What is the use of notch filters in Loran-C receivers?

Aeronautical & Aerospace Engineering : Avionics - Quiz(MCQ)

Reduce atmospheric noise

Reduce interference from sky waves

Reduce interference from other frequencies

Reduce interference from other stations

Correct Answer : Reduce interference from other frequencies

Explanation : Loran-C signal reception can be impaired by interference from other signal broadcast on slightly different frequencies. To avoid degradation of S/N associated with these interfering sources, Loran -C sets are equipped with notch filters.

Recently Updated in Avionics Questions

Which of the following type is not used in an Omega system?

Valley span

Insulated tower

Hanging tower

Grounded tower

Correct Answer : Option (C) : Hanging tower

Explanation : Since the Omega stations transmit in very low frequencies, the antennas are the largest physical structures in the stations. Three types of antennas are employed in the Omega system: grounded tower, insulated tower, and the valley span.

_____ acts as a coarse tuning device for the antenna?

Loop

Helix

Filters

Amplifiers

Correct Answer : Option (B) : Helix

Explanation : The RF signal that is to be transmitted is transferred to the ‘Helix,’ a large helical coil that acts as a coarse tuning device for the antenna. The helix is equipped with separate taps for each signal frequency transmitted.

What type of transmission is used in Omega system?

Phase modulated wave

Continuous wave

Amplitude modulated wave

Frequency modulated wave

Correct Answer : Option (B) : Continuous wave

Explanation : At each Omega station, continuous wave signals on four common frequencies and one station unique frequency. The signal frequencies are time shared among the stations so that a given frequency is transmitted by only one station at any given time.