13.4 - Communication / Navigation (ATA34)

Fundamentals of Radio Wave Propagations

Objectives: -

At the end of this lesson the student will be able to explain the features of ground, space and sky waves.


Fundamentals of Radio Wave Propagations

The atmosphere is divided into 3:
-Troposphere (weather layer) - up to 10 km above earth's surface.
-Stratosphere (isothermal region) - 10 km to 60 km above earth's surface.
- Ionosphere - 60 km to 300 km above earth's surface.

The ionosphere is divided into 3 layers:
- D layer
- E layer
- F layer

The F layer is divided into 2 layers:
- F 1 - 80 km to 140 km high (mean value 110 km).
- F 2 -150 km to 400 km (average 300 km).

E layer reflects medium and long waves.
F layer reflects short waves.
Very short waves (UHF and SHF) are not reflected.

A reflected wave that hits the ground is known as a ‘HOP'.

Ground waves (surface waves) - waves that propagates above the earth's surface.

Space waves (tropospheric waves) - line of sight transmission.
Line of sight - optical horizon.
Distance from the transmit and a receive antennae - radio horizon.

Sky waves - has the ability of refracting the radiated waves.

Skipping - the refracting and reflecting action of the ionosphere.
Skip distance - the distance between the transmitting antenna and the Point where the refracted wave hit the ground.

(13_4_1_1b.swf)


Fundamentals of Radio Wave Propagations

The atmosphere is divided into 3:
-Troposphere (weather layer) - up to 10 km above earth's surface.
-Stratosphere (isothermal region) - 10 km to 60 km above earth's surface.
- Ionosphere - 60 km to 300 km above earth's surface.

The ionosphere is divided into 3 layers:
- D layer
- E layer
- F layer

The F layer is divided into 2 layers:
- F 1 - 80 km to 140 km high (mean value 110 km).
- F 2 -150 km to 400 km (average 300 km).

E layer reflects medium and long waves.
F layer reflects short waves.
Very short waves (UHF and SHF) are not reflected.

A reflected wave that hits the ground is known as a ‘HOP'.

Ground waves (surface waves) - waves that propagates above the earth's surface.

Space waves (tropospheric waves) - line of sight transmission.
Line of sight - optical horizon.
Distance from the transmit and a receive antennae - radio horizon.

Sky waves - has the ability of refracting the radiated waves.

Skipping - the refracting and reflecting action of the ionosphere.
Skip distance - the distance between the transmitting antenna and the Point where the refracted wave hit the ground.

(13_4_1_1c.swf)


Fundamentals of Radio Wave Propagations

The atmosphere is divided into 3:
-Troposphere (weather layer) - up to 10 km above earth's surface.
-Stratosphere (isothermal region) - 10 km to 60 km above earth's surface.
- Ionosphere - 60 km to 300 km above earth's surface.

The ionosphere is divided into 3 layers:
- D layer
- E layer
- F layer

The F layer is divided into 2 layers:
- F 1 - 80 km to 140 km high (mean value 110 km).
- F 2 -150 km to 400 km (average 300 km).

E layer reflects medium and long waves.
F layer reflects short waves.
Very short waves (UHF and SHF) are not reflected.

A reflected wave that hits the ground is known as a ‘HOP'.

Ground waves (surface waves) - waves that propagates above the earth's surface.

Space waves (tropospheric waves) - line of sight transmission.
Line of sight - optical horizon.
Distance from the transmit and a receive antennae - radio horizon.

Sky waves - has the ability of refracting the radiated waves.

Skipping - the refracting and reflecting action of the ionosphere.
Skip distance - the distance between the transmitting antenna and the Point where the refracted wave hit the ground.

(13_4_1_1d.swf)


Fundamentals of Radio Wave Propagations

The atmosphere is divided into 3:
-Troposphere (weather layer) - up to 10 km above earth's surface.
-Stratosphere (isothermal region) - 10 km to 60 km above earth's surface.
- Ionosphere - 60 km to 300 km above earth's surface.

The ionosphere is divided into 3 layers:
- D layer
- E layer
- F layer

The F layer is divided into 2 layers:
- F 1 - 80 km to 140 km high (mean value 110 km).
- F 2 -150 km to 400 km (average 300 km).

E layer reflects medium and long waves.
F layer reflects short waves.
Very short waves (UHF and SHF) are not reflected.

A reflected wave that hits the ground is known as a ‘HOP'.

Ground waves (surface waves) - waves that propagates above the earth's surface.

Space waves (tropospheric waves) - line of sight transmission.
Line of sight - optical horizon.
Distance from the transmit and a receive antennae - radio horizon.

Sky waves - has the ability of refracting the radiated waves.

Skipping - the refracting and reflecting action of the ionosphere.
Skip distance - the distance between the transmitting antenna and the Point where the refracted wave hit the ground.

(13_4_1_1e.swf)

Fundamentals of Radio Wave Propagations

The atmosphere is divided into 3:
-Troposphere (weather layer) - up to 10 km above earth's surface.
-Stratosphere (isothermal region) - 10 km to 60 km above earth's surface.
- Ionosphere - 60 km to 300 km above earth's surface.

The ionosphere is divided into 3 layers:
- D layer
- E layer
- F layer

The F layer is divided into 2 layers:
- F 1 - 80 km to 140 km high (mean value 110 km).
- F 2 -150 km to 400 km (average 300 km).

E layer reflects medium and long waves.
F layer reflects short waves.
Very short waves (UHF and SHF) are not reflected.

A reflected wave that hits the ground is known as a ‘HOP'.

Ground waves (surface waves) - waves that propagates above the earth's surface.

Space waves (tropospheric waves) - line of sight transmission.
Line of sight - optical horizon.
Distance from the transmit and a receive antennae - radio horizon.

Sky waves - has the ability of refracting the radiated waves.

Skipping - the refracting and reflecting action of the ionosphere.
Skip distance - the distance between the transmitting antenna and the Point where the refracted wave hit the ground.

(13_4_1_1f.swf)


Questions: -

1. What is the distance of the stratosphere from the earth?
10 Km
150 Km
70 Km

2. Which layer of the atmosphere will the medium and long waves transmission be refracted?
D layer
E layer
F layer

3. When any of the transmitted energy is refracted back to earth, it is called?
Skip distance
Hop
Refraction

4. The ground waves are also known as?
Surface waves
Line-of-sight waves
Tropospheric waves

5. The reflecting and refracting action of the ionosphere is called?
Skip distance
Skipping
Hop distance

6. The radio horizon has a greater communication distance.
True/False

Fundamentals of Radio Wave Propagations

Objectives :-

At the end of this lesson, the student will be able to explain on :-

1. The causes of Fading.
2. Difference between line of sight and HF Transmission.
3. The Term “Diversity Reception”.


Fundamentals of Radio Wave Propagations

Line-of-sight (LOS) travels almost in a straight line (radio horizon).

Shadow zone
- Area behind an object where no reception is available Extensive coverage is possible with Multi-hop operation.

Critical angle
- The highest angle at which a wave can be propagated and still be returned to the ground.

Critical frequency
- The highest frequency returning to earth when transmitted vertically.

Maximum useable frequency
- The highest frequency which is returned to earth at a given distance.

Optimum working frequency
- The frequency which provides the best performance communication.

Fading
- The variations in signal strength that occur at a receiver during the time a signal is being received. Fading may occur at a point where both, both the ground and sky waves is
received in out-of-phase. A method used for reducing the fading effects is by diversity reception.

Diversity reception
- 2 or more antennae at 1 or 2 wavelength apart and their audio combined to reduce fading.

(13_4_1_2b.swf)


Fundamentals of Radio Wave Propagations

Line-of-sight (LOS) travels almost in a straight line (radio horizon).

Shadow zone
- Area behind an object where no reception is available Extensive coverage is possible with Multi-hop operation.

Critical angle
- The highest angle at which a wave can be propagated and still be returned to the ground.

Critical frequency
- The highest frequency returning to earth when transmitted vertically.

Maximum useable frequency
- The highest frequency which is returned to earth at a given distance.

Optimum working frequency
- The frequency which provides the best performance communication.

Fading
- The variations in signal strength that occur at a receiver during the time a signal is being received. Fading may occur at a point where both, both the ground and sky waves is
received in out-of-phase. A method used for reducing the fading effects is by diversity reception.

Diversity reception
- 2 or more antennae at 1 or 2 wavelength apart and their audio combined to reduce fading.

(13_4_1_2c.swf)


Fundamentals of Radio Wave Propagations

Line-of-sight (LOS) travels almost in a straight line (radio horizon).

Shadow zone
- Area behind an object where no reception is available Extensive coverage is possible with Multi-hop operation.

Critical angle
- The highest angle at which a wave can be propagated and still be returned to the ground.

Critical frequency
- The highest frequency returning to earth when transmitted vertically.

Maximum useable frequency
- The highest frequency which is returned to earth at a given distance.

Optimum working frequency
- The frequency which provides the best performance communication.

Fading
- The variations in signal strength that occur at a receiver during the time a signal is being received. Fading may occur at a point where both, both the ground and sky waves is
received in out-of-phase. A method used for reducing the fading effects is by diversity reception.

Diversity reception
- 2 or more antennae at 1 or 2 wavelength apart and their audio combined to reduce fading.

(13_4_1_2d.swf)


Fading
- The variations in signal strength that occur at a receiver during the time a signal is being received. Fading may occur at a point where both, both the ground and sky waves is
received in out-of-phase. A method used for reducing the fading effects is by diversity reception.

Diversity reception
- 2 or more antennae at 1 or 2 wavelength apart and their audio combined to reduce fading.

(13_4_1_2e.swf)


Fading
- The variations in signal strength that occur at a receiver during the time a signal is being received. Fading may occur at a point where both, both the ground and sky waves is
received in out-of-phase. A method used for reducing the fading effects is by diversity reception.

Diversity reception
- 2 or more antennae at 1 or 2 wavelength apart and their audio combined to reduce fading.

(13_4_1_2f.swf)


Questions: -

1. The area behind an object where no reception is possible is known as?
Hollow zone.
Shadow zone.
Contour zone.

2. The highest frequency returning to earth when transmitting vertically is known as?
Optimum working frequency.
Critical frequency.
Maximum useable frequency.

3. What is fading?
a. A receiving antenna receives only the ground waves in-phase.
b. A receiving antenna receives the ground and sky waves out-of-phase.
c. A receiving antenna receives the sky waves in-phase.

4. Diversity reception is a common method of reducing fading?
True/False


Fundamentals Of Antenna

Objectives: -

At the end of this lesson the student will be able to explain: -

1. Relationship between voltage and current on an antenna.
2. The term ‘Antenna Impedance’ and name Typical Values.
3. The difference between electrical and physical length of an antenna.


Fundamentals Of Antenna

Purpose of an antenna:
- Radiate electromagnetic energy into space.
- Intercept electromagnetic energy in space.
- Radiate and intercept electromagnetic energy.

Omni-directional antenna
- Radiates energy in all directions.

Directional antenna
- Radiates energy in one direction only (point-to-point communication).

λ/2 dipole antenna
- Has a theoretical length of 1/2 wavelength of the applied frequency.

Open-ended transmission line
- High voltage and low current at the end.

Short-circuited transmission line
- Low voltage and high current at the end.

Theoretical length
- Is referred to as the electrical length of the antenna .

Actual length
- Is referred to as the physical length and is 95% of the theoretical length.

Radiation resistance
- The value of the resistance that dissipates maximum Power.

(13_4_1_3b.swf)


Fundamentals Of Antenna

Purpose of an antenna:
- Radiate electromagnetic energy into space.
- Intercept electromagnetic energy in space.
- Radiate and intercept electromagnetic energy.

Omni-directional antenna
- Radiates energy in all directions.

Directional antenna
- Radiates energy in one direction only (point-to-point communication).

λ/2 dipole antenna
- Has a theoretical length of 1/2 wavelength of the applied frequency.

Open-ended transmission line
- High voltage and low current at the end.

Short-circuited transmission line
- Low voltage and high current at the end.

Theoretical length
- Is referred to as the electrical length of the antenna .

Actual length
- Is referred to as the physical length and is 95% of the theoretical length.

Radiation resistance
- The value of the resistance that dissipates maximum Power.

(13_4_1_3c.swf)


Fundamentals Of Antenna

Purpose of an antenna:
- Radiate electromagnetic energy into space.
- Intercept electromagnetic energy in space.
- Radiate and intercept electromagnetic energy.

Omni-directional antenna
- Radiates energy in all directions.

Directional antenna
- Radiates energy in one direction only (point-to-point communication).

λ/2 dipole antenna
- Has a theoretical length of 1/2 wavelength of the applied frequency.

Open-ended transmission line
- High voltage and low current at the end.

Short-circuited transmission line
- Low voltage and high current at the end.

Theoretical length
- Is referred to as the electrical length of the antenna .

Actual length
- Is referred to as the physical length and is 95% of the theoretical length.

Radiation resistance
- The value of the resistance that dissipates maximum Power.

(13_4_1_3d.swf)


Fundamentals Of Antenna

Purpose of an antenna:
- Radiate electromagnetic energy into space.
- Intercept electromagnetic energy in space.
- Radiate and intercept electromagnetic energy.

Omni-directional antenna
- Radiates energy in all directions.

Directional antenna
- Radiates energy in one direction only (point-to-point communication).

λ/2 dipole antenna
- Has a theoretical length of 1/2 wavelength of the applied frequency.

Open-ended transmission line
- High voltage and low current at the end.

Short-circuited transmission line
- Low voltage and high current at the end.

Theoretical length
- Is referred to as the electrical length of the antenna .

Actual length
- Is referred to as the physical length and is 95% of the theoretical length.

Radiation resistance
- The value of the resistance that dissipates maximum Power.

(13_4_1_3e.swf)

Fundamentals Of Antenna

Purpose of an antenna:
- Radiate electromagnetic energy into space.
- Intercept electromagnetic energy in space.
- Radiate and intercept electromagnetic energy.

Omni-directional antenna
- Radiates energy in all directions.

Directional antenna
- Radiates energy in one direction only (point-to-point communication).

λ/2 dipole antenna
- Has a theoretical length of 1/2 wavelength of the applied frequency.

Open-ended transmission line
- High voltage and low current at the end.

Short-circuited transmission line
- Low voltage and high current at the end.

Theoretical length
- Is referred to as the electrical length of the antenna .

Actual length
- Is referred to as the physical length and is 95% of the theoretical length.

Radiation resistance
- The value of the resistance that dissipates maximum Power.

(13_4_1_3f.swf)

Questions: -

1. What is the purpose of an antenna?
a. To intercept electromagnetic energy.
b. To radiate and intercept electromagnetic energy.
c. To radiate electromagnetic energy.

2. What is an omni-directional antenna?
a. An antenna which radiates energy only in one direction.
b. An antenna which radiates 180 degrees only.
c. An antenna which radiates energy in all directions.


3. In an open-ended transmission line, what is the voltage level?
a. Minimum.
b. Maximum.
c. Average.

4. If the theoretical length of an antenna is 10 meters, what will the physical length of the antenna be?
a. 0.95 meters.
b. 10.95 meters.
c. 9.5 meters.


Fundamentals of Antenna

Objective: -

At the end of this lesson the student will be able to explain the characteristics of a typical antenna application.


Fundamentals of Antenna

Marconi antenna is ½ of a dipole antenna. That is ¼ wave length the ground acts as the other ¼ wave length.

Counterpoise
- Burying a large number of heavy copper wires into the ground the antenna to provide a good grounding.

Folded dipole
- 1 wave length aluminium tube that is folded into a λ/2 flattened loop.

Yagi antenna
- A linear array consisting of a dipole and 2 or more Parasitic elements. Increases gain and directivity of antenna.

Log-periodic antenna
- Consists of an array of dipoles, cut at different lengths so as to have a wide bandwidth.

(13_4_1_4b.swf)


Fundamentals of Antenna

Marconi antenna is ½ of a dipole antenna. That is ¼ wave length the ground acts as the other ¼ wave length.

Counterpoise
- Burying a large number of heavy copper wires into the ground the antenna to provide a good grounding.

Folded dipole
- 1 wave length aluminium tube that is folded into a λ/2 flattened loop.

Yagi antenna
- A linear array consisting of a dipole and 2 or more Parasitic elements. Increases gain and directivity of antenna.

Log-periodic antenna
- Consists of an array of dipoles, cut at different lengths so as to have a wide bandwidth.

(13_4_1_4c.swf)


Fundamentals of Antenna

Marconi antenna is ½ of a dipole antenna. That is ¼ wave length the ground acts as the other ¼ wave length.

Counterpoise
- Burying a large number of heavy copper wires into the ground the antenna to provide a good grounding.

Folded dipole
- 1 wave length aluminium tube that is folded into a λ/2 flattened loop.

Yagi antenna
- A linear array consisting of a dipole and 2 or more Parasitic elements. Increases gain and directivity of antenna.

Log-periodic antenna
- Consists of an array of dipoles, cut at different lengths so as to have a wide bandwidth.

(13_4_1_4d.swf)


Fundamentals of Antenna

Marconi antenna is ½ of a dipole antenna. That is ¼ wave length the ground acts as the other ¼ wave length.

Counterpoise
- Burying a large number of heavy copper wires into the ground the antenna to provide a good grounding.

Folded dipole
- 1 wave length aluminium tube that is folded into a λ/2 flattened loop.

Yagi antenna
- A linear array consisting of a dipole and 2 or more Parasitic elements. Increases gain and directivity of antenna.

Log-periodic antenna
- Consists of an array of dipoles, cut at different lengths so as to have a wide bandwidth.

(13_4_1_4e.swf)


Questions: -

1. What is the length of a Marconi antenna?
¼ wave length.
½ wave length.
1 wave length.

2. What is the purpose of counterpoise?
To lower the ground conductivity.
To hold the antenna in position.
To better the ground conductivity.

3. With the same input power, the FD antenna input current will be __________ that of the ½ wave dipole with the same input voltage.
a. 1/4
b. 1/2
c. 1

4. What is the bandwidth of the Log-periodic dipole array?
Narrow.
Medium.
Broad.

5. The Yagi antenna is a linear array consisting of a dipole and 2 or more parasitic elements.
True/False

Fundamentals of Antenna

Objectives: -

At the end of this lesson the student will be able to: -

1. Origin of standing waves on a transmission line.
2. Term ‘Voltage Standing Wave Ratio’.
3. Purpose of impedance matching.


Fundamentals of Antenna

Standing waves - produced when load impedance is not equal to the input impedance of the transmission line.
ZL = ZO - no standing waves are produced.
ZL > ZO - standing waves are produced.

Maximum VSWR is formed when the incident and reflected waves are exactly in-phase.

(13_4_1_5b.swf)


Fundamentals of Antenna

Standing waves - produced when load impedance is not equal to the input impedance of the transmission line.
ZL = ZO - no standing waves are produced.
ZL > ZO - standing waves are produced.

Maximum VSWR is formed when the incident and reflected waves are exactly in-phase.

(13_4_1_5c.swf)


Questions: -

1. If the incident and reflected waves are in-phase, what will the VSWR be?
a. Minimum.
b. Maximum.
c. Average.

2. If a 1/4 wave length section of a transmission line is short-circuited, what will be the impedance at the shorted end?
a. High.
b. Low.
c. 73 Ohms.


Fundamentals of Transmission Lines

Objective: -

At the end of this lesson the student will be able to explain Fundamentals of Transmission Lines.


Impedance characteristics:
-At maximum voltage - infinity impedance.
- At zero voltage - low impedance.

Short-circuited transmission line:
-Maximum current at the end of transmission line.
-Zero voltage at the end of transmission line. (Repeats itself every), λ /2)

Filters:
- λ/4 line shorted at the end – low impedance to the fundamental frequency.
- λ/4 line open at one end - high impedance to the fundamental frequency.

(13_4_1_6b.swf)


Impedance characteristics:
-At maximum voltage - infinity impedance.
- At zero voltage - low impedance.

Short-circuited transmission line:
-Maximum current at the end of transmission line.
-Zero voltage at the end of transmission line. (Repeats itself every), λ /2)

Filters:
- λ/4 line shorted at the end – low impedance to the fundamental frequency.
- λ/4 line open at one end - high impedance to the fundamental frequency.

(13_4_1_6c.swf)

In a transmission line there are:
- Resistance
- Capacitance
- Inductance
- Conductance

Inductance and capacitance depends on:
- Distance between the 2 wires.
- Dielectric constant of the isolating material between the 2 wires.

Reactance depends on:
- Frequency selected.

Characteristic impedance (surge impedance)
- Calculation of current and voltage in a line by ohms law.

Zo = L/C
Characteristic impedance of 2 wires with air as dielectric:
Zo = 276 log 2D/d.
Characteristic impedance of concentric or coaxial line:
Zo = 138 log D/d.

Open-ended transmission line:
- Maximum voltage at the end of line.
- Zero current at the end of line. (Repeats itself, every λ/2).
(13_4_1_6d.swf)

In a transmission line there are:
- Resistance
- Capacitance
- Inductance
- Conductance

Inductance and capacitance depends on:
- Distance between the 2 wires.
- Dielectric constant of the isolating material between the 2 wires.

Reactance depends on:
- Frequency selected.

Characteristic impedance (surge impedance)
- Calculation of current and voltage in a line by ohms law.

Zo = L/C
Characteristic impedance of 2 wires with air as dielectric:
Zo = 276 log 2D/d.
Characteristic impedance of concentric or coaxial line:
Zo = 138 log D/d.

Open-ended transmission line:
- Maximum voltage at the end of line.
- Zero current at the end of line. (Repeats itself, every λ/2).
(13_4_1_6e.swf)


In a transmission line there are:
- Resistance
- Capacitance
- Inductance
- Conductance

Inductance and capacitance depends on:
- Distance between the 2 wires.
- Dielectric constant of the isolating material between the 2 wires.

Reactance depends on:
- Frequency selected.

Characteristic impedance (surge impedance)
- Calculation of current and voltage in a line by ohms law.

Zo = L/C
Characteristic impedance of 2 wires with air as dielectric:
Zo = 276 log 2D/d.
Characteristic impedance of concentric or coaxial line:
Zo = 138 log D/d.

Open-ended transmission line:
- Maximum voltage at the end of line.
- Zero current at the end of line. (Repeats itself, every λ/2).
(13_4_1_6f.swf)


In a transmission line there are:
- Resistance
- Capacitance
- Inductance
- Conductance

Inductance and capacitance depends on:
- Distance between the 2 wires.
- Dielectric constant of the isolating material between the 2 wires.

Reactance depends on:
- Frequency selected.

Characteristic impedance (surge impedance)
- Calculation of current and voltage in a line by ohms law.

Zo = L/C
Characteristic impedance of 2 wires with air as dielectric:
Zo = 276 log 2D/d.
Characteristic impedance of concentric or coaxial line:
Zo = 138 log D/d.

Open-ended transmission line:
- Maximum voltage at the end of line.
- Zero current at the end of line. (Repeats itself, every λ/2).
(13_4_1_6g.swf)


Questions: -

1. What factor contributes to the reactance of a transmission line?
a. Frequency.
b. Capacitance.
c. Resistance.

2. What is the possible impedance at the end of an open-ended transmission line?
Low.
High.
Infinity.

3. What is the possible voltage at the end of a short-circuit transmission line?
a. High.
b. Zero.
c. Medium.

Fundamentals of Communications Transmitters and Receivers

Objectives: -

At the end of this lesson, the student will be to explain fundamentals of communication transmitters and receivers.


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7b.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7c.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7d.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7e.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7f.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7g.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7h.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7i.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7j.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7k.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7l.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7m.swf)


Peak power
- Carrier power and both sidebands are in phase. A SSB transmitter power is often rated in Peak Envelope Power (PEP). An AM transmitter power is often rated in peak instantaneous power. P = U² /R

1. Basic receiver should carry out the following:
- Reception of the signal.
- Selection of the wanted signal.
- Detection of the intelligence.
- Reproduction of the intelligence.

2. Selectivity
- Ability of a receiver to reproduce the signal of a weak station.

3. Selectivity
- Ability of a receiver to reject the unwanted signal and reproduce the wanted signal.

4. Fidelity
- When a receiver determines the highest modulating frequency contained in the sidebands that can be reproduced.

5. Image frequency
- A frequency which is 2 times the intermediate frequency.

6. AGC.
- To maintain a constant output level at all times.

(13_4_1_7n.swf)

Question: -

1. What is Selectivity?
a. The ability of a receiver to reproduce a weak signal.
b. The ability of a receiver to reproduce only the wanted signal and reject the unwanted signal.
c. The ability of a receiver to provide a very high gain output.

2. If the IF is 455KHz and the selected frequency is 1505 KHz, what is the image frequency?
2000 KHz.
2455KHz.
1505 KHz.

3. What is the purpose of an AGC circuit in a receiver?
To maintain the output at constant level at all times.
To vary the output level according to the operator's requirement.
To select a new intermediate frequency automatically.

4. How many intermediate frequencies does a double superhet receiver have?
a. 3.
b. 2.
c. 1.

Very High Frequency (VHF)

Objectives: -

At the end of this lesson, the student will be to: -

1. List the main sections of the VHF Communication Systems.
2. Explain the principle of Operations of the Receiver, Transmitter and Control Section.
3. Describe the theory of operation of the major sections of the VHF system.

Very High Frequency (VHF)

- Frequency range - 118 MHz to 136.975 MHz.
- Purpose - Air to air and air to ground communication.

- Intermediate Frequency - 11.4 MHz.

- Power requirement - 27.5 volts.
- A typical VHF transceiver consists of:
- Receiver section.
- Transmitter section.
- Control and power supply sections.

- During transmit mode, a ‘T’ is displayed on the display window.
- A photo cell - Decreases the density of the display during the night.
- Audio amp output - 100 m W.
- If non-volatile memory fails - 120.000 MHz will be displayed.

(13_4_2_1b.swf)


Very High Frequency (VHF)

- Frequency range - 118 MHz to 136.975 MHz.
- Purpose - Air to air and air to ground communication.

- Intermediate Frequency - 11.4 MHz.

- Power requirement - 27.5 volts.
- A typical VHF transceiver consists of:
- Receiver section.
- Transmitter section.
- Control and power supply sections.

- During transmit mode, a ‘T’ is displayed on the display window.
- A photo cell - Decreases the density of the display during the night.
- Audio amp output - 100 m W.
- If non-volatile memory fails - 120.000 MHz will be displayed.

(13_4_2_1c.swf)


Very High Frequency (VHF)

- Frequency range - 118 MHz to 136.975 MHz.
- Purpose - Air to air and air to ground communication.

- Intermediate Frequency - 11.4 MHz.

- Power requirement - 27.5 volts.
- A typical VHF transceiver consists of:
- Receiver section.
- Transmitter section.
- Control and power supply sections.

- During transmit mode, a ‘T’ is displayed on the display window.
- A photo cell - Decreases the density of the display during the night.
- Audio amp output - 100 m W.
- If non-volatile memory fails - 120.000 MHz will be displayed.

(13_4_2_1d.swf)


Very High Frequency (VHF)

- Frequency range - 118 MHz to 136.975 MHz.
- Purpose - Air to air and air to ground communication.

- Intermediate Frequency - 11.4 MHz.

- Power requirement - 27.5 volts.
- A typical VHF transceiver consists of:
- Receiver section.
- Transmitter section.
- Control and power supply sections.

- During transmit mode, a ‘T’ is displayed on the display window.
- A photo cell - Decreases the density of the display during the night.
- Audio amp output - 100 m W.
- If non-volatile memory fails - 120.000 MHz will be displayed.

(13_4_2_1e.swf)

Very High Frequency (VHF)

- Frequency range - 118 MHz to 136.975 MHz.
- Purpose - Air to air and air to ground communication.

- Intermediate Frequency - 11.4 MHz.

- Power requirement - 27.5 volts.
- A typical VHF transceiver consists of:
- Receiver section.
- Transmitter section.
- Control and power supply sections.

- During transmit mode, a ‘T’ is displayed on the display window.
- A photo cell - Decreases the density of the display during the night.
- Audio amp output - 100 m W.
- If non-volatile memory fails - 120.000 MHz will be displayed.

(13_4_2_1f.swf)


Very High Frequency (VHF)

- Frequency range - 118 MHz to 136.975 MHz.
- Purpose - Air to air and air to ground communication.

- Intermediate Frequency - 11.4 MHz.

- Power requirement - 27.5 volts.
- A typical VHF transceiver consists of:
- Receiver section.
- Transmitter section.
- Control and power supply sections.

- During transmit mode, a ‘T’ is displayed on the display window.
- A photo cell - Decreases the density of the display during the night.
- Audio amp output - 100 m W.
- If non-volatile memory fails - 120.000 MHz will be displayed.

(13_4_2_1g.swf)


Very High Frequency (VHF)

- Frequency range - 118 MHz to 136.975 MHz.
- Purpose - Air to air and air to ground communication.

- Intermediate Frequency - 11.4 MHz.

- Power requirement - 27.5 volts.
- A typical VHF transceiver consists of:
- Receiver section.
- Transmitter section.
- Control and power supply sections.

- During transmit mode, a ‘T’ is displayed on the display window.
- A photo cell - Decreases the density of the display during the night.
- Audio amp output - 100 m W.
- If non-volatile memory fails - 120.000 MHz will be displayed.

(13_4_2_1h.swf)


Very High Frequency (VHF)

- Frequency range - 118 MHz to 136.975 MHz.
- Purpose - Air to air and air to ground communication.

- Intermediate Frequency - 11.4 MHz.

- Power requirement - 27.5 volts.
- A typical VHF transceiver consists of:
- Receiver section.
- Transmitter section.
- Control and power supply sections.

- During transmit mode, a ‘T’ is displayed on the display window.
- A photo cell - Decreases the density of the display during the night.
- Audio amp output - 100 m W.
- If non-volatile memory fails - 120.000 MHz will be displayed.

(13_4_2_1i.swf)

Questions: -

1. What is the output power of the preamplifier?
a. 100 W
b. 1000 W
c. 100 m W

2. What is the intermediate frequency of the VHF system?
a. 1.14 MHz
b. 11.4 MHz
c. 114 MHz
3. What is the frequency range of the VHF system?
187 MHz to 236.975 MHz
119 MHz to 336.975 MHz
118 MHz to 136.975 MHz

High Frequency (HF)

Objectives: -

At the end of this lesson the student will be able to: -

1. Describe a typical HF communication system used in an airplane.
2. List the major units of a typical system and explain their functions.
3. Explain with the aid of block diagrams, the signal flow and operation of the major units.

High Frequency (HF)

Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2b.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2c.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2d.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2e.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2f.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2g.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2h.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2i.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2j.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2k.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2l.swf)


Frequency range

- 2 MHz to 30 MHz.
- 280,000 channels @ 0.1 KHz increment.
- 40 simplex programmed channels.
- 136 half duplex programmed channels.
- Exciter output power -250 mW PEP.
- Power amplifier output - 100 Watts PEP.
- Output impedance of power amp - 50 ohms.
- Power supply 28 volts.

A typical airborne HF system consists of:

- Control / display unit.
- Power on off switch.
- Selection of USB, LSB or AM.
- Selection of A3A or A3J modes.
- Volume control.
- Squelch control.
- Clarifier control (±100 Hz).
- Channel/frequency switch.
- Channel/frequency controls.

- Transceiver.
- Frequency synthesizer (fixed 69.3 MHz USB, 70.3 MHz LSB and 500 khz).
- Receive function.
- Transmit function

- Power amplifier.
- Automatic antenna coupler.
- Tuning cycle.
- Home.
- Standby
- Tune.
- Operate.

(13_4_2_2m.swf)

Questions: -

1. A typical airborne HF communication system consists of: -
a. 4 unit.
b. 2 unit.
c. 6 unit.

2. What is the frequency range of the HF system?
2 KHz to 30 MHz.
2 MHz to 30 MHz.
20 MHz to 30 MHz.

3. What is the output power of the exciter?
250 W.
100 W.
250 mW.

4. What is the purpose of the clarifier control?
To vary the receiver injection frequency by 100 Hz on USB or A3A/A3i mode.
To vary the receiver injection frequency by 100 Hz on AM.
To vary the transmit frequency.

5. What is the purpose of the antenna coupler?
To amplify the transmit signal.
To provide impedance matching.
To amplify the receive signal.

6. State the sequence of the 4 steps of the tuning cycle: -
Home, standby, tune and operate.
Operate, tune, standby and home.
Tune, operate, standby and home.

Audio Integration

Objectives: -

At the end of this lesson the student will be able to: -

1. Describe the purpose of the Audio system.
2. Explain with the Aid of a Block Diagram, the function of the components of a typical Audio integrating system.
3. Describe the purpose of the Public Address System.


Audio Integration

Flight inter-phone system.
- Communication between flight crewmembers.

Service inter-phone system.
- Communication between flight crew, attendant and ground service personnel.

Power supply: 28 volts DC.

GND CREW switch.
- To alert the ground crew that the pilot wants intercommunication.

PILOT CALL switch.
- To tell the pilot that the ground crew wants to intercommunicate.

SERVICE INTERPHONE switch.
- To energize numerous interphone jacks throughout the aircraft.

CAB switch and volume control.
- Lets the flight crew to use the service interphone.

EMERGENCY SERVICE SELECTION.
- To by pass the isolation amplifier in case of the iso-amp failure.

ANTI - CROSSTALK NETWORK.
- To prevent unwanted interaction between selected receiver audio.

AMPSPEAKERS.
- To amplify the received audio and supply to the speakers.

OVERRIDE.
- The pilot’s priority to switch on the intercom systems.

PA amplifier.
- To provide 2 tone chime before announcement or when Cabin ‘SEAT BELT’ or ‘NO SMOKE’ are activated.

High-level switches.
- When engine power levers are at 80%, the audios to the speakers are increased.

(13_4_2_3b.swf)

Audio Integration

Flight inter-phone system.
- Communication between flight crewmembers.

Service inter-phone system.
- Communication between flight crew, attendant and ground service personnel.

Power supply: 28 volts DC.

GND CREW switch.
- To alert the ground crew that the pilot wants intercommunication.

PILOT CALL switch.
- To tell the pilot that the ground crew wants to intercommunicate.

SERVICE INTERPHONE switch.
- To energize numerous interphone jacks throughout the aircraft.

CAB switch and volume control.
- Lets the flight crew to use the service interphone.

EMERGENCY SERVICE SELECTION.
- To by pass the isolation amplifier in case of the iso-amp failure.

ANTI - CROSSTALK NETWORK.
- To prevent unwanted interaction between selected receiver audio.

AMPSPEAKERS.
- To amplify the received audio and supply to the speakers.

OVERRIDE.
- The pilot’s priority to switch on the intercom systems.

PA amplifier.
- To provide 2 tone chime before announcement or when Cabin ‘SEAT BELT’ or ‘NO SMOKE’ are activated.

High-level switches.
- When engine power levers are at 80%, the audios to the speakers are increased.

(13_4_2_3c.swf)

Flight inter-phone system.
- Communication between flight crewmembers.

Service inter-phone system.
- Communication between flight crew, attendant and ground service personnel.

Power supply: 28 volts DC.

GND CREW switch.
- To alert the ground crew that the pilot wants intercommunication.

PILOT CALL switch.
- To tell the pilot that the ground crew wants to intercommunicate.

SERVICE INTERPHONE switch.
- To energize numerous interphone jacks throughout the aircraft.

CAB switch and volume control.
- Lets the flight crew to use the service interphone.

EMERGENCY SERVICE SELECTION.
- To by pass the isolation amplifier in case of the iso-amp failure.

ANTI - CROSSTALK NETWORK.
- To prevent unwanted interaction between selected receiver audio.

AMPSPEAKERS.
- To amplify the received audio and supply to the speakers.

OVERRIDE.
- The pilot’s priority to switch on the intercom systems.

PA amplifier.
- To provide 2 tone chime before announcement or when Cabin ‘SEAT BELT’ or ‘NO SMOKE’ are activated.

High-level switches.
- When engine power levers are at 80%, the audios to the speakers are increased.

(13_4_2_3d.swf)

Flight inter-phone system.
- Communication between flight crewmembers.

Service inter-phone system.
- Communication between flight crew, attendant and ground service personnel.

Power supply: 28 volts DC.

GND CREW switch.
- To alert the ground crew that the pilot wants intercommunication.

PILOT CALL switch.
- To tell the pilot that the ground crew wants to intercommunicate.

SERVICE INTERPHONE switch.
- To energize numerous interphone jacks throughout the aircraft.

CAB switch and volume control.
- Lets the flight crew to use the service interphone.

EMERGENCY SERVICE SELECTION.
- To by pass the isolation amplifier in case of the iso-amp failure.

ANTI - CROSSTALK NETWORK.
- To prevent unwanted interaction between selected receiver audio.

AMPSPEAKERS.
- To amplify the received audio and supply to the speakers.

OVERRIDE.
- The pilot’s priority to switch on the intercom systems.

PA amplifier.
- To provide 2 tone chime before announcement or when Cabin ‘SEAT BELT’ or ‘NO SMOKE’ are activated.

High-level switches.
- When engine power levers are at 80%, the audios to the speakers are increased.

(13_4_2_3e.swf)

Flight inter-phone system.
- Communication between flight crewmembers.

Service inter-phone system.
- Communication between flight crew, attendant and ground service personnel.

Power supply: 28 volts DC.

GND CREW switch.
- To alert the ground crew that the pilot wants intercommunication.

PILOT CALL switch.
- To tell the pilot that the ground crew wants to intercommunicate.

SERVICE INTERPHONE switch.
- To energize numerous interphone jacks throughout the aircraft.

CAB switch and volume control.
- Lets the flight crew to use the service interphone.

EMERGENCY SERVICE SELECTION.
- To by pass the isolation amplifier in case of the iso-amp failure.

ANTI - CROSSTALK NETWORK.
- To prevent unwanted interaction between selected receiver audio.

AMPSPEAKERS.
- To amplify the received audio and supply to the speakers.

OVERRIDE.
- The pilot’s priority to switch on the intercom systems.

PA amplifier.
- To provide 2 tone chime before announcement or when Cabin ‘SEAT BELT’ or ‘NO SMOKE’ are activated.

High-level switches.
- When engine power levers are at 80%, the audios to the speakers are increased.

(13_4_2_3f.swf)

Flight inter-phone system.
- Communication between flight crewmembers.

Service inter-phone system.
- Communication between flight crew, attendant and ground service personnel.

Power supply: 28 volts DC.

GND CREW switch.
- To alert the ground crew that the pilot wants intercommunication.

PILOT CALL switch.
- To tell the pilot that the ground crew wants to intercommunicate.

SERVICE INTERPHONE switch.
- To energize numerous interphone jacks throughout the aircraft.

CAB switch and volume control.
- Lets the flight crew to use the service interphone.

EMERGENCY SERVICE SELECTION.
- To by pass the isolation amplifier in case of the iso-amp failure.

ANTI - CROSSTALK NETWORK.
- To prevent unwanted interaction between selected receiver audio.

AMPSPEAKERS.
- To amplify the received audio and supply to the speakers.

OVERRIDE.
- The pilot’s priority to switch on the intercom systems.

PA amplifier.
- To provide 2 tone chime before announcement or when Cabin ‘SEAT BELT’ or ‘NO SMOKE’ are activated.

High-level switches.
- When engine power levers are at 80%, the audios to the speakers are increased.

(13_4_2_3g.swf)

Flight inter-phone system.
- Communication between flight crewmembers.

Service inter-phone system.
- Communication between flight crew, attendant and ground service personnel.

Power supply: 28 volts DC.

GND CREW switch.
- To alert the ground crew that the pilot wants intercommunication.

PILOT CALL switch.
- To tell the pilot that the ground crew wants to intercommunicate.

SERVICE INTERPHONE switch.
- To energize numerous interphone jacks throughout the aircraft.

CAB switch and volume control.
- Lets the flight crew to use the service interphone.

EMERGENCY SERVICE SELECTION.
- To by pass the isolation amplifier in case of the iso-amp failure.

ANTI - CROSSTALK NETWORK.
- To prevent unwanted interaction between selected receiver audio.

AMPSPEAKERS.
- To amplify the received audio and supply to the speakers.

OVERRIDE.
- The pilot’s priority to switch on the intercom systems.

PA amplifier.
- To provide 2 tone chime before announcement or when Cabin ‘SEAT BELT’ or ‘NO SMOKE’ are activated.

High-level switches.
- When engine power levers are at 80%, the audios to the speakers are increased.

(13_4_2_3h.swf)

Questions: -

1. What is the purpose of the flight interphone system?
To provide intercommunication between flight crew and attendant.
To provide intercommunication between the flight crew members.
To provide intercommunication between the flight crew and ground service personnel.

2. What is the purpose of the service interphone switch at the flight engineer's auxiliary panel?
To energize the ground service interphone jacks.
To provide intercommunication with the pilot.
To communicate with the tower.

3. What is the purpose of the cross-talk network?
To provide amplification of the attenuated audio.
To provide 90 dB gain to the unwanted audio.
To prevent interaction between selected receiver audio.

4. The am speaker provides amplification of the receiver audio to drive the speakers.
True/False

5. What is the purpose of the PA amplifier?
To amplify the audio signal and generate the 2 tone-chime.
To illuminate the 'seat belt' sign.
To illuminate the 'seat belt' and 'no smoke' signs.

6. What is the purpose of the High-level switches?
To provide attenuation of the audio when the engine power lever is at 80%.
To provide amplified audio to the headset.
To provide amplification of the audio when the engine power lever is at 80%.


Emergency Locator Transmitter (ELT)

Objectives: -

At the end of this lesson the student will be able to: -

1. State the purpose of an emergency locator transmitter.
2. Explain the principle of operation of the emergency locator transmitter.
3. Correctly test an emergency locator transmitter.


Emergency Locator Transmitter (ELT)

Purpose: to assist in locating crashed aircraft.

Battery powered.

Frequency: 121.5 MHz and 245 MHz.

May be fitted to aircraft or handheld.

Fitment: longitudinal to the aircraft axis.

Water resistant.

Powered by either a lithium (5 years) or magnesium battery (3 years).

Replaced after 1 hour of total operation.

Down swept transmission signal of 1.6 KHz to 0.3 KHz.

Modulation level: 90%.

Transmitter power: 75m W (PERP).

Duration: 40 hours.

Test: either within the 1st 5 min of the hour or prior coordination with control power tower or air traffic station.

(13_4_2_4b.swf)

Emergency Locator Transmitter (ELT)

Purpose: to assist in locating crashed aircraft.

Battery powered.

Frequency: 121.5 MHz and 245 MHz.

May be fitted to aircraft or handheld.

Fitment: longitudinal to the aircraft axis.

Water resistant.

Powered by either a lithium (5 years) or magnesium battery (3 years).

Replaced after 1 hour of total operation.

Down swept transmission signal of 1.6 KHz to 0.3 KHz.

Modulation level: 90%.

Transmitter power: 75m W (PERP).

Duration: 40 hours.

Test: either within the 1st 5 min of the hour or prior coordination with control power tower or air traffic station.

(13_4_2_4c.swf)

Questions: -

1. What is the frequency of the ELT?
121.5 MHz to 245 MHz.
121.5 MHz and 245 MHz.
245 MHz.

2. The ELT is fitted permanently at the back portion of the aircraft.
True/False

3. What is the total duration of operation of the ELT?
4.8 hours.
48 min.
48 hours.

4. The peak effective radiated power is _______ watts.
75 milli.
75.
7.5 milli.

5. What is the duration of operation of the lithium battery?
5 years.
4 years.
3 years.

6. When can an operator test the ELT for functionality?
The first 5 minutes of the hour.
Prior permission of the control tower or air traffic control.
Both the above.


Cockpit Voice Recorder (CVR) System

Objectives: -

At the end of this lesson the student will be able to: -

1. State the purpose of the cockpit voice Recorder.
2. Describe the overview of the CVR System.
3. Explain the principle of operation of the CVR System.

Cockpit Voice Recorder (CVR) System
Consists of: -

1. An endless magnetic tape with a recording capacity of 30 minutes.

2. An orange colored case with 2 fluorescent white lines.

3. Labeled on the side "FLIGHT RECORDER DO NOT OPEN".

4. Underwater locator device which transmits an ultrasonic pulse signal if the aircraft crashes on water.

(13_4_2_5b.swf)

Questions: -

1. What is the duration of the endless magnetic tape in a CVR recorder?
3 minutes of communication and conversation recording.
30 minutes of communication and conversation recording.
300 minutes of communication and conversation recording.

2. What will happen to the CVR if the aircraft crashes on the water?
The underwater locator will transmit an ultrasonic pulse signal.
The underwater locator will transmit a supersonic pulse signal.
The underwater locator will transmit a Radio frequency signal.

3. The color of the CVR is __________.
Yellow.
Black.
Orange

Cockpit Voice Recorder (CVR) System

- The CVR consists of 6 components within the orange case.

- The tape is a 4 track magnetic tape which records 4 different channels.

- Recorded information can only be erased on ground after a safe landing.

- When system is tested the Control panel indicator will point to green or red.

Green - tape is serviceable
Red - tape has to be replaced

- During test 600 Hz tone is audible at the headset.

(13_4_2_5c.swf)

Question: -

1. How many components are there in the recorder?
4
6
5

Operation of the CVR System

- The cockpit voice recorder is divided into two parts:
- Fire and crash protected stainless steel module.
- Electronic circuitry.

- Power requirement:
115 V AC and 18 V DC

- During test :
Oscillator produces 600 Hz.

- Erase button:
To erase the information, 5 minutes after landing and brakes applied. Erased in 8 seconds.

(13_4_2_5d.swf)

Question: -

1. The Cockpit Voice Recorder can be divided into two parts, they are:
The electronics circuitry and the monitor head C.
The power supply and the bias oscillator.
The fire and crash protected module and the electronic circuitry.

VOR System

Objectives: -

At the end of this lesson the student will be able to: -

1. Explain the principles and function of VOR equipment.
2. Describe the layout of a typical VOR system as installed in aircraft.
3. Describe the signal flow in a VHF NAV system with the aid of a block diagram.

VOR System

VHF Omni Range Or VOR System

- Provides a continuous selection of courses around a circle with the VOR ground station at the center.

- VHF frequency, 108.00 MHz –117.95 MHz assigned worldwide for VOR stations

Advantages: -
a. Minimum electrical interference.
b. Not affected by ground or sky wave.
c. Propagate in nearly straight line.

- VOR may be used to fly in bound or out bound on a selected radial.

- VOR (VHF omni directional range) beacon for lateral guidance in airway flight.

(13_4_2_6_1b.swf)


VHF Omni Range Or VOR System

- Provides a continuous selection of courses around a circle with the VOR ground station at the center.

- VHF frequency, 108.00 MHz –117.95 MHz assigned worldwide for VOR stations

Advantages: -
a. Minimum electrical interference.
b. Not affected by ground or sky wave.
c. Propagate in nearly straight line.

- VOR may be used to fly in bound or out bound on a selected radial.

- VOR (VHF omni directional range) beacon for lateral guidance in airway flight.

(13_4_2_6_1c.avi)


VOR Principle

- Operates in the frequency range from 108.00 MHz – 117.95 MHz.

- The VOR beacon is a ground station that transmits signal in all directions.

- The VOR beacon transmits on its carrier frequency two modulation signals a 30 Hz reference and a 30 Hz variable signal.

- The radial is measured from the difference in phase between the reference and variable signal.

- Lighthouse Analogy.

(13_4_2_6_2b.swf)


Automatic VOR

The automatic VOR measures the direction to the station which we call bearing.

Bearing is the opposite direction of the radial on which the aircraft is.

Manual VOR

Manual VOR gives information about the aircraft deviation from a pre-selected course.

It measures the difference between selected course and the receiver radial, termed as difference deviation.

To / From

Also measured from the difference between received radial and selected course.

The navigation display shows: -
1. Selected course
2. Lateral deviation
3. To – From information

VHF Navigation System

NAV receiver: converts the composite signal (VOR / LOC) from the VHF NAV receiver into navigation signals.

Converter: accepts the VOR / LOC antenna signals and generate the composite and audio signals.

HSI: display navigation information.
RMI: display station bearing.

(13_4_2_6_3b.swf)


Automatic VOR

The automatic VOR measures the direction to the station which we call bearing.

Bearing is the opposite direction of the radial on which the aircraft is.

Manual VOR

Manual VOR gives information about the aircraft deviation from a pre-selected course.

It measures the difference between selected course and the receiver radial, termed as difference deviation.

To / From

Also measured from the difference between received radial and selected course.

The navigation display shows: -
1. Selected course
2. Lateral deviation
3. To – From information

VHF Navigation System

NAV receiver: converts the composite signal (VOR / LOC) from the VHF NAV receiver into navigation signals.

Converter: accepts the VOR / LOC antenna signals and generate the composite and audio signals.

HSI: display navigation information.
RMI: display station bearing.

(13_4_2_6_4b.swf)


What is VOR?

VOR is a system combining ground base and air bone equipment to provide bearing to or from a ground station.

Why use VOR?

VOR is used for position fixing, maintaining course track, and navigation along established arrays.
Basically, it provides the ability to follow a roadway in the air.

The VOR system

The airborne portion of the VOR system consists of a receiver, a control unit, an antenna and an indicator that provides bearing, course heading, and to-from information. The ground facility consists of a transmitter and an antenna array.

(13_4_2_6_5b.swf)

Question: -

1. Very high frequency omni directional range (VOR) transmitting frequencies ranges from: -
a. 108.0 MHz to 117.95 MHz.
b. 108.0 MHz to 111.95 MHz.
c. 108.0 MHz to 112.0 MHz.

2. Radio signal from a VOR beacon radiates outwards like the spokes of cycle wheel called: -
a. Gradients.
b. Radials.
c. Radians.

3. The VOR receiver calculates the bearing, to / from and lateral deviations and display these information on the: -
Horizontal Situation indicator.
Radio Magnetic indicator.
Attitude Deviation indicator.

4. With a VOR frequency selected on the VHF NAV receiver KN 53, the composite signal comprises of: -
9960 Hz fm variable phase signal and 30 KHz reference signal.
9960 Hz am variable phase signal and 30 KHz reference signal.
9960 Hz fm reference signal and 30 Hz variable phase signal.

5. How many radials does a VOR ground station provides: -
270.
360.
180.

6. The horizontal situation indicator, when used with a VOR, each dot on the lateral deviation scale denotes: -
2° of course deviation.
5° of course deviation.
0.5° of course deviation.

7. The transmission principle of VOR is based on the creation of phase differences between 2 signals. It operates in the frequency range from: -
a. 108.00 MHz to 117.95 MHz with 40 channels at 50 KHz spacing.
b. 108.00 MHz to 111.95 MHz on even tenths with 40 channels.
c. 108.00 MHz on odd tenths with 40 channels.

8. On the HSI, if the NAV flag appears, this will indicate: -
a. GS output of the NAV receiver is invalid.
b. ILS composite signal is invalid.
c. VOR / LOC output signal is invalid.

9. The VOR audio identification is at: -
a. 1350 Hz
b. 1000 Hz
c. 1020 Hz

Automatic Direction Finding (ADF)

Objectives: -

At the end of this lesson the student will be able to: -

1. Describe the principle of automatic direction finding.
2. Describe, with the aid of a block diagram, the system configuration of a typical ADF system.
3. Explain the functions of the main components of a typical ADF receiver.
4. Explain the functions and the signal flow within a typical RMI converter and a typical RMI.



ADF System – Principles

Detects the direction to the non-directional beacon (NDB) and receiver audio identification from the NDB.

NDB’s operates in the low and medium frequency range. Shows the direction to the NDB on the instruments with bearing pointers (RMI). NDB ground station transmits an AM signal in a circular pattern in all direction.

The radio energy induces RF signals in a combined loop and sense antenna assembly.

The receiver ADF measures and calculates the received antenna signals to give relative station bearing.

The relative station bearing output from the ADF receiver controls the bearing pointers in RMI’s.

The pointer indication with respect to the fixed lubber line is the relative bearing.

(13_4_2_7_1b.swf)


Ground Facilities

The frequency range of ground station used for ADF is from 190 KHz to 1750 KHz.

The stations in this range include the commercial standard broadcast stations (550 to 1660 KHz) the non-directional beacons (NDB) in the 190 KHz to 550 KHz range and the consolan stations approximately 300 KHz.

The NDB is a low to medium frequency navigation aid, radiates an omni directional signal modulated by 1020 Hz.

The consolan system is a keyed, CW navigation aid, which is limited in use today.

(13_4_2_7_1c.swf)

Mode Selector / Control Panel

Contains selector controls and frequency display.

Operational modes are ANT, ADF, BFO, Frequency transfer button and elapsed timer.

Operation Mode

1. ADF mode
- The system gives relative bearing to the RMI bearing pointers.

2. ANT mode
- The receiver only uses the sense antenna signal.
- In this mode we tune the system to a station.

3. BFO mode
- The receiver operates as in the ADF mode.
- This makes it possible to hear radio stations that transmit a carrier without audio modulation (CW stations).

(13_4_2_7_2b.swf)


ADF System – Principles

Detects the direction to the non-directional beacon (NDB) and receiver audio identification from the NDB.

NDB’s operates in the low and medium frequency range. Shows the direction to the NDB on the instruments with bearing pointers (RMI). NDB ground station transmits an AM signal in a circular pattern in all direction.

The radio energy induces RF signals in a combined loop and sense antenna assembly.

The receiver ADF measures and calculates the received antenna signals to give relative station bearing.

The relative station bearing output from the ADF receiver controls the bearing pointers in RMI’s.

The pointer indication with respect to the fixed lubber line is the relative bearing.

(13_4_2_7_2c.swf)


Mode Selector / Control Panel

Contains selector controls and frequency display.

Operational modes are ANT, ADF, BFO, Frequency transfer button and elapsed timer.

Operation Mode

1. ADF mode
- The system gives relative bearing to the RMI bearing pointers.

2. ANT mode
- The receiver only uses the sense antenna signal.
- In this mode we tune the system to a station.

3. BFO mode
- The receiver operates as in the ADF mode.
- This makes it possible to hear radio stations that transmit a carrier without audio modulation (CW stations).

(13_4_2_7_3b.avi)


ADF System –_Principles

Detects the direction to the non-directional beacon (NDB) and receiver audio identification from the NDB.

NDB’s operates in the low and medium frequency range. Shows the direction to the NDB on the instruments with bearing pointers (RMI). NDB ground station transmits an AM signal in a circular pattern in all direction.

The radio energy induces RF signals in a combined loop and sense antenna assembly.

The receiver ADF measures and calculates the received antenna signals to give relative station bearing.

The relative station bearing output from the ADF receiver controls the bearing pointers in RMI’s.

The pointer indication with respect to the fixed lubber line is the relative bearing.

(13_4_2_7_4b.swf)


Questions: -


1. The ADF antenna consist of 2 antennae in one housing namely.
a. Loop and sense antenna.
b. Whip and yagi antenna.
c. Yagi and sense antenna.

2. The frequency bands within which ADF operates are covering in the range of ____________.
a. low frequency below 200 kHz.
b. 200 kHz to 1750 kHz.
c. medium frequency above 1799 kHz.

3. The loop antenna in the ADF system determine the ___________ of the received signal, where as the sense antenna detects the _________ of the signal.
a. direction , polarity
b. polarity , direction
c. strength , polarity

4. The ground facilities used by ADF are low and medium frequency navigation station that includes:
a. Non-directed beacon.
b. Any of the above.
c. Commercial broadcast stations.

5. In an ADF system, when selected to 'ANT' mode of operation, the output usable is _____________.
a. only from the loop antenna.
b. from both the loop and sense antenna.
c. only from the sense antenna.

6. A non directional beacon (NDB) transmits a _________.
a. LF in the range of 3 kHz to 30 kHz.
b. LF in the range of the 200 kHz to 415 kHz.
c. HF in the range of 3 MHz to MHz.


Instrument Landing System (ILS)

Objectives: -

At the end of this lesson the student will be able to: -

1. State the purpose and arrangement of an instrument landing system and its components.
2. Describe the principle of operation of the components of an ILS.
3. Explain, with the aid of a block diagram, the signal flow in a VHF navigation system.
4. Describe, with the aid of a block diagram, the operation of the localizer and glide slope receiver and converter.
5. Explain, with the aid of a block diagram, the signal flow in a marker beacon receiver.


What is ILS?

In order to glide an aircraft from several miles out to a runway, a system-supplying lateral, along course and vertical guidance is used. This system using ground based and airborne equipment is called ILS (Instrument Landing System).

Why use ILS?

ILS is used for aircraft approach to a runway and places the aircraft at the proper altitude and course for a landing.

The ILS System

The ILS system consists of ground based and airborne equipment.

The airborne portion of the ILS system consists of a receiver, with localizer, glide slope and marker beacon function, three antennas, a control unit, an indicator displaying localizer and glide slope deviation and a set of marker beacon lights.

(13_4_2_8_1b.swf)


What is ILS?

In order to glide an aircraft from several miles out to a runway, a system-supplying lateral, along course and vertical guidance is used. This system using ground based and airborne equipment is called ILS (Instrument Landing System).

Why use ILS?

ILS is used for aircraft approach to a runway and places the aircraft at the proper altitude and course for a landing.

The ILS System

The ILS system consists of ground based and airborne equipment.

The airborne portion of the ILS system consists of a receiver, with localizer, glide slope and marker beacon function, three antennas, a control unit, an indicator displaying localizer and glide slope deviation and a set of marker beacon lights.

(13_4_2_8_2b.swf)


What is ILS?

In order to glide an aircraft from several miles out to a runway, a system-supplying lateral, along course and vertical guidance is used. This system using ground based and airborne equipment is called ILS (Instrument Landing System).

Why use ILS?

ILS is used for aircraft approach to a runway and places the aircraft at the proper altitude and course for a landing.

The ILS System

The ILS system consists of ground based and airborne equipment.

The airborne portion of the ILS system consists of a receiver, with localizer, glide slope and marker beacon function, three antennas, a control unit, an indicator displaying localizer and glide slope deviation and a set of marker beacon lights.

(13_4_2_8_2c.swf)


What is ILS?

In order to glide an aircraft from several miles out to a runway, a system-supplying lateral, along course and vertical guidance is used. This system using ground based and airborne equipment is called ILS (Instrument Landing System).

Why use ILS?

ILS is used for aircraft approach to a runway and places the aircraft at the proper altitude and course for a landing.

The ILS System

The ILS system consists of ground based and airborne equipment.

The airborne portion of the ILS system consists of a receiver, with localizer, glide slope and marker beacon function, three antennas, a control unit, an indicator displaying localizer and glide slope deviation and a set of marker beacon lights.

(13_4_2_8_2d.swf)

VHF Navigation System

- VHF navigation receiver KN 53, including the glide slope receiver and converter.

- VOR/LOC converter KN 72.

- Horizontal situation indicator KPI 552.

- The 200 VOR/LOC channels are spaced at 50 kHz in the range from 108.00 Mhz to 117.95 Mhz. They can be selected at the receiver. For glide slope operation, 40 channels are
spaced at 150 kHz in the range from 329.15 Mhz to 335.00 Mhz.

- The glide slope frequencies are paired with the localizer frequencies.

- The VOR/LOC receiver is a single conversion super heterodyne receiver with an IF of 11.1 Mhz.

- The glide slope receiver is a single conversion super heterodyne receiver with an IF of 33.3 Mhz.

(13_4_2_8_3b.swf)


Airborne Equipment

Receiver

Three receivers are used is ILS operation: a VHF localizer receiver, a vhf glide slope receiver and a marker beacon receiver. Localizer and glide slope receivers are often contained within the same unit. The receiver contains all the necessary circuits for receiving, decoding and computing the localizer and glide slope signals transmitted by the ground facilities. The receiver also contains the self-monitoring circuits that check the reliability of the decoded signals sent to the indicator. The marker beacon receiver contains the circuits required to receive a modulated carrier signal and to convert it to an aural and visual output to indicate passage over one of three marker beacons.

Antennas

Three-antenna assembly are required. A horizontally polarized, omni directional antenna operating in the 108.0 to 112.0 mega hertz range. A folded dipole antenna capable of receiving signals in the 329.0 to 335.0-mega hertz range. A loop antenna operating a 75-mega hertz.

(13_4_2_8_4b.swf)


Airborne Equipment

Receiver

Three receivers are used is ILS operation: a VHF localizer receiver, a VHF glide slope receiver and a marker beacon receiver. Localizer and glide slope receivers are often contained within the same unit. The receiver contains all the necessary circuits for receiving, decoding and computing the localizer and glide slope signals transmitted by the ground facilities. The receiver also contains the self-monitoring circuits that check the reliability of the decoded signals sent to the indicator. The marker beacon receiver contains the circuits required to receive a modulated carrier signal and to convert it to an aural and visual output to indicate passage over one of three marker beacons.

Antennas

Three-antenna assembly are required. A horizontally polarized, omni directional antenna operating in the 108.0 to 112.0 mega hertz range. A folded dipole antenna capable of receiving signals in the 329.0 to 335.0-mega hertz range. A loop antenna operating a 75-mega hertz.

(13_4_2_8_5b.swf)

Airborne Equipment

Receiver

Three receivers are used is ILS operation: a VHF localizer receiver, a VHF glide slope receiver and a marker beacon receiver. Localizer and glide slope receivers are often contained within the same unit. The receiver contains all the necessary circuits for receiving, decoding and computing the localizer and glide slope signals transmitted by the ground facilities. The receiver also contains the self-monitoring circuits that check the reliability of the decoded signals sent to the indicator. The marker beacon receiver contains the circuits required to receive a modulated carrier signal and to convert it to an aural and visual output to indicate passage over one of three marker beacons.

Antennas

Three-antenna assembly are required. A horizontally polarized, omni directional antenna operating in the 108.0 to 112.0 mega hertz range. A folded dipole antenna capable of receiving signals in the 329.0 to 335.0-mega hertz range. A loop antenna operating a 75-mega hertz.

(13_4_2_8_6b.swf)


Questions: -

1. The operating frequency of a marker beacon system is at: -
a. 75 MHz
b. 150 MHz
c. 90 MHz

2. The frequency allocation for VOR / LOC in the range of 108.0 MHz to 111.95 MHz is differentiated by: -
Even tenths for LOC and odd tenth for VOR.
Even tenths for VOR and odd tenth for LOC.
Modulated 30 Hz variable and 30 Hz reference signals.

3. The marker beacons OM, MM, IM activates coloured lights in the cockpit, they are respectively: -
a. Amber, white and blue.
b. White, amber and blue.
c. Blue, amber and white.

4. The LOC transmitter 2 overlapping beams which are modulated with different frequencies, they are (from the approach view): -
The left beam with 30 Hz variable and the right beam with 30 Hz reference.
The left beam with 90 Hz and the right beam with 150 Hz modulation.
The Left beam with 150 Hz and the right beam with 90 Hertz modulation.

5. The glide slope UHF channels are paired with localizer channels are in the range between: -"
329.15 MHz and 334.70 MHz.
329.3 KHz and 335.0 KHz.
329.3 MHz and 335.0 MHz.

6. The marker transmitter are modulated with different audio signal at the OM, MM, IM position, they are respectively: -
3000 Hz, 1300 Hz and 400 Hz.
400 Hz, 1300 Hz and 3000 Hz.
400 Hz, 3000 Hz and 1300 Hz.

7. In which of the following bands does glide slope operate: -
UHF.
VHF.
HF.

8. Which of the following is a localiser frequency: -
110.20 MHz
112.10 MHz
109.15 MHz

Microwave Landing System

Objective: -

At the end of this lesson the student will be able to explain the purpose and operating principle of microwave landing system.

Microwave Landing System

Based on a time reference-scanning beam (TRSB). MLS provide azimuth (course), elevation (glide path) and distance. TRSB MLS operates with a scanning beam, with a carrier frequency in the 5 GHz regions. There are 200 MLS channel from 5031.0 –_5090.7 MHz.

Advantages: -

1. MLS permit approaches other than straight in on a constant glide path.

2. MLS has the advantage of portable ground stations which can be quickly installed without sitting problems.

3. MLS can be transported to a temporary landing field without extensive flight tests and antenna adjustment.

4. MLS is the least expensive and effective way to achieve CAT III capability.

5. MLS is flexible and it is possible to fly an approach that is not the nominal, including curved approaches.

(13_4_2_9b.swf)


Questions: -

1. MLS operating range from:
a. 5031 - 5091 Ghz.
b. 5031 - 5091 Mhz.
c. 5.39 Mhz to 5.91 Mhz.

2. Microwave Landing System is based on:
Time reference scanning beam.
Doppler shift reference beam.
Time scanning 'fro' beam.


Flight Director System

Objectives: -

At the end of this lesson the student will be able to: -

1. Define the term flight director.
2. Describe two principal display units of a flight director system.


Flight Director System

- The flight director system does not have servos to operate the aircraft coated surface; all it can do is command the pilot to operate the control surfaces.

- In airplane built today, the auto pilot computers are also used as flight director computers.

- The pilot can, at his discretion, allow the autopilot to operate the controls, or he can follow the commands of the flight director.

- Typically, autopilot to control the airplane and the flight director become a monitor of autopilot operation.

(13_4_2_10b.swf)

1. 2 Principal Display Unit.
- Attitude Director Indicator (ADI).
- Horizontal Situation Indicator (HSI).

2. Attitude Direction Indicator.
- Presents aircraft attitude and direction.
- Information in the form of 3 dimensional display.

3. Horizontal Situation Indicator.
- Presents a pictorial display of information situation shown as a plan view of the aircraft position and heading.

(13_4_2_10c.swf)

1. 2 Principal Display Unit.
- Attitude Director Indicator (ADI).
- Horizontal Situation Indicator (HSI).

2. Attitude Direction Indicator.
- Presents aircraft attitude and direction.
- Information in the form of 3 dimensional display.

3. Horizontal Situation Indicator.
- Presents a pictorial display of information situation shown as a plan view of the aircraft position and heading.

(13_4_2_10d.avi)


1. 2 Principal Display Unit.
- Attitude Director Indicator (ADI).
- Horizontal Situation Indicator (HSI).

2. Attitude Direction Indicator.
- Presents aircraft attitude and direction.
- Information in the form of 3 dimensional display.

3. Horizontal Situation Indicator.
- Presents a pictorial display of information situation shown as a plan view of the aircraft position and heading.

(13_4_2_10e.avi)


1. 2 Principal Display Unit.
- Attitude Director Indicator (ADI).
- Horizontal Situation Indicator (HSI).

2. Attitude Direction Indicator.
- Presents aircraft attitude and direction.
- Information in the form of 3 dimensional display.

3. Horizontal Situation Indicator.
- Presents a pictorial display of information situation shown as a plan view of the aircraft position and heading.

(13_4_2_10f.swf)


1. 2 Principal Display Unit.
- Attitude Director Indicator (ADI).
- Horizontal Situation Indicator (HSI).

2. Attitude Direction Indicator.
- Presents aircraft attitude and direction.
- Information in the form of 3 dimensional display.

3. Horizontal Situation Indicator.
- Presents a pictorial display of information situation shown as a plan view of the aircraft position and heading.

(13_4_2_10g.swf)


Questions: -

1. A flight director system is designed to: -
a. Provide servo controls to the aircraft control surfaces.
b. Provide steering commands as displayed on ADI.
c. Provide steering commands to the aircraft servo controls.

2. The 2 principal indicator of the FDS are: -
ADI and HSI.
ADI and RMI.
BDHI and RSI.


Distance Measuring Equipment (DME)

Objectives: -

At the end of this lesson the student will be able to: -

1. Explain the principle of operation of an airborne DME.
2. Describe the search and track mode of the DME.
3. Describe the function of the DME system with the aid of a block diagram.
4. Explain the signal flow within the DME system.

Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_11b.swf)


Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_11c.swf)


Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_11d.swf)


Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_11e.swf)


Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_11f.swf)


Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_11g.swf)


Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_11h.swf)


Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_11i.swf)


Distance Measuring Equipment (DME)
- DME provides slant range.
- Ground station is the transponder.
- Airborne equipment is the interrogator.
- 2 channels: X and Y.
- X: Pair of Pulses separated by 12 microseconds on transmit and receive.
- Y: Pair of pulses separated by 36 microseconds on transmit and 30 microseconds on receive.
- Ground station transmits random pulse pair known as squitter.
- Total squitters: 2700 pulse pairs per seconds.
- Identification signal: every 30 seconds.
- Transponder delay time: 50 microseconds.
- Search mode: approximately 100 pulse pair per second.
- Track mode: approximately 20 pulse pairs per second.
- Memory mode: remains in track mode for 10 seconds before going into search mode.
- Identification pulse: 1350 pairs per seconds (3 letter code).
- Power requirement: 115 volts (Collins 618M-1)or 28 volts DC (Kings KN 63) depending on the type of system.
- Receiver frequency: 962 MHz to 1213 MHz.
- Transmitter frequency: 1025 MHz to 1150 MHz.
- Intermediate frequency: 63 MHz Number of channels: X - 126 and Y - 126 channels (total 252 channels).

(13_4_2_1j.swf)


Questions: -

1. The airborne equipment is also known as?
Interrogator
Transponder
Transmitter

2. What is the pulse separation between the 2 pulses of the X mode interrogation?
30 Micro seconds.
12 Micro seconds.
36 Micro seconds.

3. In the search mode, what is the number of interrogation transmitted?
50 pulse pairs per second.
20 pulse pairs per second.
100 pulse pairs per second.

4. The ground station operates on a constant duty cycle random pulses of: -
2700 PPPS.
100 PPPS.
20 PPPS.

5. What is the delay duration of the transponder?
50 microseconds.
20 seconds.
50 seconds.

6. What is the number of PPPS, when the DME is in the track mode?
50 PPPS.
20 PPPS.
100 PPPS.

7. The system can remain in the memory mode for duration of: -
20 seconds.
30 seconds.
10 seconds.

8. The identification frequency is 1350 KHz with a __________ letter code.
3
2
1

9. The transponder transmits the identification code every 30 seconds.
True/False

10. A 50% of the interrogation replies are enough to track and provide a valid distance.
True/False

Very Low Frequency / Omega Navigation

Objectives: -

At the end of this lesson the student will able to: -

1. Explain the principle of operation of the hyperbolic and omega navigation.
2. Describe the layout of a typical aircraft omega system and list it’s main components.


Very Low Frequency / Omega Navigation

- Very, long distance radio communication system.
- Frequency spectrum: 10 KHz to 14 KHz.
- Purpose: provides present position of the aircraft with respect to the magnetic heading.
- LOP: lines of position of the hyperbola.
- Number of stations: 8 worldwide.
- Accuracy: ± 1 nautical mile during day and ± 2 nautical miles during the night.
- Outputs: to HSI and AFCS.
- LORAN-C.
- Frequency: 100 KHz (mound waves).
- Calculates time difference between stations.
- Chains: Triad - 1 master and 2 slaves.
- Wve - 1 master and 3 slaves.
- Star - 1 master and 4 slaves.
- Provides longitude and latitude co-ordinations.
- Accuracy: 2.8 Km (1.5 nm).

(13_4_2_12b.swf)


Very Low Frequency / Omega Navigation

- Very, long distance radio communication system.
- Frequency spectrum: 10 KHz to 14 KHz.
- Purpose: provides present position of the aircraft with respect to the magnetic heading.
- LOP: lines of position of the hyperbola.
- Number of stations: 8 worldwide.
- Accuracy: ± 1 nautical mile during day and ± 2 nautical miles during the night.
- Outputs: to HSI and AFCS.
- LORAN-C.
- Frequency: 100 KHz (mound waves).
- Calculates time difference between stations.
- Chains: Triad - 1 master and 2 slaves.
- Wve - 1 master and 3 slaves.
- Star - 1 master and 4 slaves.
- Provides longitude and latitude co-ordinations.
- Accuracy: 2.8 Km (1.5 nm).

(13_4_2_12c.swf)


Very Low Frequency / Omega Navigation

- Very, long distance radio communication system.
- Frequency spectrum: 10 KHz to 14 KHz.
- Purpose: provides present position of the aircraft with respect to the magnetic heading.
- LOP: lines of position of the hyperbola.
- Number of stations: 8 worldwide.
- Accuracy: ± 1 nautical mile during day and ± 2 nautical miles during the night.
- Outputs: to HSI and AFCS.
- LORAN-C.
- Frequency: 100 KHz (mound waves).
- Calculates time difference between stations.
- Chains: Triad - 1 master and 2 slaves.
- Wve - 1 master and 3 slaves.
- Star - 1 master and 4 slaves.
- Provides longitude and latitude co-ordinations.
- Accuracy: 2.8 Km (1.5 nm).

(13_4_2_12d.swf)


Questions: -

1. What is each Omega station's transmitting coverage?
160000 Km.
1600 Km.
16000 Km.

2. What s the frequency spectrum of the Omega transmitters?
10 KHz to 14 KHz.
10 KHz to 100 KHz.
100 KHz.

3. What is the number of lines between 2 stations?
750
8
6000

4. The navigation command signals are used to show the desired flight plan to the pilot.
True/False

5. What type of information does the LORAN C system provide?
Longitude point.
Latitude point.
Longitude and latitude points.


Doppler Navigation System

Objectives: -

At the end of this lesson the student will be able to: -

1. Describe the functions of the Doppler navigation system with aid of a block diagram.
2. Explain the function of the control on the control display panel (CDU).

Doppler Navigation System

A basic Doppler system consists of: -
- Receiver Transmitter Radar (RTR).
- Signal Data Converter (SDC).
- Control Display Unit (CDU).
- Pilot Steering Indicator (PSI).

Transmits and receives 4 RF beams.

Microcomputer is incorporated with ROM and RAM devices The CDU is located at the center pedestal.

The CDU is composed of:-
- A CRT with 6 rows of 12 characters each.
- Data entry keyboard.
- Display mode selection push-button.

Can be read at any ambient light condition.

Multi-function keys: -
- 2N+
- 4WL
- 6ER
- 8S

CLR/LIST key
- Deletes the characters on the arrowed row and recall the waypoint or the list of options.

BKSP key
- Sequentially deletes characters starting from the last insertion.
- Return the index to the previous characters row.
- Reverses the page key function allowing the selection of previous page.

Indication on the PSI in HOVER position: -
- Longitudinal axis velocity.
- Lateral axis velocity.
- Velocity axis velocity.
- Distance to go.
- Ground speed.
- Track pointer.

Indicator in NAV position: -
- Distance to go (N / S) sector.
- Distance to go (E / W) SECTOR.
- Vertical velocity.
- Distance to active destination.
- Route angle.

(13_4_2_13b.swf)


Doppler Navigation System

A basic Doppler system consists of: -
- Receiver Transmitter Radar (RTR).
- Signal Data Converter (SDC).
- Control Display Unit (CDU).
- Pilot Steering Indicator (PSI).

Transmits and receives 4 RF beams.

Microcomputer is incorporated with ROM and RAM devices The CDU is located at the center pedestal.

The CDU is composed of:-
- A CRT with 6 rows of 12 characters each.
- Data entry keyboard.
- Display mode selection push-button.

Can be read at any ambient light condition.

Multi-function keys: -
- 2N+
- 4WL
- 6ER
- 8S

CLR/LIST key
- Deletes the characters on the arrowed row and recall the waypoint or the list of options.

BKSP key
- Sequentially deletes characters starting from the last insertion.
- Return the index to the previous characters row.
- Reverses the page key function allowing the selection of previous page.

Indication on the PSI in HOVER position: -
- Longitudinal axis velocity.
- Lateral axis velocity.
- Velocity axis velocity.
- Distance to go.
- Ground speed.
- Track pointer.

Indicator in NAV position: -
- Distance to go (N / S) sector.
- Distance to go (E / W) SECTOR.
- Vertical velocity.
- Distance to active destination.
- Route angle.
-
(13_4_2_13bc.swf)


Doppler Navigation System

A basic Doppler system consists of: -
- Receiver Transmitter Radar (RTR).
- Signal Data Converter (SDC).
- Control Display Unit (CDU).
- Pilot Steering Indicator (PSI).

Transmits and receives 4 RF beams.

Microcomputer is incorporated with ROM and RAM devices The CDU is located at the center pedestal.

The CDU is composed of:-
- A CRT with 6 rows of 12 characters each.
- Data entry keyboard.
- Display mode selection push-button.

Can be read at any ambient light condition.

Multi-function keys: -
- 2N+
- 4WL
- 6ER
- 8S

CLR/LIST key
- Deletes the characters on the arrowed row and recall the waypoint or the list of options.

BKSP key
- Sequentially deletes characters starting from the last insertion.
- Return the index to the previous characters row.
- Reverses the page key function allowing the selection of previous page.

Indication on the PSI in HOVER position: -
- Longitudinal axis velocity.
- Lateral axis velocity.
- Velocity axis velocity.
- Distance to go.
- Ground speed.
- Track pointer.

Indicator in NAV position: -
- Distance to go (N / S) sector.
- Distance to go (E / W) SECTOR.
- Vertical velocity.
- Distance to active destination.
- Route angle.

(13_4_2_13d.swf)


Doppler Navigation System

A basic Doppler system consists of: -
- Receiver Transmitter Radar (RTR).
- Signal Data Converter (SDC).
- Control Display Unit (CDU).
- Pilot Steering Indicator (PSI).

Transmits and receives 4 RF beams.

Microcomputer is incorporated with ROM and RAM devices The CDU is located at the center pedestal.

The CDU is composed of:-
- A CRT with 6 rows of 12 characters each.
- Data entry keyboard.
- Display mode selection push-button.

Can be read at any ambient light condition.

Multi-function keys: -
- 2N+
- 4WL
- 6ER
- 8S

CLR/LIST key
- Deletes the characters on the arrowed row and recall the waypoint or the list of options.

BKSP key
- Sequentially deletes characters starting from the last insertion.
- Return the index to the previous characters row.
- Reverses the page key function allowing the selection of previous page.

Indication on the PSI in HOVER position: -
- Longitudinal axis velocity.
- Lateral axis velocity.
- Velocity axis velocity.
- Distance to go.
- Ground speed.
- Track pointer.

Indicator in NAV position: -
- Distance to go (N / S) sector.
- Distance to go (E / W) SECTOR.
- Vertical velocity.
- Distance to active destination.
- Route angle.

(13_4_2_13e.swf)


Doppler Navigation System

A basic Doppler system consists of: -
- Receiver Transmitter Radar (RTR).
- Signal Data Converter (SDC).
- Control Display Unit (CDU).
- Pilot Steering Indicator (PSI).

Transmits and receives 4 RF beams.

Microcomputer is incorporated with ROM and RAM devices The CDU is located at the center pedestal.

The CDU is composed of:-
- A CRT with 6 rows of 12 characters each.
- Data entry keyboard.
- Display mode selection push-button.

Can be read at any ambient light condition.

Multi-function keys: -
- 2N+
- 4WL
- 6ER
- 8S

CLR/LIST key
- Deletes the characters on the arrowed row and recall the waypoint or the list of options.

BKSP key
- Sequentially deletes characters starting from the last insertion.
- Return the index to the previous characters row.
- Reverses the page key function allowing the selection of previous page.

Indication on the PSI in HOVER position: -
- Longitudinal axis velocity.
- Lateral axis velocity.
- Velocity axis velocity.
- Distance to go.
- Ground speed.
- Track pointer.

Indicator in NAV position: -
- Distance to go (N / S) sector.
- Distance to go (E / W) SECTOR.
- Vertical velocity.
- Distance to active destination.
- Route angle.

(13_4_2_13f.swf)


Questions: -

1. What is the number of beams transmitted and received by the Doppler system?
4 and 4
2 and 4
2 and 2

2. What is the number of row of characters available on the CRT?
5
4
6

3. How many characters are there in each row of the CDU?
12
6
4

4. When will the MAL annunciator light illuminate?
When the system is in memory mode.
When a fault occurs during a self-test.
When the system is processing the magnetic heading.

5. What is the flashing LEG annunciator frequency?
2 Hz.
2 KHz.
20 KHz.

6. Which of the following keys is used to delete a particular row of the display?
CLR/LIST key.
BKSP key.
ENT key.

Area Navigation Systems

Objectives: -

At the end of this lesson the student will be able to: -

1. Explain the principle of operation of the area navigation system.
2. Describe the layout of a typical aircraft area navigation system and the main components.


Area Navigation Systems

Navigation and guidance system requires:-
- VOR bearing.
- DME slant range.
- Barometric altitude.

Can be used only in the service area of a VOR/DME station.

Methods of area navigation: -
- Rho-Theta.
- Rho-Rho.

Advantages: -
- Capable of deriving courses offset from a VOR radial.
- Eliminate the use of marker beacon on approach.
- Provides more airspace between cities.

Disadvantage: -
- Cannot be used for oversea navigation.

(13_4_2_14b.swf)


Area Navigation Systems

Navigation and guidance system requires:-
- VOR bearing.
- DME slant range.
- Barometric altitude.

Can be used only in the service area of a VOR/DME station.

Methods of area navigation: -
- Rho-Theta.
- Rho-Rho.

Advantages: -
- Capable of deriving courses offset from a VOR radial.
- Eliminate the use of marker beacon on approach.
- Provides more airspace between cities.

Disadvantage: -
- Cannot be used for oversea navigation.

(13_4_2_14c.swf)


Questions: -

1. To operate, what does the navigation and guidance system requires?
DME slant range, barometric altitude and VOR bearing.
VOR bearing and DME slant range.
DME slant distance and barometric altitude.

2. What type of information will the Rho-Rho method of operation requires?
1 DME and 1 VOR information.
2 DME information.
2 VOR information.

3. The disadvantage of the RNAV system is that
It eliminates the use of the Marker Beacon system during approach.
It provides more airspace between cities.
It cannot be used for oversea navigation.

4. What type of information does the Rho-Theta mode of operation require?
1 DME and 1 VOR information.
1 DME and 2 VOR information.
2 DME information.

Flight Management System

Objectives: -

At the end of this lesson the student will be able to explain the general arrangement and the operation of the flight management system.


Flight Management System

The primary function of the FMS is to provide: -

- Accurate short and long range navigation.
- Lateral and vertical navigation.

To calculate an accurate position, the FMS can be connected to sensors: -
- VOR
- DME
- AHRS
- IRS
- VLF / OMEGA
- GPS

The FMS gathers information from the sensors and determines the airplane’s current position known as ‘BLANKING’.

There are 2 data buses in the FMS memory: -
- The navigation data bus.
- The custom data bus.

Then main components of the FMS system: -
- Control display unit.
- Flight management system computer.
- FMS data loader.

(13_4_2_15b.swf)


Control Display Unit

The CDU provides the primary means for the pilot to make inputs into the system.

(13_4_2_15c.swf)


The flight management system computer performs 7 major functions: -
- Input / output function.
- The CDU function.
- The BITE and monitoring function.
- The navigation function.
- The performance function.
- The guidance function.
- The EFIS function.

(13_4_2_15d.swf)


FMS Data Loader

The data loader provides the following: -
- Navigation database loading.
- Flight plan loading.
- Download fault monitor.

(13_4_2_15e.swf)


Question: -

1. What is the primary function of the FMS?
a. Provide short / long rang navigation.
Provide short / long rang navigation and provides lateral and vertical navigation.
Provides lateral and vertical navigation.


Global Positioning System

Objectives: -

At the end of this lesson the student will be able to explain on the typical arrangement and the operation of the global positioning system.


Global Positioning System

Distance of satellite from earth – approx. 20200 km.

No of satellites – 24.

No of orbits – 6.

No of satellites per orbit – 4.

No of orbits per satellite per day – 2 (11 hour 58 minute).

Inclination of orbit – 55 degrees.

Spacing from one orbit to another - 60 degrees.

Type of transmission –line – of – sight.

Minimum no of satellites to track a position – 3.

No of atomic clocks per satellite – 4.

The receiver clock should synchronize with the satellite clock.

The satellite code and the receiver code should be same so that the receiver can decode the signal.

Transmitted every 1 millisecond in the form of pseudo-random code.

L1 freq – 1575.42 MHz.

L2 freq – 1227.6 MHz.

The satellite that has the exact orbital location and system status is called system condition message ’or ‘ data message’.

Satellite provides – positioning, velocity and précised timing information. The receiver output can be used to drive the HSI or RMI.

(13_4_2_16b.swf)


Global Positioning System

Distance of satellite from earth – approx. 20200 km.

No of satellites – 24.

No of orbits – 6.

No of satellites per orbit – 4.

No of orbits per satellite per day – 2 (11 hour 58 minute).

Inclination of orbit – 55 degrees.

Spacing from one orbit to another - 60 degrees.

Type of transmission –line – of – sight.

Minimum no of satellites to track a position – 3.

No of atomic clocks per satellite – 4.

The receiver clock should synchronize with the satellite clock.

The satellite code and the receiver code should be same so that the receiver can decode the signal.

Transmitted every 1 millisecond in the form of pseudo-random code.

L1 freq – 1575.42 MHz.

L2 freq – 1227.6 MHz.

The satellite that has the exact orbital location and system status is called system condition message ’or ‘ data message’.

Satellite provides – positioning, velocity and précised timing information. The receiver output can be used to drive the HSI or RMI.

(13_4_2_16c.swf)


Global Positioning System

Distance of satellite from earth – approx. 20200 km.

No of satellites – 24.

No of orbits – 6.

No of satellites per orbit – 4.

No of orbits per satellite per day – 2 (11 hour 58 minute).

Inclination of orbit – 55 degrees.

Spacing from one orbit to another - 60 degrees.

Type of transmission –line – of – sight.

Minimum no of satellites to track a position – 3.

No of atomic clocks per satellite – 4.

The receiver clock should synchronize with the satellite clock.

The satellite code and the receiver code should be same so that the receiver can decode the signal.

Transmitted every 1 millisecond in the form of pseudo-random code.

L1 freq – 1575.42 MHz.

L2 freq – 1227.6 MHz.

The satellite that has the exact orbital location and system status is called system condition message ’or ‘ data message’.

Satellite provides – positioning, velocity and précised timing information. The receiver output can be used to drive the HSI or RMI.

(13_4_2_16d.swf)


Global Positioning System

Distance of satellite from earth – approx. 20200 km.

No of satellites – 24.

No of orbits – 6.

No of satellites per orbit – 4.

No of orbits per satellite per day – 2 (11 hour 58 minute).

Inclination of orbit – 55 degrees.

Spacing from one orbit to another - 60 degrees.

Type of transmission –line – of – sight.

Minimum no of satellites to track a position – 3.

No of atomic clocks per satellite – 4.

The receiver clock should synchronize with the satellite clock.

The satellite code and the receiver code should be same so that the receiver can decode the signal.

Transmitted every 1 millisecond in the form of pseudo-random code.

L1 freq – 1575.42 MHz.

L2 freq – 1227.6 MHz.

The satellite that has the exact orbital location and system status is called system condition message ’or ‘ data message’.

Satellite provides – positioning, velocity and précised timing information. The receiver output can be used to drive the HSI or RMI.

(13_4_2_16e.swf)


Global Positioning System

Distance of satellite from earth – approx. 20200 km.

No of satellites – 24.

No of orbits – 6.

No of satellites per orbit – 4.

No of orbits per satellite per day – 2 (11 hour 58 minute).

Inclination of orbit – 55 degrees.

Spacing from one orbit to another - 60 degrees.

Type of transmission –line – of – sight.

Minimum no of satellites to track a position – 3.

No of atomic clocks per satellite – 4.

The receiver clock should synchronize with the satellite clock.

The satellite code and the receiver code should be same so that the receiver can decode the signal.

Transmitted every 1 millisecond in the form of pseudo-random code.

L1 freq – 1575.42 MHz.

L2 freq – 1227.6 MHz.

The satellite that has the exact orbital location and system status is called system condition message ’or ‘ data message’.

Satellite provides – positioning, velocity and précised timing information. The receiver output can be used to drive the HSI or RMI.

(13_4_2_16f.swf)


Questions: -

1. What is the total number of satellites that are orbiting the space?
24
4
6

2. What is the formula used for calculating the distance of a satellite from earth?
Distance = Time / speed of light.
Distance = Speed of light / time.
Distance = Time x speed of light.


Airtraffic Control/Secondary Suerveillence Radar (ATC/SSR) Radar Beacon System


Objectives: -

At the end of this lesson the student will be able to: -

1. Describe the purpose of the ATC transponder.
2. Distinguish between primary and secondary radar.
3. Describe the function of the ground and airborne parts of the system.
4. Explain with the aid of a block diagram, the function of the component of a typical aircraft transponder system.


Airtraffic Control/Secondary Suerveillence Radar (ATC/SSR) Radar Beacon System

- Ground station: interrogator.
- Airborne station: transponder.
- Primary radar: receives reflected signals.
- Secondary radar: receives a new signal at another frequency.
- Interrogator frequency: 1030 MHz.
- Transponder frequency: 1090 MHz.
- Interrogation pulses: 0.8 microseconds with 824 peaks within.
- Transponder pulses: pulse width - 0.45 microseconds.
- Mode A (identification): 5 microseconds spacing between the 2 pulses.
- Mode B (identification): 17 microseconds spacing between the 2 pulses.
- Mode C (altitude): 21 microseconds spacing between the 2 pulses.
- Duration of SPI: 20 seconds.
- Code selectable: 0000 to 7777.
- Total codes 4096 codes.
- Emergency code: 7700.
- Suppression pulse: 20 microseconds after the first pulse.
- Intermediate frequency: 60 MHz.

(13_4_2_17b.swf)


Airtraffic Control/Secondary Suerveillence Radar (ATC/SSR) Radar Beacon System

- Ground station: interrogator.
- Airborne station: transponder.
- Primary radar: receives reflected signals.
- Secondary radar: receives a new signal at another frequency.
- Interrogator frequency: 1030 MHz.
- Transponder frequency: 1090 MHz.
- Interrogation pulses: 0.8 microseconds with 824 peaks within.
- Transponder pulses: pulse width - 0.45 microseconds.
- Mode A (identification): 5 microseconds spacing between the 2 pulses.
- Mode B (identification): 17 microseconds spacing between the 2 pulses.
- Mode C (altitude): 21 microseconds spacing between the 2 pulses.
- Duration of SPI: 20 seconds.
- Code selectable: 0000 to 7777.
- Total codes 4096 codes.
- Emergency code: 7700.
- Suppression pulse: 20 microseconds after the first pulse.
- Intermediate frequency: 60 MHz.

(13_4_2_17c.swf)


Airtraffic Control/Secondary Suerveillence Radar (ATC/SSR) Radar Beacon System

- Ground station: interrogator.
- Airborne station: transponder.
- Primary radar: receives reflected signals.
- Secondary radar: receives a new signal at another frequency.
- Interrogator frequency: 1030 MHz.
- Transponder frequency: 1090 MHz.
- Interrogation pulses: 0.8 microseconds with 824 peaks within.
- Transponder pulses: pulse width - 0.45 microseconds.
- Mode A (identification): 5 microseconds spacing between the 2 pulses.
- Mode B (identification): 17 microseconds spacing between the 2 pulses.
- Mode C (altitude): 21 microseconds spacing between the 2 pulses.
- Duration of SPI: 20 seconds.
- Code selectable: 0000 to 7777.
- Total codes 4096 codes.
- Emergency code: 7700.
- Suppression pulse: 20 microseconds after the first pulse.
- Intermediate frequency: 60 MHz.

(13_4_2_17d.swf)


Airtraffic Control/Secondary Suerveillence Radar (ATC/SSR) Radar Beacon System

- Ground station: interrogator.
- Airborne station: transponder.
- Primary radar: receives reflected signals.
- Secondary radar: receives a new signal at another frequency.
- Interrogator frequency: 1030 MHz.
- Transponder frequency: 1090 MHz.
- Interrogation pulses: 0.8 microseconds with 824 peaks within.
- Transponder pulses: pulse width - 0.45 microseconds.
- Mode A (identification): 5 microseconds spacing between the 2 pulses.
- Mode B (identification): 17 microseconds spacing between the 2 pulses.
- Mode C (altitude): 21 microseconds spacing between the 2 pulses.
- Duration of SPI: 20 seconds.
- Code selectable: 0000 to 7777.
- Total codes 4096 codes.
- Emergency code: 7700.
- Suppression pulse: 20 microseconds after the first pulse.
- Intermediate frequency: 60 MHz.

(13_4_2_17e.swf)


Airtraffic Control/Secondary Suerveillence Radar (ATC/SSR) Radar Beacon System

- Ground station: interrogator.
- Airborne station: transponder.
- Primary radar: receives reflected signals.
- Secondary radar: receives a new signal at another frequency.
- Interrogator frequency: 1030 MHz.
- Transponder frequency: 1090 MHz.
- Interrogation pulses: 0.8 microseconds with 824 peaks within.
- Transponder pulses: pulse width - 0.45 microseconds.
- Mode A (identification): 5 microseconds spacing between the 2 pulses.
- Mode B (identification): 17 microseconds spacing between the 2 pulses.
- Mode C (altitude): 21 microseconds spacing between the 2 pulses.
- Duration of SPI: 20 seconds.
- Code selectable: 0000 to 7777.
- Total codes 4096 codes.
- Emergency code: 7700.
- Suppression pulse: 20 microseconds after the first pulse.
- Intermediate frequency: 60 MHz.

(13_4_2_17f.swf)


Airtraffic Control/Secondary Suerveillence Radar (ATC/SSR) Radar Beacon System

- Ground station: interrogator.
- Airborne station: transponder.
- Primary radar: receives reflected signals.
- Secondary radar: receives a new signal at another frequency.
- Interrogator frequency: 1030 MHz.
- Transponder frequency: 1090 MHz.
- Interrogation pulses: 0.8 microseconds with 824 peaks within.
- Transponder pulses: pulse width - 0.45 microseconds.
- Mode A (identification): 5 microseconds spacing between the 2 pulses.
- Mode B (identification): 17 microseconds spacing between the 2 pulses.
- Mode C (altitude): 21 microseconds spacing between the 2 pulses.
- Duration of SPI: 20 seconds.
- Code selectable: 0000 to 7777.
- Total codes 4096 codes.
- Emergency code: 7700.
- Suppression pulse: 20 microseconds after the first pulse.
- Intermediate frequency: 60 MHz.

(13_4_2_17g.swf)


Airtraffic Control/Secondary Suerveillence Radar (ATC/SSR) Radar Beacon System

- Ground station: interrogator.
- Airborne station: transponder.
- Primary radar: receives reflected signals.
- Secondary radar: receives a new signal at another frequency.
- Interrogator frequency: 1030 MHz.
- Transponder frequency: 1090 MHz.
- Interrogation pulses: 0.8 microseconds with 824 peaks within.
- Transponder pulses: pulse width - 0.45 microseconds.
- Mode A (identification): 5 microseconds spacing between the 2 pulses.
- Mode B (identification): 17 microseconds spacing between the 2 pulses.
- Mode C (altitude): 21 microseconds spacing between the 2 pulses.
- Duration of SPI: 20 seconds.
- Code selectable: 0000 to 7777.
- Total codes 4096 codes.
- Emergency code: 7700.
- Suppression pulse: 20 microseconds after the first pulse.
- Intermediate frequency: 60 MHz.

(13_4_2_17h.swf)


Questions: -

1. The primary radar receives a signal different from that of the transmitted signal.
True/False

2. On what frequency does the transponder transmit?
a. 1090 MHz.
1030 MHz.
1090 KHz.

3. What type of information does mode C provide?
Identification.
Altitude.
Test.

4. What is the pulse duration of the mode C from the transponder
17 microseconds.
8 microseconds.
21 microseconds.

5. What is the emergency frequency of the transponder?
7700
0077
7007

6. What is the number of codes selectable in the transponder?
4076
4086
4096

7. What is the intermediate frequency of the transponder?
60 MHz
63 MHz
65 MHz

8. When will the pilot use the LO-SENSE switch?
When ever the pilot wishes to do so.
When the ground controller instructs the pilot to do so.
When the aircraft is very far away from the interrogator.

Traffic Alerting And Collision Avoidance System

Objectives: -

At the end of this lesson the student will be able to explain on the general arrangement of the TCAS and its associated testing system.

Traffic Alerting And Collision Avoidance System

TCAS I is normally used in small commuter airplanes that provides TA only.

TCAS II is used in larger airplanes that provides TA and RA.

Frequency: -
- 1030 MHz for transmit.
- 1090 MHz for receive.

Displayed on EHSI or EADI are: -
- Intruder priority.
- Position.
- Relative speed (arrow).
- Collision avoidance flight cue (EADI).

(13_4_2_18b.swf)


Traffic Alerting And Collision Avoidance System

TCAS I is normally used in small commuter airplanes that provides TA only.

TCAS II is used in larger airplanes that provides TA and RA.

Frequency: -
- 1030 MHz for transmit.
- 1090 MHz for receive.

Displayed on EHSI or EADI are: -
- Intruder priority.
- Position.
- Relative speed (arrow).
- Collision avoidance flight cue (EADI).

(13_4_2_18c.swf)


Maximum detectable targets / intruders – 30 targets at up to 30 nm.

TA mode – only traffic advisory is displayed.

TA / RA mode – traffic and resolution advisories are displayed.

Test mode – system does its own self-test.

TFC push button – controls the displays on the EHSI.

(13_4_2_18d.swf)

TCAS II interrogates ATCRBS intruders on whisper and shout technique.

Types of intruder symbols: -
- Other traffic.
- Proximity traffic.
- Traffic advisory.
- Resolution advisory.

(13_4_2_18e.swf)


Non threat (white diamond): -
- When 2 airplanes at greater than 6 nm apart.
- At pressure altitude below 30000 feet with a separation of more than 850 feet relative altitude.
- At pressure altitude above 30000 feet with a separation of more than 1200 feet relative altitude.

Proximity traffic (solid white diamond): -
- Airplanes within 6 nm.
- At pressure altitude below 30000 feet with a relative altitude of less than 850 feet.
- At pressure altitude above 30000 feet with a relative altitude of less than 1200 feet.

Traffic advisory (solid yellow circular dot): -
- Intruders can be visually acquired.
- No vertical collision avoidance manoeuvres.

Resolution advisory (red square): -
- Warns pilot when a collision course is determined.
- Provides vertical flight cues to avoid a flight collision.
- Below 1000 feet, RAs are inhibited.
- Below 500 feet, aural announcements are inhibited.

(13_4_2_18f.swf)


Non threat (white diamond): -
- When 2 airplanes at greater than 6 nm apart.
- At pressure altitude below 30000 feet with a separation of more than 850 feet relative altitude.
- At pressure altitude above 30000 feet with a separation of more than 1200 feet relative altitude.

Proximity traffic (solid white diamond): -
- Airplanes within 6 nm.
- At pressure altitude below 30000 feet with a relative altitude of less than 850 feet.
- At pressure altitude above 30000 feet with a relative altitude of less than 1200 feet.

Traffic advisory (solid yellow circular dot): -
- Intruders can be visually acquired.
- No vertical collision avoidance manoeuvres.

Resolution advisory (red square): -
- Warns pilot when a collision course is determined.
- Provides vertical flight cues to avoid a flight collision.
- Below 1000 feet, RAs are inhibited.
- Below 500 feet, aural announcements are inhibited.

(13_4_2_18g.swf)


Alert messages types: -
- Preventive.
- Corrective.

(13_4_2_18h.swf)


Questions: -

1. What type of information can the TCAS II provide?
Traffic advisory.
Resolution advisory.
Traffic and resolution advisories.

2. The transmit and receive frequencies of the TCAS II are?
1030 MHz and 1090 MHz.
1090 MHz and 1030 MHz.
1070 MHz and 1030 MHz.

3. What is the purpose of the TFC push button?
To turn on the TCAS symbols on the EHS.I
To turn on and off the symbols on the EHSI.
To turn on and off the TCAS II system.

Radio Altimeter (RA)

Objectives: -

At the end of this lesson the student will be able to: -

1. Describe the principle of operation of the radio altimeter system.
2. Explain with the aid of a block diagram the function of the main components of the radar altimeter system.
3. Explain with aid of a block diagram the signal flow in the radar altimeter system.


Radio Altimeter (RA)
- FMCW frequency range: 4.2 MHz to 4.4 MHz. The variable intermediate frequency is proportional to the height of the aircraft above the terrain (AGL).

Internal errors: -
1. Uncontrolled transmitter frequency.
2. The modulation frequency.

External errors: -
1. Reflection due to impedance mismatch.
2. VSWR of the reference signal due to poor mixer match.
3. Leakage signal between the transmitter and the receiver at high altitude.
4. At low altitude, the reflected transmitted signal at the transmit antenna can cause interference.
5. Multi-path signal due to multiple reflection.
6. Signals reflected by the landing gear.

Calibration loop frequency: 2.5 KHz
Calibration LOOP IF information: 50 feet
Decision height (DH): provides a visual indication when a predetermined height is reached.

(13_4_2_19_1b.swf)


Radio Altimeter (RA)
- FMCW frequency range: 4.2 MHz to 4.4 MHz. The variable intermediate frequency is proportional to the height of the aircraft above the terrain (AGL).

Internal errors: -
1. Uncontrolled transmitter frequency.
2. The modulation frequency.

External errors: -
1. Reflection due to impedance mismatch.
2. VSWR of the reference signal due to poor mixer match.
3. Leakage signal between the transmitter and the receiver at high altitude.
4. At low altitude, the reflected transmitted signal at the transmit antenna can cause interference.
5. Multi-path signal due to multiple reflection.
6. Signals reflected by the landing gear.

Calibration loop frequency: 2.5 KHz
Calibration LOOP IF information: 50 feet
Decision height (DH): provides a visual indication when a predetermined height is reached.

(13_4_2_19_1c.swf)


Radio Altimeter (RA)
- FMCW frequency range: 4.2 MHz to 4.4 MHz. The variable intermediate frequency is proportional to the height of the aircraft above the terrain (AGL).

Internal errors: -
1. Uncontrolled transmitter frequency.
2. The modulation frequency.

External errors: -
1. Reflection due to impedance mismatch.
2. VSWR of the reference signal due to poor mixer match.
3. Leakage signal between the transmitter and the receiver at high altitude.
4. At low altitude, the reflected transmitted signal at the transmit antenna can cause interference.
5. Multi-path signal due to multiple reflection.
6. Signals reflected by the landing gear.

Calibration loop frequency: 2.5 KHz
Calibration LOOP IF information: 50 feet
Decision height (DH): provides a visual indication when a predetermined height is reached.

(13_4_2_19_1d.swf)


Radio Altimeter (RA)
- FMCW frequency range: 4.2 MHz to 4.4 MHz. The variable intermediate frequency is proportional to the height of the aircraft above the terrain (AGL).

Internal errors: -
1. Uncontrolled transmitter frequency.
2. The modulation frequency.

External errors: -
1. Reflection due to impedance mismatch.
2. VSWR of the reference signal due to poor mixer match.
3. Leakage signal between the transmitter and the receiver at high altitude.
4. At low altitude, the reflected transmitted signal at the transmit antenna can cause interference.
5. Multi-path signal due to multiple reflection.
6. Signals reflected by the landing gear.

Calibration loop frequency: 2.5 KHz
Calibration LOOP IF information: 50 feet
Decision height (DH): provides a visual indication when a predetermined height is reached.

(13_4_2_19_1e.swf)


Radio Altimeter (RA)
- FMCW frequency range: 4.2 MHz to 4.4 MHz. The variable intermediate frequency is proportional to the height of the aircraft above the terrain (AGL).

Internal errors: -
1. Uncontrolled transmitter frequency.
2. The modulation frequency.

External errors: -
1. Reflection due to impedance mismatch.
2. VSWR of the reference signal due to poor mixer match.
3. Leakage signal between the transmitter and the receiver at high altitude.
4. At low altitude, the reflected transmitted signal at the transmit antenna can cause interference.
5. Multi-path signal due to multiple reflection.
6. Signals reflected by the landing gear.

Calibration loop frequency: 2.5 KHz
Calibration LOOP IF information: 50 feet
Decision height (DH): provides a visual indication when a predetermined height is reached.

(13_4_2_19_1f.swf)


Radio Altimeter (RA)
- FMCW frequency range: 4.2 MHz to 4.4 MHz. The variable intermediate frequency is proportional to the height of the aircraft above the terrain (AGL).

Internal errors: -
1. Uncontrolled transmitter frequency.
2. The modulation frequency.

External errors: -
1. Reflection due to impedance mismatch.
2. VSWR of the reference signal due to poor mixer match.
3. Leakage signal between the transmitter and the receiver at high altitude.
4. At low altitude, the reflected transmitted signal at the transmit antenna can cause interference.
5. Multi-path signal due to multiple reflection.
6. Signals reflected by the landing gear.

Calibration loop frequency: 2.5 KHz
Calibration LOOP IF information: 50 feet
Decision height (DH): provides a visual indication when a predetermined height is reached.

(13_4_2_19_1g.swf)


Radio Altimeter (RA)
- FMCW frequency range: 4.2 MHz to 4.4 MHz. The variable intermediate frequency is proportional to the height of the aircraft above the terrain (AGL).

Internal errors: -
1. Uncontrolled transmitter frequency.
2. The modulation frequency.

External errors: -
1. Reflection due to impedance mismatch.
2. VSWR of the reference signal due to poor mixer match.
3. Leakage signal between the transmitter and the receiver at high altitude.
4. At low altitude, the reflected transmitted signal at the transmit antenna can cause interference.
5. Multi-path signal due to multiple reflection.
6. Signals reflected by the landing gear.

Calibration loop frequency: 2.5 KHz
Calibration LOOP IF information: 50 feet
Decision height (DH): provides a visual indication when a predetermined height is reached.

(13_4_2_19_1h.swf)


Radio Altimeter (RA)
- FMCW frequency range: 4.2 MHz to 4.4 MHz. The variable intermediate frequency is proportional to the height of the aircraft above the terrain (AGL).

Internal errors: -
1. Uncontrolled transmitter frequency.
2. The modulation frequency.

External errors: -
1. Reflection due to impedance mismatch.
2. VSWR of the reference signal due to poor mixer match.
3. Leakage signal between the transmitter and the receiver at high altitude.
4. At low altitude, the reflected transmitted signal at the transmit antenna can cause interference.
5. Multi-path signal due to multiple reflection.
6. Signals reflected by the landing gear.

Calibration loop frequency: 2.5 KHz
Calibration LOOP IF information: 50 feet
Decision height (DH): provides a visual indication when a predetermined height is reached.

(13_4_2_19_1i.swf)


Questions: -

1. What is the FMCW radio altimeter frequency?
4.2 GHz to 4.4 GHz.
4.2 MHz to 4.4 MHz.
4.2 KHz to 4.4 KHz.

2. The beat frequency is proportional to the height of the aircraft.
True/False


3. Which of the following error is an internal error?
Variation of the modulating frequency.
Signal reflected by the landing gear.
Reflection of the reference signal to the receiver.

4. When the test button is pressed, what is the indication on the indicator?
100 feet.
500 feet.
50 feet.

5. On what occasion will the DH lamp illuminate?
The aircraft's height has above the preset height.
The aircraft is on ground only.
The aircraft's height is reached the preset height and below.

Weather Avoidance Radar

Objectives: -

At the end of this lesson the student will be able to: -

1. Describe the functions of a typical weather radar system.
2. Describe the selectable modes of a typical weather radar system.


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2b.swf">(13_4_2_19_2b.swf)


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2c.swf">(13_4_2_19_2c.swf)


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2d.swf">(13_4_2_19_2d.swf)


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2e.swf">(13_4_2_19_2e.swf)


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2f.swf">(13_4_2_19_2f.swf)


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2g.swf">(13_4_2_19_2g.swf)


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2h.swf">(13_4_2_19_2h.swf)


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2i.swf">(13_4_2_19_2i.swf)


Weather Avoidance Radar

- G band frequency range: 5.2 GHz to 5.9GHz.
- 1 band frequency: 8.5 GHz to 10 GHz.
- Distance: time taken for the signal to travel from the transmitter to the target and back divided by 12.36 microseconds.
- Very heavy rainfall (> 12 mm/h): in red colour.
- Medium level rainfall (>4 and <12 href="file:///C:/Documents%20and%20Settings/All%20Users/Documents/cbt%20mas%20JARR%2066/Report/Module%2013/13_4/13_4_2_19_2j.swf">(13_4_2_19_2j.swf)


Questions: -

1. What is the frequency range allocated for the I - band weather radar?
a. 8.5 to 10 GHz.
b. 5.2 to 5.9 GHz.
c. 5.2 to 10 GHz.

2. If the indication on the PPI is a red cloud, what is the rainfall level?
4 to 12 mm/h.
Greater than 12 mm/h.
Less than 4 mm/h.

3. At what frequency does the alert annuciator flash?
1 Kz.
1 Hz.
1 MHz.

4. What is the intermediate frequency of the PRIMUS 100?
30 MHz.
30 GHz.
30 KHz.

5. In how many colours can the detected signal be displayed?
a. 4.
b. 2.
c. 3.

6. What is the maximum range of the PRIMUS 100?
200 nm.
10 nm.
50 nm.


Aircraft (ARINC) Communication, Addressing And Reporting System

Objectives: -

At the end of this lesson the student will be able to explain on the Genera arrangement and operation of the aircraft communication, addressing and reporting system.

Aircraft (ARINC) Communication, Addressing And Reporting System
Provides exchange of data and message between airplane and ground base operations centre.

The interactive display unit supplies the facilities necessary to enter the next into the DFDAU for data storage, review and transmission.

ACARS system consists of: -
1. Management unit.
2. Interactive display unit.

If the management unit fails, the ‘MU FAIL’ lamp illuminates.

If an internal IDU or power supply for the IDU fails, the ‘MU FAIL’ lamp illuminates.

(13_4_2_20b.swf)

Aircraft (ARINC) Communication, Addressing And Reporting System
Provides exchange of data and message between airplane and ground base operations centre.

The interactive display unit supplies the facilities necessary to enter the next into the DFDAU for data storage, review and transmission.

ACARS system consists of: -
1. Management unit.
2. Interactive display unit.

If the management unit fails, the ‘MU FAIL’ lamp illuminates.

If an internal IDU or power supply for the IDU fails, the ‘MU FAIL’ lamp illuminates.

(13_4_2_20c.swf)

Aircraft (ARINC) Communication, Addressing And Reporting System
Provides exchange of data and message between airplane and ground base operations centre.

The interactive display unit supplies the facilities necessary to enter the next into the DFDAU for data storage, review and transmission.

ACARS system consists of: -
1. Management unit.
2. Interactive display unit.

If the management unit fails, the ‘MU FAIL’ lamp illuminates.

If an internal IDU or power supply for the IDU fails, the ‘MU FAIL’ lamp illuminates.

(13_4_2_20d.swf)

Aircraft (ARINC) Communication, Addressing And Reporting System
Provides exchange of data and message between airplane and ground base operations centre.

The interactive display unit supplies the facilities necessary to enter the next into the DFDAU for data storage, review and transmission.

ACARS system consists of: -
1. Management unit.
2. Interactive display unit.

If the management unit fails, the ‘MU FAIL’ lamp illuminates.

If an internal IDU or power supply for the IDU fails, the ‘MU FAIL’ lamp illuminates.

(13_4_2_20e.swf)

Aircraft (ARINC) Communication, Addressing And Reporting System
Provides exchange of data and message between airplane and ground base operations centre.

The interactive display unit supplies the facilities necessary to enter the next into the DFDAU for data storage, review and transmission.

ACARS system consists of: -
1. Management unit.
2. Interactive display unit.

If the management unit fails, the ‘MU FAIL’ lamp illuminates.

If an internal IDU or power supply for the IDU fails, the ‘MU FAIL’ lamp illuminates.

(13_4_2_20f.swf)

Aircraft (ARINC) Communication, Addressing And Reporting System
Provides exchange of data and message between airplane and ground base operations centre.

The interactive display unit supplies the facilities necessary to enter the next into the DFDAU for data storage, review and transmission.

ACARS system consists of: -
1. Management unit.
2. Interactive display unit.

If the management unit fails, the ‘MU FAIL’ lamp illuminates.

If an internal IDU or power supply for the IDU fails, the ‘MU FAIL’ lamp illuminates.

(13_4_2_20g.swf)

Questions: -
1. If a message is not acknowledged. The system will automatically repeat the message for a maximum of _______ times.
5.
6.
4.

2. When will the CU FAIL lamp illuminate: -
If a malfunction occurs in the IDU.
If the microprocessor fails.
If the interactive display fails.

3. What is the purpose of the 'DISPLAY ILLUM / TEST' page?
To allow the operator to set the display intensity.
To provide a test pattern on the display unit.
To set the display intensity and to test the IDU display and LINK TEST functions.