What is the channel spacing for authorized...

Question 1 / 27070J4jFOke0UoG0LxbaeCvm

Question 1 of 27070J4jFOke0UoG0LxbaeCvm

What is the channel spacing for authorized F1B/J2B frequencies?

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Question 1 of 27070

Q

What is the channel spacing for authorized F1B/J2B frequencies?

🔍 Key Concepts

• F1B/J2B emissions are types of narrow-band direct-printing (NBDP) telegraphy used in maritime HF and MF bands • Channel spacing is the separation between adjacent assigned frequencies, typically expressed in Hz or kHz • Think about standard international HF NBDP channel plans and their typical spacing

💭 Think About

• Are F1B/J2B channels spaced more like very-low-frequency audio filters (hundreds of Hz) or like standard radio channels (kHz range)? • Compare the sizes: which of these values would practically allow many distinct NBDP channels across a small HF band segment? • Which spacing value is consistent with other narrow‑band digital/telex maritime services (e.g., 500 Hz, 1 kHz, 3 kHz, etc.)?

✅ Before You Answer

• Make sure you are thinking about radio channel spacing, not audio tone frequency differences • Ask whether 170 Hz or 300 Hz is more typical of frequency shift (FSK shift) between mark and space, rather than channel spacing • Confirm which option matches standard HF narrow‑band data/telex channel spacing used in ITU maritime allocations

Question 1 of 27070

Q

What is the channel spacing for authorized F1B/J2B frequencies?

A

170 Hz

B

300 Hz

C

3.0 kHz

D

500 Hz

Question 1 / 27070J4jFOke0UoG0LxbaeCvm

Question 1 of 27070J4jFOke0UoG0LxbaeCvm

What is the channel spacing for authorized F1B/J2B frequencies?

Back

Question 1 of 27070

Q

What is the channel spacing for authorized F1B/J2B frequencies?

🔍 Key Concepts

• F1B/J2B emissions are types of narrow-band direct-printing (NBDP) telegraphy used in maritime HF and MF bands • Channel spacing is the separation between adjacent assigned frequencies, typically expressed in Hz or kHz • Think about standard international HF NBDP channel plans and their typical spacing

💭 Think About

• Are F1B/J2B channels spaced more like very-low-frequency audio filters (hundreds of Hz) or like standard radio channels (kHz range)? • Compare the sizes: which of these values would practically allow many distinct NBDP channels across a small HF band segment? • Which spacing value is consistent with other narrow‑band digital/telex maritime services (e.g., 500 Hz, 1 kHz, 3 kHz, etc.)?

✅ Before You Answer

• Make sure you are thinking about radio channel spacing, not audio tone frequency differences • Ask whether 170 Hz or 300 Hz is more typical of frequency shift (FSK shift) between mark and space, rather than channel spacing • Confirm which option matches standard HF narrow‑band data/telex channel spacing used in ITU maritime allocations