. Test your knowledge on radio wave behavior and the impact of frequencies on navigation.
