Key Topic 71: Automatic Direction Finding Equipment (ADF) & Transponders Flashcards
3-71K1: What is the frequency range of an aircraft’s Automatic Direction Finding (ADF) equipment?
A. 190 kHz to 1750 kHz.
B. 190 MHz to 1750 MHz.
C. 108.10 MHz to 111.95 MHz.
D. 108.00 MHz to 117.95 MHz.
A. 190 kHz to 1750 kHz.
3-71K2: What is meant by the term “night effect” when using an aircraft’s Automatic Direction Finding (ADF) equipment? Night effect refers to the fact that:
A. All Non Directional Beacon (NBD) transmitters are turned-off at dusk and turned-on at dawn.
B. Non Directional Beacon (NDB) transmissions can bounce-off the Earth’s ionosphere at night and be received at almost any direction.
C. An aircraft’s ADF transmissions will be slowed at night due to the increased density of the Earth’s atmosphere after sunset.
D. An aircraft’s ADF antennas usually collect dew moisture after sunset which decreases their effective reception distance from an NDB transmitter.
B. Non Directional Beacon (NDB) transmissions can bounce-off the Earth’s ionosphere at night and be received at almost any direction.
3-71K3: What are the transmit and receive frequencies of an aircraft’s mode C transponder operating in the Air Traffic Control RADAR Beacon System (ATCRBS)?
A. Transmit at 1090 MHz, and receive at 1030 MHz.
B. Transmit at 1030 kHz, and receive at 1090 kHz.
C. Transmit at 1090 kHz, and receive at 1030 kHz.
D. Transmit at 1030 MHz, and receive at 1090 MHz.
A. Transmit at 1090 MHz, and receive at 1030 MHz.
3-71K4: In addition to duplicating the functions of a mode C transponder, an aircraft’s ode S transponder can also provide:
A. Primary RADAR surveillance capabilities.
B. Long range lightning detection.
C. Mid-Air collision avoidance capabilities.
D. Backup VHF voice communication abilities.
C. Mid-Air collision avoidance capabilities.
3-71K5: What type of encoding is used in an aircraft’s mode C transponder transmission to a ground station of the Air Traffic Control RADAR Beacon System (ATCRBS)?
A. Differential phase shift keying.
B. Pulse position modulation.
C. Doppler effect compressional encryption.
D. Amplitude modulation at 95%.
B. Pulse position modulation.
3-71K6: Choose the only correct statement about an aircraft’s Automatic Direction Finding (ADF) equipment.
A. An aircraft’s ADF transmission exhibits primarily a line-of-sight range to the ground-based target station and will not follow the curvature of the Earth.
B. Only a single omnidirectional sense antenna is required to receive an NDB transmission and process the signal to calculate the aircraft’s bearing to the selected ground station.
C. All frequencies in the ADF’s operating range except the commercial standard broadcast stations (550 to 1660 kHz) can be utilized as a navigational Non Directional Beacon (NDB) signal.
D. An aircraft’s ADF antennas can receive transmissions that are over the Earth’s horizon (sometimes several hundred miles away) since these signals will follow the curvature of the Earth.
D. An aircraft’s ADF antennas can receive transmissions that are over the Earth’s horizon (sometimes several hundred miles away) since these signals will follow the curvature of the Earth.
