What is the maximum allowable deviation of a...

Question 1 / 27070mpAK3Gybb6yKFRBUuaqT

Question 1 of 27070mpAK3Gybb6yKFRBUuaqT

What is the maximum allowable deviation of a marine VHF transmitter?

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Question 1 of 27070

Q

What is the maximum allowable deviation of a marine VHF transmitter?

🔍 Key Concepts

• Marine VHF uses narrowband FM on channels spaced 25 kHz apart • The maximum frequency deviation must be small enough to prevent interference with adjacent channels • Relevant rules are found in 47 CFR Part 80 (FCC rules for maritime services), not the Navigation Rules

💭 Think About

• Think about how much of the 25 kHz channel spacing can safely be used by the transmitter’s deviation without causing overlap into neighboring channels • Compare each option to the 25 kHz channel spacing and ask which value would be reasonable for a narrowband FM system • Consider typical commercial land-mobile and marine VHF FM deviations—are they usually more or less than 10 kHz?

✅ Before You Answer

• Verify the channel spacing for standard marine VHF channels (in kHz) • Check what narrowband FM deviation is commonly used in similar services (e.g., land mobile VHF) • Confirm in 47 CFR Part 80 what deviation limit is specified for marine VHF transmitters

Question 1 of 27070

Q

What is the maximum allowable deviation of a marine VHF transmitter?

A

12 kHz

B

10 kHz

C

7. 5 kHz

D

5 kHz

Question 1 / 27070mpAK3Gybb6yKFRBUuaqT

Question 1 of 27070mpAK3Gybb6yKFRBUuaqT

What is the maximum allowable deviation of a marine VHF transmitter?

Back

Question 1 of 27070

Q

What is the maximum allowable deviation of a marine VHF transmitter?

🔍 Key Concepts

• Marine VHF uses narrowband FM on channels spaced 25 kHz apart • The maximum frequency deviation must be small enough to prevent interference with adjacent channels • Relevant rules are found in 47 CFR Part 80 (FCC rules for maritime services), not the Navigation Rules

💭 Think About

• Think about how much of the 25 kHz channel spacing can safely be used by the transmitter’s deviation without causing overlap into neighboring channels • Compare each option to the 25 kHz channel spacing and ask which value would be reasonable for a narrowband FM system • Consider typical commercial land-mobile and marine VHF FM deviations—are they usually more or less than 10 kHz?

✅ Before You Answer

• Verify the channel spacing for standard marine VHF channels (in kHz) • Check what narrowband FM deviation is commonly used in similar services (e.g., land mobile VHF) • Confirm in 47 CFR Part 80 what deviation limit is specified for marine VHF transmitters