Avionics Fundamentals - ADF

1. The ADF indicator shows the relative bearing to the station?

True

False

Displays the bearing to station relative to the nose of the aircraft

Explanation

Displays the bearing to station relative to the nose of the aircraft

2. The sense antenna has an Omni-directional pattern?

True

False

The sense antenna has an omni-directional pattern, meaning that it can receive signals from all directions equally. This allows it to detect signals from any direction without the need for pointing or adjusting the antenna.

Explanation

The sense antenna has an omni-directional pattern, meaning that it can receive signals from all directions equally. This allows it to detect signals from any direction without the need for pointing or adjusting the antenna.

3. The ADF can have audio Morse Code ident?

True

False

An NDB station is capable of transmitting a 2 or 3 letter Morse code identifier.

Explanation

An NDB station is capable of transmitting a 2 or 3 letter Morse code identifier.

4. The Pilot can actually listen to and steer by an ADF signal?

True

False

A useful ADF application is to locate a particular NDB and then track – or home – directly to it. The ADF receiver is tuned to the NDB frequency, and the audio volume turned up, so that the NDB can be identified as soon as the aircraft comes within range. The ADF needle indicates the bearing to the NDB and the wind correction angle necessary to maintain that track.

Explanation

A useful ADF application is to locate a particular NDB and then track – or home – directly to it. The ADF receiver is tuned to the NDB frequency, and the audio volume turned up, so that the NDB can be identified as soon as the aircraft comes within range. The ADF needle indicates the bearing to the NDB and the wind correction angle necessary to maintain that track.

5. The ADF requires two seperate antenna?

True

False

The aircraft consist of two antennas. The two antennas are called LOOP antenna and SENSE antenna

Explanation

The aircraft consist of two antennas. The two antennas are called LOOP antenna and SENSE antenna

6. The ADF signals induced to the antenna(s) are phase shifted by 90deg.?

True

False

The ADF signals induced to the antenna(s) being phase shifted by 90 degrees means that the signals are shifted in their timing or position by a quarter of a complete cycle. This phase shift is a characteristic feature of ADF systems and is necessary for accurate direction finding. By having the signals phase shifted, the ADF system can determine the direction of the signal source relative to the aircraft. Therefore, the statement is true.

Explanation

The ADF signals induced to the antenna(s) being phase shifted by 90 degrees means that the signals are shifted in their timing or position by a quarter of a complete cycle. This phase shift is a characteristic feature of ADF systems and is necessary for accurate direction finding. By having the signals phase shifted, the ADF system can determine the direction of the signal source relative to the aircraft. Therefore, the statement is true.

7. The ADF system is a VHF Navigation system?

True

False

They receive radio signals in the medium frequency band.

Explanation

They receive radio signals in the medium frequency band.

8. The ADF system frequency band is from 250-1250Khz?

True

False

ADF is the radio signals in the low to medium frequency band of 190 to 1750 Khz

Explanation

ADF is the radio signals in the low to medium frequency band of 190 to 1750 Khz

9. A cardioid pattern is obtained from the sense antenna?

True

False

A cardioid pattern is not obtained from the sense antenna. A cardioid pattern refers to a specific directional pattern of radiation or reception, typically resembling a heart shape. It is commonly achieved with microphones or antennas that have specific design elements to focus or reject signals from certain directions. However, the sense antenna does not have the necessary characteristics to produce a cardioid pattern. Therefore, the correct answer is False.

Explanation

A cardioid pattern is not obtained from the sense antenna. A cardioid pattern refers to a specific directional pattern of radiation or reception, typically resembling a heart shape. It is commonly achieved with microphones or antennas that have specific design elements to focus or reject signals from certain directions. However, the sense antenna does not have the necessary characteristics to produce a cardioid pattern. Therefore, the correct answer is False.

10. Name one source of ADF error.

Precession Error

Reflection Error

Shore Effect

Field Effect

Ground waves are refracted when passing across coast lines at low angles and this will affect the indicated bearing for an aircraft tracking to seaward and following the shore line.

Explanation

Ground waves are refracted when passing across coast lines at low angles and this will affect the indicated bearing for an aircraft tracking to seaward and following the shore line.